* [PATCHv7 20/33] x86/vdso: Provide vdso_data offset on vvar_page
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
VDSO support for Time namespace needs to set up a page with the same
layout as VVAR. That timens page will be placed on position of VVAR page
inside namespace. That page has vdso_data->seq set to 1 to enforce
the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce
the time namespace handling path.
To prepare timens page kernel needs to know the vdso_data offset.
Provide arch_get_vdso_data() helper for locating vdso_data on VVAR page.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vdso-layout.lds.S | 2 --
arch/x86/entry/vdso/vma.c | 11 +++++++++++
arch/x86/include/asm/vvar.h | 8 ++++----
arch/x86/kernel/vmlinux.lds.S | 4 +---
include/linux/time_namespace.h | 1 +
5 files changed, 17 insertions(+), 9 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S
index 93c6dc7812d0..2330daad67c3 100644
--- a/arch/x86/entry/vdso/vdso-layout.lds.S
+++ b/arch/x86/entry/vdso/vdso-layout.lds.S
@@ -21,9 +21,7 @@ SECTIONS
/* Place all vvars at the offsets in asm/vvar.h. */
#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
-#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR
pvclock_page = vvar_start + PAGE_SIZE;
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 000db8282cc8..5dab706aca2e 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -24,6 +24,17 @@
#include <asm/cpufeature.h>
#include <clocksource/hyperv_timer.h>
+#undef _ASM_X86_VVAR_H
+#define EMIT_VVAR(name, offset) \
+ const size_t name ## _offset = offset;
+#include <asm/vvar.h>
+
+struct vdso_data *arch_get_vdso_data(void *vvar_page)
+{
+ return (struct vdso_data *)(vvar_page + _vdso_data_offset);
+}
+#undef EMIT_VVAR
+
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
#endif
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 32f5d9a0b90e..ff2de3025388 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -19,10 +19,10 @@
#ifndef _ASM_X86_VVAR_H
#define _ASM_X86_VVAR_H
-#if defined(__VVAR_KERNEL_LDS)
-
-/* The kernel linker script defines its own magic to put vvars in the
- * right place.
+#ifdef EMIT_VVAR
+/*
+ * EMIT_VVAR() is used by the kernel linker script to put vvars in the
+ * right place. Also, it's used by kernel code to import offsets values.
*/
#define DECLARE_VVAR(offset, type, name) \
EMIT_VVAR(name, offset)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e2feacf921a0..ca02d0d301cd 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -195,12 +195,10 @@ SECTIONS
__vvar_beginning_hack = .;
/* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) \
+#define EMIT_VVAR(name, offset) \
. = __vvar_beginning_hack + offset; \
*(.vvar_ ## name)
-#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR
/*
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index 9a77d3854830..772911945944 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -37,6 +37,7 @@ extern struct time_namespace *copy_time_ns(unsigned long flags,
struct user_namespace *user_ns, struct time_namespace *old_ns);
extern void free_time_ns(struct kref *kref);
extern int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
+extern struct vdso_data *arch_get_vdso_data(void *vvar_page);
static inline void put_time_ns(struct time_namespace *ns)
{
--
2.23.0
^ permalink raw reply related
* [PATCHv7 21/33] x86/vdso: Add timens page
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
To support time namespaces in the VDSO with a minimal impact on regular non
time namespace affected tasks, the namespace handling needs to be hidden in
a slow path.
The most obvious place is vdso_seq_begin(). If a task belongs to a time
namespace then the VVAR page which contains the system wide VDSO data is
replaced with a namespace specific page which has the same layout as the
VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path
and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time
namespace handling path.
The extra check in the case that vdso_data->seq is odd, e.g. a concurrent
update of the VDSO data is in progress, is not really affecting regular
tasks which are not part of a time namespace as the task is spin waiting
for the update to finish and vdso_data->seq to become even again.
If a time namespace task hits that code path, it invokes the corresponding
time getter function which retrieves the real VVAR page, reads host time
and then adds the offset for the requested clock which is stored in the
special VVAR page.
Allocate Timens page among VVAR pages and place vdso_data on it.
Provide __arch_get_timens_vdso_data() helper for VDSO code to get the
code-relative position of VVARs on that special page.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/Kconfig | 1 +
arch/x86/entry/vdso/vdso-layout.lds.S | 11 +++++++++--
arch/x86/entry/vdso/vdso2c.c | 3 +++
arch/x86/include/asm/vdso.h | 1 +
arch/x86/include/asm/vdso/gettimeofday.h | 9 +++++++++
arch/x86/include/asm/vvar.h | 5 ++++-
6 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d6e1faa28c58..15f076eb2b1c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -226,6 +226,7 @@ config X86
select VIRT_TO_BUS
select X86_FEATURE_NAMES if PROC_FS
select PROC_PID_ARCH_STATUS if PROC_FS
+ select VDSO_TIMENS if TIME_NS
config INSTRUCTION_DECODER
def_bool y
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S
index 2330daad67c3..ea7e0155c604 100644
--- a/arch/x86/entry/vdso/vdso-layout.lds.S
+++ b/arch/x86/entry/vdso/vdso-layout.lds.S
@@ -16,8 +16,8 @@ SECTIONS
* segment.
*/
- vvar_start = . - 3 * PAGE_SIZE;
- vvar_page = vvar_start;
+ vvar_start = . - 4 * PAGE_SIZE;
+ vvar_page = vvar_start;
/* Place all vvars at the offsets in asm/vvar.h. */
#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
@@ -26,6 +26,13 @@ SECTIONS
pvclock_page = vvar_start + PAGE_SIZE;
hvclock_page = vvar_start + 2 * PAGE_SIZE;
+ timens_page = vvar_start + 3 * PAGE_SIZE;
+
+#undef _ASM_X86_VVAR_H
+ /* Place all vvars in timens too at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) timens_ ## name = timens_page + offset;
+#include <asm/vvar.h>
+#undef EMIT_VVAR
. = SIZEOF_HEADERS;
diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c
index 3a4d8d4d39f8..3842873b3ae3 100644
--- a/arch/x86/entry/vdso/vdso2c.c
+++ b/arch/x86/entry/vdso/vdso2c.c
@@ -75,12 +75,14 @@ enum {
sym_vvar_page,
sym_pvclock_page,
sym_hvclock_page,
+ sym_timens_page,
};
const int special_pages[] = {
sym_vvar_page,
sym_pvclock_page,
sym_hvclock_page,
+ sym_timens_page,
};
struct vdso_sym {
@@ -93,6 +95,7 @@ struct vdso_sym required_syms[] = {
[sym_vvar_page] = {"vvar_page", true},
[sym_pvclock_page] = {"pvclock_page", true},
[sym_hvclock_page] = {"hvclock_page", true},
+ [sym_timens_page] = {"timens_page", true},
{"VDSO32_NOTE_MASK", true},
{"__kernel_vsyscall", true},
{"__kernel_sigreturn", true},
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 230474e2ddb5..bbcdc7b8f963 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -21,6 +21,7 @@ struct vdso_image {
long sym_vvar_page;
long sym_pvclock_page;
long sym_hvclock_page;
+ long sym_timens_page;
long sym_VDSO32_NOTE_MASK;
long sym___kernel_sigreturn;
long sym___kernel_rt_sigreturn;
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index e9ee139cf29e..39a551df4fea 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -21,6 +21,7 @@
#include <clocksource/hyperv_timer.h>
#define __vdso_data (VVAR(_vdso_data))
+#define __timens_vdso_data (TIMENS(_vdso_data))
#define VDSO_HAS_TIME 1
@@ -56,6 +57,14 @@ extern struct ms_hyperv_tsc_page hvclock_page
__attribute__((visibility("hidden")));
#endif
+#ifdef CONFIG_VDSO_TIMENS
+static __always_inline
+const struct vdso_data *__arch_get_timens_vdso_data(void)
+{
+ return __timens_vdso_data;
+}
+#endif
+
#ifndef BUILD_VDSO32
static __always_inline
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index ff2de3025388..183e98e49ab9 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -33,9 +33,12 @@ extern char __vvar_page;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name[CS_BASES] \
- __attribute__((visibility("hidden")));
+ __attribute__((visibility("hidden"))); \
+ extern type timens_ ## name[CS_BASES] \
+ __attribute__((visibility("hidden"))); \
#define VVAR(name) (vvar_ ## name)
+#define TIMENS(name) (timens_ ## name)
#define DEFINE_VVAR(type, name) \
type name[CS_BASES] \
--
2.23.0
^ permalink raw reply related
* [PATCHv7 22/33] time: Allocate per-timens vvar page
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
VDSO support for Time namespace needs to set up a page with the same
layout as VVAR. That timens page will be placed on position of VVAR page
inside namespace. That page contains time namespace clock offsets and it
has vdso_data->seq set to 1 to enforce the slow path and
vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace
handling path.
Allocate the timens page during namespace creation. Setup the offsets
when the first task enters the ns and freeze them to guarantee the pace
of monotonic/boottime clocks and to avoid breakage of applications.
The design decision is to have a global offset_lock which is used
during namespace offsets set up and to freeze offsets when first task
joins the new ns. That is better in terms of memory usage comparing
to having per-ns mutex that's used only during the set up period.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Based-on-work-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
include/linux/time_namespace.h | 3 +
kernel/time/namespace.c | 103 ++++++++++++++++++++++++++++++++-
2 files changed, 105 insertions(+), 1 deletion(-)
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index 772911945944..c479cfda2c3e 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -23,6 +23,9 @@ struct time_namespace {
struct ucounts *ucounts;
struct ns_common ns;
struct timens_offsets offsets;
+ struct page *vvar_page;
+ /* Disallow changing offsets after any task joined namespace. */
+ bool frozen_offsets;
} __randomize_layout;
extern struct time_namespace init_time_ns;
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 1a0fbaa5d2d4..e14cd1ca387d 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -15,6 +15,7 @@
#include <linux/cred.h>
#include <linux/err.h>
#include <linux/mm.h>
+#include <vdso/datapage.h>
ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
struct timens_offsets *ns_offsets)
@@ -90,16 +91,23 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
kref_init(&ns->kref);
+ ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!ns->vvar_page)
+ goto fail_free;
+
err = ns_alloc_inum(&ns->ns);
if (err)
- goto fail_free;
+ goto fail_free_page;
ns->ucounts = ucounts;
ns->ns.ops = &timens_operations;
ns->user_ns = get_user_ns(user_ns);
ns->offsets = old_ns->offsets;
+ ns->frozen_offsets = false;
return ns;
+fail_free_page:
+ __free_page(ns->vvar_page);
fail_free:
kfree(ns);
fail_dec:
@@ -128,6 +136,93 @@ struct time_namespace *copy_time_ns(unsigned long flags,
return clone_time_ns(user_ns, old_ns);
}
+static struct timens_offset offset_from_ts(struct timespec64 off)
+{
+ struct timens_offset ret;
+
+ ret.sec = off.tv_sec;
+ ret.nsec = off.tv_nsec;
+
+ return ret;
+}
+
+/*
+ * A time namespace VVAR page has the same layout as the VVAR page which
+ * contains the system wide VDSO data.
+ *
+ * For a normal task the VVAR pages are installed in the normal ordering:
+ * VVAR
+ * PVCLOCK
+ * HVCLOCK
+ * TIMENS <- Not really required
+ *
+ * Now for a timens task the pages are installed in the following order:
+ * TIMENS
+ * PVCLOCK
+ * HVCLOCK
+ * VVAR
+ *
+ * The check for vdso_data->clock_mode is in the unlikely path of
+ * the seq begin magic. So for the non-timens case most of the time
+ * 'seq' is even, so the branch is not taken.
+ *
+ * If 'seq' is odd, i.e. a concurrent update is in progress, the extra check
+ * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
+ * update to finish and for 'seq' to become even anyway.
+ *
+ * Timens page has vdso_data->clock_mode set to VCLOCK_TIMENS which enforces
+ * the time namespace handling path.
+ */
+static void timens_setup_vdso_data(struct vdso_data *vdata,
+ struct time_namespace *ns)
+{
+ struct timens_offset *offset = vdata->offset;
+ struct timens_offset monotonic = offset_from_ts(ns->offsets.monotonic);
+ struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
+
+ vdata->seq = 1;
+ vdata->clock_mode = VCLOCK_TIMENS;
+ offset[CLOCK_MONOTONIC] = monotonic;
+ offset[CLOCK_MONOTONIC_RAW] = monotonic;
+ offset[CLOCK_MONOTONIC_COARSE] = monotonic;
+ offset[CLOCK_BOOTTIME] = boottime;
+ offset[CLOCK_BOOTTIME_ALARM] = boottime;
+}
+
+/*
+ * Protects possibly multiple offsets writers racing each other
+ * and tasks entering the namespace.
