* Re: [PATCH 4/5] x86: don't use asm-generic/ptrace.h
From: Oleg Nesterov @ 2019-05-20 16:02 UTC (permalink / raw)
To: Christoph Hellwig
Cc: linux-arch, Arnd Bergmann, linux-sh, x86, linux-mips,
linux-kernel, linuxppc-dev, Ingo Molnar, linux-arm-kernel
In-Reply-To: <20190520060018.25569-5-hch@lst.de>
On 05/20, Christoph Hellwig wrote:
>
> Doing the indirection through macros for the regs accessors just
> makes them harder to read, so implement the helpers directly.
Acked-by: Oleg Nesterov <oleg@redhat.com>
^ permalink raw reply
* [PATCH v3 1/2] pid: add pidfd_open()
From: Christian Brauner @ 2019-05-20 15:56 UTC (permalink / raw)
To: jannh, oleg, viro, torvalds, linux-kernel, arnd
Cc: linux-ia64, linux-sh, linux-mips, dhowells, joel, linux-kselftest,
sparclinux, elena.reshetova, linux-arch, linux-s390, dancol,
Christian Brauner, kernel-team, serge, linux-xtensa, keescook,
linux-m68k, luto, tglx, surenb, linux-arm-kernel, linux-parisc,
linux-api, cyphar, luto, ebiederm, linux-alpha, akpm,
linuxppc-dev
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a problem for
Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfds for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
---
v1:
- kbuild test robot <lkp@intel.com>:
- add missing entry for pidfd_open to arch/arm/tools/syscall.tbl
- Oleg Nesterov <oleg@redhat.com>:
- use simpler thread-group leader check
v2:
- Oleg Nesterov <oleg@redhat.com>:
- avoid using additional variable
- remove unneeded comment
- Arnd Bergmann <arnd@arndb.de>:
- switch from 428 to 434 since the new mount api has taken it
- bump syscall numbers in arch/arm64/include/asm/unistd.h
- Joel Fernandes (Google) <joel@joelfernandes.org>:
- switch from ESRCH to EINVAL when the passed-in pid does not refer to a
thread-group leader
- Christian Brauner <christian@brauner.io>:
- rebase on v5.2-rc1
- adapt syscall number to account for new mount api syscalls
v3:
- Arnd Bergmann <arnd@arndb.de>:
- add missing syscall entries for mips-o32 and mips-n64
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd.h | 2 +-
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/pid.h | 1 +
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/fork.c | 2 +-
kernel/pid.c | 43 +++++++++++++++++++++
23 files changed, 68 insertions(+), 3 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 9e7704e44f6d..1db9bbcfb84e 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
541 common fsconfig sys_fsconfig
542 common fsmount sys_fsmount
543 common fspick sys_fspick
+544 common pidfd_open sys_pidfd_open
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index aaf479a9e92d..81e6e1817c45 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -447,3 +447,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 70e6882853c0..e8f7d95a1481 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -44,7 +44,7 @@
#define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5)
#define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800)
-#define __NR_compat_syscalls 434
+#define __NR_compat_syscalls 435
#endif
#define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index c39e90600bb3..7a3158ccd68e 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index e01df3f2f80d..ecc44926737b 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -354,3 +354,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7e3d0734b2f3..9a3eb2558568 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 26339e417695..ad706f83c755 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0e2dd68ade57..97035e19ad03 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -372,3 +372,4 @@
431 n32 fsconfig sys_fsconfig
432 n32 fsmount sys_fsmount
433 n32 fspick sys_fspick
+434 n32 pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 5eebfa0d155c..d7292722d3b0 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -348,3 +348,4 @@
431 n64 fsconfig sys_fsconfig
432 n64 fsmount sys_fsmount
433 n64 fspick sys_fspick
+434 n64 pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 3cc1374e02d0..dba084c92f14 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -421,3 +421,4 @@
431 o32 fsconfig sys_fsconfig
432 o32 fsmount sys_fsmount
433 o32 fspick sys_fspick
+434 o32 pidfd_open sys_pidfd_open
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c9e377d59232..5022b9e179c2 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 103655d84b4b..f2c3bda2d39f 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -515,3 +515,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index e822b2964a83..6ebacfeaf853 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig sys_fsconfig
432 common fsmount sys_fsmount sys_fsmount
433 common fspick sys_fspick sys_fspick
+434 common pidfd_open sys_pidfd_open sys_pidfd_open
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 016a727d4357..834c9c7d79fa 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index e047480b1605..c58e71f21129 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -479,3 +479,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..43e4429a5272 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+434 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..1bee0a77fdd3 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+434 common pidfd_open __x64_sys_pidfd_open
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 5fa0ee1c8e00..782b81945ccc 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -404,3 +404,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..c938a92eab99 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -67,6 +67,7 @@ struct pid
extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+extern int pidfd_create(struct pid *pid);
static inline struct pid *get_pid(struct pid *pid)
{
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..989055e0b501 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock,
struct old_timex32 __user *tx);
asmlinkage long sys_syncfs(int fd);
asmlinkage long sys_setns(int fd, int nstype);
+asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags);
asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags);
asmlinkage long sys_process_vm_readv(pid_t pid,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..e5684a4512c0 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 435
/*
* 32 bit systems traditionally used different
diff --git a/kernel/fork.c b/kernel/fork.c
index b4cba953040a..c3df226f47a1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1724,7 +1724,7 @@ const struct file_operations pidfd_fops = {
* Return: On success, a cloexec pidfd is returned.
* On error, a negative errno number will be returned.
*/
-static int pidfd_create(struct pid *pid)
+int pidfd_create(struct pid *pid)
{
int fd;
diff --git a/kernel/pid.c b/kernel/pid.c
index 89548d35eefb..8fc9d94f6ac1 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -37,6 +37,7 @@
#include <linux/syscalls.h>
#include <linux/proc_ns.h>
#include <linux/proc_fs.h>
+#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/idr.h>
@@ -450,6 +451,48 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return idr_get_next(&ns->idr, &nr);
}
+/**
+ * pidfd_open() - Open new pid file descriptor.
+ *
+ * @pid: pid for which to retrieve a pidfd
+ * @flags: flags to pass
+ *
+ * This creates a new pid file descriptor with the O_CLOEXEC flag set for
+ * the process identified by @pid. Currently, the process identified by
+ * @pid must be a thread-group leader. This restriction currently exists
+ * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot
+ * be used with CLONE_THREAD) and pidfd polling (only supports thread group
+ * leaders).
+ *
+ * Return: On success, a cloexec pidfd is returned.
+ * On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
+{
+ int fd, ret;
+ struct pid *p;
+
+ if (flags)
+ return -EINVAL;
+
+ if (pid <= 0)
+ return -EINVAL;
+
+ p = find_get_pid(pid);
+ if (!p)
+ return -ESRCH;
+
+ ret = 0;
+ rcu_read_lock();
+ if (!pid_task(p, PIDTYPE_TGID))
+ ret = -EINVAL;
+ rcu_read_unlock();
+
+ fd = ret ?: pidfd_create(p);
+ put_pid(p);
+ return fd;
+}
+
void __init pid_idr_init(void)
{
/* Verify no one has done anything silly: */
--
2.21.0
^ permalink raw reply related
* [PATCH v3 2/2] tests: add pidfd_open() tests
From: Christian Brauner @ 2019-05-20 15:56 UTC (permalink / raw)
To: jannh, oleg, viro, torvalds, linux-kernel, arnd
Cc: linux-ia64, linux-sh, linux-mips, dhowells, joel, linux-kselftest,
sparclinux, elena.reshetova, linux-arch, linux-s390, dancol,
Christian Brauner, kernel-team, serge, linux-xtensa, keescook,
linux-m68k, luto, tglx, surenb, linux-arm-kernel, linux-parisc,
linux-api, cyphar, luto, ebiederm, linux-alpha,
Michael Kerrisk (man-pages), akpm, linuxppc-dev
In-Reply-To: <20190520155630.21684-1-christian@brauner.io>
This adds testing for the new pidfd_open() syscalls. Specifically, we test:
- that no invalid flags can be passed to pidfd_open()
- that no invalid pid can be passed to pidfd_open()
- that a pidfd can be retrieved with pidfd_open()
- that the retrieved pidfd references the correct pid
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
---
v1: unchanged
v2:
- Christian Brauner <christian@brauner.io>:
- set number of planned tests via ksft_set_plan()
v3: unchanged
---
tools/testing/selftests/pidfd/.gitignore | 1 +
tools/testing/selftests/pidfd/Makefile | 2 +-
tools/testing/selftests/pidfd/pidfd.h | 57 ++++++
.../testing/selftests/pidfd/pidfd_open_test.c | 169 ++++++++++++++++++
tools/testing/selftests/pidfd/pidfd_test.c | 41 +----
5 files changed, 229 insertions(+), 41 deletions(-)
create mode 100644 tools/testing/selftests/pidfd/pidfd.h
create mode 100644 tools/testing/selftests/pidfd/pidfd_open_test.c
diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore
index 822a1e63d045..16d84d117bc0 100644
--- a/tools/testing/selftests/pidfd/.gitignore
+++ b/tools/testing/selftests/pidfd/.gitignore
@@ -1 +1,2 @@
+pidfd_open_test
pidfd_test
diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index deaf8073bc06..b36c0be70848 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,6 +1,6 @@
CFLAGS += -g -I../../../../usr/include/
-TEST_GEN_PROGS := pidfd_test
+TEST_GEN_PROGS := pidfd_test pidfd_open_test
include ../lib.mk
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
new file mode 100644
index 000000000000..8452e910463f
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __PIDFD_H
+#define __PIDFD_H
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/mount.h>
+
+#include "../kselftest.h"
+
+/*
+ * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
+ * That means, when it wraps around any pid < 300 will be skipped.
+ * So we need to use a pid > 300 in order to test recycling.
+ */
+#define PID_RECYCLE 1000
+
+/*
+ * Define a few custom error codes for the child process to clearly indicate
+ * what is happening. This way we can tell the difference between a system
+ * error, a test error, etc.
+ */
+#define PIDFD_PASS 0
+#define PIDFD_FAIL 1
+#define PIDFD_ERROR 2
+#define PIDFD_SKIP 3
+#define PIDFD_XFAIL 4
+
+int wait_for_pid(pid_t pid)
+{
+ int status, ret;
+
+again:
+ ret = waitpid(pid, &status, 0);
+ if (ret == -1) {
+ if (errno == EINTR)
+ goto again;
+
+ return -1;
+ }
+
+ if (!WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+}
+
+
+#endif /* __PIDFD_H */
diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c
new file mode 100644
index 000000000000..0377133dd6dc
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_open_test.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pidfd.h"
+#include "../kselftest.h"
+
+static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
+{
+ return syscall(__NR_pidfd_open, pid, flags);
+}
+
+static int safe_int(const char *numstr, int *converted)
+{
+ char *err = NULL;
+ long sli;
+
+ errno = 0;
+ sli = strtol(numstr, &err, 0);
+ if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN))
+ return -ERANGE;
+
+ if (errno != 0 && sli == 0)
+ return -EINVAL;
+
+ if (err == numstr || *err != '\0')
+ return -EINVAL;
+
+ if (sli > INT_MAX || sli < INT_MIN)
+ return -ERANGE;
+
+ *converted = (int)sli;
+ return 0;
+}
+
+static int char_left_gc(const char *buffer, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (buffer[i] == ' ' ||
+ buffer[i] == '\t')
+ continue;
+
+ return i;
+ }
+
+ return 0;
+}
+
+static int char_right_gc(const char *buffer, size_t len)
+{
+ int i;
+
+ for (i = len - 1; i >= 0; i--) {
+ if (buffer[i] == ' ' ||
+ buffer[i] == '\t' ||
+ buffer[i] == '\n' ||
+ buffer[i] == '\0')
+ continue;
+
+ return i + 1;
+ }
+
+ return 0;
+}
+
+static char *trim_whitespace_in_place(char *buffer)
+{
+ buffer += char_left_gc(buffer, strlen(buffer));
+ buffer[char_right_gc(buffer, strlen(buffer))] = '\0';
+ return buffer;
+}
+
+static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen)
+{
+ int ret;
+ char path[512];
+ FILE *f;
+ size_t n = 0;
+ pid_t result = -1;
+ char *line = NULL;
+
+ snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd);
+
+ f = fopen(path, "re");
+ if (!f)
+ return -1;
+
+ while (getline(&line, &n, f) != -1) {
+ char *numstr;
+
+ if (strncmp(line, key, keylen))
+ continue;
+
+ numstr = trim_whitespace_in_place(line + 4);
+ ret = safe_int(numstr, &result);
+ if (ret < 0)
+ goto out;
+
+ break;
+ }
+
+out:
+ free(line);
+ fclose(f);
+ return result;
+}
+
+int main(int argc, char **argv)
+{
+ int pidfd = -1, ret = 1;
+ pid_t pid;
+
+ ksft_set_plan(3);
+
+ pidfd = sys_pidfd_open(-1, 0);
+ if (pidfd >= 0) {
+ ksft_print_msg(
+ "%s - succeeded to open pidfd for invalid pid -1\n",
+ strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("do not allow invalid pid test: passed\n");
+
+ pidfd = sys_pidfd_open(getpid(), 1);
+ if (pidfd >= 0) {
+ ksft_print_msg(
+ "%s - succeeded to open pidfd with invalid flag value specified\n",
+ strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("do not allow invalid flag test: passed\n");
+
+ pidfd = sys_pidfd_open(getpid(), 0);
+ if (pidfd < 0) {
+ ksft_print_msg("%s - failed to open pidfd\n", strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("open a new pidfd test: passed\n");
+
+ pid = get_pid_from_fdinfo_file(pidfd, "Pid:", sizeof("Pid:") - 1);
+ ksft_print_msg("pidfd %d refers to process with pid %d\n", pidfd, pid);
+
+ ret = 0;
+
+on_error:
+ if (pidfd >= 0)
+ close(pidfd);
+
+ return !ret ? ksft_exit_pass() : ksft_exit_fail();
+}
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 5bae1792e3d6..a03387052aa7 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -14,6 +14,7 @@
#include <sys/wait.h>
#include <unistd.h>
+#include "pidfd.h"
#include "../kselftest.h"
static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
@@ -62,28 +63,6 @@ static int test_pidfd_send_signal_simple_success(void)
return 0;
}
-static int wait_for_pid(pid_t pid)
-{
- int status, ret;
-
-again:
- ret = waitpid(pid, &status, 0);
- if (ret == -1) {
- if (errno == EINTR)
- goto again;
-
- return -1;
- }
-
- if (ret != pid)
- goto again;
-
- if (!WIFEXITED(status))
- return -1;
-
- return WEXITSTATUS(status);
-}
-
static int test_pidfd_send_signal_exited_fail(void)
{
int pidfd, ret, saved_errno;
@@ -128,13 +107,6 @@ static int test_pidfd_send_signal_exited_fail(void)
return 0;
}
-/*
- * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
- * That means, when it wraps around any pid < 300 will be skipped.
- * So we need to use a pid > 300 in order to test recycling.
- */
-#define PID_RECYCLE 1000
-
/*
* Maximum number of cycles we allow. This is equivalent to PID_MAX_DEFAULT.
* If users set a higher limit or we have cycled PIDFD_MAX_DEFAULT number of
@@ -143,17 +115,6 @@ static int test_pidfd_send_signal_exited_fail(void)
*/
#define PIDFD_MAX_DEFAULT 0x8000
-/*
- * Define a few custom error codes for the child process to clearly indicate
- * what is happening. This way we can tell the difference between a system
- * error, a test error, etc.
- */
-#define PIDFD_PASS 0
-#define PIDFD_FAIL 1
-#define PIDFD_ERROR 2
-#define PIDFD_SKIP 3
-#define PIDFD_XFAIL 4
-
static int test_pidfd_send_signal_recycled_pid_fail(void)
{
int i, ret;
--
2.21.0
^ permalink raw reply related
* Re: [PATCH] mm: add account_locked_vm utility function
From: Daniel Jordan @ 2019-05-20 15:30 UTC (permalink / raw)
To: Alexey Kardashevskiy
Cc: Mark Rutland, Davidlohr Bueso, kvm, Alan Tull, linux-fpga,
linux-kernel, kvm-ppc, Daniel Jordan, linux-mm, Alex Williamson,
Jason Gunthorpe, Moritz Fischer, Steve Sistare, akpm,
linuxppc-dev, Christoph Lameter, Wu Hao
In-Reply-To: <4b42057f-b998-f87c-4e0f-a91abcb366f9@ozlabs.ru>
On Mon, May 20, 2019 at 04:19:34PM +1000, Alexey Kardashevskiy wrote:
> On 04/05/2019 06:16, Daniel Jordan wrote:
> > locked_vm accounting is done roughly the same way in five places, so
> > unify them in a helper. Standardize the debug prints, which vary
> > slightly.
