* [PATCH v2 1/2] powerpc/rtas: Restrict RTAS requests from userspace
From: Andrew Donnellan @ 2020-08-20 4:45 UTC (permalink / raw)
To: linuxppc-dev; +Cc: nathanl, leobras.c, stable, dja
A number of userspace utilities depend on making calls to RTAS to retrieve
information and update various things.
The existing API through which we expose RTAS to userspace exposes more
RTAS functionality than we actually need, through the sys_rtas syscall,
which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they
want with arbitrary arguments.
Many RTAS calls take the address of a buffer as an argument, and it's up to
the caller to specify the physical address of the buffer as an argument. We
allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can
access, and then expose the physical address and size of this buffer in
/proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address,
poke at the buffer using /dev/mem, and pass an address in the RMO buffer to
the RTAS call.
However, there's nothing stopping the caller from specifying whatever
address they want in the RTAS call, and it's easy to construct a series of
RTAS calls that can overwrite arbitrary bytes (even without /dev/mem
access).
Additionally, there are some RTAS calls that do potentially dangerous
things and for which there are no legitimate userspace use cases.
In the past, this would not have been a particularly big deal as it was
assumed that root could modify all system state freely, but with Secure
Boot and lockdown we need to care about this.
We can't fundamentally change the ABI at this point, however we can address
this by implementing a filter that checks RTAS calls against a list
of permitted calls and forces the caller to use addresses within the RMO
buffer.
The list is based off the list of calls that are used by the librtas
userspace library, and has been tested with a number of existing userspace
RTAS utilities. For compatibility with any applications we are not aware of
that require other calls, the filter can be turned off at build time.
Reported-by: Daniel Axtens <dja@axtens.net>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v1->v2:
- address comments from mpe
- shorten the names of some struct members
- make the filter array static/ro_after_init, use const char *
- genericise the fixed buffer size cases
- simplify/get rid of some of the error printing
- get rid of rtas_token_name()
---
arch/powerpc/Kconfig | 13 ++++
arch/powerpc/kernel/rtas.c | 153 +++++++++++++++++++++++++++++++++++++
2 files changed, 166 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..8dd42b82379b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -989,6 +989,19 @@ config PPC_SECVAR_SYSFS
read/write operations on these variables. Say Y if you have
secure boot enabled and want to expose variables to userspace.
+config PPC_RTAS_FILTER
+ bool "Enable filtering of RTAS syscalls"
+ default y
+ depends on PPC_RTAS
+ help
+ The RTAS syscall API has security issues that could be used to
+ compromise system integrity. This option enforces restrictions on the
+ RTAS calls and arguments passed by userspace programs to mitigate
+ these issues.
+
+ Say Y unless you know what you are doing and the filter is causing
+ problems for you.
+
endmenu
config ISA_DMA_API
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 806d554ce357..954f41676f69 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -992,6 +992,147 @@ struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
return NULL;
}
+#ifdef CONFIG_PPC_RTAS_FILTER
+
+/*
+ * The sys_rtas syscall, as originally designed, allows root to pass
+ * arbitrary physical addresses to RTAS calls. A number of RTAS calls
+ * can be abused to write to arbitrary memory and do other things that
+ * are potentially harmful to system integrity, and thus should only
+ * be used inside the kernel and not exposed to userspace.
+ *
+ * All known legitimate users of the sys_rtas syscall will only ever
+ * pass addresses that fall within the RMO buffer, and use a known
+ * subset of RTAS calls.
+ *
+ * Accordingly, we filter RTAS requests to check that the call is
+ * permitted, and that provided pointers fall within the RMO buffer.
+ * The rtas_filters list contains an entry for each permitted call,
+ * with the indexes of the parameters which are expected to contain
+ * addresses and sizes of buffers allocated inside the RMO buffer.