+ */
+static DEFINE_MUTEX(offset_lock);
+
+static void timens_set_vvar_page(struct task_struct *task,
+ struct time_namespace *ns)
+{
+ struct vdso_data *vdata;
+ unsigned int i;
+
+ if (ns == &init_time_ns)
+ return;
+
+ /* Fast-path, taken by every task in namespace except the first. */
+ if (likely(ns->frozen_offsets))
+ return;
+
+ mutex_lock(&offset_lock);
+ /* Nothing to-do: vvar_page has been already initialized. */
+ if (ns->frozen_offsets)
+ goto out;
+
+ ns->frozen_offsets = true;
+ vdata = arch_get_vdso_data(page_address(ns->vvar_page));
+
+ for (i = 0; i < CS_BASES; i++)
+ timens_setup_vdso_data(&vdata[i], ns);
+
+out:
+ mutex_unlock(&offset_lock);
+}
+
void free_time_ns(struct kref *kref)
{
struct time_namespace *ns;
@@ -136,6 +231,7 @@ void free_time_ns(struct kref *kref)
dec_time_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
+ __free_page(ns->vvar_page);
kfree(ns);
}
@@ -192,6 +288,8 @@ static int timens_install(struct nsproxy *nsproxy, struct ns_common *new)
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
+ timens_set_vvar_page(current, ns);
+
get_time_ns(ns);
put_time_ns(nsproxy->time_ns);
nsproxy->time_ns = ns;
@@ -211,6 +309,8 @@ int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk)
if (nsproxy->time_ns == nsproxy->time_ns_for_children)
return 0;
+ timens_set_vvar_page(tsk, ns);
+
get_time_ns(ns);
put_time_ns(nsproxy->time_ns);
nsproxy->time_ns = ns;
@@ -246,6 +346,7 @@ struct time_namespace init_time_ns = {
.user_ns = &init_user_ns,
.ns.inum = PROC_TIME_INIT_INO,
.ns.ops = &timens_operations,
+ .frozen_offsets = true,
};
static int __init time_ns_init(void)
--
2.23.0
^ permalink raw reply related
* [PATCHv7 23/33] x86/vdso: Handle faults on timens page
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
If a task belongs to a time namespace then the VVAR page which contains
the system wide VDSO data is replaced with a namespace specific page
which has the same layout as the VVAR page.
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vma.c | 53 +++++++++++++++++++++++++++++++++++++--
mm/mmap.c | 2 ++
2 files changed, 53 insertions(+), 2 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 5dab706aca2e..f6e13ab29d94 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -14,11 +14,13 @@
#include <linux/elf.h>
#include <linux/cpu.h>
#include <linux/ptrace.h>
+#include <linux/time_namespace.h>
#include <asm/pvclock.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/vvar.h>
+#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
@@ -107,10 +109,36 @@ static int vvar_mremap(const struct vm_special_mapping *sm,
return 0;
}
+#ifdef CONFIG_TIME_NS
+static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+ if (likely(vma->vm_mm == current->mm))
+ return current->nsproxy->time_ns->vvar_page;
+
+ /*
+ * VM_PFNMAP | VM_IO protect .fault() handler from being called
+ * through interfaces like /proc/$pid/mem or
+ * process_vm_{readv,writev}() as long as there's no .access()
+ * in special_mapping_vmops().
+ * For more details check_vma_flags() and __access_remote_vm()
+ */
+
+ WARN(1, "vvar_page accessed remotely");
+
+ return NULL;
+}
+#else
+static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+ return NULL;
+}
+#endif
+
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
const struct vdso_image *image = vma->vm_mm->context.vdso_image;
+ unsigned long pfn;
long sym_offset;
if (!image)
@@ -130,8 +158,21 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
return VM_FAULT_SIGBUS;
if (sym_offset == image->sym_vvar_page) {
- return vmf_insert_pfn(vma, vmf->address,
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT);
+ struct page *timens_page = find_timens_vvar_page(vma);
+
+ pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+
+ /*
+ * If a task belongs to a time namespace then a namespace
+ * specific VVAR is mapped with the sym_vvar_page offset and
+ * the real VVAR page is mapped with the sym_timens_page
+ * offset.
+ * See also the comment near timens_setup_vdso_data().
+ */
+ if (timens_page)
+ pfn = page_to_pfn(timens_page);
+
+ return vmf_insert_pfn(vma, vmf->address, pfn);
} else if (sym_offset == image->sym_pvclock_page) {
struct pvclock_vsyscall_time_info *pvti =
pvclock_get_pvti_cpu0_va();
@@ -146,6 +187,14 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
return vmf_insert_pfn(vma, vmf->address,
virt_to_phys(tsc_pg) >> PAGE_SHIFT);
+ } else if (sym_offset == image->sym_timens_page) {
+ struct page *timens_page = find_timens_vvar_page(vma);
+
+ if (!timens_page)
+ return VM_FAULT_SIGBUS;
+
+ pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+ return vmf_insert_pfn(vma, vmf->address, pfn);
}
return VM_FAULT_SIGBUS;
diff --git a/mm/mmap.c b/mm/mmap.c
index a7d8c84d19b7..af722a47db3c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3363,6 +3363,8 @@ static const struct vm_operations_struct special_mapping_vmops = {
.fault = special_mapping_fault,
.mremap = special_mapping_mremap,
.name = special_mapping_name,
+ /* vDSO code relies that VVAR can't be accessed remotely */
+ .access = NULL,
};
static const struct vm_operations_struct legacy_special_mapping_vmops = {
--
2.23.0
^ permalink raw reply related
* [PATCHv7 24/33] x86/vdso: On timens page fault prefault also VVAR page
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
As timens page has offsets to data on VVAR page VVAR is going
to be accessed shortly. Set it up with timens in one page fault
as optimization.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vma.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index f6e13ab29d94..d6cb8a16f368 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -169,8 +169,23 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
* offset.
* See also the comment near timens_setup_vdso_data().
*/
- if (timens_page)
+ if (timens_page) {
+ unsigned long addr;
+ vm_fault_t err;
+
+ /*
+ * Optimization: inside time namespace pre-fault
+ * VVAR page too. As on timens page there are only
+ * offsets for clocks on VVAR, it'll be faulted
+ * shortly by VDSO code.
+ */
+ addr = vmf->address + (image->sym_timens_page - sym_offset);
+ err = vmf_insert_pfn(vma, addr, pfn);
+ if (unlikely(err & VM_FAULT_ERROR))
+ return err;
+
pfn = page_to_pfn(timens_page);
+ }
return vmf_insert_pfn(vma, vmf->address, pfn);
} else if (sym_offset == image->sym_pvclock_page) {
--
2.23.0
^ permalink raw reply related
* [PATCHv7 25/33] x86/vdso: Zap vvar pages on switch a time namspace
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
The VVAR page layout depends on whether a task belongs to the root or
non-root time namespace. Whenever a task changes its namespace, the VVAR
page tables are cleared and then they will re-faulted with a
corresponding layout.
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vma.c | 27 +++++++++++++++++++++++++++
include/linux/time_namespace.h | 3 +++
kernel/time/namespace.c | 10 ++++++++++
3 files changed, 40 insertions(+)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index d6cb8a16f368..57ada3e95f8d 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -50,6 +50,7 @@ void __init init_vdso_image(const struct vdso_image *image)
image->alt_len));
}
+static const struct vm_special_mapping vvar_mapping;
struct linux_binprm;
static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
@@ -127,6 +128,32 @@ static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
return NULL;
}
+
+/*
+ * The vvar page layout depends on whether a task belongs to the root or
+ * non-root time namespace. Whenever a task changes its namespace, the VVAR
+ * page tables are cleared and then they will re-faulted with a
+ * corresponding layout.
+ * See also the comment near timens_setup_vdso_data() for details.
+ */
+int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
+{
+ struct mm_struct *mm = task->mm;
+ struct vm_area_struct *vma;
+
+ if (down_write_killable(&mm->mmap_sem))
+ return -EINTR;
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ unsigned long size = vma->vm_end - vma->vm_start;
+
+ if (vma_is_special_mapping(vma, &vvar_mapping))
+ zap_page_range(vma, vma->vm_start, size);
+ }
+
+ up_write(&mm->mmap_sem);
+ return 0;
+}
#else
static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
{
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index c479cfda2c3e..dcf3dbf2836b 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -30,6 +30,9 @@ struct time_namespace {
extern struct time_namespace init_time_ns;
#ifdef CONFIG_TIME_NS
+extern int vdso_join_timens(struct task_struct *task,
+ struct time_namespace *ns);
+
static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
{
kref_get(&ns->kref);
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index e14cd1ca387d..0dc0742ed1ee 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -280,6 +280,7 @@ static void timens_put(struct ns_common *ns)
static int timens_install(struct nsproxy *nsproxy, struct ns_common *new)
{
struct time_namespace *ns = to_time_ns(new);
+ int err;
if (!current_is_single_threaded())
return -EUSERS;
@@ -290,6 +291,10 @@ static int timens_install(struct nsproxy *nsproxy, struct ns_common *new)
timens_set_vvar_page(current, ns);
+ err = vdso_join_timens(current, ns);
+ if (err)
+ return err;
+
get_time_ns(ns);
put_time_ns(nsproxy->time_ns);
nsproxy->time_ns = ns;
@@ -304,6 +309,7 @@ int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk)
{
struct ns_common *nsc = &nsproxy->time_ns_for_children->ns;
struct time_namespace *ns = to_time_ns(nsc);
+ int err;
/* create_new_namespaces() already incremented the ref counter */
if (nsproxy->time_ns == nsproxy->time_ns_for_children)
@@ -311,6 +317,10 @@ int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk)
timens_set_vvar_page(tsk, ns);
+ err = vdso_join_timens(tsk, ns);
+ if (err)
+ return err;
+
get_time_ns(ns);
put_time_ns(nsproxy->time_ns);
nsproxy->time_ns = ns;
--
2.23.0
^ permalink raw reply related
* [PATCHv7 26/33] fs/proc: Introduce /proc/pid/timens_offsets
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andrei Vagin, Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@gmail.com>
API to set time namespace offsets for children processes, i.e.:
echo "clockid off_ses off_nsec" > /proc/self/timens_offsets
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
fs/proc/base.c | 95 +++++++++++++++++++++++++++++++
include/linux/time_namespace.h | 10 ++++
kernel/time/namespace.c | 100 +++++++++++++++++++++++++++++++++
3 files changed, 205 insertions(+)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ebea9501afb8..1d2007365e87 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -94,6 +94,7 @@
#include <linux/sched/debug.h>
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
+#include <linux/time_namespace.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
@@ -1533,6 +1534,97 @@ static const struct file_operations proc_pid_sched_autogroup_operations = {
#endif /* CONFIG_SCHED_AUTOGROUP */
+#ifdef CONFIG_TIME_NS
+static int timens_offsets_show(struct seq_file *m, void *v)
+{
+ struct task_struct *p;
+
+ p = get_proc_task(file_inode(m->file));
+ if (!p)
+ return -ESRCH;
+ proc_timens_show_offsets(p, m);
+
+ put_task_struct(p);
+
+ return 0;
+}
+
+static ssize_t
+timens_offsets_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode *inode = file_inode(file);
+ struct proc_timens_offset offsets[2];
+ char *kbuf = NULL, *pos, *next_line;
+ struct task_struct *p;
+ int ret, noffsets;
+
+ /* Only allow < page size writes at the beginning of the file */
+ if ((*ppos != 0) || (count >= PAGE_SIZE))
+ return -EINVAL;
+
+ /* Slurp in the user data */
+ kbuf = memdup_user_nul(buf, count);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ /* Parse the user data */
+ ret = -EINVAL;
+ noffsets = 0;
+ for (pos = kbuf; pos; pos = next_line) {
+ struct proc_timens_offset *off = &offsets[noffsets];
+ int err;
+
+ /* Find the end of line and ensure we don't look past it */
+ next_line = strchr(pos, '\n');
+ if (next_line) {
+ *next_line = '\0';
+ next_line++;
+ if (*next_line == '\0')
+ next_line = NULL;
+ }
+
+ err = sscanf(pos, "%u %lld %lu", &off->clockid,
+ &off->val.tv_sec, &off->val.tv_nsec);
+ if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
+ goto out;
+ noffsets++;
+ if (noffsets == ARRAY_SIZE(offsets)) {
+ if (next_line)
+ count = next_line - kbuf;
+ break;
+ }
+ }
+
+ ret = -ESRCH;
+ p = get_proc_task(inode);
+ if (!p)
+ goto out;
+ ret = proc_timens_set_offset(file, p, offsets, noffsets);
+ put_task_struct(p);
+ if (ret)
+ goto out;
+
+ ret = count;
+out:
+ kfree(kbuf);
+ return ret;
+}
+
+static int timens_offsets_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, timens_offsets_show, inode);
+}
+
+static const struct file_operations proc_timens_offsets_operations = {
+ .open = timens_offsets_open,
+ .read = seq_read,
+ .write = timens_offsets_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif /* CONFIG_TIME_NS */
+
static ssize_t comm_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
@@ -3015,6 +3107,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
+#endif
+#ifdef CONFIG_TIME_NS
+ REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
#endif
REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index dcf3dbf2836b..7cc80051cd17 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -50,6 +50,16 @@ static inline void put_time_ns(struct time_namespace *ns)
kref_put(&ns->kref, free_time_ns);
}
+extern void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
+
+struct proc_timens_offset {
+ int clockid;
+ struct timespec64 val;
+};
+
+extern int proc_timens_set_offset(struct file *file, struct task_struct *p,
+ struct proc_timens_offset *offsets, int n);
+
static inline void timens_add_monotonic(struct timespec64 *ts)
{
struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 0dc0742ed1ee..267120f31699 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -8,6 +8,7 @@
#include <linux/user_namespace.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
+#include <linux/seq_file.h>
#include <linux/proc_ns.h>
#include <linux/export.h>
#include <linux/time.h>
@@ -333,6 +334,105 @@ static struct user_namespace *timens_owner(struct ns_common *ns)
return to_time_ns(ns)->user_ns;
}
+static void show_offset(struct seq_file *m, int clockid, struct timespec64 *ts)
+{
+ seq_printf(m, "%d %lld %ld\n", clockid, ts->tv_sec, ts->tv_nsec);
+}
+
+void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m)
+{
+ struct ns_common *ns;
+ struct time_namespace *time_ns;
+
+ ns = timens_for_children_get(p);
+ if (!ns)
+ return;
+ time_ns = to_time_ns(ns);
+
+ show_offset(m, CLOCK_MONOTONIC, &time_ns->offsets.monotonic);
+ show_offset(m, CLOCK_BOOTTIME, &time_ns->offsets.boottime);
+ put_time_ns(time_ns);
+}
+
+int proc_timens_set_offset(struct file *file, struct task_struct *p,
+ struct proc_timens_offset *offsets, int noffsets)
+{
+ struct ns_common *ns;
+ struct time_namespace *time_ns;
+ struct timespec64 tp;
+ int i, err;
+
+ ns = timens_for_children_get(p);
+ if (!ns)
+ return -ESRCH;
+ time_ns = to_time_ns(ns);
+
+ if (!file_ns_capable(file, time_ns->user_ns, CAP_SYS_TIME)) {
+ put_time_ns(time_ns);
+ return -EPERM;
+ }
+
+ for (i = 0; i < noffsets; i++) {
+ struct proc_timens_offset *off = &offsets[i];
+
+ switch (off->clockid) {
+ case CLOCK_MONOTONIC:
+ ktime_get_ts64(&tp);
+ break;
+ case CLOCK_BOOTTIME:
+ ktime_get_boottime_ts64(&tp);
+ break;
+ default:
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = -ERANGE;
+
+ if (off->val.tv_sec > KTIME_SEC_MAX || off->val.tv_sec < -KTIME_SEC_MAX)
+ goto out;
+
+ tp = timespec64_add(tp, off->val);
+ /*
+ * KTIME_SEC_MAX is divided by 2 to be sure that KTIME_MAX is
+ * still unreachable.