>
> And I rather liked that prints were different and tell precisely which
> one of three each printk is.
I'm not following. One of three...callsites? But there were five callsites.
Anyway, I added a _RET_IP_ to the debug print so you can differentiate.
> I commented below but in general this seems working.
>
> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Thanks! And for the review as well.
> > diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
> > index 6b64e45a5269..d39a1b830d82 100644
> > --- a/drivers/vfio/vfio_iommu_spapr_tce.c
> > +++ b/drivers/vfio/vfio_iommu_spapr_tce.c
> > @@ -34,49 +35,13 @@
> > static void tce_iommu_detach_group(void *iommu_data,
> > struct iommu_group *iommu_group);
> >
> > -static long try_increment_locked_vm(struct mm_struct *mm, long npages)
> > +static int tce_account_locked_vm(struct mm_struct *mm, unsigned long npages,
> > + bool inc)
> > {
> > - long ret = 0, locked, lock_limit;
> > -
> > if (WARN_ON_ONCE(!mm))
> > return -EPERM;
>
>
> If this WARN_ON is the only reason for having tce_account_locked_vm()
> instead of calling account_locked_vm() directly, you can then ditch the
> check as I have never ever seen this triggered.
Great, will do.
> > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> > index d0f731c9920a..15ac76171ccd 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -273,25 +273,14 @@ static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
> > return -ESRCH; /* process exited */
> >
> > ret = down_write_killable(&mm->mmap_sem);
> > - if (!ret) {
> > - if (npage > 0) {
> > - if (!dma->lock_cap) {
> > - unsigned long limit;
> > -
> > - limit = task_rlimit(dma->task,
> > - RLIMIT_MEMLOCK) >> PAGE_SHIFT;
> > -
> > - if (mm->locked_vm + npage > limit)
> > - ret = -ENOMEM;
> > - }
> > - }
> > + if (ret)
> > + goto out;
>
>
> A single "goto" to jump just 3 lines below seems unnecessary.
No strong preference here, I'll take out the goto.
> > +int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc,
> > + struct task_struct *task, bool bypass_rlim)
> > +{
> > + unsigned long locked_vm, limit;
> > + int ret = 0;
> > +
> > + locked_vm = mm->locked_vm;
> > + if (inc) {
> > + if (!bypass_rlim) {
> > + limit = task_rlimit(task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
> > + if (locked_vm + pages > limit) {
> > + ret = -ENOMEM;
> > + goto out;
> > + }
> > + }
>
> Nit:
>
> if (!ret)
>
> and then you don't need "goto out".
Ok, sure.
> > + mm->locked_vm = locked_vm + pages;
> > + } else {
> > + WARN_ON_ONCE(pages > locked_vm);
> > + mm->locked_vm = locked_vm - pages;
>
>
> Can go negative here. Not a huge deal but inaccurate imo.
I hear you, but setting a negative value to zero, as we had done previously,
doesn't make much sense to me.
^ permalink raw reply
* Re: PROBLEM: Power9: kernel oops on memory hotunplug from ppc64le guest
From: Aneesh Kumar K.V @ 2019-05-20 15:20 UTC (permalink / raw)
To: Nicholas Piggin, bharata
Cc: linux-kernel, srikanth, linux-next, bharata, linuxppc-dev
In-Reply-To: <1558363500.jsgl4a2lfa.astroid@bobo.none>
On 5/20/19 8:25 PM, Nicholas Piggin wrote:
> Bharata B Rao's on May 21, 2019 12:29 am:
>> On Mon, May 20, 2019 at 01:50:35PM +0530, Bharata B Rao wrote:
>>> On Mon, May 20, 2019 at 05:00:21PM +1000, Nicholas Piggin wrote:
>>>> Bharata B Rao's on May 20, 2019 3:56 pm:
>>>>> On Mon, May 20, 2019 at 02:48:35PM +1000, Nicholas Piggin wrote:
>>>>>>>>> git bisect points to
>>>>>>>>>
>>>>>>>>> commit 4231aba000f5a4583dd9f67057aadb68c3eca99d
>>>>>>>>> Author: Nicholas Piggin <npiggin@gmail.com>
>>>>>>>>> Date: Fri Jul 27 21:48:17 2018 +1000
>>>>>>>>>
>>>>>>>>> powerpc/64s: Fix page table fragment refcount race vs speculative references
>>>>>>>>>
>>>>>>>>> The page table fragment allocator uses the main page refcount racily
>>>>>>>>> with respect to speculative references. A customer observed a BUG due
>>>>>>>>> to page table page refcount underflow in the fragment allocator. This
>>>>>>>>> can be caused by the fragment allocator set_page_count stomping on a
>>>>>>>>> speculative reference, and then the speculative failure handler
>>>>>>>>> decrements the new reference, and the underflow eventually pops when
>>>>>>>>> the page tables are freed.
>>>>>>>>>
>>>>>>>>> Fix this by using a dedicated field in the struct page for the page
>>>>>>>>> table fragment allocator.
>>>>>>>>>
>>>>>>>>> Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage")
>>>>>>>>> Cc: stable@vger.kernel.org # v3.10+
>>>>>>>>
>>>>>>>> That's the commit that added the BUG_ON(), so prior to that you won't
>>>>>>>> see the crash.
>>>>>>>
>>>>>>> Right, but the commit says it fixes page table page refcount underflow by
>>>>>>> introducing a new field &page->pt_frag_refcount. Now we are hitting the underflow
>>>>>>> for this pt_frag_refcount.
>>>>>>
>>>>>> The fixed underflow is caused by a bug (race on page count) that got
>>>>>> fixed by that patch. You are hitting a different underflow here. It's
>>>>>> not certain my patch caused it, I'm just trying to reproduce now.
>>>>>
>>>>> Ok.
>>>>
>>>> Can't reproduce I'm afraid, tried adding and removing 8GB memory from a
>>>> 4GB guest (via host adding / removing memory device), and it just works.
>>>
>>> Boot, add 8G, reboot, remove 8G is the sequence to reproduce.
>>>
>>>>
>>>> It's likely to be an edge case like an off by one or rounding error
>>>> that just happens to trigger in your config. Might be easiest if you
>>>> could test with a debug patch.
>>>
>>> Sure, I will continue debugging.
>>
>> When the guest is rebooted after hotplug, the entire memory (which includes
>> the hotplugged memory) gets remapped again freshly. However at this time
>> since no slab is available yet, pt_frag_refcount never gets initialized as we
>> never do pte_fragment_alloc() for these mappings. So we right away hit the
>> underflow during the first unplug itself, it looks like.
>
> Nice catch, good debugging work.
>
>> I will check how this can be fixed.
>
> Tricky problem. What do you think? You might be able to make the early
> page table allocations in the same pattern as the frag allocations, and
> then fill in the struct page metadata when you have those.
I guess we need to do something similar to what x86 does. We need to
walk the init_mm page table again and re-init struct page and other data
structures backing the tables?
-aneesh
^ permalink raw reply
* Re: PROBLEM: Power9: kernel oops on memory hotunplug from ppc64le guest
From: Bharata B Rao @ 2019-05-20 15:12 UTC (permalink / raw)
To: Nicholas Piggin
Cc: bharata, linux-kernel, linux-next, aneesh.kumar, srikanth,
linuxppc-dev
In-Reply-To: <1558363500.jsgl4a2lfa.astroid@bobo.none>
On Tue, May 21, 2019 at 12:55:49AM +1000, Nicholas Piggin wrote:
> Bharata B Rao's on May 21, 2019 12:29 am:
> > On Mon, May 20, 2019 at 01:50:35PM +0530, Bharata B Rao wrote:
> >> On Mon, May 20, 2019 at 05:00:21PM +1000, Nicholas Piggin wrote:
> >> > Bharata B Rao's on May 20, 2019 3:56 pm:
> >> > > On Mon, May 20, 2019 at 02:48:35PM +1000, Nicholas Piggin wrote:
> >> > >> >> > git bisect points to
> >> > >> >> >
> >> > >> >> > commit 4231aba000f5a4583dd9f67057aadb68c3eca99d
> >> > >> >> > Author: Nicholas Piggin <npiggin@gmail.com>
> >> > >> >> > Date: Fri Jul 27 21:48:17 2018 +1000
> >> > >> >> >
> >> > >> >> > powerpc/64s: Fix page table fragment refcount race vs speculative references
> >> > >> >> >
> >> > >> >> > The page table fragment allocator uses the main page refcount racily
> >> > >> >> > with respect to speculative references. A customer observed a BUG due
> >> > >> >> > to page table page refcount underflow in the fragment allocator. This
> >> > >> >> > can be caused by the fragment allocator set_page_count stomping on a
> >> > >> >> > speculative reference, and then the speculative failure handler
> >> > >> >> > decrements the new reference, and the underflow eventually pops when
> >> > >> >> > the page tables are freed.
> >> > >> >> >
> >> > >> >> > Fix this by using a dedicated field in the struct page for the page
> >> > >> >> > table fragment allocator.
> >> > >> >> >
> >> > >> >> > Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage")
> >> > >> >> > Cc: stable@vger.kernel.org # v3.10+
> >> > >> >>
> >> > >> >> That's the commit that added the BUG_ON(), so prior to that you won't
> >> > >> >> see the crash.
> >> > >> >
> >> > >> > Right, but the commit says it fixes page table page refcount underflow by
> >> > >> > introducing a new field &page->pt_frag_refcount. Now we are hitting the underflow
> >> > >> > for this pt_frag_refcount.
> >> > >>
> >> > >> The fixed underflow is caused by a bug (race on page count) that got
> >> > >> fixed by that patch. You are hitting a different underflow here. It's
> >> > >> not certain my patch caused it, I'm just trying to reproduce now.
> >> > >
> >> > > Ok.
> >> >
> >> > Can't reproduce I'm afraid, tried adding and removing 8GB memory from a
> >> > 4GB guest (via host adding / removing memory device), and it just works.
> >>
> >> Boot, add 8G, reboot, remove 8G is the sequence to reproduce.
> >>
> >> >
> >> > It's likely to be an edge case like an off by one or rounding error
> >> > that just happens to trigger in your config. Might be easiest if you
> >> > could test with a debug patch.
> >>
> >> Sure, I will continue debugging.
> >
> > When the guest is rebooted after hotplug, the entire memory (which includes
> > the hotplugged memory) gets remapped again freshly. However at this time
> > since no slab is available yet, pt_frag_refcount never gets initialized as we
> > never do pte_fragment_alloc() for these mappings. So we right away hit the
> > underflow during the first unplug itself, it looks like.
>
> Nice catch, good debugging work.
Thanks, with help from Aneesh.
>
> > I will check how this can be fixed.
>
> Tricky problem. What do you think? You might be able to make the early
> page table allocations in the same pattern as the frag allocations, and
> then fill in the struct page metadata when you have those.
Will explore.
>
> Other option may be create a new set of page tables after mm comes up
> to replace the early page tables with. That's a bigger hammer though.
Will also check if similar scenario exists on x86 and if so, how and when
pte frag data is fixed there.
Regards,
Bharata.
^ permalink raw reply
* Re: [PATCH 1/3] powerpc/pseries: Simplify cpu readd to use drc_index
From: Nathan Lynch @ 2019-05-20 15:01 UTC (permalink / raw)
To: Tyrel Datwyler; +Cc: mingming.cao, linuxppc-dev
In-Reply-To: <05a4295b-dea5-bea2-5fd3-c8fbee7bac48@linux.vnet.ibm.com>
Tyrel Datwyler <tyreld@linux.vnet.ibm.com> writes:
> On 05/16/2019 12:17 PM, Nathan Lynch wrote:
>> Tyrel Datwyler <tyreld@linux.ibm.com> writes:
>>> The current dlpar_cpu_readd() takes in a cpu_id and uses that to look up
>>> the cpus device_node so that we can get at the ibm,my-drc-index
>>> property. The only user of cpu readd is an OF notifier call back. This
>>> call back already has a reference to the device_node and therefore can
>>> retrieve the drc_index from the device_node.
>>
>> dlpar_cpu_readd is a hack to try to change the CPU-node relationship at
>> runtime without destabilizing the system. It doesn't accomplish that and
>> it should just be removed (and I'm working on that).
>>
>
> I will politely disagree. We've done exactly this from userspace for
> years. My experience still suggests that memory affinity is the
> problem area, and that the work to push this all into the kernel
> originally was poorly tested.
Kernel implementation details aside, how do you change the cpu-node
relationship at runtime without breaking NUMA-aware applications? Is
this not a fundamental issue to address before adding code like this?
^ permalink raw reply
* Re: [PATCH v2 1/2] pid: add pidfd_open()
From: Arnd Bergmann @ 2019-05-20 14:59 UTC (permalink / raw)
To: Christian Brauner
Cc: linux-ia64, Linux-sh list, Linux Kernel Mailing List,
David Howells, Joel Fernandes,
open list:KERNEL SELFTEST FRAMEWORK, sparclinux, Linux API,
Reshetova, Elena, linux-arch, linux-s390, Daniel Colascione,
Android Kernel Team, Serge E. Hallyn, linux-xtensa, Kees Cook,
Jann Horn, linux-m68k, Al Viro, Andy Lutomirski, Oleg Nesterov,
Thomas Gleixner, Suren Baghdasaryan, Linux ARM, Parisc List,
cyphar, Linus Torvalds, linux-mips, Andy Lutomirski,
Eric W . Biederman, alpha, Andrew Morton, linuxppc-dev
In-Reply-To: <20190520144822.xfaifawi65jus6ng@brauner.io>
On Mon, May 20, 2019 at 4:48 PM Christian Brauner <christian@brauner.io> wrote:
>
> On Mon, May 20, 2019 at 04:37:03PM +0200, Arnd Bergmann wrote:
> > On Mon, May 20, 2019 at 3:46 PM Christian Brauner <christian@brauner.io> wrote:
> > >
> > > In line with Arnd's recent changes to consolidate syscall numbers across
> > > architectures, I have added the pidfd_open() syscall to all architectures
> > > at the same time.
> >
> > Thanks! I've checked that the ones you have added are all
> > done correctly. However, double-checking that you got all of them,
> > I noticed that you missed mips-o32 and mips-n64. With those added:
> >
> > Acked-by: Arnd Bergmann <arnd@arndb.de>
>
> Perfect, will plumb mips-o32 and mips-n64 and resend once more with your
> ack added.
> Sidenote: You plan on merging the common syscall tables or will there be
> a script to do this work per-arch in the future?
David Howells also asked about this. I think having a common table will
be best in the long run, patches welcome.
As you noticed, there are still a few minor differences between the files
on mips, arm, x86, alpha and s390, and we are missing the .tbl files
for arm-compat and asm-generic, as well as an architecture independent
script.
Once that is all taken care of, we can move the entries for syscall
403 and higher into a common file, and change the script to pick
up the contents from there in addition to the architecture specific
file.
Arnd
^ permalink raw reply
* Re: PROBLEM: Power9: kernel oops on memory hotunplug from ppc64le guest
From: Nicholas Piggin @ 2019-05-20 14:55 UTC (permalink / raw)
To: bharata
Cc: bharata, linux-kernel, linux-next, aneesh.kumar, srikanth,
linuxppc-dev
In-Reply-To: <20190520142922.GE22939@in.ibm.com>
Bharata B Rao's on May 21, 2019 12:29 am:
> On Mon, May 20, 2019 at 01:50:35PM +0530, Bharata B Rao wrote:
>> On Mon, May 20, 2019 at 05:00:21PM +1000, Nicholas Piggin wrote:
>> > Bharata B Rao's on May 20, 2019 3:56 pm:
>> > > On Mon, May 20, 2019 at 02:48:35PM +1000, Nicholas Piggin wrote:
>> > >> >> > git bisect points to
>> > >> >> >
>> > >> >> > commit 4231aba000f5a4583dd9f67057aadb68c3eca99d
>> > >> >> > Author: Nicholas Piggin <npiggin@gmail.com>
>> > >> >> > Date: Fri Jul 27 21:48:17 2018 +1000
>> > >> >> >
>> > >> >> > powerpc/64s: Fix page table fragment refcount race vs speculative references
>> > >> >> >
>> > >> >> > The page table fragment allocator uses the main page refcount racily
>> > >> >> > with respect to speculative references. A customer observed a BUG due
>> > >> >> > to page table page refcount underflow in the fragment allocator. This
>> > >> >> > can be caused by the fragment allocator set_page_count stomping on a
>> > >> >> > speculative reference, and then the speculative failure handler
>> > >> >> > decrements the new reference, and the underflow eventually pops when
>> > >> >> > the page tables are freed.