+ */
+struct rtas_filter {
+ const char *name;
+ int token;
+ /* Indexes into the args buffer, -1 if not used */
+ int buf_idx1;
+ int size_idx1;
+ int buf_idx2;
+ int size_idx2;
+
+ int fixed_size;
+};
+
+static struct rtas_filter rtas_filters[] __ro_after_init = {
+ { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
+ { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
+ { "display-character", -1, -1, -1, -1, -1 },
+ { "ibm,display-message", -1, 0, -1, -1, -1 },
+ { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
+ { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
+ { "ibm,open-errinct", -1, -1, -1, -1, -1 },
+ { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
+ { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
+ { "ibm,get-indices", -1, 2, 3, -1, -1 },
+ { "get-power-level", -1, -1, -1, -1, -1 },
+ { "get-sensor-state", -1, -1, -1, -1, -1 },
+ { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
+ { "get-time-of-day", -1, -1, -1, -1, -1 },
+ { "ibm,get-vpd", -1, 0, -1, 1, 2 },
+ { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
+ { "ibm,platform-dump", -1, 4, 5, -1, -1 },
+ { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
+ { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
+ { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
+ { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
+ { "set-indicator", -1, -1, -1, -1, -1 },
+ { "set-power-level", -1, -1, -1, -1, -1 },
+ { "set-time-for-power-on", -1, -1, -1, -1, -1 },
+ { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
+ { "set-time-of-day", -1, -1, -1, -1, -1 },
+ { "ibm,suspend-me", -1, -1, -1, -1, -1 },
+ { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
+ { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
+ { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
+};
+
+static bool in_rmo_buf(u32 base, u32 end)
+{
+ return base >= rtas_rmo_buf &&
+ base < (rtas_rmo_buf + RTAS_RMOBUF_MAX) &&
+ base <= end &&
+ end >= rtas_rmo_buf &&
+ end < (rtas_rmo_buf + RTAS_RMOBUF_MAX);
+}
+
+static bool block_rtas_call(int token, int nargs,
+ struct rtas_args *args)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
+ struct rtas_filter *f = &rtas_filters[i];
+ u32 base, size, end;
+
+ if (token != f->token)
+ continue;
+
+ if (f->buf_idx1 != -1) {
+ base = be32_to_cpu(args->args[f->buf_idx1]);
+ if (f->size_idx1 != -1)
+ size = be32_to_cpu(args->args[f->size_idx1]);
+ else if (f->fixed_size)
+ size = f->fixed_size;
+ else
+ size = 1;
+
+ end = base + size - 1;
+ if (!in_rmo_buf(base, end))
+ goto err;
+ }
+
+ if (f->buf_idx2 != -1) {
+ base = be32_to_cpu(args->args[f->buf_idx2]);
+ if (f->size_idx2 != -1)
+ size = be32_to_cpu(args->args[f->size_idx2]);
+ else if (f->fixed_size)
+ size = f->fixed_size;
+ else
+ size = 1;
+ end = base + size - 1;
+
+ /*
+ * Special case for ibm,configure-connector where the
+ * address can be 0
+ */
+ if (!strcmp(f->name, "ibm,configure-connector") &&
+ base == 0)
+ return false;
+
+ if (!in_rmo_buf(base, end))
+ goto err;
+ }
+
+ return false;
+ }
+
+err:
+ pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
+ pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
+ token, nargs, current->comm);
+ return true;
+}
+
+#else
+
+static bool block_rtas_call(int token, int nargs,
+ struct rtas_args *args)
+{
+ return false;
+}
+
+#endif /* CONFIG_PPC_RTAS_FILTER */
+
/* We assume to be passed big endian arguments */
SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
{
@@ -1029,6 +1170,9 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
args.rets = &args.args[nargs];
memset(args.rets, 0, nret * sizeof(rtas_arg_t));
+ if (block_rtas_call(token, nargs, &args))
+ return -EINVAL;
+
/* Need to handle ibm,suspend_me call specially */
if (token == ibm_suspend_me_token) {
@@ -1090,6 +1234,9 @@ void __init rtas_initialize(void)
unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
u32 base, size, entry;
int no_base, no_size, no_entry;
+#ifdef CONFIG_PPC_RTAS_FILTER
+ int i;
+#endif
/* Get RTAS dev node and fill up our "rtas" structure with infos
* about it.
@@ -1129,6 +1276,12 @@ void __init rtas_initialize(void)
#ifdef CONFIG_RTAS_ERROR_LOGGING
rtas_last_error_token = rtas_token("rtas-last-error");
#endif
+
+#ifdef CONFIG_PPC_RTAS_FILTER
+ for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
+ rtas_filters[i].token = rtas_token(rtas_filters[i].name);
+ }
+#endif
}
int __init early_init_dt_scan_rtas(unsigned long node,
--
2.20.1
^ permalink raw reply related
* [PATCH v2 2/2] selftests/powerpc: Add a rtas_filter selftest
From: Andrew Donnellan @ 2020-08-20 4:45 UTC (permalink / raw)
To: linuxppc-dev; +Cc: nathanl, leobras.c, dja
In-Reply-To: <20200820044512.7543-1-ajd@linux.ibm.com>
Add a selftest to test the basic functionality of CONFIG_RTAS_FILTER.
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v1->v2:
- new patch
---
.../selftests/powerpc/syscalls/Makefile | 2 +-
.../selftests/powerpc/syscalls/rtas_filter.c | 285 ++++++++++++++++++
2 files changed, 286 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/syscalls/rtas_filter.c
diff --git a/tools/testing/selftests/powerpc/syscalls/Makefile b/tools/testing/selftests/powerpc/syscalls/Makefile
index 01b22775ca87..b63f8459c704 100644
--- a/tools/testing/selftests/powerpc/syscalls/Makefile
+++ b/tools/testing/selftests/powerpc/syscalls/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-TEST_GEN_PROGS := ipc_unmuxed
+TEST_GEN_PROGS := ipc_unmuxed rtas_filter
CFLAGS += -I../../../../../usr/include
diff --git a/tools/testing/selftests/powerpc/syscalls/rtas_filter.c b/tools/testing/selftests/powerpc/syscalls/rtas_filter.c
new file mode 100644
index 000000000000..3b0ac4ff64e5
--- /dev/null
+++ b/tools/testing/selftests/powerpc/syscalls/rtas_filter.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2005-2020 IBM Corporation.