+ */
+ if (tp.tv_sec < 0 || tp.tv_sec > KTIME_SEC_MAX / 2)
+ goto out;
+ }
+
+ mutex_lock(&offset_lock);
+ if (time_ns->frozen_offsets) {
+ err = -EACCES;
+ goto out_unlock;
+ }
+
+ err = 0;
+ /* don't report errors after this line */
+ for (i = 0; i < noffsets; i++) {
+ struct proc_timens_offset *off = &offsets[i];
+ struct timespec64 *offset = NULL;
+
+ switch (off->clockid) {
+ case CLOCK_MONOTONIC:
+ offset = &time_ns->offsets.monotonic;
+ break;
+ case CLOCK_BOOTTIME:
+ offset = &time_ns->offsets.boottime;
+ break;
+ }
+
+ *offset = off->val;
+ }
+
+out_unlock:
+ mutex_unlock(&offset_lock);
+out:
+ put_time_ns(time_ns);
+
+ return err;
+}
+
const struct proc_ns_operations timens_operations = {
.name = "time",
.type = CLONE_NEWTIME,
--
2.23.0
^ permalink raw reply related
* [PATCHv7 27/33] selftests/timens: Add Time Namespace test for supported clocks
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
A test to check that all supported clocks work on host and inside
a new time namespace. Use both ways to get time: through VDSO and
by entering the kernel with implicit syscall.
Introduce a new timens directory in selftests framework for
the next timens tests.
Output on success:
1..10
ok 1 Passed for CLOCK_BOOTTIME (syscall)
ok 2 Passed for CLOCK_BOOTTIME (vdso)
ok 3 Passed for CLOCK_BOOTTIME_ALARM (syscall)
ok 4 Passed for CLOCK_BOOTTIME_ALARM (vdso)
ok 5 Passed for CLOCK_MONOTONIC (syscall)
ok 6 Passed for CLOCK_MONOTONIC (vdso)
ok 7 Passed for CLOCK_MONOTONIC_COARSE (syscall)
ok 8 Passed for CLOCK_MONOTONIC_COARSE (vdso)
ok 9 Passed for CLOCK_MONOTONIC_RAW (syscall)
ok 10 Passed for CLOCK_MONOTONIC_RAW (vdso)
# Pass 10 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..10
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..10
not ok 1 # SKIP Time namespaces are not supported
Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 5 +
tools/testing/selftests/timens/config | 1 +
tools/testing/selftests/timens/log.h | 26 +++
tools/testing/selftests/timens/timens.c | 185 ++++++++++++++++++++++
tools/testing/selftests/timens/timens.h | 73 +++++++++
7 files changed, 292 insertions(+)
create mode 100644 tools/testing/selftests/timens/.gitignore
create mode 100644 tools/testing/selftests/timens/Makefile
create mode 100644 tools/testing/selftests/timens/config
create mode 100644 tools/testing/selftests/timens/log.h
create mode 100644 tools/testing/selftests/timens/timens.c
create mode 100644 tools/testing/selftests/timens/timens.h
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 4cdbae6f4e61..f6c3329946a6 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -47,6 +47,7 @@ TARGETS += splice
TARGETS += static_keys
TARGETS += sync
TARGETS += sysctl
+TARGETS += timens
ifneq (1, $(quicktest))
TARGETS += timers
endif
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
new file mode 100644
index 000000000000..27a693229ce1
--- /dev/null
+++ b/tools/testing/selftests/timens/.gitignore
@@ -0,0 +1 @@
+timens
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
new file mode 100644
index 000000000000..b877efb78974
--- /dev/null
+++ b/tools/testing/selftests/timens/Makefile
@@ -0,0 +1,5 @@
+TEST_GEN_PROGS := timens
+
+CFLAGS := -Wall -Werror
+
+include ../lib.mk
diff --git a/tools/testing/selftests/timens/config b/tools/testing/selftests/timens/config
new file mode 100644
index 000000000000..4480620f6f49
--- /dev/null
+++ b/tools/testing/selftests/timens/config
@@ -0,0 +1 @@
+CONFIG_TIME_NS=y
diff --git a/tools/testing/selftests/timens/log.h b/tools/testing/selftests/timens/log.h
new file mode 100644
index 000000000000..db64df2a8483
--- /dev/null
+++ b/tools/testing/selftests/timens/log.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __SELFTEST_TIMENS_LOG_H__
+#define __SELFTEST_TIMENS_LOG_H__
+
+#define pr_msg(fmt, lvl, ...) \
+ ksft_print_msg("[%s] (%s:%d)\t" fmt "\n", \
+ lvl, __FILE__, __LINE__, ##__VA_ARGS__)
+
+#define pr_p(func, fmt, ...) func(fmt ": %m", ##__VA_ARGS__)
+
+#define pr_err(fmt, ...) \
+ ({ \
+ ksft_test_result_error(fmt "\n", ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_fail(fmt, ...) \
+ ({ \
+ ksft_test_result_fail(fmt, ##__VA_ARGS__); \
+ -1; \
+ })
+
+#define pr_perror(fmt, ...) pr_p(pr_err, fmt, ##__VA_ARGS__)
+
+#endif
diff --git a/tools/testing/selftests/timens/timens.c b/tools/testing/selftests/timens/timens.c
new file mode 100644
index 000000000000..9fc362d5a168
--- /dev/null
+++ b/tools/testing/selftests/timens/timens.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+/*
+ * Test shouldn't be run for a day, so add 10 days to child
+ * time and check parent's time to be in the same day.
+ */
+#define DAY_IN_SEC (60*60*24)
+#define TEN_DAYS_IN_SEC (10*DAY_IN_SEC)
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+struct test_clock {
+ clockid_t id;
+ char *name;
+ /*
+ * off_id is -1 if a clock has own offset, or it contains an index
+ * which contains a right offset of this clock.
+ */
+ int off_id;
+ time_t offset;
+};
+
+#define ct(clock, off_id) { clock, #clock, off_id }
+static struct test_clock clocks[] = {
+ ct(CLOCK_BOOTTIME, -1),
+ ct(CLOCK_BOOTTIME_ALARM, 1),
+ ct(CLOCK_MONOTONIC, -1),
+ ct(CLOCK_MONOTONIC_COARSE, 1),
+ ct(CLOCK_MONOTONIC_RAW, 1),
+};
+#undef ct
+
+static int child_ns, parent_ns = -1;
+
+static int switch_ns(int fd)
+{
+ if (setns(fd, CLONE_NEWTIME)) {
+ pr_perror("setns()");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int init_namespaces(void)
+{
+ char path[] = "/proc/self/ns/time_for_children";
+ struct stat st1, st2;
+
+ if (parent_ns == -1) {
+ parent_ns = open(path, O_RDONLY);
+ if (parent_ns <= 0)
+ return pr_perror("Unable to open %s", path);
+ }
+
+ if (fstat(parent_ns, &st1))
+ return pr_perror("Unable to stat the parent timens");
+
+ if (unshare_timens())
+ return -1;
+
+ child_ns = open(path, O_RDONLY);
+ if (child_ns <= 0)
+ return pr_perror("Unable to open %s", path);
+
+ if (fstat(child_ns, &st2))
+ return pr_perror("Unable to stat the timens");
+
+ if (st1.st_ino == st2.st_ino)
+ return pr_perror("The same child_ns after CLONE_NEWTIME");
+
+ return 0;
+}
+
+static int test_gettime(clockid_t clock_index, bool raw_syscall, time_t offset)
+{
+ struct timespec child_ts_new, parent_ts_old, cur_ts;
+ char *entry = raw_syscall ? "syscall" : "vdso";
+ double precision = 0.0;
+
+ switch (clocks[clock_index].id) {
+ case CLOCK_MONOTONIC_COARSE:
+ case CLOCK_MONOTONIC_RAW:
+ precision = -2.0;
+ break;
+ }
+
+ if (switch_ns(parent_ns))
+ return pr_err("switch_ns(%d)", child_ns);
+
+ if (_gettime(clocks[clock_index].id, &parent_ts_old, raw_syscall))
+ return -1;
+
+ child_ts_new.tv_nsec = parent_ts_old.tv_nsec;
+ child_ts_new.tv_sec = parent_ts_old.tv_sec + offset;
+
+ if (switch_ns(child_ns))
+ return pr_err("switch_ns(%d)", child_ns);
+
+ if (_gettime(clocks[clock_index].id, &cur_ts, raw_syscall))
+ return -1;
+
+ if (difftime(cur_ts.tv_sec, child_ts_new.tv_sec) < precision) {
+ ksft_test_result_fail(
+ "Child's %s (%s) time has not changed: %lu -> %lu [%lu]\n",
+ clocks[clock_index].name, entry, parent_ts_old.tv_sec,
+ child_ts_new.tv_sec, cur_ts.tv_sec);
+ return -1;
+ }
+
+ if (switch_ns(parent_ns))
+ return pr_err("switch_ns(%d)", parent_ns);
+
+ if (_gettime(clocks[clock_index].id, &cur_ts, raw_syscall))
+ return -1;
+
+ if (difftime(cur_ts.tv_sec, parent_ts_old.tv_sec) > DAY_IN_SEC) {
+ ksft_test_result_fail(
+ "Parent's %s (%s) time has changed: %lu -> %lu [%lu]\n",
+ clocks[clock_index].name, entry, parent_ts_old.tv_sec,
+ child_ts_new.tv_sec, cur_ts.tv_sec);
+ /* Let's play nice and put it closer to original */
+ clock_settime(clocks[clock_index].id, &cur_ts);
+ return -1;
+ }
+
+ ksft_test_result_pass("Passed for %s (%s)\n",
+ clocks[clock_index].name, entry);
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int i;
+ time_t offset;
+ int ret = 0;
+
+ nscheck();
+
+ ksft_set_plan(ARRAY_SIZE(clocks) * 2);
+
+ if (init_namespaces())
+ return 1;
+
+ /* Offsets have to be set before tasks enter the namespace. */
+ for (i = 0; i < ARRAY_SIZE(clocks); i++) {
+ if (clocks[i].off_id != -1)
+ continue;
+ offset = TEN_DAYS_IN_SEC + i * 1000;
+ clocks[i].offset = offset;
+ if (_settime(clocks[i].id, offset))
+ return 1;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(clocks); i++) {
+ if (clocks[i].off_id != -1)
+ offset = clocks[clocks[i].off_id].offset;
+ else
+ offset = clocks[i].offset;
+ ret |= test_gettime(i, true, offset);
+ ret |= test_gettime(i, false, offset);
+ }
+
+ if (ret)
+ ksft_exit_fail();
+
+ ksft_exit_pass();
+ return !!ret;
+}
diff --git a/tools/testing/selftests/timens/timens.h b/tools/testing/selftests/timens/timens.h
new file mode 100644
index 000000000000..0cba32fdaffd
--- /dev/null
+++ b/tools/testing/selftests/timens/timens.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TIMENS_H__
+#define __TIMENS_H__
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "../kselftest.h"
+
+#ifndef CLONE_NEWTIME
+# define CLONE_NEWTIME 0x00000080
+#endif
+
+static inline int unshare_timens(void)
+{
+ if (unshare(CLONE_NEWTIME)) {
+ if (errno == EPERM)
+ ksft_exit_skip("need to run as root\n");
+ return pr_perror("Can't unshare() timens");
+ }
+ return 0;
+}
+
+static inline int _settime(clockid_t clk_id, time_t offset)
+{
+ int fd, len;
+ char buf[4096];
+
+ if (clk_id == CLOCK_MONOTONIC_COARSE || clk_id == CLOCK_MONOTONIC_RAW)
+ clk_id = CLOCK_MONOTONIC;
+
+ len = snprintf(buf, sizeof(buf), "%d %ld 0", clk_id, offset);
+
+ fd = open("/proc/self/timens_offsets", O_WRONLY);
+ if (fd < 0)
+ return pr_perror("/proc/self/timens_offsets");
+
+ if (write(fd, buf, len) != len)
+ return pr_perror("/proc/self/timens_offsets");
+
+ close(fd);
+
+ return 0;
+}
+
+static inline int _gettime(clockid_t clk_id, struct timespec *res, bool raw_syscall)
+{
+ int err;
+
+ if (!raw_syscall) {
+ if (clock_gettime(clk_id, res)) {
+ pr_perror("clock_gettime(%d)", (int)clk_id);
+ return -1;
+ }
+ return 0;
+ }
+
+ err = syscall(SYS_clock_gettime, clk_id, res);
+ if (err)
+ pr_perror("syscall(SYS_clock_gettime(%d))", (int)clk_id);
+
+ return err;
+}
+
+static inline void nscheck(void)
+{
+ if (access("/proc/self/ns/time", F_OK) < 0)
+ ksft_exit_skip("Time namespaces are not supported\n");
+}
+
+#endif
--
2.23.0
^ permalink raw reply related
* [PATCHv7 28/33] selftests/timens: Add a test for timerfd
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andrei Vagin, Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@gmail.com>
Check that timerfd_create() takes into account clock offsets.