>> > >> >> >
>> > >> >> > Fix this by using a dedicated field in the struct page for the page
>> > >> >> > table fragment allocator.
>> > >> >> >
>> > >> >> > Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage")
>> > >> >> > Cc: stable@vger.kernel.org # v3.10+
>> > >> >>
>> > >> >> That's the commit that added the BUG_ON(), so prior to that you won't
>> > >> >> see the crash.
>> > >> >
>> > >> > Right, but the commit says it fixes page table page refcount underflow by
>> > >> > introducing a new field &page->pt_frag_refcount. Now we are hitting the underflow
>> > >> > for this pt_frag_refcount.
>> > >>
>> > >> The fixed underflow is caused by a bug (race on page count) that got
>> > >> fixed by that patch. You are hitting a different underflow here. It's
>> > >> not certain my patch caused it, I'm just trying to reproduce now.
>> > >
>> > > Ok.
>> >
>> > Can't reproduce I'm afraid, tried adding and removing 8GB memory from a
>> > 4GB guest (via host adding / removing memory device), and it just works.
>>
>> Boot, add 8G, reboot, remove 8G is the sequence to reproduce.
>>
>> >
>> > It's likely to be an edge case like an off by one or rounding error
>> > that just happens to trigger in your config. Might be easiest if you
>> > could test with a debug patch.
>>
>> Sure, I will continue debugging.
>
> When the guest is rebooted after hotplug, the entire memory (which includes
> the hotplugged memory) gets remapped again freshly. However at this time
> since no slab is available yet, pt_frag_refcount never gets initialized as we
> never do pte_fragment_alloc() for these mappings. So we right away hit the
> underflow during the first unplug itself, it looks like.
Nice catch, good debugging work.
> I will check how this can be fixed.
Tricky problem. What do you think? You might be able to make the early
page table allocations in the same pattern as the frag allocations, and
then fill in the struct page metadata when you have those.
Other option may be create a new set of page tables after mm comes up
to replace the early page tables with. That's a bigger hammer though.
Thanks,
Nick
^ permalink raw reply
* Re: [RFC PATCH 2/4] x86/ftrace: Fix use of flags in ftrace_replace_code()
From: Steven Rostedt @ 2019-05-20 14:55 UTC (permalink / raw)
To: Naveen N. Rao; +Cc: linuxppc-dev, linux-kernel, Nicholas Piggin
In-Reply-To: <1558363129.y2x8hf9shq.naveen@linux.ibm.com>
On Mon, 20 May 2019 20:12:48 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> Thanks, that definitely helps make things clearer. A very small nit from
> your first patch -- it would be good to also convert the calls to
> ftrace_check_record() to use 'true' or 'false' for the 'update' field.
Heh, I was so focused on the "enable" part, I did the "update" as a
second thought, and forgot to update the callers. Thanks for pointing
that out.
>
> I will test my series in more detail and post a v1.
Great.
-- Steve
^ permalink raw reply
* Re: [PATCH v2 1/2] pid: add pidfd_open()
From: Christian Brauner @ 2019-05-20 14:48 UTC (permalink / raw)
To: Arnd Bergmann
Cc: linux-ia64, Linux-sh list, Linux Kernel Mailing List,
David Howells, Joel Fernandes,
open list:KERNEL SELFTEST FRAMEWORK, sparclinux, Linux API,
Reshetova, Elena, linux-arch, linux-s390, Daniel Colascione,
Android Kernel Team, Serge E. Hallyn, linux-xtensa, Kees Cook,
Jann Horn, linux-m68k, Al Viro, Andy Lutomirski, Oleg Nesterov,
Thomas Gleixner, Suren Baghdasaryan, Linux ARM, Parisc List,
cyphar, Linus Torvalds, linux-mips, Andy Lutomirski,
Eric W . Biederman, alpha, Andrew Morton, linuxppc-dev
In-Reply-To: <CAK8P3a1cZZ6SQe5mGjhga=MgTvCGF6OKyjvosR8J6z6EpH+rVA@mail.gmail.com>
On Mon, May 20, 2019 at 04:37:03PM +0200, Arnd Bergmann wrote:
> On Mon, May 20, 2019 at 3:46 PM Christian Brauner <christian@brauner.io> wrote:
> >
> > In line with Arnd's recent changes to consolidate syscall numbers across
> > architectures, I have added the pidfd_open() syscall to all architectures
> > at the same time.
>
> Thanks! I've checked that the ones you have added are all
> done correctly. However, double-checking that you got all of them,
> I noticed that you missed mips-o32 and mips-n64. With those added:
>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
Perfect, will plumb mips-o32 and mips-n64 and resend once more with your
ack added.
Sidenote: You plan on merging the common syscall tables or will there be
a script to do this work per-arch in the future?
^ permalink raw reply
* [PATCH 10/10] docs: fix broken documentation links
From: Mauro Carvalho Chehab @ 2019-05-20 14:47 UTC (permalink / raw)
To: Linux Doc Mailing List
Cc: kvm, linux-pci, virtualization, linux-mm, linux-i2c,
linux-kselftest, Mauro Carvalho Chehab, devel, Jonathan Corbet,
x86, linux-acpi, xen-devel, linux-edac, devicetree, linux-arm-msm,
Mauro Carvalho Chehab, linux-gpio, linux-amlogic,
platform-driver-x86, linux-arm-kernel, devel, netdev,
linux-kernel, linux-security-module, linuxppc-dev
In-Reply-To: <cover.1558362030.git.mchehab+samsung@kernel.org>
Mostly due to x86 and acpi conversion, several documentation
links are still pointing to the old file. Fix them.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
Documentation/acpi/dsd/leds.txt | 2 +-
Documentation/admin-guide/kernel-parameters.rst | 6 +++---
Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++--------
Documentation/admin-guide/ras.rst | 2 +-
.../devicetree/bindings/net/fsl-enetc.txt | 7 +++----
.../bindings/pci/amlogic,meson-pcie.txt | 2 +-
.../bindings/regulator/qcom,rpmh-regulator.txt | 2 +-
Documentation/devicetree/booting-without-of.txt | 2 +-
Documentation/driver-api/gpio/board.rst | 2 +-
Documentation/driver-api/gpio/consumer.rst | 2 +-
.../firmware-guide/acpi/enumeration.rst | 2 +-
.../firmware-guide/acpi/method-tracing.rst | 2 +-
Documentation/i2c/instantiating-devices | 2 +-
Documentation/sysctl/kernel.txt | 4 ++--
.../translations/it_IT/process/4.Coding.rst | 2 +-
.../translations/it_IT/process/howto.rst | 2 +-
.../it_IT/process/stable-kernel-rules.rst | 4 ++--
.../translations/zh_CN/process/4.Coding.rst | 2 +-
Documentation/x86/x86_64/5level-paging.rst | 2 +-
Documentation/x86/x86_64/boot-options.rst | 4 ++--
.../x86/x86_64/fake-numa-for-cpusets.rst | 2 +-
MAINTAINERS | 6 +++---
arch/arm/Kconfig | 2 +-
arch/arm64/kernel/kexec_image.c | 2 +-
arch/powerpc/Kconfig | 2 +-
arch/x86/Kconfig | 16 ++++++++--------
arch/x86/Kconfig.debug | 2 +-
| 2 +-
arch/x86/entry/entry_64.S | 2 +-
arch/x86/include/asm/bootparam_utils.h | 2 +-
arch/x86/include/asm/page_64_types.h | 2 +-
arch/x86/include/asm/pgtable_64_types.h | 2 +-
arch/x86/kernel/cpu/microcode/amd.c | 2 +-
arch/x86/kernel/kexec-bzimage64.c | 2 +-
arch/x86/kernel/pci-dma.c | 2 +-
arch/x86/mm/tlb.c | 2 +-
arch/x86/platform/pvh/enlighten.c | 2 +-
drivers/acpi/Kconfig | 10 +++++-----
drivers/net/ethernet/faraday/ftgmac100.c | 2 +-
.../fieldbus/Documentation/fieldbus_dev.txt | 4 ++--
drivers/vhost/vhost.c | 2 +-
include/acpi/acpi_drivers.h | 2 +-
include/linux/fs_context.h | 2 +-
include/linux/lsm_hooks.h | 2 +-
mm/Kconfig | 2 +-
security/Kconfig | 2 +-
tools/include/linux/err.h | 2 +-
tools/objtool/Documentation/stack-validation.txt | 4 ++--
tools/testing/selftests/x86/protection_keys.c | 2 +-
49 files changed, 78 insertions(+), 79 deletions(-)
diff --git a/Documentation/acpi/dsd/leds.txt b/Documentation/acpi/dsd/leds.txt
index 81a63af42ed2..cc58b1a574c5 100644
--- a/Documentation/acpi/dsd/leds.txt
+++ b/Documentation/acpi/dsd/leds.txt
@@ -96,4 +96,4 @@ where
<URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.1.pdf>,
referenced 2019-02-21.
-[7] Documentation/acpi/dsd/data-node-reference.txt
+[7] Documentation/firmware-guide/acpi/dsd/data-node-references.rst
diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst
index 0124980dca2d..8d3273e32eb1 100644
--- a/Documentation/admin-guide/kernel-parameters.rst
+++ b/Documentation/admin-guide/kernel-parameters.rst
@@ -167,7 +167,7 @@ parameter is applicable::
X86-32 X86-32, aka i386 architecture is enabled.
X86-64 X86-64 architecture is enabled.
More X86-64 boot options can be found in
- Documentation/x86/x86_64/boot-options.txt .
+ Documentation/x86/x86_64/boot-options.rst.
X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
X86_UV SGI UV support is enabled.
XEN Xen support is enabled
@@ -181,10 +181,10 @@ In addition, the following text indicates that the option::
Parameters denoted with BOOT are actually interpreted by the boot
loader, and have no meaning to the kernel directly.
Do not modify the syntax of boot loader parameters without extreme
-need or coordination with <Documentation/x86/boot.txt>.
+need or coordination with <Documentation/x86/boot.rst>.
There are also arch-specific kernel-parameters not documented here.
-See for example <Documentation/x86/x86_64/boot-options.txt>.
+See for example <Documentation/x86/x86_64/boot-options.rst>.
Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
a trailing = on the name of any parameter states that that parameter will
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 138f6664b2e2..bc5f202d42ec 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -53,7 +53,7 @@
ACPI_DEBUG_PRINT statements, e.g.,
ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
The debug_level mask defaults to "info". See
- Documentation/acpi/debug.txt for more information about
+ Documentation/firmware-guide/acpi/debug.rst for more information about
debug layers and levels.
Enable processor driver info messages:
@@ -963,7 +963,7 @@
for details.
nompx [X86] Disables Intel Memory Protection Extensions.
- See Documentation/x86/intel_mpx.txt for more
+ See Documentation/x86/intel_mpx.rst for more
information about the feature.
nopku [X86] Disable Memory Protection Keys CPU feature found
@@ -1189,7 +1189,7 @@
that is to be dynamically loaded by Linux. If there are
multiple variables with the same name but with different
vendor GUIDs, all of them will be loaded. See
- Documentation/acpi/ssdt-overlays.txt for details.
+ Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
eisa_irq_edge= [PARISC,HW]
@@ -2383,7 +2383,7 @@
mce [X86-32] Machine Check Exception
- mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
+ mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
md= [HW] RAID subsystems devices and level
See Documentation/admin-guide/md.rst.
@@ -2439,7 +2439,7 @@
set according to the
CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config
option.
- See Documentation/memory-hotplug.txt.
+ See Documentation/admin-guide/mm/memory-hotplug.rst.
memmap=exactmap [KNL,X86] Enable setting of an exact
E820 memory map, as specified by the user.
@@ -2528,7 +2528,7 @@
mem_encrypt=on: Activate SME
mem_encrypt=off: Do not activate SME
- Refer to Documentation/x86/amd-memory-encryption.txt
+ Refer to Documentation/x86/amd-memory-encryption.rst
for details on when memory encryption can be activated.
mem_sleep_default= [SUSPEND] Default system suspend mode:
@@ -3528,7 +3528,7 @@
See Documentation/blockdev/paride.txt.
pirq= [SMP,APIC] Manual mp-table setup
- See Documentation/x86/i386/IO-APIC.txt.
+ See Documentation/x86/i386/IO-APIC.rst.
plip= [PPT,NET] Parallel port network link
Format: { parport<nr> | timid | 0 }
@@ -5054,7 +5054,7 @@
Can be used multiple times for multiple devices.
vga= [BOOT,X86-32] Select a particular video mode
- See Documentation/x86/boot.txt and
+ See Documentation/x86/boot.rst and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst
index c7495e42e6f4..2b20f5f7380d 100644
--- a/Documentation/admin-guide/ras.rst
+++ b/Documentation/admin-guide/ras.rst
@@ -199,7 +199,7 @@ Architecture (MCA)\ [#f3]_.
mode).
.. [#f3] For more details about the Machine Check Architecture (MCA),
- please read Documentation/x86/x86_64/machinecheck at the Kernel tree.
+ please read Documentation/x86/x86_64/machinecheck.rst at the Kernel tree.
EDAC - Error Detection And Correction
*************************************
diff --git a/Documentation/devicetree/bindings/net/fsl-enetc.txt b/Documentation/devicetree/bindings/net/fsl-enetc.txt
index c812e25ae90f..25fc687419db 100644
--- a/Documentation/devicetree/bindings/net/fsl-enetc.txt
+++ b/Documentation/devicetree/bindings/net/fsl-enetc.txt
@@ -16,8 +16,8 @@ Required properties:
In this case, the ENETC node should include a "mdio" sub-node
that in turn should contain the "ethernet-phy" node describing the
external phy. Below properties are required, their bindings
-already defined in ethernet.txt or phy.txt, under
-Documentation/devicetree/bindings/net/*.
+already defined in Documentation/devicetree/bindings/net/ethernet.txt or
+Documentation/devicetree/bindings/net/phy.txt.
Required:
@@ -51,8 +51,7 @@ Example:
connection:
In this case, the ENETC port node defines a fixed link connection,
-as specified by "fixed-link.txt", under
-Documentation/devicetree/bindings/net/*.
+as specified by Documentation/devicetree/bindings/net/fixed-link.txt.
Required:
diff --git a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
index 12b18f82d441..efa2c8b9b85a 100644
--- a/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/amlogic,meson-pcie.txt
@@ -3,7 +3,7 @@ Amlogic Meson AXG DWC PCIE SoC controller
Amlogic Meson PCIe host controller is based on the Synopsys DesignWare PCI core.
It shares common functions with the PCIe DesignWare core driver and
inherits common properties defined in
-Documentation/devicetree/bindings/pci/designware-pci.txt.
+Documentation/devicetree/bindings/pci/designware-pcie.txt.
Additional properties are described here:
diff --git a/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt b/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt
index 7ef2dbe48e8a..14d2eee96b3d 100644
--- a/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.txt
@@ -97,7 +97,7 @@ Second Level Nodes - Regulators
sent for this regulator including those which are for a
strictly lower power state.
-Other properties defined in Documentation/devicetree/bindings/regulator.txt
+Other properties defined in Documentation/devicetree/bindings/regulator/regulator.txt
may also be used. regulator-initial-mode and regulator-allowed-modes may be
specified for VRM regulators using mode values from
include/dt-bindings/regulator/qcom,rpmh-regulator.h. regulator-allow-bypass
diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index e86bd2f64117..60f8640f2b2f 100644
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -277,7 +277,7 @@ it with special cases.
the decompressor (the real mode entry point goes to the same 32bit
entry point once it switched into protected mode). That entry point
supports one calling convention which is documented in
- Documentation/x86/boot.txt
+ Documentation/x86/boot.rst
The physical pointer to the device-tree block (defined in chapter II)
is passed via setup_data which requires at least boot protocol 2.09.
The type filed is defined as
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst
index b37f3f7b8926..ce91518bf9f4 100644
--- a/Documentation/driver-api/gpio/board.rst
+++ b/Documentation/driver-api/gpio/board.rst
@@ -101,7 +101,7 @@ with the help of _DSD (Device Specific Data), introduced in ACPI 5.1::
}
For more information about the ACPI GPIO bindings see
-Documentation/acpi/gpio-properties.txt.