+ *
+ * Includes code from librtas (https://github.com/ibm-power-utilities/librtas/)
+ */
+
+#include <byteswap.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include "utils.h"
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define cpu_to_be32(x) bswap_32(x)
+#define be32_to_cpu(x) bswap_32(x)
+#else
+#define cpu_to_be32(x) (x)
+#define be32_to_cpu(x) (x)
+#endif
+
+#define RTAS_IO_ASSERT -1098 /* Unexpected I/O Error */
+#define RTAS_UNKNOWN_OP -1099 /* No Firmware Implementation of Function */
+#define BLOCK_SIZE 4096
+#define PAGE_SIZE 4096
+#define MAX_PAGES 64
+
+static const char *ofdt_rtas_path = "/proc/device-tree/rtas";
+
+typedef __be32 uint32_t;
+struct rtas_args {
+ __be32 token;
+ __be32 nargs;
+ __be32 nret;
+ __be32 args[16];
+ __be32 *rets; /* Pointer to return values in args[]. */
+};
+
+struct region {
+ uint64_t addr;
+ uint32_t size;
+ struct region *next;
+};
+
+int read_entire_file(int fd, char **buf, size_t *len)
+{
+ size_t buf_size = 0;
+ size_t off = 0;
+ int rc;
+
+ *buf = NULL;
+ do {
+ buf_size += BLOCK_SIZE;
+ if (*buf == NULL)
+ *buf = malloc(buf_size);
+ else
+ *buf = realloc(*buf, buf_size);
+
+ if (*buf == NULL)
+ return -ENOMEM;
+
+ rc = read(fd, *buf + off, BLOCK_SIZE);
+ if (rc < 0)
+ return -EIO;
+
+ off += rc;
+ } while (rc == BLOCK_SIZE);
+
+ if (len)
+ *len = off;
+
+ return 0;
+}
+
+static int open_prop_file(const char *prop_path, const char *prop_name, int *fd)
+{
+ char *path;
+ int len;
+
+ /* allocate enough for two string, a slash and trailing NULL */
+ len = strlen(prop_path) + strlen(prop_name) + 1 + 1;
+ path = malloc(len);
+ if (path == NULL)
+ return -ENOMEM;
+
+ snprintf(path, len, "%s/%s", prop_path, prop_name);
+
+ *fd = open(path, O_RDONLY);
+ free(path);
+ if (*fd < 0)
+ return -errno;
+
+ return 0;
+}
+
+static int get_property(const char *prop_path, const char *prop_name,
+ char **prop_val, size_t *prop_len)
+{
+ int rc, fd;
+
+ rc = open_prop_file(prop_path, prop_name, &fd);
+ if (rc)
+ return rc;
+
+ rc = read_entire_file(fd, prop_val, prop_len);
+ close(fd);
+
+ return rc;
+}
+
+int rtas_token(const char *call_name)
+{
+ char *prop_buf = NULL;
+ size_t len;
+ int rc;
+
+ rc = get_property(ofdt_rtas_path, call_name, &prop_buf, &len);
+ if (rc < 0) {
+ rc = RTAS_UNKNOWN_OP;
+ goto err;
+ }
+
+ rc = be32_to_cpu(*(int *)prop_buf);
+
+err:
+ free(prop_buf);
+ return rc;
+}
+
+static int read_kregion_bounds(struct region *kregion)
+{
+ char *buf;
+ int fd;
+ int rc;
+
+ fd = open("/proc/ppc64/rtas/rmo_buffer", O_RDONLY);
+ if (fd < 0) {
+ printf("Could not open rmo_buffer file\n");
+ return RTAS_IO_ASSERT;
+ }
+
+ rc = read_entire_file(fd, &buf, NULL);
+ close(fd);
+ if (rc) {
+ free(buf);
+ return rc;
+ }
+
+ sscanf(buf, "%" SCNx64 " %x", &kregion->addr, &kregion->size);
+ free(buf);
+
+ if (!(kregion->size && kregion->addr) ||
+ (kregion->size > (PAGE_SIZE * MAX_PAGES))) {
+ printf("Unexpected kregion bounds\n");
+ return RTAS_IO_ASSERT;
+ }
+
+ return 0;
+}
+
+static int rtas_call(const char *name, int nargs,
+ int nrets, ...)