Output on success:
1..3
ok 1 clockid=7
ok 2 clockid=1
ok 3 clockid=9
# Pass 3 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output on failure:
1..3
not ok 1 clockid: 7 elapsed: 0
not ok 2 clockid: 1 elapsed: 0
not ok 3 clockid: 9 elapsed: 0
Bail out!
Output with lack of permissions:
1..3
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..3
not ok 1 # SKIP Time namespaces are not supported
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 2 +-
tools/testing/selftests/timens/timerfd.c | 129 ++++++++++++++++++++++
3 files changed, 131 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/timerfd.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 27a693229ce1..b609f6ee9fb9 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1 +1,2 @@
timens
+timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index b877efb78974..66b90cd28e5c 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens
+TEST_GEN_PROGS := timens timerfd
CFLAGS := -Wall -Werror
diff --git a/tools/testing/selftests/timens/timerfd.c b/tools/testing/selftests/timens/timerfd.c
new file mode 100644
index 000000000000..619b096b7fe5
--- /dev/null
+++ b/tools/testing/selftests/timens/timerfd.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/timerfd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include "log.h"
+#include "timens.h"
+
+static int tclock_gettime(clock_t clockid, struct timespec *now)
+{
+ if (clockid == CLOCK_BOOTTIME_ALARM)
+ clockid = CLOCK_BOOTTIME;
+ return clock_gettime(clockid, now);
+}
+
+int run_test(int clockid, struct timespec now)
+{
+ struct itimerspec new_value;
+ long long elapsed;
+ int fd, i;
+
+ if (tclock_gettime(clockid, &now))
+ return pr_perror("clock_gettime(%d)", clockid);
+
+ for (i = 0; i < 2; i++) {
+ int flags = 0;
+
+ new_value.it_value.tv_sec = 3600;
+ new_value.it_value.tv_nsec = 0;
+ new_value.it_interval.tv_sec = 1;
+ new_value.it_interval.tv_nsec = 0;
+
+ if (i == 1) {
+ new_value.it_value.tv_sec += now.tv_sec;
+ new_value.it_value.tv_nsec += now.tv_nsec;
+ }
+
+ fd = timerfd_create(clockid, 0);
+ if (fd == -1)
+ return pr_perror("timerfd_create(%d)", clockid);
+
+ if (i == 1)
+ flags |= TFD_TIMER_ABSTIME;
+
+ if (timerfd_settime(fd, flags, &new_value, NULL))
+ return pr_perror("timerfd_settime(%d)", clockid);
+
+ if (timerfd_gettime(fd, &new_value))
+ return pr_perror("timerfd_gettime(%d)", clockid);
+
+ elapsed = new_value.it_value.tv_sec;
+ if (abs(elapsed - 3600) > 60) {
+ ksft_test_result_fail("clockid: %d elapsed: %lld\n",
+ clockid, elapsed);
+ return 1;
+ }
+
+ close(fd);
+ }
+
+ ksft_test_result_pass("clockid=%d\n", clockid);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret, status, len, fd;
+ char buf[4096];
+ pid_t pid;
+ struct timespec btime_now, mtime_now;
+
+ nscheck();
+
+ ksft_set_plan(3);
+
+ clock_gettime(CLOCK_MONOTONIC, &mtime_now);
+ clock_gettime(CLOCK_BOOTTIME, &btime_now);
+
+ if (unshare_timens())
+ return 1;
+
+ len = snprintf(buf, sizeof(buf), "%d %d 0\n%d %d 0",
+ CLOCK_MONOTONIC, 70 * 24 * 3600,
+ CLOCK_BOOTTIME, 9 * 24 * 3600);
+ fd = open("/proc/self/timens_offsets", O_WRONLY);
+ if (fd < 0)
+ return pr_perror("/proc/self/timens_offsets");
+
+ if (write(fd, buf, len) != len)
+ return pr_perror("/proc/self/timens_offsets");
+
+ close(fd);
+ mtime_now.tv_sec += 70 * 24 * 3600;
+ btime_now.tv_sec += 9 * 24 * 3600;
+
+ pid = fork();
+ if (pid < 0)
+ return pr_perror("Unable to fork");
+ if (pid == 0) {
+ ret = 0;
+ ret |= run_test(CLOCK_BOOTTIME, btime_now);
+ ret |= run_test(CLOCK_MONOTONIC, mtime_now);
+ ret |= run_test(CLOCK_BOOTTIME_ALARM, btime_now);
+
+ if (ret)
+ ksft_exit_fail();
+ ksft_exit_pass();
+ return ret;
+ }
+
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Unable to wait the child process");
+
+ if (WIFEXITED(status))
+ return WEXITSTATUS(status);
+
+ return 1;
+}
+
--
2.23.0
^ permalink raw reply related
* [PATCHv7 29/33] selftests/timens: Add a test for clock_nanosleep()
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andrei Vagin, Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@gmail.com>
Check that clock_nanosleep() takes into account clock offsets.
Output on success:
1..4
ok 1 clockid: 1 abs:0
ok 2 clockid: 1 abs:1
ok 3 clockid: 9 abs:0
ok 4 clockid: 9 abs:1
Output with lack of permissions:
1..4
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..4
not ok 1 # SKIP Time namespaces are not supported
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 4 +-
.../selftests/timens/clock_nanosleep.c | 143 ++++++++++++++++++
3 files changed, 146 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/timens/clock_nanosleep.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index b609f6ee9fb9..9b6c8ddac2c8 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,2 +1,3 @@
+clock_nanosleep
timens
timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index 66b90cd28e5c..801e7ab2f8bf 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,5 +1,5 @@
-TEST_GEN_PROGS := timens timerfd
+TEST_GEN_PROGS := timens timerfd clock_nanosleep
-CFLAGS := -Wall -Werror
+CFLAGS := -Wall -Werror -pthread
include ../lib.mk
diff --git a/tools/testing/selftests/timens/clock_nanosleep.c b/tools/testing/selftests/timens/clock_nanosleep.c
new file mode 100644
index 000000000000..0f4eab6e4669
--- /dev/null
+++ b/tools/testing/selftests/timens/clock_nanosleep.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/timerfd.h>
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+void test_sig(int sig) {
+ if (sig == SIGUSR2)
+ pthread_exit(NULL);
+}
+
+struct thread_args {
+ struct timespec *now, *rem;
+ pthread_mutex_t *lock;
+ int clockid;
+ int abs;
+};
+
+void *call_nanosleep(void *_args)
+{
+ struct thread_args *args = _args;
+ clock_nanosleep(args->clockid, args->abs ? TIMER_ABSTIME : 0, args->now, args->rem);
+ pthread_mutex_unlock(args->lock);
+ return NULL;
+}
+
+int run_test(int clockid, int abs)
+{
+ struct timespec now = {}, rem;
+ struct thread_args args = { .now = &now, .rem = &rem, .clockid = clockid};
+ struct timespec start;
+ pthread_mutex_t lock;
+ pthread_t thread;
+ int j, ok, ret;
+
+ signal(SIGUSR1, test_sig);
+ signal(SIGUSR2, test_sig);
+
+ pthread_mutex_init(&lock, NULL);
+ pthread_mutex_lock(&lock);
+
+ if (clock_gettime(clockid, &start) == -1)
+ return pr_perror("clock_gettime");
+
+
+ if (abs) {
+ now.tv_sec = start.tv_sec;
+ now.tv_nsec = start.tv_nsec;
+ }
+
+ now.tv_sec += 3600;
+ args.abs = abs;
+ args.lock = &lock;
+ ret = pthread_create(&thread, NULL, call_nanosleep, &args);
+ if (ret != 0) {
+ pr_err("Unable to create a thread: %s", strerror(ret));
+ return 1;
+ }
+
+ /* Wait when the thread will call clock_nanosleep(). */
+ ok = 0;
+ for (j = 0; j < 8; j++) {
+ /* The maximum timeout is about 5 seconds. */
+ usleep(10000 << j);
+
+ /* Try to interrupt clock_nanosleep(). */
+ pthread_kill(thread, SIGUSR1);
+
+ usleep(10000 << j);
+ /* Check whether clock_nanosleep() has been interrupted or not. */
+ if (pthread_mutex_trylock(&lock) == 0) {
+ /**/
+ ok = 1;
+ break;
+ }
+ }
+ if (!ok)
+ pthread_kill(thread, SIGUSR2);
+ pthread_join(thread, NULL);
+ pthread_mutex_destroy(&lock);
+
+ if (!ok) {
+ ksft_test_result_pass("clockid: %d abs:%d timeout\n", clockid, abs);
+ return 1;
+ }
+
+ if (rem.tv_sec < 3300 || rem.tv_sec > 3900) {
+ pr_fail("clockid: %d abs: %d remain: %ld\n",
+ clockid, abs, rem.tv_sec);
+ return 1;
+ }
+ ksft_test_result_pass("clockid: %d abs:%d\n", clockid, abs);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret, nsfd;
+
+ nscheck();
+
+ ksft_set_plan(4);
+
+ if (unshare_timens())
+ return 1;
+
+ if (_settime(CLOCK_MONOTONIC, 7 * 24 * 3600))
+ return 1;
+ if (_settime(CLOCK_BOOTTIME, 9 * 24 * 3600))
+ return 1;
+
+ nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);
+ if (nsfd < 0)
+ return pr_perror("Unable to open timens_for_children");
+
+ if (setns(nsfd, CLONE_NEWTIME))
+ return pr_perror("Unable to set timens");
+
+ ret = 0;
+ ret |= run_test(CLOCK_MONOTONIC, 0);
+ ret |= run_test(CLOCK_MONOTONIC, 1);
+ ret |= run_test(CLOCK_BOOTTIME_ALARM, 0);
+ ret |= run_test(CLOCK_BOOTTIME_ALARM, 1);
+
+ if (ret)
+ ksft_exit_fail();
+ ksft_exit_pass();
+ return ret;
+}
+
--
2.23.0
^ permalink raw reply related
* [PATCHv7 30/33] selftests/timens: Add procfs selftest
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Dmitry Safonov, Adrian Reber, Andrei Vagin,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
Check that /proc/uptime is correct inside a new time namespace.
Output on success:
1..1
ok 1 Passed for /proc/uptime
# Pass 1 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..1
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..1
not ok 1 # SKIP Time namespaces are not supported
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 2 +-
tools/testing/selftests/timens/procfs.c | 144 ++++++++++++++++++++++
3 files changed, 146 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/procfs.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 9b6c8ddac2c8..94ffdd9cead7 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,3 +1,4 @@
clock_nanosleep
+procfs
timens
timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index 801e7ab2f8bf..e4913f2991d4 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens timerfd clock_nanosleep
+TEST_GEN_PROGS := timens timerfd clock_nanosleep procfs
CFLAGS := -Wall -Werror -pthread
diff --git a/tools/testing/selftests/timens/procfs.c b/tools/testing/selftests/timens/procfs.c
new file mode 100644
index 000000000000..43d93f4006b9
--- /dev/null
+++ b/tools/testing/selftests/timens/procfs.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "log.h"
+#include "timens.h"
+
+/*
+ * Test shouldn't be run for a day, so add 10 days to child
+ * time and check parent's time to be in the same day.