+Documentation/firmware-guide/acpi/gpio-properties.rst.
Platform Data
-------------
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst
index 5e4d8aa68913..fdecb6d711db 100644
--- a/Documentation/driver-api/gpio/consumer.rst
+++ b/Documentation/driver-api/gpio/consumer.rst
@@ -437,7 +437,7 @@ case, it will be handled by the GPIO subsystem automatically. However, if the
_DSD is not present, the mappings between GpioIo()/GpioInt() resources and GPIO
connection IDs need to be provided by device drivers.
-For details refer to Documentation/acpi/gpio-properties.txt
+For details refer to Documentation/firmware-guide/acpi/gpio-properties.rst
Interacting With the Legacy GPIO Subsystem
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index 6b32b7be8c85..65f5bb5725ac 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -339,7 +339,7 @@ a code like this::
There are also devm_* versions of these functions which release the
descriptors once the device is released.
-See Documentation/acpi/gpio-properties.txt for more information about the
+See Documentation/firmware-guide/acpi/gpio-properties.rst for more information about the
_DSD binding related to GPIOs.
MFD devices
diff --git a/Documentation/firmware-guide/acpi/method-tracing.rst b/Documentation/firmware-guide/acpi/method-tracing.rst
index d0b077b73f5f..0aa7e2c5d32a 100644
--- a/Documentation/firmware-guide/acpi/method-tracing.rst
+++ b/Documentation/firmware-guide/acpi/method-tracing.rst
@@ -68,7 +68,7 @@ c. Filter out the debug layer/level matched logs when the specified
Where:
0xXXXXXXXX/0xYYYYYYYY
- Refer to Documentation/acpi/debug.txt for possible debug layer/level
+ Refer to Documentation/firmware-guide/acpi/debug.rst for possible debug layer/level
masking values.
\PPPP.AAAA.TTTT.HHHH
Full path of a control method that can be found in the ACPI namespace.
diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices
index 0d85ac1935b7..5a3e2f331e8c 100644
--- a/Documentation/i2c/instantiating-devices
+++ b/Documentation/i2c/instantiating-devices
@@ -85,7 +85,7 @@ Method 1c: Declare the I2C devices via ACPI
-------------------------------------------
ACPI can also describe I2C devices. There is special documentation for this
-which is currently located at Documentation/acpi/enumeration.txt.
+which is currently located at Documentation/firmware-guide/acpi/enumeration.rst.
Method 2: Instantiate the devices explicitly
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index f0c86fbb3b48..92f7f34b021a 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -155,7 +155,7 @@ is 0x15 and the full version number is 0x234, this file will contain
the value 340 = 0x154.
See the type_of_loader and ext_loader_type fields in
-Documentation/x86/boot.txt for additional information.
+Documentation/x86/boot.rst for additional information.
==============================================================
@@ -167,7 +167,7 @@ The complete bootloader version number. In the example above, this
file will contain the value 564 = 0x234.
See the type_of_loader and ext_loader_ver fields in
-Documentation/x86/boot.txt for additional information.
+Documentation/x86/boot.rst for additional information.
==============================================================
diff --git a/Documentation/translations/it_IT/process/4.Coding.rst b/Documentation/translations/it_IT/process/4.Coding.rst
index c05b89e616dd..1d23e951491f 100644
--- a/Documentation/translations/it_IT/process/4.Coding.rst
+++ b/Documentation/translations/it_IT/process/4.Coding.rst
@@ -370,7 +370,7 @@ con cosa stanno lavorando. Consultate: Documentation/ABI/README per avere una
descrizione di come questi documenti devono essere impostati e quali
informazioni devono essere fornite.
-Il file :ref:`Documentation/translations/it_IT/admin-guide/kernel-parameters.rst <kernelparameters>`
+Il file :ref:`Documentation/admin-guide/kernel-parameters.rst <kernelparameters>`
descrive tutti i parametri di avvio del kernel. Ogni patch che aggiunga
nuovi parametri dovrebbe aggiungere nuove voci a questo file.
diff --git a/Documentation/translations/it_IT/process/howto.rst b/Documentation/translations/it_IT/process/howto.rst
index 9903ac7c566b..44e6077730e8 100644
--- a/Documentation/translations/it_IT/process/howto.rst
+++ b/Documentation/translations/it_IT/process/howto.rst
@@ -131,7 +131,7 @@ Di seguito una lista di file che sono presenti nei sorgente del kernel e che
"Linux kernel patch submission format"
http://linux.yyz.us/patch-format.html
- :ref:`Documentation/process/translations/it_IT/stable-api-nonsense.rst <it_stable_api_nonsense>`
+ :ref:`Documentation/translations/it_IT/process/stable-api-nonsense.rst <it_stable_api_nonsense>`
Questo file descrive la motivazioni sottostanti la conscia decisione di
non avere un API stabile all'interno del kernel, incluso cose come:
diff --git a/Documentation/translations/it_IT/process/stable-kernel-rules.rst b/Documentation/translations/it_IT/process/stable-kernel-rules.rst
index 48e88e5ad2c5..4f206cee31a7 100644
--- a/Documentation/translations/it_IT/process/stable-kernel-rules.rst
+++ b/Documentation/translations/it_IT/process/stable-kernel-rules.rst
@@ -33,7 +33,7 @@ Regole sul tipo di patch che vengono o non vengono accettate nei sorgenti
- Non deve includere alcuna correzione "banale" (correzioni grammaticali,
pulizia dagli spazi bianchi, eccetera).
- Deve rispettare le regole scritte in
- :ref:`Documentation/translation/it_IT/process/submitting-patches.rst <it_submittingpatches>`
+ :ref:`Documentation/translations/it_IT/process/submitting-patches.rst <it_submittingpatches>`
- Questa patch o una equivalente deve esistere già nei sorgenti principali di
Linux
@@ -43,7 +43,7 @@ Procedura per sottomettere patch per i sorgenti -stable
- Se la patch contiene modifiche a dei file nelle cartelle net/ o drivers/net,
allora seguite le linee guida descritte in
- :ref:`Documentation/translation/it_IT/networking/netdev-FAQ.rst <it_netdev-FAQ>`;
+ :ref:`Documentation/translations/it_IT/networking/netdev-FAQ.rst <it_netdev-FAQ>`;
ma solo dopo aver verificato al seguente indirizzo che la patch non sia
già in coda:
https://patchwork.ozlabs.org/bundle/davem/stable/?series=&submitter=&state=*&q=&archive=
diff --git a/Documentation/translations/zh_CN/process/4.Coding.rst b/Documentation/translations/zh_CN/process/4.Coding.rst
index 5301e9d55255..8bb777941394 100644
--- a/Documentation/translations/zh_CN/process/4.Coding.rst
+++ b/Documentation/translations/zh_CN/process/4.Coding.rst
@@ -241,7 +241,7 @@ scripts/coccinelle目录下已经打包了相当多的内核“语义补丁”
任何添加新用户空间界面的代码（包括新的sysfs或/proc文件）都应该包含该界面的
文档，该文档使用户空间开发人员能够知道他们在使用什么。请参阅
-Documentation/abi/readme，了解如何格式化此文档以及需要提供哪些信息。
+Documentation/ABI/README，了解如何格式化此文档以及需要提供哪些信息。
文件 :ref:`Documentation/admin-guide/kernel-parameters.rst <kernelparameters>`
描述了内核的所有引导时间参数。任何添加新参数的补丁都应该向该文件添加适当的
diff --git a/Documentation/x86/x86_64/5level-paging.rst b/Documentation/x86/x86_64/5level-paging.rst
index ab88a4514163..44856417e6a5 100644
--- a/Documentation/x86/x86_64/5level-paging.rst
+++ b/Documentation/x86/x86_64/5level-paging.rst
@@ -20,7 +20,7 @@ physical address space. This "ought to be enough for anybody" ©.
QEMU 2.9 and later support 5-level paging.
Virtual memory layout for 5-level paging is described in
-Documentation/x86/x86_64/mm.txt
+Documentation/x86/x86_64/mm.rst
Enabling 5-level paging
diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst
index 2f69836b8445..6a4285a3c7a4 100644
--- a/Documentation/x86/x86_64/boot-options.rst
+++ b/Documentation/x86/x86_64/boot-options.rst
@@ -9,7 +9,7 @@ only the AMD64 specific ones are listed here.
Machine check
=============
-Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
+Please see Documentation/x86/x86_64/machinecheck.rst for sysfs runtime tunables.
mce=off
Disable machine check
@@ -89,7 +89,7 @@ APICs
Don't use the local APIC (alias for i386 compatibility)
pirq=...
- See Documentation/x86/i386/IO-APIC.txt
+ See Documentation/x86/i386/IO-APIC.rst
noapictimer
Don't set up the APIC timer
diff --git a/Documentation/x86/x86_64/fake-numa-for-cpusets.rst b/Documentation/x86/x86_64/fake-numa-for-cpusets.rst
index 74fbb78b3c67..04df57b9aa3f 100644
--- a/Documentation/x86/x86_64/fake-numa-for-cpusets.rst
+++ b/Documentation/x86/x86_64/fake-numa-for-cpusets.rst
@@ -18,7 +18,7 @@ For more information on the features of cpusets, see
Documentation/cgroup-v1/cpusets.txt.
There are a number of different configurations you can use for your needs. For
more information on the numa=fake command line option and its various ways of
-configuring fake nodes, see Documentation/x86/x86_64/boot-options.txt.
+configuring fake nodes, see Documentation/x86/x86_64/boot-options.rst.
For the purposes of this introduction, we'll assume a very primitive NUMA
emulation setup of "numa=fake=4*512,". This will split our system memory into
diff --git a/MAINTAINERS b/MAINTAINERS
index 0c84bf76d165..47aa4f6defb9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3874,7 +3874,7 @@ F: Documentation/devicetree/bindings/hwmon/cirrus,lochnagar.txt
F: Documentation/devicetree/bindings/pinctrl/cirrus,lochnagar.txt
F: Documentation/devicetree/bindings/regulator/cirrus,lochnagar.txt
F: Documentation/devicetree/bindings/sound/cirrus,lochnagar.txt
-F: Documentation/hwmon/lochnagar
+F: Documentation/hwmon/lochnagar.rst
CISCO FCOE HBA DRIVER
M: Satish Kharat <satishkh@cisco.com>
@@ -11272,7 +11272,7 @@ NXP FXAS21002C DRIVER
M: Rui Miguel Silva <rmfrfs@gmail.com>
L: linux-iio@vger.kernel.org
S: Maintained
-F: Documentation/devicetree/bindings/iio/gyroscope/fxas21002c.txt
+F: Documentation/devicetree/bindings/iio/gyroscope/nxp,fxas21002c.txt
F: drivers/iio/gyro/fxas21002c_core.c
F: drivers/iio/gyro/fxas21002c.h
F: drivers/iio/gyro/fxas21002c_i2c.c
@@ -13043,7 +13043,7 @@ M: Niklas Cassel <niklas.cassel@linaro.org>
L: netdev@vger.kernel.org
S: Maintained
F: drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
-F: Documentation/devicetree/bindings/net/qcom,dwmac.txt
+F: Documentation/devicetree/bindings/net/qcom,ethqos.txt
QUALCOMM GENERIC INTERFACE I2C DRIVER
M: Alok Chauhan <alokc@codeaurora.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8869742a85df..0f220264cc23 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1263,7 +1263,7 @@ config SMP
uniprocessor machines. On a uniprocessor machine, the kernel
will run faster if you say N here.
- See also <file:Documentation/x86/i386/IO-APIC.txt>,
+ See also <file:Documentation/x86/i386/IO-APIC.rst>,
<file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
<http://tldp.org/HOWTO/SMP-HOWTO.html>.
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index 07bf740bea91..31cc2f423aa8 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -53,7 +53,7 @@ static void *image_load(struct kimage *image,
/*
* We require a kernel with an unambiguous Image header. Per
- * Documentation/booting.txt, this is the case when image_size
+ * Documentation/arm64/booting.txt, this is the case when image_size
* is non-zero (practically speaking, since v3.17).
*/
h = (struct arm64_image_header *)kernel;
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8c1c636308c8..e868d2bd48b8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -898,7 +898,7 @@ config PPC_MEM_KEYS
page-based protections, but without requiring modification of the
page tables when an application changes protection domains.
- For details, see Documentation/vm/protection-keys.rst
+ For details, see Documentation/x86/protection-keys.rst
If unsure, say y.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2bbbd4d1ba31..78fdf2dd71d1 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -395,7 +395,7 @@ config SMP
Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
Management" code will be disabled if you say Y here.
- See also <file:Documentation/x86/i386/IO-APIC.txt>,
+ See also <file:Documentation/x86/i386/IO-APIC.rst>,
<file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
<http://www.tldp.org/docs.html#howto>.
@@ -1290,7 +1290,7 @@ config MICROCODE
the Linux kernel.
The preferred method to load microcode from a detached initrd is described
- in Documentation/x86/microcode.txt. For that you need to enable
+ in Documentation/x86/microcode.rst. For that you need to enable
CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
initrd for microcode blobs.
@@ -1329,7 +1329,7 @@ config MICROCODE_OLD_INTERFACE
It is inadequate because it runs too late to be able to properly
load microcode on a machine and it needs special tools. Instead, you
should've switched to the early loading method with the initrd or
- builtin microcode by now: Documentation/x86/microcode.txt
+ builtin microcode by now: Documentation/x86/microcode.rst
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
@@ -1478,7 +1478,7 @@ config X86_5LEVEL
A kernel with the option enabled can be booted on machines that
support 4- or 5-level paging.
- See Documentation/x86/x86_64/5level-paging.txt for more
+ See Documentation/x86/x86_64/5level-paging.rst for more
information.
Say N if unsure.
@@ -1626,7 +1626,7 @@ config ARCH_MEMORY_PROBE
depends on X86_64 && MEMORY_HOTPLUG
help
This option enables a sysfs memory/probe interface for testing.
- See Documentation/memory-hotplug.txt for more information.
+ See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
If you are unsure how to answer this question, answer N.
config ARCH_PROC_KCORE_TEXT
@@ -1783,7 +1783,7 @@ config MTRR
You can safely say Y even if your machine doesn't have MTRRs, you'll
just add about 9 KB to your kernel.
- See <file:Documentation/x86/mtrr.txt> for more information.
+ See <file:Documentation/x86/mtrr.rst> for more information.
config MTRR_SANITIZER
def_bool y
@@ -1895,7 +1895,7 @@ config X86_INTEL_MPX
process and adds some branches to paths used during
exec() and munmap().
- For details, see Documentation/x86/intel_mpx.txt
+ For details, see Documentation/x86/intel_mpx.rst
If unsure, say N.
@@ -1911,7 +1911,7 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
page-based protections, but without requiring modification of the
page tables when an application changes protection domains.
- For details, see Documentation/x86/protection-keys.txt
+ For details, see Documentation/x86/protection-keys.rst
If unsure, say y.
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index f730680dc818..59f598543203 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -156,7 +156,7 @@ config IOMMU_DEBUG
code. When you use it make sure you have a big enough
IOMMU/AGP aperture. Most of the options enabled by this can
be set more finegrained using the iommu= command line
- options. See Documentation/x86/x86_64/boot-options.txt for more
+ options. See Documentation/x86/x86_64/boot-options.rst for more
details.
config IOMMU_LEAK
--git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 850b8762e889..90d791ca1a95 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -313,7 +313,7 @@ start_sys_seg: .word SYSSEG # obsolete and meaningless, but just
type_of_loader: .byte 0 # 0 means ancient bootloader, newer
# bootloaders know to change this.
- # See Documentation/x86/boot.txt for
+ # See Documentation/x86/boot.rst for
# assigned ids
# flags, unused bits must be zero (RFU) bit within loadflags
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 11aa3b2afa4d..33f9fc38d014 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -8,7 +8,7 @@
*
* entry.S contains the system-call and fault low-level handling routines.
*
- * Some of this is documented in Documentation/x86/entry_64.txt
+ * Some of this is documented in Documentation/x86/entry_64.rst
*
* A note on terminology:
* - iret frame: Architecture defined interrupt frame from SS to RIP
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h
index f6f6ef436599..101eb944f13c 100644
--- a/arch/x86/include/asm/bootparam_utils.h
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -24,7 +24,7 @@ static void sanitize_boot_params(struct boot_params *boot_params)
* IMPORTANT NOTE TO BOOTLOADER AUTHORS: do not simply clear
* this field. The purpose of this field is to guarantee
* compliance with the x86 boot spec located in
- * Documentation/x86/boot.txt . That spec says that the
+ * Documentation/x86/boot.rst . That spec says that the
* *whole* structure should be cleared, after which only the
* portion defined by struct setup_header (boot_params->hdr)
* should be copied in.