+{
+ struct rtas_args args;
+ __be32 *rets[16];
+ int i, rc, token;
+ va_list ap;
+
+ va_start(ap, nrets);
+
+ token = rtas_token(name);
+ if (token == RTAS_UNKNOWN_OP) {
+ // We don't care if the call doesn't exist
+ printf("call '%s' not available, skipping...", name);
+ rc = RTAS_UNKNOWN_OP;
+ goto err;
+ }
+
+ args.token = cpu_to_be32(token);
+ args.nargs = cpu_to_be32(nargs);
+ args.nret = cpu_to_be32(nrets);
+
+ for (i = 0; i < nargs; i++)
+ args.args[i] = (__be32) va_arg(ap, unsigned long);
+
+ for (i = 0; i < nrets; i++)
+ rets[i] = (__be32 *) va_arg(ap, unsigned long);
+
+ rc = syscall(__NR_rtas, &args);
+ if (rc) {
+ rc = -errno;
+ goto err;
+ }
+
+ if (nrets) {
+ *(rets[0]) = be32_to_cpu(args.args[nargs]);
+
+ for (i = 1; i < nrets; i++) {
+ *(rets[i]) = args.args[nargs + i];
+ }
+ }
+
+err:
+ va_end(ap);
+ return rc;
+}
+
+static int test(void)
+{
+ struct region rmo_region;
+ uint64_t rmo_start;
+ uint64_t rmo_end;
+ __be32 rets[1];
+ int rc;
+
+ // Test a legitimate harmless call
+ // Expected: call succeeds
+ printf("Test a permitted call, no parameters... ");
+ rc = rtas_call("get-time-of-day", 0, 1, rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != 0 && rc != RTAS_UNKNOWN_OP);
+
+ // Test a prohibited call
+ // Expected: call returns -EINVAL
+ printf("Test a prohibited call... ");
+ rc = rtas_call("nvram-fetch", 0, 1, rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
+
+ // Get RMO
+ rc = read_kregion_bounds(&rmo_region);
+ if (rc) {
+ printf("Couldn't read RMO region bounds, skipping remaining cases\n");
+ return 0;
+ }
+ rmo_start = rmo_region.addr;
+ rmo_end = rmo_start + rmo_region.size - 1;
+ printf("RMO range: %08lx - %08lx\n", rmo_start, rmo_end);
+
+ // Test a permitted call, user-supplied size, buffer inside RMO
+ // Expected: call succeeds
+ printf("Test a permitted call, user-supplied size, buffer inside RMO... ");
+ rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_start),
+ cpu_to_be32(rmo_end - rmo_start + 1), rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != 0 && rc != RTAS_UNKNOWN_OP);
+
+ // Test a permitted call, user-supplied size, buffer start outside RMO
+ // Expected: call returns -EINVAL
+ printf("Test a permitted call, user-supplied size, buffer start outside RMO... ");
+ rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_end + 1),
+ cpu_to_be32(4000), rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
+
+ // Test a permitted call, user-supplied size, buffer end outside RMO
+ // Expected: call returns -EINVAL
+ printf("Test a permitted call, user-supplied size, buffer end outside RMO... ");
+ rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_start),
+ cpu_to_be32(rmo_end - rmo_start + 2), rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
+
+ // Test a permitted call, fixed size, buffer end outside RMO
+ // Expected: call returns -EINVAL
+ printf("Test a permitted call, fixed size, buffer end outside RMO... ");
+ rc = rtas_call("ibm,configure-connector", 2, 1, cpu_to_be32(rmo_end - 4000), 0, rets);
+ printf("rc: %d\n", rc);
+ FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(test, "rtas_filter");
+}
--
2.20.1
^ permalink raw reply related
* Re: [PATCH v2 04/13] mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support.
From: Aneesh Kumar K.V @ 2020-08-20 5:31 UTC (permalink / raw)
To: kernel test robot, linux-mm, akpm
Cc: kbuild-all, linuxppc-dev, Anshuman Khandual
In-Reply-To: <202008200034.CGkDyB26%lkp@intel.com>
kernel test robot <lkp@intel.com> writes:
> Hi "Aneesh,
>
> I love your patch! Yet something to improve:
>
> [auto build test ERROR on hnaz-linux-mm/master]
> [also build test ERROR on powerpc/next linus/master v5.9-rc1 next-20200819]
> [cannot apply to mmotm/master]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
>
> url: https://github.com/0day-ci/linux/commits/Aneesh-Kumar-K-V/mm-debug_vm_pgtable-fixes/20200819-213446
> base: https://github.com/hnaz/linux-mm master
> config: i386-randconfig-s002-20200818 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> reproduce:
> # apt-get install sparse
> # sparse version: v0.6.2-183-gaa6ede3b-dirty
> # save the attached .config to linux build tree
> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>>> arch/x86/mm/ioremap.c:484:12: error: redefinition of 'arch_ioremap_p4d_supported'
> 484 | int __init arch_ioremap_p4d_supported(void)
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~
> In file included from arch/x86/mm/ioremap.c:12:
> include/linux/io.h:41:19: note: previous definition of 'arch_ioremap_p4d_supported' was here
> 41 | static inline int arch_ioremap_p4d_supported(void)
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~
I guess trying to work this out without using #ifdef is complex. I ended
up with the below
1 file changed, 12 insertions(+), 2 deletions(-)
mm/debug_vm_pgtable.c | 14 ++++++++++++--
modified mm/debug_vm_pgtable.c
@@ -202,11 +202,12 @@ static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(!pmd_leaf(pmd));
}
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
{
pmd_t pmd;
- if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ if (!arch_ioremap_pmd_supported())
return;
pr_debug("Validating PMD huge\n");
@@ -220,6 +221,10 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
pmd = READ_ONCE(*pmdp);
WARN_ON(!pmd_none(pmd));
}
+#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
+#endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+
static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
{
@@ -316,11 +321,12 @@ static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(!pud_leaf(pud));
}
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
{
pud_t pud;
- if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ if (!arch_ioremap_pud_supported())
return;
pr_debug("Validating PUD huge\n");
@@ -334,6 +340,10 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
pud = READ_ONCE(*pudp);
WARN_ON(!pud_none(pud));
}
+#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
+#endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
static void __init pud_advanced_tests(struct mm_struct *mm,
^ permalink raw reply
* [PATCH v2] powerpc/pseries: Do not initiate shutdown when system is running on UPS
From: Vasant Hegde @ 2020-08-20 6:18 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Vasant Hegde, Tyrel Datwyler, stable
As per PAPR we have to look for both EPOW sensor value and event modifier to
identify type of event and take appropriate action.