+ */
+#define MAX_TEST_TIME_SEC (60*5)
+#define DAY_IN_SEC (60*60*24)
+#define TEN_DAYS_IN_SEC (10*DAY_IN_SEC)
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static int child_ns, parent_ns;
+
+static int switch_ns(int fd)
+{
+ if (setns(fd, CLONE_NEWTIME))
+ return pr_perror("setns()");
+
+ return 0;
+}
+
+static int init_namespaces(void)
+{
+ char path[] = "/proc/self/ns/time_for_children";
+ struct stat st1, st2;
+
+ parent_ns = open(path, O_RDONLY);
+ if (parent_ns <= 0)
+ return pr_perror("Unable to open %s", path);
+
+ if (fstat(parent_ns, &st1))
+ return pr_perror("Unable to stat the parent timens");
+
+ if (unshare_timens())
+ return -1;
+
+ child_ns = open(path, O_RDONLY);
+ if (child_ns <= 0)
+ return pr_perror("Unable to open %s", path);
+
+ if (fstat(child_ns, &st2))
+ return pr_perror("Unable to stat the timens");
+
+ if (st1.st_ino == st2.st_ino)
+ return pr_err("The same child_ns after CLONE_NEWTIME");
+
+ if (_settime(CLOCK_BOOTTIME, TEN_DAYS_IN_SEC))
+ return -1;
+
+ return 0;
+}
+
+static int read_proc_uptime(struct timespec *uptime)
+{
+ unsigned long up_sec, up_nsec;
+ FILE *proc;
+
+ proc = fopen("/proc/uptime", "r");
+ if (proc == NULL) {
+ pr_perror("Unable to open /proc/uptime");
+ return -1;
+ }
+
+ if (fscanf(proc, "%lu.%02lu", &up_sec, &up_nsec) != 2) {
+ if (errno) {
+ pr_perror("fscanf");
+ return -errno;
+ }
+ pr_err("failed to parse /proc/uptime");
+ return -1;
+ }
+ fclose(proc);
+
+ uptime->tv_sec = up_sec;
+ uptime->tv_nsec = up_nsec;
+ return 0;
+}
+
+static int check_uptime(void)
+{
+ struct timespec uptime_new, uptime_old;
+ time_t uptime_expected;
+ double prec = MAX_TEST_TIME_SEC;
+
+ if (switch_ns(parent_ns))
+ return pr_err("switch_ns(%d)", parent_ns);
+
+ if (read_proc_uptime(&uptime_old))
+ return 1;
+
+ if (switch_ns(child_ns))
+ return pr_err("switch_ns(%d)", child_ns);
+
+ if (read_proc_uptime(&uptime_new))
+ return 1;
+
+ uptime_expected = uptime_old.tv_sec + TEN_DAYS_IN_SEC;
+ if (fabs(difftime(uptime_new.tv_sec, uptime_expected)) > prec) {
+ pr_fail("uptime in /proc/uptime: old %ld, new %ld [%ld]",
+ uptime_old.tv_sec, uptime_new.tv_sec,
+ uptime_old.tv_sec + TEN_DAYS_IN_SEC);
+ return 1;
+ }
+
+ ksft_test_result_pass("Passed for /proc/uptime\n");
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret = 0;
+
+ nscheck();
+
+ ksft_set_plan(1);
+
+ if (init_namespaces())
+ return 1;
+
+ ret |= check_uptime();
+
+ if (ret)
+ ksft_exit_fail();
+ ksft_exit_pass();
+ return ret;
+}
--
2.23.0
^ permalink raw reply related
* [PATCHv7 31/33] selftests/timens: Add timer offsets test
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api,
x86
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@openvz.org>
Check that timer_create() takes into account clock offsets.
Output on success:
1..3
ok 1 clockid=7
ok 2 clockid=1
ok 3 clockid=9
# Pass 3 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..3
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..3
not ok 1 # SKIP Time namespaces are not supported
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 3 +-
tools/testing/selftests/timens/timer.c | 118 ++++++++++++++++++++++
3 files changed, 121 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/timer.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 94ffdd9cead7..3b7eda8f35ce 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,4 +1,5 @@
clock_nanosleep
procfs
timens
+timer
timerfd
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index e4913f2991d4..08164548a49d 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,5 +1,6 @@
-TEST_GEN_PROGS := timens timerfd clock_nanosleep procfs
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs
CFLAGS := -Wall -Werror -pthread
+LDFLAGS := -lrt
include ../lib.mk
diff --git a/tools/testing/selftests/timens/timer.c b/tools/testing/selftests/timens/timer.c
new file mode 100644
index 000000000000..5164cafd408d
--- /dev/null
+++ b/tools/testing/selftests/timens/timer.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <signal.h>
+#include <time.h>
+
+#include "log.h"
+#include "timens.h"
+
+int run_test(int clockid, struct timespec now)
+{
+ struct itimerspec new_value;
+ long long elapsed;
+ timer_t fd;
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ struct sigevent sevp = {.sigev_notify = SIGEV_NONE};
+ int flags = 0;
+
+ new_value.it_value.tv_sec = 3600;
+ new_value.it_value.tv_nsec = 0;
+ new_value.it_interval.tv_sec = 1;
+ new_value.it_interval.tv_nsec = 0;
+
+ if (i == 1) {
+ new_value.it_value.tv_sec += now.tv_sec;
+ new_value.it_value.tv_nsec += now.tv_nsec;
+ }
+
+ if (timer_create(clockid, &sevp, &fd) == -1)
+ return pr_perror("timerfd_create");
+
+ if (i == 1)
+ flags |= TIMER_ABSTIME;
+ if (timer_settime(fd, flags, &new_value, NULL) == -1)
+ return pr_perror("timerfd_settime");
+
+ if (timer_gettime(fd, &new_value) == -1)
+ return pr_perror("timerfd_gettime");
+
+ elapsed = new_value.it_value.tv_sec;
+ if (abs(elapsed - 3600) > 60) {
+ ksft_test_result_fail("clockid: %d elapsed: %lld\n",
+ clockid, elapsed);
+ return 1;
+ }
+ }
+
+ ksft_test_result_pass("clockid=%d\n", clockid);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret, status, len, fd;
+ char buf[4096];
+ pid_t pid;
+ struct timespec btime_now, mtime_now;
+
+ nscheck();
+
+ ksft_set_plan(3);
+
+ clock_gettime(CLOCK_MONOTONIC, &mtime_now);
+ clock_gettime(CLOCK_BOOTTIME, &btime_now);
+
+ if (unshare_timens())
+ return 1;
+
+ len = snprintf(buf, sizeof(buf), "%d %d 0\n%d %d 0",
+ CLOCK_MONOTONIC, 70 * 24 * 3600,
+ CLOCK_BOOTTIME, 9 * 24 * 3600);
+ fd = open("/proc/self/timens_offsets", O_WRONLY);
+ if (fd < 0)
+ return pr_perror("/proc/self/timens_offsets");
+
+ if (write(fd, buf, len) != len)
+ return pr_perror("/proc/self/timens_offsets");
+
+ close(fd);
+ mtime_now.tv_sec += 70 * 24 * 3600;
+ btime_now.tv_sec += 9 * 24 * 3600;
+
+ pid = fork();
+ if (pid < 0)
+ return pr_perror("Unable to fork");
+ if (pid == 0) {
+ ret = 0;
+ ret |= run_test(CLOCK_BOOTTIME, btime_now);
+ ret |= run_test(CLOCK_MONOTONIC, mtime_now);
+ ret |= run_test(CLOCK_BOOTTIME_ALARM, btime_now);
+
+ if (ret)
+ ksft_exit_fail();
+ ksft_exit_pass();
+ return ret;
+ }
+
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("Unable to wait the child process");
+
+ if (WIFEXITED(status))
+ return WEXITSTATUS(status);
+
+ return 1;
+}
+
--
2.23.0
^ permalink raw reply related
* [PATCHv7 32/33] selftests/timens: Add a simple perf test for clock_gettime()
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andrei Vagin, Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@gmail.com>
Output on success:
1..4
ok 1 host: clock: monotonic cycles: 148323947
ok 2 host: clock: boottime cycles: 148577503
ok 3 ns: clock: monotonic cycles: 137659217
ok 4 ns: clock: boottime cycles: 137959154
# Pass 4 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output with lack of permissions:
1..4
ok 1 host: clock: monotonic cycles: 145671139
ok 2 host: clock: boottime cycles: 146958357
not ok 3 # SKIP need to run as root
Output without support of time namespaces:
1..4
ok 1 host: clock: monotonic cycles: 145671139
ok 2 host: clock: boottime cycles: 146958357
not ok 3 # SKIP Time namespaces are not supported
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 2 +
tools/testing/selftests/timens/Makefile | 3 +-
tools/testing/selftests/timens/gettime_perf.c | 91 +++++++++++++++++++
3 files changed, 95 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/gettime_perf.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 3b7eda8f35ce..16292e4d08a5 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,4 +1,6 @@
clock_nanosleep
+gettime_perf
+gettime_perf_cold
procfs
timens
timer
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index 08164548a49d..6aefcaccb8f4 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,6 +1,7 @@
TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs
+TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread
-LDFLAGS := -lrt
+LDFLAGS := -lrt -ldl
include ../lib.mk
diff --git a/tools/testing/selftests/timens/gettime_perf.c b/tools/testing/selftests/timens/gettime_perf.c
new file mode 100644
index 000000000000..3a6d9c485de5
--- /dev/null
+++ b/tools/testing/selftests/timens/gettime_perf.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <dlfcn.h>
+
+#include "log.h"
+#include "timens.h"
+
+typedef int (*vgettime_t)(clockid_t, struct timespec *);
+
+vgettime_t vdso_clock_gettime;
+
+static void fill_function_pointers(void)
+{
+ void *vdso = dlopen("linux-vdso.so.1",
+ RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+ if (!vdso)
+ vdso = dlopen("linux-gate.so.1",
+ RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+ if (!vdso) {
+ pr_err("[WARN]\tfailed to find vDSO\n");
+ return;
+ }
+
+ vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
+ if (!vdso_clock_gettime)
+ pr_err("Warning: failed to find clock_gettime in vDSO\n");
+
+}
+
+static void test(clock_t clockid, char *clockstr, bool in_ns)
+{
+ struct timespec tp, start;
+ long i = 0;
+ const int timeout = 3;
+
+ vdso_clock_gettime(clockid, &start);
+ tp = start;
+ for (tp = start; start.tv_sec + timeout > tp.tv_sec ||
+ (start.tv_sec + timeout == tp.tv_sec &&
+ start.tv_nsec > tp.tv_nsec); i++) {
+ vdso_clock_gettime(clockid, &tp);
+ }
+
+ ksft_test_result_pass("%s:\tclock: %10s\tcycles:\t%10ld\n",
+ in_ns ? "ns" : "host", clockstr, i);
+}
+
+int main(int argc, char *argv[])
+{
+ time_t offset = 10;
+ int nsfd;
+
+ ksft_set_plan(4);
+
+ fill_function_pointers();
+
+ test(CLOCK_MONOTONIC, "monotonic", false);
+ test(CLOCK_BOOTTIME, "boottime", false);
+
+ nscheck();
+
+ if (unshare_timens())
+ return 1;
+
+ nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);
+ if (nsfd < 0)
+ return pr_perror("Can't open a time namespace");
+
+ if (_settime(CLOCK_MONOTONIC, offset))
+ return 1;
+ if (_settime(CLOCK_BOOTTIME, offset))
+ return 1;
+
+ if (setns(nsfd, CLONE_NEWTIME))
+ return pr_perror("setns");
+
+ test(CLOCK_MONOTONIC, "monotonic", true);
+ test(CLOCK_BOOTTIME, "boottime", true);
+
+ ksft_exit_pass();
+ return 0;
+}
--
2.23.0
^ permalink raw reply related
* [PATCHv7 33/33] selftests/timens: Check for right timens offsets after fork and exec
From: Dmitry Safonov @ 2019-10-11 1:23 UTC (permalink / raw)
To: linux-kernel
Cc: Dmitry Safonov, Andrei Vagin, Dmitry Safonov, Adrian Reber,
Andrei Vagin, Andy Lutomirski, Arnd Bergmann, Christian Brauner,
Cyrill Gorcunov, Eric W. Biederman, H. Peter Anvin, Ingo Molnar,
Jann Horn, Jeff Dike, Oleg Nesterov, Pavel Emelyanov, Shuah Khan,
Thomas Gleixner, Vincenzo Frascino, containers, criu, linux-api
In-Reply-To: <20191011012341.846266-1-dima@arista.com>
From: Andrei Vagin <avagin@gmail.com>
Output on success:
1..1
ok 1 exec
# Pass 1 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
Output on failure:
1..1
not ok 1 36016 16
Bail out!