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 793c14c372cb..288b065955b7 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -48,7 +48,7 @@
#define __START_KERNEL_map _AC(0xffffffff80000000, UL)
-/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
+/* See Documentation/x86/x86_64/mm.rst for a description of the memory map. */
#define __PHYSICAL_MASK_SHIFT 52
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index 88bca456da99..52e5f5f2240d 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -103,7 +103,7 @@ extern unsigned int ptrs_per_p4d;
#define PGDIR_MASK (~(PGDIR_SIZE - 1))
/*
- * See Documentation/x86/x86_64/mm.txt for a description of the memory map.
+ * See Documentation/x86/x86_64/mm.rst for a description of the memory map.
*
* Be very careful vs. KASLR when changing anything here. The KASLR address
* range must not overlap with anything except the KASAN shadow area, which
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index e1f3ba19ba54..06d4e67f31ab 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -61,7 +61,7 @@ static u8 amd_ucode_patch[PATCH_MAX_SIZE];
/*
* Microcode patch container file is prepended to the initrd in cpio
- * format. See Documentation/x86/microcode.txt
+ * format. See Documentation/x86/microcode.rst
*/
static const char
ucode_path[] __maybe_unused = "kernel/x86/microcode/AuthenticAMD.bin";
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 22f60dd26460..b07e7069b09e 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -416,7 +416,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
efi_map_offset = params_cmdline_sz;
efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
- /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
+ /* Copy setup header onto bootparams. Documentation/x86/boot.rst */
setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
/* Is there a limit on setup header size? */
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index dcd272dbd0a9..f62b498b18fb 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -70,7 +70,7 @@ void __init pci_iommu_alloc(void)
}
/*
- * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel
+ * See <Documentation/x86/x86_64/boot-options.rst> for the iommu kernel
* parameter documentation.
*/
static __init int iommu_setup(char *p)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 7f61431c75fb..400c1ba033aa 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -711,7 +711,7 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
}
/*
- * See Documentation/x86/tlb.txt for details. We choose 33
+ * See Documentation/x86/tlb.rst for details. We choose 33
* because it is large enough to cover the vast majority (at
* least 95%) of allocations, and is small enough that we are
* confident it will not cause too much overhead. Each single
diff --git a/arch/x86/platform/pvh/enlighten.c b/arch/x86/platform/pvh/enlighten.c
index 1861a2ba0f2b..c0a502f7e3a7 100644
--- a/arch/x86/platform/pvh/enlighten.c
+++ b/arch/x86/platform/pvh/enlighten.c
@@ -86,7 +86,7 @@ static void __init init_pvh_bootparams(bool xen_guest)
}
/*
- * See Documentation/x86/boot.txt.
+ * See Documentation/x86/boot.rst.
*
* Version 2.12 supports Xen entry point but we will use default x86/PC
* environment (i.e. hardware_subarch 0).
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 283ee94224c6..2438f37f2ca1 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -333,7 +333,7 @@ config ACPI_CUSTOM_DSDT_FILE
depends on !STANDALONE
help
This option supports a custom DSDT by linking it into the kernel.
- See Documentation/acpi/dsdt-override.txt
+ See Documentation/admin-guide/acpi/dsdt-override.rst
Enter the full path name to the file which includes the AmlCode
or dsdt_aml_code declaration.
@@ -355,7 +355,7 @@ config ACPI_TABLE_UPGRADE
This option provides functionality to upgrade arbitrary ACPI tables
via initrd. No functional change if no ACPI tables are passed via
initrd, therefore it's safe to say Y.
- See Documentation/acpi/initrd_table_override.txt for details
+ See Documentation/admin-guide/acpi/initrd_table_override.rst for details
config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
bool "Override ACPI tables from built-in initrd"
@@ -365,7 +365,7 @@ config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
This option provides functionality to override arbitrary ACPI tables
from built-in uncompressed initrd.
- See Documentation/acpi/initrd_table_override.txt for details
+ See Documentation/admin-guide/acpi/initrd_table_override.rst for details
config ACPI_DEBUG
bool "Debug Statements"
@@ -374,7 +374,7 @@ config ACPI_DEBUG
output and increases the kernel size by around 50K.
Use the acpi.debug_layer and acpi.debug_level kernel command-line
- parameters documented in Documentation/acpi/debug.txt and
+ parameters documented in Documentation/firmware-guide/acpi/debug.rst and
Documentation/admin-guide/kernel-parameters.rst to control the type and
amount of debug output.
@@ -445,7 +445,7 @@ config ACPI_CUSTOM_METHOD
help
This debug facility allows ACPI AML methods to be inserted and/or
replaced without rebooting the system. For details refer to:
- Documentation/acpi/method-customizing.txt.
+ Documentation/firmware-guide/acpi/method-customizing.rst.
NOTE: This option is security sensitive, because it allows arbitrary
kernel memory to be written to by root (uid=0) users, allowing them
diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index b17b79e612a3..ac6280ad43a1 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1075,7 +1075,7 @@ static int ftgmac100_mii_probe(struct ftgmac100 *priv, phy_interface_t intf)
}
/* Indicate that we support PAUSE frames (see comment in
- * Documentation/networking/phy.txt)
+ * Documentation/networking/phy.rst)
*/
phy_support_asym_pause(phydev);
diff --git a/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt b/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
index 56af3f650fa3..89fb8e14676f 100644
--- a/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
+++ b/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
@@ -54,8 +54,8 @@ a limited few common behaviours and properties. This allows us to define
a simple interface consisting of a character device and a set of sysfs files:
See:
-Documentation/ABI/testing/sysfs-class-fieldbus-dev
-Documentation/ABI/testing/fieldbus-dev-cdev
+drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev
+drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev
Note that this simple interface does not provide a way to modify adapter
configuration settings. It is therefore useful only for adapters that get their
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 1e3ed41ae1f3..69938dbae2d0 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1694,7 +1694,7 @@ EXPORT_SYMBOL_GPL(vhost_dev_ioctl);
/* TODO: This is really inefficient. We need something like get_user()
* (instruction directly accesses the data, with an exception table entry
- * returning -EFAULT). See Documentation/x86/exception-tables.txt.
+ * returning -EFAULT). See Documentation/x86/exception-tables.rst.
*/
static int set_bit_to_user(int nr, void __user *addr)
{
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index de1804aeaf69..98e3db7a89cd 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -25,7 +25,7 @@
#define ACPI_MAX_STRING 80
/*
- * Please update drivers/acpi/debug.c and Documentation/acpi/debug.txt
+ * Please update drivers/acpi/debug.c and Documentation/firmware-guide/acpi/debug.rst
* if you add to this list.
*/
#define ACPI_BUS_COMPONENT 0x00010000
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 1f966670c8dc..623eb58560b9 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -85,7 +85,7 @@ struct fs_parameter {
* Superblock creation fills in ->root whereas reconfiguration begins with this
* already set.
*
- * See Documentation/filesystems/mounting.txt
+ * See Documentation/filesystems/mount_api.txt
*/
struct fs_context {
const struct fs_context_operations *ops;
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 47f58cfb6a19..df1318d85f7d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -77,7 +77,7 @@
* state. This is called immediately after commit_creds().
*
* Security hooks for mount using fs_context.
- * [See also Documentation/filesystems/mounting.txt]
+ * [See also Documentation/filesystems/mount_api.txt]
*
* @fs_context_dup:
* Allocate and attach a security structure to sc->security. This pointer
diff --git a/mm/Kconfig b/mm/Kconfig
index ee8d1f311858..6e5fb81bde4b 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -165,7 +165,7 @@ config MEMORY_HOTPLUG_DEFAULT_ONLINE
onlining policy (/sys/devices/system/memory/auto_online_blocks) which
determines what happens to newly added memory regions. Policy setting
can always be changed at runtime.
- See Documentation/memory-hotplug.txt for more information.
+ See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Say Y here if you want all hot-plugged memory blocks to appear in
'online' state by default.
diff --git a/security/Kconfig b/security/Kconfig
index aeac3676dd4d..6d75ed71970c 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -62,7 +62,7 @@ config PAGE_TABLE_ISOLATION
ensuring that the majority of kernel addresses are not mapped
into userspace.
- See Documentation/x86/pti.txt for more details.
+ See Documentation/x86/pti.rst for more details.
config SECURITY_INFINIBAND
bool "Infiniband Security Hooks"
diff --git a/tools/include/linux/err.h b/tools/include/linux/err.h
index 2f5a12b88a86..25f2bb3a991d 100644
--- a/tools/include/linux/err.h
+++ b/tools/include/linux/err.h
@@ -20,7 +20,7 @@
* Userspace note:
* The same principle works for userspace, because 'error' pointers
* fall down to the unused hole far from user space, as described
- * in Documentation/x86/x86_64/mm.txt for x86_64 arch:
+ * in Documentation/x86/x86_64/mm.rst for x86_64 arch:
*
* 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm hole caused by [48:63] sign extension
* ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/stack-validation.txt
index 4dd11a554b9b..de094670050b 100644
--- a/tools/objtool/Documentation/stack-validation.txt
+++ b/tools/objtool/Documentation/stack-validation.txt
@@ -21,7 +21,7 @@ instructions). Similarly, it knows how to follow switch statements, for
which gcc sometimes uses jump tables.
(Objtool also has an 'orc generate' subcommand which generates debuginfo
-for the ORC unwinder. See Documentation/x86/orc-unwinder.txt in the
+for the ORC unwinder. See Documentation/x86/orc-unwinder.rst in the
kernel tree for more details.)
@@ -101,7 +101,7 @@ b) ORC (Oops Rewind Capability) unwind table generation
band. So it doesn't affect runtime performance and it can be
reliable even when interrupts or exceptions are involved.
- For more details, see Documentation/x86/orc-unwinder.txt.
+ For more details, see Documentation/x86/orc-unwinder.rst.
c) Higher live patching compatibility rate
diff --git a/tools/testing/selftests/x86/protection_keys.c b/tools/testing/selftests/x86/protection_keys.c
index 5d546dcdbc80..798a5ddeee55 100644
--- a/tools/testing/selftests/x86/protection_keys.c
+++ b/tools/testing/selftests/x86/protection_keys.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Tests x86 Memory Protection Keys (see Documentation/x86/protection-keys.txt)
+ * Tests x86 Memory Protection Keys (see Documentation/x86/protection-keys.rst)
*
* There are examples in here of:
* * how to set protection keys on memory
--
2.21.0
^ permalink raw reply related
* Re: [RFC PATCH 2/4] x86/ftrace: Fix use of flags in ftrace_replace_code()
From: Naveen N. Rao @ 2019-05-20 14:42 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linuxppc-dev, linux-kernel, Nicholas Piggin
In-Reply-To: <20190520094410.772443df@gandalf.local.home>
Hi Steven,
Steven Rostedt wrote:
> On Mon, 20 May 2019 09:13:20 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
>
>> > I haven't yet tested this patch on x86, but this looked wrong so sending
>> > this as a RFC.
>>
>> This code has been through a bit of updates, and I need to go through
>> and clean it up. I'll have to take a look and convert "int" to "bool"
>> so that "enable" is not confusing.
>>
>> Thanks, I think I'll try to do a clean up first, and then this patch
>> shouldn't "look wrong" after that.
>>
>
> I'm going to apply the attached two patches. There may be some
> conflicts between yours here and these, but nothing that Linus can't
> figure out. Do you feel more comfortable with this code, if these
> patches are applied?
Thanks, that definitely helps make things clearer. A very small nit from
your first patch -- it would be good to also convert the calls to
ftrace_check_record() to use 'true' or 'false' for the 'update' field.
I will test my series in more detail and post a v1.
- Naveen
^ permalink raw reply
* Re: [PATCH v2 1/2] pid: add pidfd_open()
From: Arnd Bergmann @ 2019-05-20 14:37 UTC (permalink / raw)
To: Christian Brauner
Cc: linux-ia64, Linux-sh list, Linux Kernel Mailing List,
David Howells, Joel Fernandes,
open list:KERNEL SELFTEST FRAMEWORK, sparclinux, Linux API,
Reshetova, Elena, linux-arch, linux-s390, Daniel Colascione,
Android Kernel Team, Serge E. Hallyn, linux-xtensa, Kees Cook,
Jann Horn, linux-m68k, Al Viro, Andy Lutomirski, Oleg Nesterov,
Thomas Gleixner, Suren Baghdasaryan, Linux ARM, Parisc List,
cyphar, Linus Torvalds, linux-mips, Andy Lutomirski,
Eric W . Biederman, alpha, Andrew Morton, linuxppc-dev
In-Reply-To: <20190520134605.29116-1-christian@brauner.io>
On Mon, May 20, 2019 at 3:46 PM Christian Brauner <christian@brauner.io> wrote:
>
> In line with Arnd's recent changes to consolidate syscall numbers across
> architectures, I have added the pidfd_open() syscall to all architectures
> at the same time.
Thanks! I've checked that the ones you have added are all
done correctly. However, double-checking that you got all of them,
I noticed that you missed mips-o32 and mips-n64. With those added:
Acked-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply
* Re: PROBLEM: Power9: kernel oops on memory hotunplug from ppc64le guest
From: Bharata B Rao @ 2019-05-20 14:29 UTC (permalink / raw)
To: Nicholas Piggin
Cc: bharata, linux-kernel, linux-next, aneesh.kumar, srikanth,
linuxppc-dev
In-Reply-To: <20190520082035.GD22939@in.ibm.com>
On Mon, May 20, 2019 at 01:50:35PM +0530, Bharata B Rao wrote:
> On Mon, May 20, 2019 at 05:00:21PM +1000, Nicholas Piggin wrote:
> > Bharata B Rao's on May 20, 2019 3:56 pm:
> > > On Mon, May 20, 2019 at 02:48:35PM +1000, Nicholas Piggin wrote:
> > >> >> > git bisect points to
> > >> >> >
> > >> >> > commit 4231aba000f5a4583dd9f67057aadb68c3eca99d
> > >> >> > Author: Nicholas Piggin <npiggin@gmail.com>
> > >> >> > Date: Fri Jul 27 21:48:17 2018 +1000
> > >> >> >
> > >> >> > powerpc/64s: Fix page table fragment refcount race vs speculative references
> > >> >> >
> > >> >> > The page table fragment allocator uses the main page refcount racily
> > >> >> > with respect to speculative references. A customer observed a BUG due
> > >> >> > to page table page refcount underflow in the fragment allocator. This
> > >> >> > can be caused by the fragment allocator set_page_count stomping on a
> > >> >> > speculative reference, and then the speculative failure handler
> > >> >> > decrements the new reference, and the underflow eventually pops when
> > >> >> > the page tables are freed.
> > >> >> >
> > >> >> > Fix this by using a dedicated field in the struct page for the page
> > >> >> > table fragment allocator.
> > >> >> >
> > >> >> > Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage")
> > >> >> > Cc: stable@vger.kernel.org # v3.10+
> > >> >>
> > >> >> That's the commit that added the BUG_ON(), so prior to that you won't
> > >> >> see the crash.
> > >> >
> > >> > Right, but the commit says it fixes page table page refcount underflow by
> > >> > introducing a new field &page->pt_frag_refcount. Now we are hitting the underflow
> > >> > for this pt_frag_refcount.
> > >>
> > >> The fixed underflow is caused by a bug (race on page count) that got
> > >> fixed by that patch. You are hitting a different underflow here. It's
> > >> not certain my patch caused it, I'm just trying to reproduce now.
> > >
> > > Ok.
> >
> > Can't reproduce I'm afraid, tried adding and removing 8GB memory from a
> > 4GB guest (via host adding / removing memory device), and it just works.
>
> Boot, add 8G, reboot, remove 8G is the sequence to reproduce.
>
> >
> > It's likely to be an edge case like an off by one or rounding error
> > that just happens to trigger in your config. Might be easiest if you
> > could test with a debug patch.
>
> Sure, I will continue debugging.
When the guest is rebooted after hotplug, the entire memory (which includes
the hotplugged memory) gets remapped again freshly. However at this time
since no slab is available yet, pt_frag_refcount never gets initialized as we
never do pte_fragment_alloc() for these mappings. So we right away hit the
underflow during the first unplug itself, it looks like.
I will check how this can be fixed.
>
> Regards,
> Bharata.