Sensor value = 3 (EPOW_SYSTEM_SHUTDOWN) schedule system to be shutdown after
OS defined delay (default 10 mins).
EPOW Event Modifier for sensor value = 3:
We have to initiate immediate shutdown for most of the event modifier except
value = 2 (system running on UPS).
Checking with firmware document its clear that we have to wait for predefined
time before initiating shutdown. If power is restored within time we should
cancel the shutdown process. I think commit 79872e35 accidently enabled
immediate poweroff for EPOW_SHUTDOWN_ON_UPS event.
We have user space tool (rtas_errd) on LPAR to monitor for EPOW_SHUTDOWN_ON_UPS.
Once it gets event it initiates shutdown after predefined time. Also starts
monitoring for any new EPOW events. If it receives "Power restored" event
before predefined time it will cancel the shutdown. Otherwise after
predefined time it will shutdown the system.
Fixes: 79872e35 (powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown)
Cc: stable@vger.kernel.org # v4.0+
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
---
Changes in v2:
- Updated patch description based on mpe, Tyrel comment.
-Vasant
arch/powerpc/platforms/pseries/ras.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index f3736fcd98fc..13c86a292c6d 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -184,7 +184,6 @@ static void handle_system_shutdown(char event_modifier)
case EPOW_SHUTDOWN_ON_UPS:
pr_emerg("Loss of system power detected. System is running on"
" UPS/battery. Check RTAS error log for details\n");
- orderly_poweroff(true);
break;
case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
--
2.26.2
^ permalink raw reply related
* Re: [PATCH] powerpc/powernv/pci: Fix typo when releasing DMA resources
From: Frederic Barrat @ 2020-08-20 7:39 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev, oohall
In-Reply-To: <874koyhrwm.fsf@mpe.ellerman.id.au>
Le 20/08/2020 à 06:18, Michael Ellerman a écrit :
> I changed the subject to:
>
> powerpc/powernv/pci: Fix possible crash when releasing DMA resources
Much better, thanks!
Fred
^ permalink raw reply
* Re: [PATCH] kernel/watchdog: fix warning -Wunused-variable for watchdog_allowed_mask in ppc64
From: Petr Mladek @ 2020-08-20 11:30 UTC (permalink / raw)
To: Balamuruhan S
Cc: ravi.bangoria, peterz, gpiccoli, linux-kernel, rdna,
Jisheng.Zhang, viro, tglx, linuxppc-dev, naveen.n.rao, sandipan
In-Reply-To: <20200814133330.210093-1-bala24@linux.ibm.com>
On Fri 2020-08-14 19:03:30, Balamuruhan S wrote:
> In ppc64 config if `CONFIG_SOFTLOCKUP_DETECTOR` is not set then it
> warns for unused declaration of `watchdog_allowed_mask` while building,
> move the declaration inside ifdef later in the code.
>
> ```
> kernel/watchdog.c:47:23: warning: ‘watchdog_allowed_mask’ defined but not used [-Wunused-variable]
> static struct cpumask watchdog_allowed_mask __read_mostly;
> ```
>
> Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
> ---
> kernel/watchdog.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/watchdog.c b/kernel/watchdog.c
> index 5abb5b22ad13..33c9b8a3d51b 100644
> --- a/kernel/watchdog.c
> +++ b/kernel/watchdog.c
> @@ -44,7 +44,6 @@ int __read_mostly soft_watchdog_user_enabled = 1;
> int __read_mostly watchdog_thresh = 10;
> static int __read_mostly nmi_watchdog_available;
>
> -static struct cpumask watchdog_allowed_mask __read_mostly;
>
> struct cpumask watchdog_cpumask __read_mostly;
> unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
> @@ -166,6 +165,7 @@ int __read_mostly sysctl_softlockup_all_cpu_backtrace;
> unsigned int __read_mostly softlockup_panic =
> CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
>
> +static struct cpumask watchdog_allowed_mask __read_mostly;
I could confirm that the variable is used only in code that is built
when CONFIG_SOFTLOCKUP_DETECTOR is enabled.
Note that the problem can't be seen on x86. There the softlockup
detector is enforced together with hardloclup detector via
via HARDLOCKUP_DETECTOR_PERF.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Best Regards,
Petr
^ permalink raw reply
* Re: [PATCH v2] powerpc/pseries: Do not initiate shutdown when system is running on UPS
From: Michael Ellerman @ 2020-08-20 12:57 UTC (permalink / raw)
To: Vasant Hegde, linuxppc-dev; +Cc: Vasant Hegde, Tyrel Datwyler, stable
In-Reply-To: <20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com>
Vasant Hegde <hegdevasant@linux.vnet.ibm.com> writes:
> As per PAPR we have to look for both EPOW sensor value and event modifier to
> identify type of event and take appropriate action.
>
> Sensor value = 3 (EPOW_SYSTEM_SHUTDOWN) schedule system to be shutdown after
> OS defined delay (default 10 mins).