Output with lack of permissions:
1..1
not ok 1 # SKIP need to run as root
Output without support of time namespaces:
1..1
not ok 1 # SKIP Time namespaces are not supported
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 2 +-
tools/testing/selftests/timens/exec.c | 94 +++++++++++++++++++++++
3 files changed, 96 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/exec.c
diff --git a/tools/testing/selftests/timens/.gitignore b/tools/testing/selftests/timens/.gitignore
index 16292e4d08a5..789f21e81028 100644
--- a/tools/testing/selftests/timens/.gitignore
+++ b/tools/testing/selftests/timens/.gitignore
@@ -1,4 +1,5 @@
clock_nanosleep
+exec
gettime_perf
gettime_perf_cold
procfs
diff --git a/tools/testing/selftests/timens/Makefile b/tools/testing/selftests/timens/Makefile
index 6aefcaccb8f4..e9fb30bd8aeb 100644
--- a/tools/testing/selftests/timens/Makefile
+++ b/tools/testing/selftests/timens/Makefile
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec
TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread
diff --git a/tools/testing/selftests/timens/exec.c b/tools/testing/selftests/timens/exec.c
new file mode 100644
index 000000000000..87b47b557a7a
--- /dev/null
+++ b/tools/testing/selftests/timens/exec.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+
+#include "log.h"
+#include "timens.h"
+
+#define OFFSET (36000)
+
+int main(int argc, char *argv[])
+{
+ struct timespec now, tst;
+ int status, i;
+ pid_t pid;
+
+ if (argc > 1) {
+ if (sscanf(argv[1], "%ld", &now.tv_sec) != 1)
+ return pr_perror("sscanf");
+
+ for (i = 0; i < 2; i++) {
+ _gettime(CLOCK_MONOTONIC, &tst, i);
+ if (abs(tst.tv_sec - now.tv_sec) > 5)
+ return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
+ }
+ return 0;
+ }
+
+ nscheck();
+
+ ksft_set_plan(1);
+
+ clock_gettime(CLOCK_MONOTONIC, &now);
+
+ if (unshare_timens())
+ return 1;
+
+ if (_settime(CLOCK_MONOTONIC, OFFSET))
+ return 1;
+
+ for (i = 0; i < 2; i++) {
+ _gettime(CLOCK_MONOTONIC, &tst, i);
+ if (abs(tst.tv_sec - now.tv_sec) > 5)
+ return pr_fail("%ld %ld\n",
+ now.tv_sec, tst.tv_sec);
+ }
+
+ if (argc > 1)
+ return 0;
+
+ pid = fork();
+ if (pid < 0)
+ return pr_perror("fork");
+
+ if (pid == 0) {
+ char now_str[64];
+ char *cargv[] = {"exec", now_str, NULL};
+ char *cenv[] = {NULL};
+
+ /* Check that a child process is in the new timens. */
+ for (i = 0; i < 2; i++) {
+ _gettime(CLOCK_MONOTONIC, &tst, i);
+ if (abs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
+ return pr_fail("%ld %ld\n",
+ now.tv_sec + OFFSET, tst.tv_sec);
+ }
+
+ /* Check for proper vvar offsets after execve. */
+ snprintf(now_str, sizeof(now_str), "%ld", now.tv_sec + OFFSET);
+ execve("/proc/self/exe", cargv, cenv);
+ return pr_perror("execve");
+ }
+
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("waitpid");
+
+ if (status)
+ ksft_exit_fail();
+
+ ksft_test_result_pass("exec\n");
+ ksft_exit_pass();
+ return 0;
+}
--
2.23.0
^ permalink raw reply related
* [PATCH] usercopy: Avoid soft lockups in test_check_nonzero_user()
From: Michael Ellerman @ 2019-10-11 2:24 UTC (permalink / raw)
To: cyphar
Cc: mingo, peterz, alexander.shishkin, jolsa, namhyung, christian,
keescook, linux, viro, torvalds, libc-alpha, linux-api,
linux-kernel
In-Reply-To: <20191010114007.o3bygjf4jlfk242e@yavin.dot.cyphar.com>
On a machine with a 64K PAGE_SIZE, the nested for loops in
test_check_nonzero_user() can lead to soft lockups, eg:
watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [modprobe:611]
Modules linked in: test_user_copy(+) vmx_crypto gf128mul crc32c_vpmsum virtio_balloon ip_tables x_tables autofs4
CPU: 4 PID: 611 Comm: modprobe Tainted: G L 5.4.0-rc1-gcc-8.2.0-00001-gf5a1a536fa14-dirty #1151
...
NIP __might_sleep+0x20/0xc0
LR __might_fault+0x40/0x60
Call Trace:
check_zeroed_user+0x12c/0x200
test_user_copy_init+0x67c/0x1210 [test_user_copy]
do_one_initcall+0x60/0x340
do_init_module+0x7c/0x2f0
load_module+0x2d94/0x30e0
__do_sys_finit_module+0xc8/0x150
system_call+0x5c/0x68
Even with a 4K PAGE_SIZE the test takes multiple seconds. Instead
tweak it to only scan a 1024 byte region, but make it cross the
page boundary.
Fixes: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")
Suggested-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
lib/test_user_copy.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
How does this look? It runs in < 1s on my machine here.
cheers
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
index 950ee88cd6ac..9fb6bc609d4c 100644
--- a/lib/test_user_copy.c
+++ b/lib/test_user_copy.c
@@ -47,9 +47,26 @@ static bool is_zeroed(void *from, size_t size)
static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
{
int ret = 0;
- size_t start, end, i;
- size_t zero_start = size / 4;
- size_t zero_end = size - zero_start;
+ size_t start, end, i, zero_start, zero_end;
+
+ if (test(size < 1024, "buffer too small"))
+ return -EINVAL;
+
+ /*
+ * We want to cross a page boundary to exercise the code more
+ * effectively. We assume the buffer we're passed has a page boundary at
+ * size / 2. We also don't want to make the size we scan too large,
+ * otherwise the test can take a long time and cause soft lockups. So
+ * scan a 1024 byte region across the page boundary.
+ */
+ start = size / 2 - 512;
+ size = 1024;
+
+ kmem += start;
+ umem += start;
+
+ zero_start = size / 4;
+ zero_end = size - zero_start;
/*
* We conduct a series of check_nonzero_user() tests on a block of memory
--
2.21.0
^ permalink raw reply related
* Re: [PATCH] usercopy: Avoid soft lockups in test_check_nonzero_user()
From: Aleksa Sarai @ 2019-10-11 3:48 UTC (permalink / raw)
To: Michael Ellerman
Cc: mingo, peterz, alexander.shishkin, jolsa, namhyung, christian,
keescook, linux, viro, torvalds, libc-alpha, linux-api,
linux-kernel
In-Reply-To: <20191011022447.24249-1-mpe@ellerman.id.au>
[-- Attachment #1: Type: text/plain, Size: 2944 bytes --]
On 2019-10-11, Michael Ellerman <mpe@ellerman.id.au> wrote:
> On a machine with a 64K PAGE_SIZE, the nested for loops in
> test_check_nonzero_user() can lead to soft lockups, eg:
>
> watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [modprobe:611]
> Modules linked in: test_user_copy(+) vmx_crypto gf128mul crc32c_vpmsum virtio_balloon ip_tables x_tables autofs4
> CPU: 4 PID: 611 Comm: modprobe Tainted: G L 5.4.0-rc1-gcc-8.2.0-00001-gf5a1a536fa14-dirty #1151
> ...
> NIP __might_sleep+0x20/0xc0
> LR __might_fault+0x40/0x60
> Call Trace:
> check_zeroed_user+0x12c/0x200
> test_user_copy_init+0x67c/0x1210 [test_user_copy]
> do_one_initcall+0x60/0x340
> do_init_module+0x7c/0x2f0
> load_module+0x2d94/0x30e0
> __do_sys_finit_module+0xc8/0x150
> system_call+0x5c/0x68
>
> Even with a 4K PAGE_SIZE the test takes multiple seconds. Instead
> tweak it to only scan a 1024 byte region, but make it cross the
> page boundary.
>
> Fixes: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")
> Suggested-by: Aleksa Sarai <cyphar@cyphar.com>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> ---
> lib/test_user_copy.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> How does this look? It runs in < 1s on my machine here.
>
> cheers
>
> diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
> index 950ee88cd6ac..9fb6bc609d4c 100644
> --- a/lib/test_user_copy.c
> +++ b/lib/test_user_copy.c
> @@ -47,9 +47,26 @@ static bool is_zeroed(void *from, size_t size)
> static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
> {
> int ret = 0;
> - size_t start, end, i;
> - size_t zero_start = size / 4;
> - size_t zero_end = size - zero_start;
> + size_t start, end, i, zero_start, zero_end;
> +
> + if (test(size < 1024, "buffer too small"))
> + return -EINVAL;
> +
> + /*
> + * We want to cross a page boundary to exercise the code more
> + * effectively. We assume the buffer we're passed has a page boundary at
> + * size / 2. We also don't want to make the size we scan too large,
> + * otherwise the test can take a long time and cause soft lockups. So
> + * scan a 1024 byte region across the page boundary.
> + */
> + start = size / 2 - 512;
> + size = 1024;
I don't think it's necessary to do "size / 2" here -- you can just use
PAGE_SIZE directly and check above that "size == 2*PAGE_SIZE" (not that
this check is exceptionally necessary -- since there's only one caller
of this function and it's in the same file).
> +
> + kmem += start;
> + umem += start;
> +
> + zero_start = size / 4;
> + zero_end = size - zero_start;
>
> /*
> * We conduct a series of check_nonzero_user() tests on a block of memory
--
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
^ permalink raw reply
* Re: [PATCH 1/2] clone3: add CLONE3_CLEAR_SIGHAND
From: Michal Hocko @ 2019-10-11 8:21 UTC (permalink / raw)
To: Christian Brauner
Cc: linux-kernel, Oleg Nesterov, Florian Weimer, libc-alpha,
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Dietmar Eggemann, Steven Rostedt, Ben Segall, Mel Gorman,
Shuah Khan, Andrew Morton, Elena Reshetova, Thomas Gleixner,
Roman Gushchin, Andrea Arcangeli, Al Viro, Aleksa Sarai,
Dmitry V. Levin
In-Reply-To: <20191010133518.5420-1-christian.brauner@ubuntu.com>
[Cc linux-api]
On Thu 10-10-19 15:35:17, Christian Brauner wrote:
> Reset all signal handlers of the child not set to SIG_IGN to SIG_DFL.
> Mutually exclusive with CLONE_SIGHAND to not disturb other thread's
> signal handler.
>
> In the spirit of closer cooperation between glibc developers and kernel
> developers (cf. [2]) this patchset came out of a discussion on the glibc
> mailing list for improving posix_spawn() (cf. [1], [3], [4]). Kernel
> support for this feature has been explicitly requested by glibc and I
> see no reason not to help them with this.
>
> The child helper process on Linux posix_spawn must ensure that no signal
> handlers are enabled, so the signal disposition must be either SIG_DFL
> or SIG_IGN. However, it requires a sigprocmask to obtain the current
> signal mask and at least _NSIG sigaction calls to reset the signal
> handlers for each posix_spawn call or complex state tracking that might
> lead to data corruption in glibc. Adding this flags lets glibc avoid
> these problems.
>
> [1]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00149.html
> [3]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00158.html
> [4]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00160.html
> [2]: https://lwn.net/Articles/799331/
> '[...] by asking for better cooperation with the C-library projects
> in general. They should be copied on patches containing ABI
> changes, for example. I noted that there are often times where
> C-library developers wish the kernel community had done things
> differently; how could those be avoided in the future? Members of
> the audience suggested that more glibc developers should perhaps
> join the linux-api list. The other suggestion was to "copy Florian
> on everything".'
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Florian Weimer <fweimer@redhat.com>
> Cc: libc-alpha@sourceware.org
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
> ---
> include/uapi/linux/sched.h | 3 +++
> kernel/fork.c | 11 ++++++++++-
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
> index 99335e1f4a27..c583720f689f 100644
> --- a/include/uapi/linux/sched.h
> +++ b/include/uapi/linux/sched.h
> @@ -33,6 +33,9 @@
> #define CLONE_NEWNET 0x40000000 /* New network namespace */
> #define CLONE_IO 0x80000000 /* Clone io context */
>
> +/* Flags for the clone3() syscall */
> +#define CLONE3_CLEAR_SIGHAND 0x100000000ULL /* Clear any signal handler and reset to SIG_DFL. */
> +
> #ifndef __ASSEMBLY__
> /**
> * struct clone_args - arguments for the clone3 syscall
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 1f6c45f6a734..661f8d1f3881 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1517,6 +1517,11 @@ static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
> spin_lock_irq(¤t->sighand->siglock);
> memcpy(sig->action, current->sighand->action, sizeof(sig->action));
> spin_unlock_irq(¤t->sighand->siglock);
> +
> + /* Reset all signal handler not set to SIG_IGN to SIG_DFL. */
> + if (clone_flags & CLONE3_CLEAR_SIGHAND)
> + flush_signal_handlers(tsk, 0);
> +
> return 0;
> }
>
> @@ -2567,7 +2572,7 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
> * All lower bits of the flag word are taken.