^ permalink raw reply
* [PATCH] misc: remove redundant 'default n' from Kconfig-s
From: Bartlomiej Zolnierkiewicz @ 2019-05-20 14:10 UTC (permalink / raw)
To: Arnd Bergmann, Greg Kroah-Hartman
Cc: Eric Piel, Andrew Donnellan, Frank Haverkamp, linux-kernel,
Michał Mirosław, Frederic Barrat, linuxppc-dev
In-Reply-To: <CGME20190520141047eucas1p2c6006d1ecfc3eb287b6b33d131f66180@eucas1p2.samsung.com>
'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
drivers/misc/Kconfig | 10 ----------
drivers/misc/altera-stapl/Kconfig | 1 -
drivers/misc/c2port/Kconfig | 2 --
drivers/misc/cb710/Kconfig | 1 -
drivers/misc/cxl/Kconfig | 3 ---
drivers/misc/echo/Kconfig | 1 -
drivers/misc/genwqe/Kconfig | 1 -
drivers/misc/lis3lv02d/Kconfig | 2 --
drivers/misc/ocxl/Kconfig | 1 -
9 files changed, 22 deletions(-)
Index: b/drivers/misc/Kconfig
===================================================================
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -8,7 +8,6 @@ config SENSORS_LIS3LV02D
tristate
depends on INPUT
select INPUT_POLLDEV
- default n
config AD525X_DPOT
tristate "Analog Devices Digital Potentiometers"
@@ -61,7 +60,6 @@ config ATMEL_TCLIB
config DUMMY_IRQ
tristate "Dummy IRQ handler"
- default n
---help---
This module accepts a single 'irq' parameter, which it should register for.
The sole purpose of this module is to help with debugging of systems on
@@ -117,7 +115,6 @@ config PHANTOM
config INTEL_MID_PTI
tristate "Parallel Trace Interface for MIPI P1149.7 cJTAG standard"
depends on PCI && TTY && (X86_INTEL_MID || COMPILE_TEST)
- default n
help
The PTI (Parallel Trace Interface) driver directs
trace data routed from various parts in the system out
@@ -193,7 +190,6 @@ config ATMEL_SSC
config ENCLOSURE_SERVICES
tristate "Enclosure Services"
- default n
help
Provides support for intelligent enclosures (bays which
contain storage devices). You also need either a host
@@ -217,7 +213,6 @@ config SGI_XP
config CS5535_MFGPT
tristate "CS5535/CS5536 Geode Multi-Function General Purpose Timer (MFGPT) support"
depends on MFD_CS5535
- default n
help
This driver provides access to MFGPT functionality for other
drivers that need timers. MFGPTs are available in the CS5535 and
@@ -250,7 +245,6 @@ config CS5535_CLOCK_EVENT_SRC
config HP_ILO
tristate "Channel interface driver for the HP iLO processor"
depends on PCI
- default n
help
The channel interface driver allows applications to communicate
with iLO management processors present on HP ProLiant servers.
@@ -285,7 +279,6 @@ config QCOM_FASTRPC
config SGI_GRU
tristate "SGI GRU driver"
depends on X86_UV && SMP
- default n
select MMU_NOTIFIER
---help---
The GRU is a hardware resource located in the system chipset. The GRU
@@ -300,7 +293,6 @@ config SGI_GRU
config SGI_GRU_DEBUG
bool "SGI GRU driver debug"
depends on SGI_GRU
- default n
---help---
This option enables additional debugging code for the SGI GRU driver.
If you are unsure, say N.
@@ -358,7 +350,6 @@ config SENSORS_BH1770
config SENSORS_APDS990X
tristate "APDS990X combined als and proximity sensors"
depends on I2C
- default n
---help---
Say Y here if you want to build a driver for Avago APDS990x
combined ambient light and proximity sensor chip.
@@ -386,7 +377,6 @@ config DS1682
config SPEAR13XX_PCIE_GADGET
bool "PCIe gadget support for SPEAr13XX platform"
depends on ARCH_SPEAR13XX && BROKEN
- default n
help
This option enables gadget support for PCIe controller. If
board file defines any controller as PCIe endpoint then a sysfs
Index: b/drivers/misc/altera-stapl/Kconfig
===================================================================
--- a/drivers/misc/altera-stapl/Kconfig
+++ b/drivers/misc/altera-stapl/Kconfig
@@ -4,6 +4,5 @@ comment "Altera FPGA firmware download m
config ALTERA_STAPL
tristate "Altera FPGA firmware download module"
depends on I2C
- default n
help
An Altera FPGA module. Say Y when you want to support this tool.
Index: b/drivers/misc/c2port/Kconfig
===================================================================
--- a/drivers/misc/c2port/Kconfig
+++ b/drivers/misc/c2port/Kconfig
@@ -4,7 +4,6 @@
menuconfig C2PORT
tristate "Silicon Labs C2 port support"
- default n
help
This option enables support for Silicon Labs C2 port used to
program Silicon micro controller chips (and other 8051 compatible).
@@ -23,7 +22,6 @@ if C2PORT
config C2PORT_DURAMAR_2150
tristate "C2 port support for Eurotech's Duramar 2150"
depends on X86
- default n
help
This option enables C2 support for the Eurotech's Duramar 2150
on board micro controller.
Index: b/drivers/misc/cb710/Kconfig
===================================================================
--- a/drivers/misc/cb710/Kconfig
+++ b/drivers/misc/cb710/Kconfig
@@ -14,7 +14,6 @@ config CB710_CORE
config CB710_DEBUG
bool "Enable driver debugging"
depends on CB710_CORE != n
- default n
help
This is an option for use by developers; most people should
say N here. This adds a lot of debugging output to dmesg.
Index: b/drivers/misc/cxl/Kconfig
===================================================================
--- a/drivers/misc/cxl/Kconfig
+++ b/drivers/misc/cxl/Kconfig
@@ -4,16 +4,13 @@
config CXL_BASE
bool
- default n
select PPC_COPRO_BASE
config CXL_AFU_DRIVER_OPS
bool
- default n
config CXL_LIB
bool
- default n
config CXL
tristate "Support for IBM Coherent Accelerators (CXL)"
Index: b/drivers/misc/echo/Kconfig
===================================================================
--- a/drivers/misc/echo/Kconfig
+++ b/drivers/misc/echo/Kconfig
@@ -1,6 +1,5 @@
config ECHO
tristate "Line Echo Canceller support"
- default n
---help---
This driver provides line echo cancelling support for mISDN and
Zaptel drivers.
Index: b/drivers/misc/genwqe/Kconfig
===================================================================
--- a/drivers/misc/genwqe/Kconfig
+++ b/drivers/misc/genwqe/Kconfig
@@ -6,7 +6,6 @@ menuconfig GENWQE
tristate "GenWQE PCIe Accelerator"
depends on PCI && 64BIT
select CRC_ITU_T
- default n
help
Enables PCIe card driver for IBM GenWQE accelerators.
The user-space interface is described in
Index: b/drivers/misc/lis3lv02d/Kconfig
===================================================================
--- a/drivers/misc/lis3lv02d/Kconfig
+++ b/drivers/misc/lis3lv02d/Kconfig
@@ -6,7 +6,6 @@ config SENSORS_LIS3_SPI
tristate "STMicroeletronics LIS3LV02Dx three-axis digital accelerometer (SPI)"
depends on !ACPI && SPI_MASTER && INPUT
select SENSORS_LIS3LV02D
- default n
help
This driver provides support for the LIS3LV02Dx accelerometer connected
via SPI. The accelerometer data is readable via
@@ -23,7 +22,6 @@ config SENSORS_LIS3_I2C
tristate "STMicroeletronics LIS3LV02Dx three-axis digital accelerometer (I2C)"
depends on I2C && INPUT
select SENSORS_LIS3LV02D
- default n
help
This driver provides support for the LIS3LV02Dx accelerometer connected
via I2C. The accelerometer data is readable via
Index: b/drivers/misc/ocxl/Kconfig
===================================================================
--- a/drivers/misc/ocxl/Kconfig
+++ b/drivers/misc/ocxl/Kconfig
@@ -4,7 +4,6 @@
config OCXL_BASE
bool
- default n
select PPC_COPRO_BASE
config OCXL
^ permalink raw reply
* Re: [PATCH v2 1/2] pid: add pidfd_open()
From: Geert Uytterhoeven @ 2019-05-20 14:00 UTC (permalink / raw)
To: Christian Brauner
Cc: linux-ia64@vger.kernel.org, Linux-sh list, Oleg Nesterov,
David Howells, Joel Fernandes,
open list:KERNEL SELFTEST FRAMEWORK, sparclinux, elena.reshetova,
Linux-Arch, linux-s390, Daniel Colascione, linux-mips,
Android Kernel Team, Serge E. Hallyn, linux-xtensa, Kees Cook,
Arnd Bergmann, Jann Horn, linuxppc-dev, linux-m68k, Al Viro,
Andy Lutomirski, Thomas Gleixner, surenb, Linux ARM, Parisc List,
cyphar, Linux API, Linux Kernel Mailing List, Andy Lutomirski,
Eric W. Biederman, alpha, Andrew Morton,
torvalds@linux-foundation.org
In-Reply-To: <20190520134605.29116-1-christian@brauner.io>
On Mon, May 20, 2019 at 3:46 PM Christian Brauner <christian@brauner.io> wrote:
> This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
> pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
> process that is created via traditional fork()/clone() calls that is only
> referenced by a PID:
>
> int pidfd = pidfd_open(1234, 0);
> ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
>
> With the introduction of pidfds through CLONE_PIDFD it is possible to
> created pidfds at process creation time.
> However, a lot of processes get created with traditional PID-based calls
> such as fork() or clone() (without CLONE_PIDFD). For these processes a
> caller can currently not create a pollable pidfd. This is a problem for
> Android's low memory killer (LMK) and service managers such as systemd.
> Both are examples of tools that want to make use of pidfds to get reliable
> notification of process exit for non-parents (pidfd polling) and race-free
> signal sending (pidfd_send_signal()). They intend to switch to this API for
> process supervision/management as soon as possible. Having no way to get
> pollable pidfds from PID-only processes is one of the biggest blockers for
> them in adopting this api. With pidfd_open() making it possible to retrieve
> pidfds for PID-based processes we enable them to adopt this api.
>
> In line with Arnd's recent changes to consolidate syscall numbers across
> architectures, I have added the pidfd_open() syscall to all architectures
> at the same time.
>
> Signed-off-by: Christian Brauner <christian@brauner.io>
> Reviewed-by: Oleg Nesterov <oleg@redhat.com>
> arch/m68k/kernel/syscalls/syscall.tbl | 1 +
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* [PATCH v7 1/1] iommu: enhance IOMMU dma mode build options
From: Zhen Lei @ 2019-05-20 13:59 UTC (permalink / raw)
To: Jean-Philippe Brucker, John Garry, Robin Murphy, Will Deacon,
Joerg Roedel, Jonathan Corbet, linux-doc, Sebastian Ott,
Gerald Schaefer, Martin Schwidefsky, Heiko Carstens,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Tony Luck, Fenghua Yu, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H . Peter Anvin, David Woodhouse, iommu,
linux-kernel, linux-s390, linuxppc-dev, x86, linux-ia64
Cc: Hanjun Guo, Zhen Lei
In-Reply-To: <20190520135947.14960-1-thunder.leizhen@huawei.com>
First, add build option IOMMU_DEFAULT_{LAZY|STRICT}, so that we have the
opportunity to set {lazy|strict} mode as default at build time. Then put
the three config options in an choice, make people can only choose one of
the three at a time.
The default IOMMU dma modes on each ARCHs have no change.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
arch/ia64/kernel/pci-dma.c | 2 +-
arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++-
arch/s390/pci/pci_dma.c | 2 +-
arch/x86/kernel/pci-dma.c | 7 ++---
drivers/iommu/Kconfig | 44 ++++++++++++++++++++++++++-----
drivers/iommu/amd_iommu_init.c | 3 ++-
drivers/iommu/intel-iommu.c | 2 +-
drivers/iommu/iommu.c | 3 ++-
8 files changed, 48 insertions(+), 18 deletions(-)
diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c
index fe988c49f01ce6a..655511dbf3c3b34 100644
--- a/arch/ia64/kernel/pci-dma.c
+++ b/arch/ia64/kernel/pci-dma.c
@@ -22,7 +22,7 @@
int force_iommu __read_mostly;
#endif
-int iommu_pass_through;
+int iommu_pass_through = IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH);
static int __init pci_iommu_init(void)
{
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 3ead4c237ed0ec9..383e082a9bb985c 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -85,7 +85,8 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
va_end(args);
}
-static bool pnv_iommu_bypass_disabled __read_mostly;
+static bool pnv_iommu_bypass_disabled __read_mostly =
+ !IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH);
static bool pci_reset_phbs __read_mostly;
static int __init iommu_setup(char *str)
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 9e52d1527f71495..784ad1e0acecfb1 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -17,7 +17,7 @@
static struct kmem_cache *dma_region_table_cache;
static struct kmem_cache *dma_page_table_cache;
-static int s390_iommu_strict;
+static int s390_iommu_strict = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT);
static int zpci_refresh_global(struct zpci_dev *zdev)
{
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index d460998ae828514..fb2bab42a0a3173 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -43,11 +43,8 @@
* It is also possible to disable by default in kernel config, and enable with
* iommu=nopt at boot time.
*/
-#ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH
-int iommu_pass_through __read_mostly = 1;
-#else
-int iommu_pass_through __read_mostly;
-#endif
+int iommu_pass_through __read_mostly =
+ IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH);
extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 6f07f3b21816c64..8a1f1793cde76b4 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -74,17 +74,47 @@ config IOMMU_DEBUGFS
debug/iommu directory, and then populate a subdirectory with
entries as required.
-config IOMMU_DEFAULT_PASSTHROUGH
- bool "IOMMU passthrough by default"
+choice
+ prompt "IOMMU default DMA mode"
depends on IOMMU_API
- help
- Enable passthrough by default, removing the need to pass in
- iommu.passthrough=on or iommu=pt through command line. If this
- is enabled, you can still disable with iommu.passthrough=off
- or iommu=nopt depending on the architecture.
+ default IOMMU_DEFAULT_PASSTHROUGH if (PPC_POWERNV && PCI)
+ default IOMMU_DEFAULT_LAZY if (AMD_IOMMU || INTEL_IOMMU || S390_IOMMU)
+ default IOMMU_DEFAULT_STRICT
+ help
+ This option allows IOMMU DMA mode to be chose at build time, to
+ override the default DMA mode of each ARCHs, removing the need to
+ pass in kernel parameters through command line. You can still use
+ ARCHs specific boot options to override this option again.
+
+config IOMMU_DEFAULT_PASSTHROUGH
+ bool "passthrough"
+ help
+ In this mode, the DMA access through IOMMU without any addresses
+ translation. That means, the wrong or illegal DMA access can not
+ be caught, no error information will be reported.
If unsure, say N here.
+config IOMMU_DEFAULT_LAZY
+ bool "lazy"
+ help
+ Support lazy mode, where for every IOMMU DMA unmap operation, the
+ flush operation of IOTLB and the free operation of IOVA are deferred.
+ They are only guaranteed to be done before the related IOVA will be
+ reused.
+
+config IOMMU_DEFAULT_STRICT
+ bool "strict"
+ help
+ For every IOMMU DMA unmap operation, the flush operation of IOTLB and
+ the free operation of IOVA are guaranteed to be done in the unmap
+ function.
+
+ This mode is safer than the two above, but it maybe slower in some
+ high performace scenarios.