>
> EPOW Event Modifier for sensor value = 3:
> We have to initiate immediate shutdown for most of the event modifier except
> value = 2 (system running on UPS).
>
> Checking with firmware document its clear that we have to wait for predefined
> time before initiating shutdown. If power is restored within time we should
> cancel the shutdown process. I think commit 79872e35 accidently enabled
> immediate poweroff for EPOW_SHUTDOWN_ON_UPS event.
It's not that clear to me :)
LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes":
SYSTEM_SHUTDOWN 3
The system must be shut down. An EPOW-aware OS logs the EPOW error
log information, then schedules the system to be shut down to begin
after an OS defined delay internal (default is 10 minutes.)
And then in section 10.3.2.2.8 there is table 146 "Platform Event Log
Format, Version 6, EPOW Section", which includes the "EPOW Event
Modifier":
For EPOW sensor value = 3
0x01 = Normal system shutdown with no additional delay
0x02 = Loss of utility power, system is running on UPS/Battery
0x03 = Loss of system critical functions, system should be shutdown
0x04 = Ambient temperature too high
All other values = reserved
There is also section 7.3.6.4 which includes a note saying:
2. The report that a system needs to be shutdown due to running under
a UPS would be given by the platform as an EPOW event with EPOW event
modifier being given as, 0x02 = Loss of utility power, system is
running on UPS/Battery, as described in section Section 10.3.2.2.8‚
“Platform Event Log Format, EPOW Section‚” on page 308.
So the only mention of the 10 minutes is in relation to all
SYSTEM_SHUTDOWN events. ie. according to that we should not be doing an
immediate shutdown for any of the events.
> We have user space tool (rtas_errd) on LPAR to monitor for EPOW_SHUTDOWN_ON_UPS.
> Once it gets event it initiates shutdown after predefined time. Also starts
> monitoring for any new EPOW events. If it receives "Power restored" event
> before predefined time it will cancel the shutdown. Otherwise after
> predefined time it will shutdown the system.
What event are you referring to as the "Power restored" event? AFAICS
PAPR just says we "may" receive an EPOW_RESET.
I can't see anything else about what we're supposed to do if power is
restored.
Anyway I'm not opposed to the change, but I don't think it's correct to
say that PAPR defines the behaviour.
Rather we used to implement a certain behaviour, and we have at least
one customer who relies on that old behaviour and dislikes the new
behaviour. It's also generally good to defer decisions like this to
userspace, so that administrators can customise the behaviour.
Anyway I'll massage the change log a bit to incorporate some of the
above and apply it.
cheers
> Fixes: 79872e35 (powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown)
> Cc: stable@vger.kernel.org # v4.0+
> Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
> ---
> Changes in v2:
> - Updated patch description based on mpe, Tyrel comment.
>
> -Vasant
> arch/powerpc/platforms/pseries/ras.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
> index f3736fcd98fc..13c86a292c6d 100644
> --- a/arch/powerpc/platforms/pseries/ras.c
> +++ b/arch/powerpc/platforms/pseries/ras.c
> @@ -184,7 +184,6 @@ static void handle_system_shutdown(char event_modifier)
> case EPOW_SHUTDOWN_ON_UPS:
> pr_emerg("Loss of system power detected. System is running on"
> " UPS/battery. Check RTAS error log for details\n");
> - orderly_poweroff(true);
> break;
>
> case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
> --
> 2.26.2
^ permalink raw reply
* Re: [PATCH] powerpc/powernv/pci: Fix typo when releasing DMA resources
From: Michael Ellerman @ 2020-08-20 13:31 UTC (permalink / raw)
To: oohall, linuxppc-dev, Frederic Barrat
In-Reply-To: <20200819130741.16769-1-fbarrat@linux.ibm.com>
On Wed, 19 Aug 2020 15:07:41 +0200, Frederic Barrat wrote:
> Fix typo introduced during recent code cleanup, which could lead to
> silently not freeing resources or oops message (on PCI hotplug or CAPI
> reset).
> Only impacts ioda2, the code path for ioda1 is correct.
Applied to powerpc/fixes.
[1/1] powerpc/powernv/pci: Fix possible crash when releasing DMA resources
https://git.kernel.org/powerpc/c/e17a7c0e0aebb956719ce2a8465f649859c2da7d
cheers
^ permalink raw reply
* Re: [PATCH] powerpc/perf: Account for interrupts during PMC overflow for an invalid SIAR check
From: Michael Ellerman @ 2020-08-20 13:31 UTC (permalink / raw)
To: mpe, Athira Rajeev; +Cc: aik, maddy, linuxppc-dev
In-Reply-To: <1596717992-7321-1-git-send-email-atrajeev@linux.vnet.ibm.com>
On Thu, 6 Aug 2020 08:46:32 -0400, Athira Rajeev wrote:
> Performance monitor interrupt handler checks if any counter has overflown
> and calls `record_and_restart` in core-book3s which invokes
> `perf_event_overflow` to record the sample information.
> Apart from creating sample, perf_event_overflow also does the interrupt
> and period checks via perf_event_account_interrupt.
>
> Currently we record information only if the SIAR valid bit is set
> ( using `siar_valid` check ) and hence the interrupt check.