> * Verify that no other unknown flags are passed along.
> */
> - if (kargs->flags & ~CLONE_LEGACY_FLAGS)
> + if (kargs->flags & ~(CLONE_LEGACY_FLAGS | CLONE3_CLEAR_SIGHAND))
> return false;
>
> /*
> @@ -2577,6 +2582,10 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
> if (kargs->flags & (CLONE_DETACHED | CSIGNAL))
> return false;
>
> + if ((kargs->flags & (CLONE_SIGHAND | CLONE3_CLEAR_SIGHAND)) ==
> + (CLONE_SIGHAND | CLONE3_CLEAR_SIGHAND))
> + return false;
> +
> if ((kargs->flags & (CLONE_THREAD | CLONE_PARENT)) &&
> kargs->exit_signal)
> return false;
> --
> 2.23.0
--
Michal Hocko
SUSE Labs
^ permalink raw reply
* Re: [PATCH 1/2] clone3: add CLONE3_CLEAR_SIGHAND
From: Christian Brauner @ 2019-10-11 9:40 UTC (permalink / raw)
To: Michal Hocko
Cc: linux-kernel, Oleg Nesterov, Florian Weimer, libc-alpha,
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Dietmar Eggemann, Steven Rostedt, Ben Segall, Mel Gorman,
Shuah Khan, Andrew Morton, Elena Reshetova, Thomas Gleixner,
Roman Gushchin, Andrea Arcangeli, Al Viro, Aleksa Sarai,
Dmitry V. Levin
In-Reply-To: <20191011082118.GA26368@dhcp22.suse.cz>
On Fri, Oct 11, 2019 at 10:21:18AM +0200, Michal Hocko wrote:
> [Cc linux-api]
Right, thanks Michal.
Christian
^ permalink raw reply
* Re: [PATCH] usercopy: Avoid soft lockups in test_check_nonzero_user()
From: Christian Brauner @ 2019-10-11 9:43 UTC (permalink / raw)
To: Aleksa Sarai, Michael Ellerman
Cc: mingo, peterz, alexander.shishkin, jolsa, namhyung, keescook,
linux, viro, torvalds, libc-alpha, linux-api, linux-kernel
In-Reply-To: <20191011034810.xkmz3e4l5ezxvq57@yavin.dot.cyphar.com>
On Fri, Oct 11, 2019 at 02:48:10PM +1100, Aleksa Sarai wrote:
> On 2019-10-11, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > On a machine with a 64K PAGE_SIZE, the nested for loops in
> > test_check_nonzero_user() can lead to soft lockups, eg:
> >
> > watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [modprobe:611]
> > Modules linked in: test_user_copy(+) vmx_crypto gf128mul crc32c_vpmsum virtio_balloon ip_tables x_tables autofs4
> > CPU: 4 PID: 611 Comm: modprobe Tainted: G L 5.4.0-rc1-gcc-8.2.0-00001-gf5a1a536fa14-dirty #1151
> > ...
> > NIP __might_sleep+0x20/0xc0
> > LR __might_fault+0x40/0x60
> > Call Trace:
> > check_zeroed_user+0x12c/0x200
> > test_user_copy_init+0x67c/0x1210 [test_user_copy]
> > do_one_initcall+0x60/0x340
> > do_init_module+0x7c/0x2f0
> > load_module+0x2d94/0x30e0
> > __do_sys_finit_module+0xc8/0x150
> > system_call+0x5c/0x68
> >
> > Even with a 4K PAGE_SIZE the test takes multiple seconds. Instead
> > tweak it to only scan a 1024 byte region, but make it cross the
> > page boundary.
> >
> > Fixes: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper")
> > Suggested-by: Aleksa Sarai <cyphar@cyphar.com>
> > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> > ---
> > lib/test_user_copy.c | 23 ++++++++++++++++++++---
> > 1 file changed, 20 insertions(+), 3 deletions(-)
> >
> > How does this look? It runs in < 1s on my machine here.
> >
> > cheers
> >
> > diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
> > index 950ee88cd6ac..9fb6bc609d4c 100644
> > --- a/lib/test_user_copy.c
> > +++ b/lib/test_user_copy.c
> > @@ -47,9 +47,26 @@ static bool is_zeroed(void *from, size_t size)
> > static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
> > {
> > int ret = 0;
> > - size_t start, end, i;
> > - size_t zero_start = size / 4;
> > - size_t zero_end = size - zero_start;
> > + size_t start, end, i, zero_start, zero_end;
> > +
> > + if (test(size < 1024, "buffer too small"))
> > + return -EINVAL;
> > +
> > + /*
> > + * We want to cross a page boundary to exercise the code more
> > + * effectively. We assume the buffer we're passed has a page boundary at
> > + * size / 2. We also don't want to make the size we scan too large,
> > + * otherwise the test can take a long time and cause soft lockups. So
> > + * scan a 1024 byte region across the page boundary.
> > + */
> > + start = size / 2 - 512;
> > + size = 1024;
>
> I don't think it's necessary to do "size / 2" here -- you can just use
> PAGE_SIZE directly and check above that "size == 2*PAGE_SIZE" (not that
> this check is exceptionally necessary -- since there's only one caller
> of this function and it's in the same file).
Michael, in case you resend, can you make my life a little easier and do
it on top of
https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=copy_struct_from_user
please. I have a fix from Aleksa sitting in there laready that _might_
cause a conflict otherwise.
Christian
^ permalink raw reply
* [PATCH v2 1/2] clone3: add CLONE3_CLEAR_SIGHAND
From: Christian Brauner @ 2019-10-11 10:25 UTC (permalink / raw)
To: linux-kernel, Oleg Nesterov, Florian Weimer, libc-alpha
Cc: Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Dietmar Eggemann, Steven Rostedt, Ben Segall, Mel Gorman,
Shuah Khan, Andrew Morton, Michal Hocko, Elena Reshetova,
Thomas Gleixner, Roman Gushchin, Andrea Arcangeli, Al Viro,
Aleksa Sarai, Dmitry V. Levin, linux-kselftest, Christian Brauner
Reset all signal handlers of the child not set to SIG_IGN to SIG_DFL.
Mutually exclusive with CLONE_SIGHAND to not disturb other thread's
signal handler.
In the spirit of closer cooperation between glibc developers and kernel
developers (cf. [2]) this patchset came out of a discussion on the glibc
mailing list for improving posix_spawn() (cf. [1], [3], [4]). Kernel
support for this feature has been explicitly requested by glibc and I
see no reason not to help them with this.
The child helper process on Linux posix_spawn must ensure that no signal
handlers are enabled, so the signal disposition must be either SIG_DFL
or SIG_IGN. However, it requires a sigprocmask to obtain the current
signal mask and at least _NSIG sigaction calls to reset the signal
handlers for each posix_spawn call or complex state tracking that might
lead to data corruption in glibc. Adding this flags lets glibc avoid
these problems.
[1]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00149.html
[3]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00158.html
[4]: https://www.sourceware.org/ml/libc-alpha/2019-10/msg00160.html
[2]: https://lwn.net/Articles/799331/
'[...] by asking for better cooperation with the C-library projects
in general. They should be copied on patches containing ABI
changes, for example. I noted that there are often times where
C-library developers wish the kernel community had done things
differently; how could those be avoided in the future? Members of
the audience suggested that more glibc developers should perhaps
join the linux-api list. The other suggestion was to "copy Florian
on everything".'
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: libc-alpha@sourceware.org
Cc: linux-api@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v1 */
Link: https://lore.kernel.org/r/20191010133518.5420-1-christian.brauner@ubuntu.com
/* v2 */
- Florian Weimer <fweimer@redhat.com>:
- update comment in clone3_args_valid()
---
include/uapi/linux/sched.h | 3 +++
kernel/fork.c | 16 +++++++++++-----
2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index 99335e1f4a27..c583720f689f 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -33,6 +33,9 @@
#define CLONE_NEWNET 0x40000000 /* New network namespace */
#define CLONE_IO 0x80000000 /* Clone io context */
+/* Flags for the clone3() syscall */
+#define CLONE3_CLEAR_SIGHAND 0x100000000ULL /* Clear any signal handler and reset to SIG_DFL. */
+
#ifndef __ASSEMBLY__
/**
* struct clone_args - arguments for the clone3 syscall
diff --git a/kernel/fork.c b/kernel/fork.c
index 1f6c45f6a734..0a0269cb2c18 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1517,6 +1517,11 @@ static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
spin_lock_irq(¤t->sighand->siglock);
memcpy(sig->action, current->sighand->action, sizeof(sig->action));
spin_unlock_irq(¤t->sighand->siglock);
+
+ /* Reset all signal handler not set to SIG_IGN to SIG_DFL. */
+ if (clone_flags & CLONE3_CLEAR_SIGHAND)
+ flush_signal_handlers(tsk, 0);
+
return 0;
}
@@ -2563,11 +2568,8 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
static bool clone3_args_valid(const struct kernel_clone_args *kargs)
{
- /*
- * All lower bits of the flag word are taken.
- * Verify that no other unknown flags are passed along.
- */
- if (kargs->flags & ~CLONE_LEGACY_FLAGS)
+ /* Verify that no unknown flags are passed along. */
+ if (kargs->flags & ~(CLONE_LEGACY_FLAGS | CLONE3_CLEAR_SIGHAND))
return false;
/*
@@ -2577,6 +2579,10 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
if (kargs->flags & (CLONE_DETACHED | CSIGNAL))
return false;
+ if ((kargs->flags & (CLONE_SIGHAND | CLONE3_CLEAR_SIGHAND)) ==
+ (CLONE_SIGHAND | CLONE3_CLEAR_SIGHAND))
+ return false;
+
if ((kargs->flags & (CLONE_THREAD | CLONE_PARENT)) &&
kargs->exit_signal)
return false;
--
2.23.0
^ permalink raw reply related
* [PATCH v2 2/2] tests: test CLONE3_CLEAR_SIGHAND
From: Christian Brauner @ 2019-10-11 10:25 UTC (permalink / raw)
To: linux-kernel, Oleg Nesterov, Florian Weimer, libc-alpha
Cc: Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Dietmar Eggemann, Steven Rostedt, Ben Segall, Mel Gorman,
Shuah Khan, Andrew Morton, Michal Hocko, Elena Reshetova,
Thomas Gleixner, Roman Gushchin, Andrea Arcangeli, Al Viro,
Aleksa Sarai, Dmitry V. Levin, linux-kselftest, Christian Brauner
In-Reply-To: <20191011102537.27502-1-christian.brauner@ubuntu.com>
Test that CLONE3_CLEAR_SIGHAND resets signal handlers to SIG_DFL for the
child process and that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are
mutually exclusive.
Cc: Florian Weimer <fweimer@redhat.com>
Cc: libc-alpha@sourceware.org
Cc: linux-api@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v1 */
Link: https://lore.kernel.org/r/20191010133518.5420-2-christian.brauner@ubuntu.com
/* v2 */
- Christian Brauner <christian.brauner@ubuntu.com>:
- remove unused variable
- reuse variable in child process instead od declaring a new one
- move check for mutual exclusivity of CLONE_SIGHAND and
CLONE3_CLEAR_SIGHAND to top of test before setting up signal
handlers
- rename variables
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/clone3/.gitignore | 1 +
tools/testing/selftests/clone3/Makefile | 7 +
.../selftests/clone3/clone3_clear_sighand.c | 172 ++++++++++++++++++
5 files changed, 182 insertions(+)
create mode 100644 tools/testing/selftests/clone3/.gitignore
create mode 100644 tools/testing/selftests/clone3/Makefile
create mode 100644 tools/testing/selftests/clone3/clone3_clear_sighand.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 55199ef7fa74..582275d85607 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12828,6 +12828,7 @@ S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
F: samples/pidfd/
F: tools/testing/selftests/pidfd/
+F: tools/testing/selftests/clone3/
K: (?i)pidfd
K: (?i)clone3
K: \b(clone_args|kernel_clone_args)\b
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index c3feccb99ff5..6bf7aeb47650 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -4,6 +4,7 @@ TARGETS += bpf
TARGETS += breakpoints
TARGETS += capabilities
TARGETS += cgroup
+TARGETS += clone3
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
new file mode 100644
index 000000000000..6c9f98097774
--- /dev/null
+++ b/tools/testing/selftests/clone3/.gitignore
@@ -0,0 +1 @@
+clone3_clear_sighand
diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
new file mode 100644
index 000000000000..3ecd56ebc99d
--- /dev/null
+++ b/tools/testing/selftests/clone3/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -g -I../../../../usr/include/
+
+TEST_GEN_PROGS := clone3_clear_sighand
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/clone3/clone3_clear_sighand.c b/tools/testing/selftests/clone3/clone3_clear_sighand.c
new file mode 100644
index 000000000000..1a3adc206e74
--- /dev/null
+++ b/tools/testing/selftests/clone3/clone3_clear_sighand.c
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+
+#ifndef CLONE3_CLEAR_SIGHAND
+#define CLONE3_CLEAR_SIGHAND 0x100000000ULL
+#endif
+
+#ifndef __NR_clone3
+#define __NR_clone3 -1
+struct clone_args {
+ __aligned_u64 flags;
+ __aligned_u64 pidfd;
+ __aligned_u64 child_tid;
+ __aligned_u64 parent_tid;
+ __aligned_u64 exit_signal;
+ __aligned_u64 stack;
+ __aligned_u64 stack_size;
+ __aligned_u64 tls;
+};
+#endif
+
+static pid_t sys_clone3(struct clone_args *args, size_t size)
+{
+ return syscall(__NR_clone3, args, size);
+}
+
+static void test_clone3_supported(void)
+{
+ pid_t pid;
+ struct clone_args args = {};
+
+ if (__NR_clone3 < 0)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ /* Set to something that will always cause EINVAL. */
+ args.exit_signal = -1;
+ pid = sys_clone3(&args, sizeof(args));
+ if (!pid)
+ exit(EXIT_SUCCESS);
+
+ if (pid > 0) {
+ wait(NULL);
+ ksft_exit_fail_msg(
+ "Managed to create child process with invalid exit_signal\n");
+ }
+
+ if (errno == ENOSYS)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ ksft_print_msg("clone3() syscall supported\n");
+}
+
+static void nop_handler(int signo)
+{
+}
+
+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 (!WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+}
+
+static void test_clone3_clear_sighand(void)
+{
+ int ret;
+ pid_t pid;
+ struct clone_args args = {};
+ struct sigaction act;
+
+ /*
+ * Check that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
+ * exclusive.