+
+endchoice
+
config OF_IOMMU
def_bool y
depends on OF && IOMMU_API
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index ff40ba758cf365e..16c02b08adb4cb2 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -166,7 +166,8 @@ struct ivmd_header {
to handle */
LIST_HEAD(amd_iommu_unity_map); /* a list of required unity mappings
we find in ACPI */
-bool amd_iommu_unmap_flush; /* if true, flush on every unmap */
+bool amd_iommu_unmap_flush = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT);
+ /* if true, flush on every unmap */
LIST_HEAD(amd_iommu_list); /* list of all AMD IOMMUs in the
system */
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 28cb713d728ceef..0c3cc716210f35a 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -362,7 +362,7 @@ static int domain_detach_iommu(struct dmar_domain *domain,
static int dmar_map_gfx = 1;
static int dmar_forcedac;
-static int intel_iommu_strict;
+static int intel_iommu_strict = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT);
static int intel_iommu_superpage = 1;
static int intel_iommu_sm;
static int iommu_identity_mapping;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 109de67d5d727c2..0ec5952ac60e2a3 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -43,7 +43,8 @@
#else
static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
#endif
-static bool iommu_dma_strict __read_mostly = true;
+static bool iommu_dma_strict __read_mostly =
+ IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT);
struct iommu_group {
struct kobject kobj;
--
1.8.3
^ permalink raw reply related
* [PATCH v7 0/1] iommu: enhance IOMMU dma mode build options
From: Zhen Lei @ 2019-05-20 13:59 UTC (permalink / raw)
To: Jean-Philippe Brucker, John Garry, Robin Murphy, Will Deacon,
Joerg Roedel, Jonathan Corbet, linux-doc, Sebastian Ott,
Gerald Schaefer, Martin Schwidefsky, Heiko Carstens,
Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
Tony Luck, Fenghua Yu, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H . Peter Anvin, David Woodhouse, iommu,
linux-kernel, linux-s390, linuxppc-dev, x86, linux-ia64
Cc: Hanjun Guo, Zhen Lei
v6 --> v7:
1. Fix some text editing errors
v5 --> v6:
1. give up adding boot option iommu.dma_mode
v4 --> v5:
As Hanjun and Thomas Gleixner's suggestion:
1. Keep the old ARCH specific boot options no change.
2. Keep build option CONFIG_IOMMU_DEFAULT_PASSTHROUGH no change.
v4:
As Robin Murphy's suggestion:
"It's also not necessarily obvious to the user how this interacts with
IOMMU_DEFAULT_PASSTHROUGH, so if we really do go down this route, maybe it
would be better to refactor the whole lot into a single selection of something
like IOMMU_DEFAULT_MODE anyway."
In this version, I tried to normalize the IOMMU dma mode boot options for all
ARCHs. When IOMMU is enabled, there are 3 dma modes: paasthrough(bypass),
lazy(mapping but defer the IOTLB invalidation), strict. But currently each
ARCHs defined their private boot options, different with each other. For
example, to enable/disable "passthrough", ARM64 use iommu.passthrough=1/0,
X86 use iommu=pt/nopt, PPC/POWERNV use iommu=nobypass.
Zhen Lei (1):
iommu: enhance IOMMU dma mode build options
arch/ia64/kernel/pci-dma.c | 2 +-
arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++-
arch/s390/pci/pci_dma.c | 2 +-
arch/x86/kernel/pci-dma.c | 7 ++---
drivers/iommu/Kconfig | 44 ++++++++++++++++++++++++++-----
drivers/iommu/amd_iommu_init.c | 3 ++-
drivers/iommu/intel-iommu.c | 2 +-
drivers/iommu/iommu.c | 3 ++-
8 files changed, 48 insertions(+), 18 deletions(-)
--
1.8.3
^ permalink raw reply
* [PATCH v2 2/2] tests: add pidfd_open() tests
From: Christian Brauner @ 2019-05-20 13:46 UTC (permalink / raw)
To: jannh, oleg, viro, torvalds, linux-kernel, arnd
Cc: linux-ia64, linux-sh, linux-mips, dhowells, joel, linux-kselftest,
sparclinux, elena.reshetova, linux-arch, linux-s390, dancol,
Christian Brauner, kernel-team, serge, linux-xtensa, keescook,
linux-m68k, luto, tglx, surenb, linux-arm-kernel, linux-parisc,
linux-api, cyphar, luto, ebiederm, linux-alpha,
Michael Kerrisk (man-pages), akpm, linuxppc-dev
In-Reply-To: <20190520134605.29116-1-christian@brauner.io>
This adds testing for the new pidfd_open() syscalls. Specifically, we test:
- that no invalid flags can be passed to pidfd_open()
- that no invalid pid can be passed to pidfd_open()
- that a pidfd can be retrieved with pidfd_open()
- that the retrieved pidfd references the correct pid
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
---
v1: unchanged
v2:
- Christian Brauner <christian@brauner.io>:
- set number of planned tests via ksft_set_plan()
---
tools/testing/selftests/pidfd/Makefile | 2 +-
tools/testing/selftests/pidfd/pidfd.h | 57 ++++++
.../testing/selftests/pidfd/pidfd_open_test.c | 169 ++++++++++++++++++
tools/testing/selftests/pidfd/pidfd_test.c | 41 +----
4 files changed, 228 insertions(+), 41 deletions(-)
create mode 100644 tools/testing/selftests/pidfd/pidfd.h
create mode 100644 tools/testing/selftests/pidfd/pidfd_open_test.c
diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index deaf8073bc06..b36c0be70848 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,6 +1,6 @@
CFLAGS += -g -I../../../../usr/include/
-TEST_GEN_PROGS := pidfd_test
+TEST_GEN_PROGS := pidfd_test pidfd_open_test
include ../lib.mk
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
new file mode 100644
index 000000000000..8452e910463f
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __PIDFD_H
+#define __PIDFD_H
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/mount.h>
+
+#include "../kselftest.h"
+
+/*
+ * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
+ * That means, when it wraps around any pid < 300 will be skipped.
+ * So we need to use a pid > 300 in order to test recycling.
+ */
+#define PID_RECYCLE 1000
+
+/*
+ * Define a few custom error codes for the child process to clearly indicate
+ * what is happening. This way we can tell the difference between a system
+ * error, a test error, etc.
+ */
+#define PIDFD_PASS 0
+#define PIDFD_FAIL 1
+#define PIDFD_ERROR 2
+#define PIDFD_SKIP 3
+#define PIDFD_XFAIL 4
+
+int wait_for_pid(pid_t pid)
+{
+ int status, ret;
+
+again:
+ ret = waitpid(pid, &status, 0);
+ if (ret == -1) {
+ if (errno == EINTR)
+ goto again;
+
+ return -1;
+ }
+
+ if (!WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+}
+
+
+#endif /* __PIDFD_H */
diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c
new file mode 100644
index 000000000000..0377133dd6dc
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_open_test.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pidfd.h"
+#include "../kselftest.h"
+
+static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
+{
+ return syscall(__NR_pidfd_open, pid, flags);
+}
+
+static int safe_int(const char *numstr, int *converted)
+{
+ char *err = NULL;
+ long sli;
+
+ errno = 0;
+ sli = strtol(numstr, &err, 0);
+ if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN))
+ return -ERANGE;
+
+ if (errno != 0 && sli == 0)
+ return -EINVAL;
+
+ if (err == numstr || *err != '\0')
+ return -EINVAL;
+
+ if (sli > INT_MAX || sli < INT_MIN)
+ return -ERANGE;
+
+ *converted = (int)sli;
+ return 0;
+}
+
+static int char_left_gc(const char *buffer, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (buffer[i] == ' ' ||
+ buffer[i] == '\t')
+ continue;
+
+ return i;
+ }
+
+ return 0;
+}
+
+static int char_right_gc(const char *buffer, size_t len)
+{
+ int i;
+
+ for (i = len - 1; i >= 0; i--) {
+ if (buffer[i] == ' ' ||
+ buffer[i] == '\t' ||
+ buffer[i] == '\n' ||
+ buffer[i] == '\0')
+ continue;
+
+ return i + 1;
+ }
+
+ return 0;
+}
+
+static char *trim_whitespace_in_place(char *buffer)
+{
+ buffer += char_left_gc(buffer, strlen(buffer));
+ buffer[char_right_gc(buffer, strlen(buffer))] = '\0';
+ return buffer;
+}
+
+static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen)
+{
+ int ret;
+ char path[512];
+ FILE *f;
+ size_t n = 0;
+ pid_t result = -1;
+ char *line = NULL;
+
+ snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd);
+
+ f = fopen(path, "re");
+ if (!f)
+ return -1;
+
+ while (getline(&line, &n, f) != -1) {
+ char *numstr;
+
+ if (strncmp(line, key, keylen))
+ continue;
+
+ numstr = trim_whitespace_in_place(line + 4);
+ ret = safe_int(numstr, &result);
+ if (ret < 0)
+ goto out;
+
+ break;
+ }
+
+out:
+ free(line);
+ fclose(f);
+ return result;
+}
+
+int main(int argc, char **argv)
+{
+ int pidfd = -1, ret = 1;
+ pid_t pid;
+
+ ksft_set_plan(3);
+
+ pidfd = sys_pidfd_open(-1, 0);
+ if (pidfd >= 0) {
+ ksft_print_msg(
+ "%s - succeeded to open pidfd for invalid pid -1\n",
+ strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("do not allow invalid pid test: passed\n");
+
+ pidfd = sys_pidfd_open(getpid(), 1);
+ if (pidfd >= 0) {
+ ksft_print_msg(
+ "%s - succeeded to open pidfd with invalid flag value specified\n",
+ strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("do not allow invalid flag test: passed\n");
+
+ pidfd = sys_pidfd_open(getpid(), 0);
+ if (pidfd < 0) {
+ ksft_print_msg("%s - failed to open pidfd\n", strerror(errno));
+ goto on_error;
+ }
+ ksft_test_result_pass("open a new pidfd test: passed\n");
+
+ pid = get_pid_from_fdinfo_file(pidfd, "Pid:", sizeof("Pid:") - 1);
+ ksft_print_msg("pidfd %d refers to process with pid %d\n", pidfd, pid);
+
+ ret = 0;
+
+on_error:
+ if (pidfd >= 0)
+ close(pidfd);
+
+ return !ret ? ksft_exit_pass() : ksft_exit_fail();
+}
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 5bae1792e3d6..a03387052aa7 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -14,6 +14,7 @@
#include <sys/wait.h>
#include <unistd.h>
+#include "pidfd.h"
#include "../kselftest.h"
static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
@@ -62,28 +63,6 @@ static int test_pidfd_send_signal_simple_success(void)
return 0;
}
-static int wait_for_pid(pid_t pid)
-{
- int status, ret;
-
-again:
- ret = waitpid(pid, &status, 0);
- if (ret == -1) {
- if (errno == EINTR)
- goto again;
-
- return -1;
- }
-
- if (ret != pid)
- goto again;
-
- if (!WIFEXITED(status))
- return -1;
-
- return WEXITSTATUS(status);
-}
-
static int test_pidfd_send_signal_exited_fail(void)
{
int pidfd, ret, saved_errno;
@@ -128,13 +107,6 @@ static int test_pidfd_send_signal_exited_fail(void)
return 0;
}
-/*
- * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
- * That means, when it wraps around any pid < 300 will be skipped.
- * So we need to use a pid > 300 in order to test recycling.
- */
-#define PID_RECYCLE 1000
-
/*
* Maximum number of cycles we allow. This is equivalent to PID_MAX_DEFAULT.
* If users set a higher limit or we have cycled PIDFD_MAX_DEFAULT number of
@@ -143,17 +115,6 @@ static int test_pidfd_send_signal_exited_fail(void)
*/
#define PIDFD_MAX_DEFAULT 0x8000
-/*
- * Define a few custom error codes for the child process to clearly indicate
- * what is happening. This way we can tell the difference between a system
- * error, a test error, etc.
- */
-#define PIDFD_PASS 0
-#define PIDFD_FAIL 1
-#define PIDFD_ERROR 2
-#define PIDFD_SKIP 3
-#define PIDFD_XFAIL 4
-
static int test_pidfd_send_signal_recycled_pid_fail(void)
{
int i, ret;
--
2.21.0
^ permalink raw reply related
* [PATCH v2 1/2] pid: add pidfd_open()
From: Christian Brauner @ 2019-05-20 13:46 UTC (permalink / raw)
To: jannh, oleg, viro, torvalds, linux-kernel, arnd
Cc: linux-ia64, linux-sh, linux-mips, dhowells, joel, linux-kselftest,
sparclinux, elena.reshetova, linux-arch, linux-s390, dancol,
Christian Brauner, kernel-team, serge, linux-xtensa, keescook,
linux-m68k, luto, tglx, surenb, linux-arm-kernel, linux-parisc,
linux-api, cyphar, luto, ebiederm, linux-alpha, akpm,
linuxppc-dev
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a problem for
Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfds for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
---
v1:
- kbuild test robot <lkp@intel.com>:
- add missing entry for pidfd_open to arch/arm/tools/syscall.tbl
- Oleg Nesterov <oleg@redhat.com>:
- use simpler thread-group leader check
v2:
- Oleg Nesterov <oleg@redhat.com>:
- avoid using additional variable
- remove unneeded comment
- Arnd Bergmann <arnd@arndb.de>:
- switch from 428 to 434 since the new mount api has taken it
- bump syscall numbers in arch/arm64/include/asm/unistd.h
- Joel Fernandes (Google) <joel@joelfernandes.org>:
- switch from ESRCH to EINVAL when the passed-in pid does not refer to a
thread-group leader
- Christian Brauner <christian@brauner.io>:
- rebase on v5.2-rc1
- adapt syscall number to account for new mount api syscalls
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd.h | 2 +-
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/pid.h | 1 +
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/fork.c | 2 +-
kernel/pid.c | 43 +++++++++++++++++++++
21 files changed, 66 insertions(+), 3 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 9e7704e44f6d..1db9bbcfb84e 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
541 common fsconfig sys_fsconfig
542 common fsmount sys_fsmount
543 common fspick sys_fspick
+544 common pidfd_open sys_pidfd_open
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index aaf479a9e92d..81e6e1817c45 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -447,3 +447,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 70e6882853c0..e8f7d95a1481 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -44,7 +44,7 @@
#define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5)
#define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800)
-#define __NR_compat_syscalls 434
+#define __NR_compat_syscalls 435
#endif
#define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index c39e90600bb3..7a3158ccd68e 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index e01df3f2f80d..ecc44926737b 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -354,3 +354,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7e3d0734b2f3..9a3eb2558568 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 26339e417695..ad706f83c755 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0e2dd68ade57..97035e19ad03 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -372,3 +372,4 @@
431 n32 fsconfig sys_fsconfig
432 n32 fsmount sys_fsmount
433 n32 fspick sys_fspick
+434 n32 pidfd_open sys_pidfd_open
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c9e377d59232..5022b9e179c2 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 103655d84b4b..f2c3bda2d39f 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -515,3 +515,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index e822b2964a83..6ebacfeaf853 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig sys_fsconfig
432 common fsmount sys_fsmount sys_fsmount
433 common fspick sys_fspick sys_fspick
+434 common pidfd_open sys_pidfd_open sys_pidfd_open
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 016a727d4357..834c9c7d79fa 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index e047480b1605..c58e71f21129 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -479,3 +479,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..43e4429a5272 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+434 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..1bee0a77fdd3 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+434 common pidfd_open __x64_sys_pidfd_open
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 5fa0ee1c8e00..782b81945ccc 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -404,3 +404,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..c938a92eab99 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -67,6 +67,7 @@ struct pid
extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+extern int pidfd_create(struct pid *pid);
static inline struct pid *get_pid(struct pid *pid)
{
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..989055e0b501 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock,
struct old_timex32 __user *tx);
asmlinkage long sys_syncfs(int fd);
asmlinkage long sys_setns(int fd, int nstype);
+asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags);
asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags);
asmlinkage long sys_process_vm_readv(pid_t pid,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..e5684a4512c0 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 435
/*
* 32 bit systems traditionally used different
diff --git a/kernel/fork.c b/kernel/fork.c
index b4cba953040a..c3df226f47a1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1724,7 +1724,7 @@ const struct file_operations pidfd_fops = {
* Return: On success, a cloexec pidfd is returned.
* On error, a negative errno number will be returned.
*/
-static int pidfd_create(struct pid *pid)
+int pidfd_create(struct pid *pid)
{
int fd;
diff --git a/kernel/pid.c b/kernel/pid.c
index 89548d35eefb..8fc9d94f6ac1 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -37,6 +37,7 @@
#include <linux/syscalls.h>
#include <linux/proc_ns.h>
#include <linux/proc_fs.h>
+#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/idr.h>
@@ -450,6 +451,48 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return idr_get_next(&ns->idr, &nr);
}
+/**
+ * pidfd_open() - Open new pid file descriptor.
+ *
+ * @pid: pid for which to retrieve a pidfd
+ * @flags: flags to pass
+ *
+ * This creates a new pid file descriptor with the O_CLOEXEC flag set for
+ * the process identified by @pid. Currently, the process identified by
+ * @pid must be a thread-group leader. This restriction currently exists
+ * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot
+ * be used with CLONE_THREAD) and pidfd polling (only supports thread group
+ * leaders).
+ *
+ * Return: On success, a cloexec pidfd is returned.