> But it is possible that we do sampling for some events that are not
> generating valid SIAR and hence there is no chance to disable the event
> if interrupts is more than max_samples_per_tick. This leads to soft lockup.
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/perf: Fix soft lockups due to missed interrupt accounting
https://git.kernel.org/powerpc/c/17899eaf88d689529b866371344c8f269ba79b5f
cheers
^ permalink raw reply
* Re: [PATCH v2] powerpc/pseries: Do not initiate shutdown when system is running on UPS
From: Michael Ellerman @ 2020-08-20 13:31 UTC (permalink / raw)
To: linuxppc-dev, Vasant Hegde; +Cc: Tyrel Datwyler, stable
In-Reply-To: <20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com>
On Thu, 20 Aug 2020 11:48:44 +0530, Vasant Hegde wrote:
> As per PAPR we have to look for both EPOW sensor value and event modifier to
> identify type of event and take appropriate action.
>
> Sensor value = 3 (EPOW_SYSTEM_SHUTDOWN) schedule system to be shutdown after
> OS defined delay (default 10 mins).
>
> EPOW Event Modifier for sensor value = 3:
> We have to initiate immediate shutdown for most of the event modifier except
> value = 2 (system running on UPS).
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/pseries: Do not initiate shutdown when system is running on UPS
https://git.kernel.org/powerpc/c/90a9b102eddf6a3f987d15f4454e26a2532c1c98
cheers
^ permalink raw reply
* Re: [PATCH v2 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry
From: Christophe Leroy @ 2020-08-20 14:32 UTC (permalink / raw)
To: Aneesh Kumar K.V, linux-mm, akpm; +Cc: linuxppc-dev, Anshuman Khandual
In-Reply-To: <20200819130107.478414-8-aneesh.kumar@linux.ibm.com>
Le 19/08/2020 à 15:01, Aneesh Kumar K.V a écrit :
> set_pte_at() should not be used to set a pte entry at locations that
> already holds a valid pte entry. Architectures like ppc64 don't do TLB
> invalidate in set_pte_at() and hence expect it to be used to set locations
> that are not a valid PTE.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
> mm/debug_vm_pgtable.c | 35 +++++++++++++++--------------------
> 1 file changed, 15 insertions(+), 20 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 76f4c713e5a3..9c7e2c9cfc76 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -74,15 +74,18 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
> {
> pte_t pte = pfn_pte(pfn, prot);
>
> + /*
> + * Architectures optimize set_pte_at by avoiding TLB flush.
> + * This requires set_pte_at to be not used to update an
> + * existing pte entry. Clear pte before we do set_pte_at
> + */
> +
> pr_debug("Validating PTE advanced\n");
> pte = pfn_pte(pfn, prot);
> set_pte_at(mm, vaddr, ptep, pte);
> ptep_set_wrprotect(mm, vaddr, ptep);
> pte = ptep_get(ptep);
> WARN_ON(pte_write(pte));
> -
> - pte = pfn_pte(pfn, prot);
> - set_pte_at(mm, vaddr, ptep, pte);
> ptep_get_and_clear(mm, vaddr, ptep);
> pte = ptep_get(ptep);
> WARN_ON(!pte_none(pte));
> @@ -96,13 +99,11 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
> ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
> pte = ptep_get(ptep);
> WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
> -
> - pte = pfn_pte(pfn, prot);
> - set_pte_at(mm, vaddr, ptep, pte);
> ptep_get_and_clear_full(mm, vaddr, ptep, 1);
> pte = ptep_get(ptep);
> WARN_ON(!pte_none(pte));
>
> + pte = pfn_pte(pfn, prot);
> pte = pte_mkyoung(pte);
> set_pte_at(mm, vaddr, ptep, pte);
> ptep_test_and_clear_young(vma, vaddr, ptep);
> @@ -164,9 +165,6 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
> pmdp_set_wrprotect(mm, vaddr, pmdp);
> pmd = READ_ONCE(*pmdp);
> WARN_ON(pmd_write(pmd));
> -
> - pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
> - set_pmd_at(mm, vaddr, pmdp, pmd);
> pmdp_huge_get_and_clear(mm, vaddr, pmdp);
> pmd = READ_ONCE(*pmdp);
> WARN_ON(!pmd_none(pmd));
> @@ -180,13 +178,11 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
> pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
> pmd = READ_ONCE(*pmdp);
> WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
> -
> - pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
> - set_pmd_at(mm, vaddr, pmdp, pmd);
> pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
> pmd = READ_ONCE(*pmdp);
> WARN_ON(!pmd_none(pmd));
>
> + pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