+ */
+ args.flags |= CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND;
+ args.exit_signal = SIGCHLD;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid > 0)
+ ksft_exit_fail_msg(
+ "clone3(CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");
+
+ act.sa_handler = nop_handler;
+ ret = sigemptyset(&act.sa_mask);
+ if (ret < 0)
+ ksft_exit_fail_msg("%s - sigemptyset() failed\n",
+ strerror(errno));
+
+ act.sa_flags = 0;
+
+ /* Register signal handler for SIGUSR1 */
+ ret = sigaction(SIGUSR1, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR1, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Register signal handler for SIGUSR2 */
+ ret = sigaction(SIGUSR2, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR2, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Check that CLONE3_CLEAR_SIGHAND works. */
+ args.flags = CLONE3_CLEAR_SIGHAND;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0)
+ ksft_exit_fail_msg("%s - clone3(CLONE3_CLEAR_SIGHAND) failed\n",
+ strerror(errno));
+
+ if (pid == 0) {
+ ret = sigaction(SIGUSR1, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ ret = sigaction(SIGUSR2, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ exit(EXIT_SUCCESS);
+ }
+
+ ret = wait_for_pid(pid);
+ if (ret)
+ ksft_exit_fail_msg(
+ "Failed to clear signal handler for child process\n");
+
+ ksft_test_result_pass("Cleared signal handlers for child process\n");
+}
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_set_plan(1);
+
+ test_clone3_supported();
+ test_clone3_clear_sighand();
+
+ return ksft_exit_pass();
+}
--
2.23.0
^ permalink raw reply related
* [PATCH v3 1/2] pidfd: show pids for nested pid namespaces in fdinfo
From: Christian Kellner @ 2019-10-11 12:23 UTC (permalink / raw)
To: linux-kernel
Cc: linux-api, Christian Kellner, Christian Brauner, Andrew Morton,
Peter Zijlstra (Intel), Ingo Molnar, Michal Hocko,
Thomas Gleixner, Elena Reshetova, Roman Gushchin,
Andrea Arcangeli, Al Viro, Aleksa Sarai, Dmitry V. Levin
In-Reply-To: <20191009160532.20674-1-ckellner@redhat.com>
From: Christian Kellner <christian@kellner.me>
The fdinfo file for a process file descriptor already contains the
pid of the process in the callers namespaces. Additionally, if pid
namespaces are configured, show the process ids of the process in
all nested namespaces in the same format as in the procfs status
file, i.e. "NSPid:\t%d\%d...". This allows the easy identification
of the processes in nested namespaces.
Signed-off-by: Christian Kellner <christian@kellner.me>
---
Changes in v2:
- Moved into separate function to avoid multiple ifdefs as suggested
by Michal Hocko
Changes in v3:
- Helper function takes struct pid_namespace *ns param and got a new
name
kernel/fork.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/kernel/fork.c b/kernel/fork.c
index bcdf53125210..183950aad82b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1695,12 +1695,27 @@ static int pidfd_release(struct inode *inode, struct file *file)
}
#ifdef CONFIG_PROC_FS
+static inline void print_pidfd_nspid(struct seq_file *m, struct pid *pid,
+ struct pid_namespace *ns)
+{
+#ifdef CONFIG_PID_NS
+ int i;
+
+ seq_puts(m, "\nNSpid:");
+ for (i = ns->level; i <= pid->level; i++) {
+ ns = pid->numbers[i].ns;
+ seq_put_decimal_ull(m, "\t", pid_nr_ns(pid, ns));
+ }
+#endif
+}
+
static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
{
struct pid_namespace *ns = proc_pid_ns(file_inode(m->file));
struct pid *pid = f->private_data;
seq_put_decimal_ull(m, "Pid:\t", pid_nr_ns(pid, ns));
+ print_pidfd_nspid(m, pid, ns);
seq_putc(m, '\n');
}
#endif
--
2.21.0
^ permalink raw reply related
* [PATCH v3 2/2] pidfd: add tests for NSpid info in fdinfo
From: Christian Kellner @ 2019-10-11 12:23 UTC (permalink / raw)
To: linux-kernel
Cc: linux-api, Christian Kellner, Christian Brauner, Shuah Khan,
Andrew Morton, Peter Zijlstra (Intel), Ingo Molnar, Michal Hocko,
Thomas Gleixner, Elena Reshetova, Roman Gushchin,
Andrea Arcangeli, Al Viro, Aleksa Sarai, Dmitry V. Levin,
linux-kselftest
In-Reply-To: <20191011122323.7770-1-ckellner@redhat.com>
From: Christian Kellner <christian@kellner.me>
Add tests that check that if pid namespaces are configured the fdinfo
file of a pidfd contains an NSpid: entry containing the process id
in the current and additionally all nested namespaces.
Signed-off-by: Christian Kellner <christian@kellner.me>
---
tools/testing/selftests/pidfd/Makefile | 2 +-
tools/testing/selftests/pidfd/pidfd.h | 12 +++
.../selftests/pidfd/pidfd_fdinfo_test.c | 98 +++++++++++++++++++
tools/testing/selftests/pidfd/pidfd_test.c | 12 ---
4 files changed, 111 insertions(+), 13 deletions(-)
create mode 100644 tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index 7550f08822a3..43db1b98e845 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
CFLAGS += -g -I../../../../usr/include/ -pthread
-TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test pidfd_wait
+TEST_GEN_PROGS := pidfd_test pidfd_fdinfo_test pidfd_open_test pidfd_poll_test pidfd_wait
include ../lib.mk
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
index c6bc68329f4b..2946d788645b 100644
--- a/tools/testing/selftests/pidfd/pidfd.h
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -84,4 +84,16 @@ static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
}
+static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *))
+{
+ size_t stack_size = 1024;
+ char *stack[1024] = { 0 };
+
+#ifdef __ia64__
+ return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd);
+#else
+ return clone(fn, stack + stack_size, flags | SIGCHLD, NULL, pidfd);
+#endif
+}
+
#endif /* __PIDFD_H */
diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
new file mode 100644
index 000000000000..fbae502ad8ad
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/types.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/wait.h>
+
+#include "pidfd.h"
+#include "../kselftest.h"
+
+static int child_fdinfo_nspid_test(void *args)
+{
+ ksft_print_msg("Child: pid %d\n", getpid());
+ return 0;
+}
+
+static int compare_fdinfo_nspid(int pidfd, char *expect, size_t len)
+{
+ char path[512];
+ FILE *f;
+ size_t n = 0;
+ ssize_t k;
+ char *line = NULL;
+ int r = -1;
+
+ snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd);
+
+ f = fopen(path, "re");
+ if (!f)
+ return -1;
+
+ while ((k = getline(&line, &n, f)) != -1) {
+ if (strncmp(line, "NSpid:", 6))
+ continue;
+
+ line[k - 1] = '\0';
+ ksft_print_msg("Child: fdinfo NSpid line: '%s'.\n", line);
+ r = strncmp(line + 6, expect, len);
+ break;
+ }
+
+ free(line);
+ fclose(f);
+
+ return r;
+}
+
+static void test_pidfd_fdinfo_nspid(void)
+{
+ char expect[512];
+ int pid, pidfd = 0;
+ int n, r;
+ const char *test_name = "pidfd check for NSpid information in fdinfo";
+
+ pid = pidfd_clone(CLONE_PIDFD | CLONE_NEWPID | CLONE_NEWUSER, &pidfd,
+ child_fdinfo_nspid_test);
+ if (pid < 0)
+ ksft_exit_fail_msg(
+ "%s test: pidfd_clone failed (ret %d, errno %d)\n",
+ test_name, pid, errno);
+
+ ksft_print_msg("Parent: child-pid: %d\n", pid);
+
+ /* The child will have pid 1 in the new pid namespace,
+ * so the line must be 'NSPid:\t<pid>\t1'
+ */
+ n = snprintf(expect, sizeof(expect), "\t%d\t%d", pid, 1);
+ r = compare_fdinfo_nspid(pidfd, expect, n);
+
+ (void)close(pidfd);
+
+ if (wait_for_pid(pid))
+ ksft_exit_fail_msg(
+ "%s test: waitpid failed (ret %d, errno %d)\n",
+ test_name, r, errno);
+
+ if (r != 0)
+ ksft_exit_fail_msg("%s test: Failed\n", test_name);
+ else
+ ksft_test_result_pass("%s test: Passed\n", test_name);
+}
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_set_plan(1);
+
+ test_pidfd_fdinfo_nspid();
+
+ return ksft_exit_pass();
+}
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 7aff2d3b42c0..9cf0b6b3e389 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -27,18 +27,6 @@
#define MAX_EVENTS 5
-static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *))
-{
- size_t stack_size = 1024;
- char *stack[1024] = { 0 };
-
-#ifdef __ia64__
- return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd);
-#else
- return clone(fn, stack + stack_size, flags | SIGCHLD, NULL, pidfd);
-#endif
-}
-
static int signal_received;
static void set_signal_received_on_sigusr1(int sig)
--
2.21.0
^ permalink raw reply related
* Re: [PATCH v3 1/2] pidfd: show pids for nested pid namespaces in fdinfo
From: Christian Brauner @ 2019-10-11 13:17 UTC (permalink / raw)
To: Christian Kellner
Cc: linux-kernel, linux-api, Christian Kellner, Andrew Morton,
Peter Zijlstra (Intel), Ingo Molnar, Michal Hocko,
Thomas Gleixner, Elena Reshetova, Roman Gushchin,
Andrea Arcangeli, Al Viro, Aleksa Sarai, Dmitry V. Levin
In-Reply-To: <20191011122323.7770-1-ckellner@redhat.com>
On Fri, Oct 11, 2019 at 02:23:20PM +0200, Christian Kellner wrote:
> From: Christian Kellner <christian@kellner.me>
>
> The fdinfo file for a process file descriptor already contains the
> pid of the process in the callers namespaces. Additionally, if pid
> namespaces are configured, show the process ids of the process in
> all nested namespaces in the same format as in the procfs status
> file, i.e. "NSPid:\t%d\%d...". This allows the easy identification
> of the processes in nested namespaces.
>
> Signed-off-by: Christian Kellner <christian@kellner.me>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
If I hear no technical objections I'll pick this up targeting the 5.5
merge window.
Thanks!
Christian
^ permalink raw reply
* Re: [PATCH v3 2/2] pidfd: add tests for NSpid info in fdinfo
From: Christian Brauner @ 2019-10-11 13:18 UTC (permalink / raw)
To: Christian Kellner
Cc: linux-kernel, linux-api, Christian Kellner, Shuah Khan,
Andrew Morton, Peter Zijlstra (Intel), Ingo Molnar, Michal Hocko,
Thomas Gleixner, Elena Reshetova, Roman Gushchin,
Andrea Arcangeli, Al Viro, Aleksa Sarai, Dmitry V. Levin,
linux-kselftest
In-Reply-To: <20191011122323.7770-2-ckellner@redhat.com>
On Fri, Oct 11, 2019 at 02:23:21PM +0200, Christian Kellner wrote:
> From: Christian Kellner <christian@kellner.me>
>
> Add tests that check that if pid namespaces are configured the fdinfo
> file of a pidfd contains an NSpid: entry containing the process id
> in the current and additionally all nested namespaces.
>
> Signed-off-by: Christian Kellner <christian@kellner.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Shuah, can I get an Ack for you from this. If you have no objections I'd
queue up this patchset for the 5.5 merge window.
Thanks!
Christian
^ permalink raw reply
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