+ * On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
+{
+ int fd, ret;
+ struct pid *p;
+
+ if (flags)
+ return -EINVAL;
+
+ if (pid <= 0)
+ return -EINVAL;
+
+ p = find_get_pid(pid);
+ if (!p)
+ return -ESRCH;
+
+ ret = 0;
+ rcu_read_lock();
+ if (!pid_task(p, PIDTYPE_TGID))
+ ret = -EINVAL;
+ rcu_read_unlock();
+
+ fd = ret ?: pidfd_create(p);
+ put_pid(p);
+ return fd;
+}
+
void __init pid_idr_init(void)
{
/* Verify no one has done anything silly: */
--
2.21.0
^ permalink raw reply related
* Re: [RFC PATCH 2/4] x86/ftrace: Fix use of flags in ftrace_replace_code()
From: Steven Rostedt @ 2019-05-20 13:44 UTC (permalink / raw)
To: Naveen N. Rao; +Cc: linuxppc-dev, linux-kernel, Nicholas Piggin
In-Reply-To: <20190520091320.01cdcfb7@gandalf.local.home>
[-- Attachment #1: Type: text/plain, Size: 708 bytes --]
On Mon, 20 May 2019 09:13:20 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> > I haven't yet tested this patch on x86, but this looked wrong so sending
> > this as a RFC.
>
> This code has been through a bit of updates, and I need to go through
> and clean it up. I'll have to take a look and convert "int" to "bool"
> so that "enable" is not confusing.
>
> Thanks, I think I'll try to do a clean up first, and then this patch
> shouldn't "look wrong" after that.
>
I'm going to apply the attached two patches. There may be some
conflicts between yours here and these, but nothing that Linus can't
figure out. Do you feel more comfortable with this code, if these
patches are applied?
-- Steve
[-- Attachment #2: 0001-ftrace-Make-enable-and-update-parameters-bool-when-a.patch --]
[-- Type: text/x-patch, Size: 4286 bytes --]
From d6b694e350e61259ad18fe2b912911b52ff4767a Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Mon, 20 May 2019 09:26:24 -0400
Subject: [PATCH 1/2] ftrace: Make enable and update parameters bool when
applicable
The code modification functions have "enable" and "update" variables that
are sometimes "int" but used as "bool". Remove the ambiguity and make them
"bool" when they are only used for true or false values.
Link: http://lkml.kernel.org/r/e1429923d9eda92a3cf5ee9e33c7eacce539781d.1558115654.git.naveen.n.rao@linux.vnet.ibm.com
Reported-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/ftrace.h | 4 ++--
kernel/trace/ftrace.c | 16 ++++++++--------
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 25e2995d4a4c..8a8cb3c401b2 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -427,8 +427,8 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
iter = ftrace_rec_iter_next(iter))
-int ftrace_update_record(struct dyn_ftrace *rec, int enable);
-int ftrace_test_record(struct dyn_ftrace *rec, int enable);
+int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
+int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
void ftrace_run_stop_machine(int command);
unsigned long ftrace_location(unsigned long ip);
unsigned long ftrace_location_range(unsigned long start, unsigned long end);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a12aff849c04..47b41502a24c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1768,7 +1768,7 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
count++;
/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
- update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
+ update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
/* Shortcut, if we handled all records, we are done. */
if (!all && count == hash->count)
@@ -2047,7 +2047,7 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
}
}
-static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
+static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
{
unsigned long flag = 0UL;
@@ -2146,12 +2146,12 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
/**
* ftrace_update_record, set a record that now is tracing or not
* @rec: the record to update
- * @enable: set to 1 if the record is tracing, zero to force disable
+ * @enable: set to true if the record is tracing, false to force disable
*
* The records that represent all functions that can be traced need
* to be updated when tracing has been enabled.
*/
-int ftrace_update_record(struct dyn_ftrace *rec, int enable)
+int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
{
return ftrace_check_record(rec, enable, 1);
}
@@ -2159,13 +2159,13 @@ int ftrace_update_record(struct dyn_ftrace *rec, int enable)
/**
* ftrace_test_record, check if the record has been enabled or not
* @rec: the record to test
- * @enable: set to 1 to check if enabled, 0 if it is disabled
+ * @enable: set to true to check if enabled, false if it is disabled
*
* The arch code may need to test if a record is already set to
* tracing to determine how to modify the function code that it
* represents.
*/
-int ftrace_test_record(struct dyn_ftrace *rec, int enable)
+int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
{
return ftrace_check_record(rec, enable, 0);
}
@@ -2356,7 +2356,7 @@ unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
}
static int
-__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
{
unsigned long ftrace_old_addr;
unsigned long ftrace_addr;
@@ -2395,7 +2395,7 @@ void __weak ftrace_replace_code(int mod_flags)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
+ bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
int failed;
--
2.20.1
[-- Attachment #3: 0002-x86-ftrace-Make-enable-parameter-bool-where-applicab.patch --]
[-- Type: text/x-patch, Size: 1758 bytes --]
From a15f59dc19e1fdf7eda74e7aec386975740d1515 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Mon, 20 May 2019 09:38:11 -0400
Subject: [PATCH 2/2] x86/ftrace: Make enable parameter bool where applicable
The code modification functions have an "enable" parameter that is an "int"
but used as a boolean. Switch its type to "bool" to remove the ambiguity
that "int" causes.
Link: http://lkml.kernel.org/r/e1429923d9eda92a3cf5ee9e33c7eacce539781d.1558115654.git.naveen.n.rao@linux.vnet.ibm.com
Reported-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/x86/kernel/ftrace.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 0927bb158ffc..ba37bcb7f92b 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -370,7 +370,7 @@ static int add_brk_on_nop(struct dyn_ftrace *rec)
return add_break(rec->ip, old);
}
-static int add_breakpoints(struct dyn_ftrace *rec, int enable)
+static int add_breakpoints(struct dyn_ftrace *rec, bool enable)
{
unsigned long ftrace_addr;
int ret;
@@ -478,7 +478,7 @@ static int add_update_nop(struct dyn_ftrace *rec)
return add_update_code(ip, new);
}
-static int add_update(struct dyn_ftrace *rec, int enable)
+static int add_update(struct dyn_ftrace *rec, bool enable)
{
unsigned long ftrace_addr;
int ret;
@@ -524,7 +524,7 @@ static int finish_update_nop(struct dyn_ftrace *rec)
return ftrace_write(ip, new, 1);
}
-static int finish_update(struct dyn_ftrace *rec, int enable)
+static int finish_update(struct dyn_ftrace *rec, bool enable)
{
unsigned long ftrace_addr;
int ret;
--
2.20.1
^ permalink raw reply related
* Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted
From: Michael S. Tsirkin @ 2019-05-20 13:16 UTC (permalink / raw)
To: Thiago Jung Bauermann
Cc: Mike Anderson, Michael Roth, Jean-Philippe Brucker, Jason Wang,
Alexey Kardashevskiy, Ram Pai, linux-kernel, virtualization,
iommu, linuxppc-dev, Christoph Hellwig, David Gibson
In-Reply-To: <87a7go71hz.fsf@morokweng.localdomain>
On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote:
> I rephrased it in terms of address translation. What do you think of
> this version? The flag name is slightly different too:
>
>
> VIRTIO_F_ACCESS_PLATFORM_NO_TRANSLATION This feature has the same
> meaning as VIRTIO_F_ACCESS_PLATFORM both when set and when not set,
> with the exception that address translation is guaranteed to be
> unnecessary when accessing memory addresses supplied to the device
> by the driver. Which is to say, the device will always use physical
> addresses matching addresses used by the driver (typically meaning
> physical addresses used by the CPU) and not translated further. This
> flag should be set by the guest if offered, but to allow for
> backward-compatibility device implementations allow for it to be
> left unset by the guest. It is an error to set both this flag and
> VIRTIO_F_ACCESS_PLATFORM.
OK so VIRTIO_F_ACCESS_PLATFORM is designed to allow unpriveledged
drivers. This is why devices fail when it's not negotiated.
This confuses me.
If driver is unpriveledged then what happens with this flag?
It can supply any address it wants. Will that corrupt kernel
memory?
--
MST
^ permalink raw reply
* Re: [RFC PATCH 2/4] x86/ftrace: Fix use of flags in ftrace_replace_code()
From: Steven Rostedt @ 2019-05-20 13:13 UTC (permalink / raw)
To: Naveen N. Rao; +Cc: linuxppc-dev, linux-kernel, Nicholas Piggin
In-Reply-To: <e1429923d9eda92a3cf5ee9e33c7eacce539781d.1558115654.git.naveen.n.rao@linux.vnet.ibm.com>
On Sat, 18 May 2019 00:32:46 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:
> In commit a0572f687fb3c ("ftrace: Allow ftrace_replace_code() to be
> schedulable), the generic ftrace_replace_code() function was modified to
> accept a flags argument in place of a single 'enable' flag. However, the
> x86 version of this function was not updated. Fix the same.
>
> Fixes: a0572f687fb3c ("ftrace: Allow ftrace_replace_code() to be schedulable")
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> I haven't yet tested this patch on x86, but this looked wrong so sending
> this as a RFC.
This code has been through a bit of updates, and I need to go through
and clean it up. I'll have to take a look and convert "int" to "bool"
so that "enable" is not confusing.
Thanks, I think I'll try to do a clean up first, and then this patch
shouldn't "look wrong" after that.
-- Steve
>
> - Naveen
>
>
> arch/x86/kernel/ftrace.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
> index 0caf8122d680..0c01b344ba16 100644
> --- a/arch/x86/kernel/ftrace.c
> +++ b/arch/x86/kernel/ftrace.c
> @@ -554,8 +554,9 @@ static void run_sync(void)
> local_irq_disable();
> }
>
> -void ftrace_replace_code(int enable)
> +void ftrace_replace_code(int mod_flags)
> {
> + int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
> struct ftrace_rec_iter *iter;
> struct dyn_ftrace *rec;
> const char *report = "adding breakpoints";
^ permalink raw reply
* Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted
From: Michael S. Tsirkin @ 2019-05-20 13:08 UTC (permalink / raw)
To: Thiago Jung Bauermann
Cc: Mike Anderson, Michael Roth, Jean-Philippe Brucker, Jason Wang,
Alexey Kardashevskiy, Ram Pai, linux-kernel, virtualization,
iommu, linuxppc-dev, Christoph Hellwig, David Gibson
In-Reply-To: <871s1o1ft0.fsf@morokweng.localdomain>
On Fri, Apr 26, 2019 at 08:56:43PM -0300, Thiago Jung Bauermann wrote:
>
> Michael S. Tsirkin <mst@redhat.com> writes:
>
> > On Wed, Apr 24, 2019 at 10:01:56PM -0300, Thiago Jung Bauermann wrote:
> >>
> >> Michael S. Tsirkin <mst@redhat.com> writes:
> >>
> >> > On Wed, Apr 17, 2019 at 06:42:00PM -0300, Thiago Jung Bauermann wrote:
> >> >>
> >> >> Michael S. Tsirkin <mst@redhat.com> writes:
> >> >>
> >> >> > On Thu, Mar 21, 2019 at 09:05:04PM -0300, Thiago Jung Bauermann wrote:
> >> >> >>
> >> >> >> Michael S. Tsirkin <mst@redhat.com> writes:
> >> >> >>
> >> >> >> > On Wed, Mar 20, 2019 at 01:13:41PM -0300, Thiago Jung Bauermann wrote:
> >> >> >> >> >From what I understand of the ACCESS_PLATFORM definition, the host will
> >> >> >> >> only ever try to access memory addresses that are supplied to it by the
> >> >> >> >> guest, so all of the secure guest memory that the host cares about is
> >> >> >> >> accessible:
> >> >> >> >>
> >> >> >> >> If this feature bit is set to 0, then the device has same access to
> >> >> >> >> memory addresses supplied to it as the driver has. In particular,
> >> >> >> >> the device will always use physical addresses matching addresses
> >> >> >> >> used by the driver (typically meaning physical addresses used by the
> >> >> >> >> CPU) and not translated further, and can access any address supplied
> >> >> >> >> to it by the driver. When clear, this overrides any
> >> >> >> >> platform-specific description of whether device access is limited or
> >> >> >> >> translated in any way, e.g. whether an IOMMU may be present.
> >> >> >> >>
> >> >> >> >> All of the above is true for POWER guests, whether they are secure
> >> >> >> >> guests or not.
> >> >> >> >>
> >> >> >> >> Or are you saying that a virtio device may want to access memory
> >> >> >> >> addresses that weren't supplied to it by the driver?
> >> >> >> >
> >> >> >> > Your logic would apply to IOMMUs as well. For your mode, there are
> >> >> >> > specific encrypted memory regions that driver has access to but device
> >> >> >> > does not. that seems to violate the constraint.
> >> >> >>
> >> >> >> Right, if there's a pre-configured 1:1 mapping in the IOMMU such that
> >> >> >> the device can ignore the IOMMU for all practical purposes I would
> >> >> >> indeed say that the logic would apply to IOMMUs as well. :-)
> >> >> >>
> >> >> >> I guess I'm still struggling with the purpose of signalling to the
> >> >> >> driver that the host may not have access to memory addresses that it
> >> >> >> will never try to access.
> >> >> >
> >> >> > For example, one of the benefits is to signal to host that driver does
> >> >> > not expect ability to access all memory. If it does, host can
> >> >> > fail initialization gracefully.
> >> >>
> >> >> But why would the ability to access all memory be necessary or even
> >> >> useful? When would the host access memory that the driver didn't tell it
> >> >> to access?
> >> >
> >> > When I say all memory I mean even memory not allowed by the IOMMU.
> >>
> >> Yes, but why? How is that memory relevant?
> >
> > It's relevant when driver is not trusted to only supply correct
> > addresses. The feature was originally designed to support userspace
> > drivers within guests.
>
> Ah, thanks for clarifying. I don't think that's a problem in our case.
> If the guest provides an incorrect address, the hardware simply won't
> allow the host to access it.
>
> >> >> >> > Another idea is maybe something like virtio-iommu?
> >> >> >>
> >> >> >> You mean, have legacy guests use virtio-iommu to request an IOMMU
> >> >> >> bypass? If so, it's an interesting idea for new guests but it doesn't
> >> >> >> help with guests that are out today in the field, which don't have A
> >> >> >> virtio-iommu driver.
> >> >> >
> >> >> > I presume legacy guests don't use encrypted memory so why do we
> >> >> > worry about them at all?
> >> >>
> >> >> They don't use encrypted memory, but a host machine will run a mix of
> >> >> secure and legacy guests. And since the hypervisor doesn't know whether
> >> >> a guest will be secure or not at the time it is launched, legacy guests
> >> >> will have to be launched with the same configuration as secure guests.
> >> >
> >> > OK and so I think the issue is that hosts generally fail if they set
> >> > ACCESS_PLATFORM and guests do not negotiate it.
> >> > So you can not just set ACCESS_PLATFORM for everyone.
> >> > Is that the issue here?
> >>
> >> Yes, that is one half of the issue. The other is that even if hosts
> >> didn't fail, existing legacy guests wouldn't "take the initiative" of
> >> not negotiating ACCESS_PLATFORM to get the improved performance. They'd
> >> have to be modified to do that.
> >
> > So there's a non-encrypted guest, hypervisor wants to set
> > ACCESS_PLATFORM to allow encrypted guests but that will slow down legacy
> > guests since their vIOMMU emulation is very slow.
>
> Yes.
>
> > So enabling support for encryption slows down non-encrypted guests. Not
> > great but not the end of the world, considering even older guests that
> > don't support ACCESS_PLATFORM are completely broken and you do not seem
> > to be too worried by that.
>
> Well, I guess that would be the third half of the issue. :-)
>
> > For future non-encrypted guests, bypassing the emulated IOMMU for when
> > that emulated IOMMU is very slow might be solvable in some other way,
> > e.g. with virtio-iommu. Which reminds me, could you look at
> > virtio-iommu as a solution for some of the issues?
> > Review of that patchset from that POV would be appreciated.
>
> Yes, I will have a look. As you mentioned already, virtio-iommu doesn't
> define a way to request iommu bypass for a device so that would have to
> be added.
I think it does have a way for guest to request bypass:
there's a feature bit which - if set - specifies that a device
that is in no domain bypasses the iommu.
> Though to be honest in practice I don't think such a feature in
> virtio-iommu would make things easier for us, at least in the short
> term. It would take the same effort to define a powerpc-specific
> hypercall to accomplish the same thing (easier, in fact since we
> wouldn't have to implement the rest of virtio-iommu). In fact, there
> already is such hypercall, but it is only defined for VIO devices
> (RTAS_IBM_SET_TCE_BYPASS in QEMU). We would have to make it work on
> virtio devices as well.
Now I'm a bit lost. Could you pls describe quickly what does it do?
> --
> Thiago Jung Bauermann
> IBM Linux Technology Center
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