> pmd = pmd_mkyoung(pmd);
> set_pmd_at(mm, vaddr, pmdp, pmd);
> pmdp_test_and_clear_young(vma, vaddr, pmdp);
> @@ -283,18 +279,10 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
> WARN_ON(pud_write(pud));
>
> #ifndef __PAGETABLE_PMD_FOLDED
Same as below, once set_put_at() is gone, I don't think this #ifndef
__PAGETABLE_PMD_FOLDED is still need, should be possible to replace by
'if (mm_pmd_folded())'
> -
> - pud = pud_mkhuge(pfn_pud(pfn, prot));
> - set_pud_at(mm, vaddr, pudp, pud);
> pudp_huge_get_and_clear(mm, vaddr, pudp);
> pud = READ_ONCE(*pudp);
> WARN_ON(!pud_none(pud));
>
> - pud = pud_mkhuge(pfn_pud(pfn, prot));
> - set_pud_at(mm, vaddr, pudp, pud);
> - pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
> - pud = READ_ONCE(*pudp);
> - WARN_ON(!pud_none(pud));
> #endif /* __PAGETABLE_PMD_FOLDED */
>
> pud = pud_mkhuge(pfn_pud(pfn, prot));
> @@ -307,6 +295,13 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
> pud = READ_ONCE(*pudp);
> WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
>
> +#ifndef __PAGETABLE_PMD_FOLDED
> + pudp_huge_get_and_clear_full(vma, vaddr, pudp, 1);
> + pud = READ_ONCE(*pudp);
> + WARN_ON(!pud_none(pud));
> +#endif /* __PAGETABLE_PMD_FOLDED */
pudp_huge_get_and_clear_full() and pud_none() are always defined, I
think this #ifndef can be replaced by an 'if (mm_pmd_folded())'
> +
> + pud = pud_mkhuge(pfn_pud(pfn, prot));
> pud = pud_mkyoung(pud);
> set_pud_at(mm, vaddr, pudp, pud);
> pudp_test_and_clear_young(vma, vaddr, pudp);
>
Christophe
^ permalink raw reply
* [PATCH] powerpc: Fix a bug in __div64_32 if divisor is zero
From: Guohua Zhong @ 2020-08-20 13:10 UTC (permalink / raw)
To: paulus, mpe, benh, gregkh
Cc: nixiaoming, wangle6, linuxppc-dev, linux-kernel, stable
When cat /proc/pid/stat, do_task_stat will call into cputime_adjust,
which call stack is like this:
[17179954.674326]BookE Watchdog detected hard LOCKUP on cpu 0
[17179954.674331]dCPU: 0 PID: 1262 Comm: TICK Tainted: P W O 4.4.176 #1
[17179954.674339]dtask: dc9d7040 task.stack: d3cb4000
[17179954.674344]NIP: c001b1a8 LR: c006a7ac CTR: 00000000
[17179954.674349]REGS: e6fe1f10 TRAP: 3202 Tainted: P W O (4.4.176)
[17179954.674355]MSR: 00021002 <CE,ME> CR: 28002224 XER: 00000000
[17179954.674364]
GPR00: 00000016 d3cb5cb0 dc9d7040 d3cb5cc0 00000000 0000025d ffe15b24 ffffffff
GPR08: de86aead 00000000 000003ff ffffffff 28002222 0084d1c0 00000000 ffffffff
GPR16: b5929ca0 b4bb7a48 c0863c08 0000048d 00000062 00000062 00000000 0000000f
GPR24: 00000000 d3cb5d08 d3cb5d60 d3cb5d64 00029002 d3e9c214 fffff30e d3e9c20c
[17179954.674410]NIP [c001b1a8] __div64_32+0x60/0xa0
[17179954.674422]LR [c006a7ac] cputime_adjust+0x124/0x138
[17179954.674434]Call Trace:
[17179961.832693]Call Trace:
[17179961.832695][d3cb5cb0] [c006a6dc] cputime_adjust+0x54/0x138 (unreliable)
[17179961.832705][d3cb5cf0] [c006a818] task_cputime_adjusted+0x58/0x80
[17179961.832713][d3cb5d20] [c01dab44] do_task_stat+0x298/0x870
[17179961.832720][d3cb5de0] [c01d4948] proc_single_show+0x60/0xa4
[17179961.832728][d3cb5e10] [c01963d8] seq_read+0x2d8/0x52c
[17179961.832736][d3cb5e80] [c01702fc] __vfs_read+0x40/0x114
[17179961.832744][d3cb5ef0] [c0170b1c] vfs_read+0x9c/0x10c
[17179961.832751][d3cb5f10] [c0171440] SyS_read+0x68/0xc4
[17179961.832759][d3cb5f40] [c0010a40] ret_from_syscall+0x0/0x3c
do_task_stat->task_cputime_adjusted->cputime_adjust->scale_stime->div_u64
->div_u64_rem->do_div->__div64_32
In some corner case, stime + utime = 0 if overflow. Even in v5.8.2 kernel
the cputime has changed from unsigned long to u64 data type. About 200
days, the lowwer 32 bit will be 0x00000000. Because divisor for __div64_32
is unsigned long data type,which is 32 bit for powepc 32, the bug still
exists.
So it is also a bug in the cputime_adjust which does not check if
stime + utime = 0
time = scale_stime((__force u64)stime, (__force u64)rtime,
(__force u64)(stime + utime));
The commit 3dc167ba5729 ("sched/cputime: Improve cputime_adjust()") in
mainline kernel may has fixed this case. But it is also better to check
if divisor is 0 in __div64_32 for other situation.
Signed-off-by: Guohua Zhong <zhongguohua1@huawei.com>
Fixes:14cf11af6cf6 "( powerpc: Merge enough to start building in arch/powerpc.)"
Fixes:94b212c29f68 "( powerpc: Move ppc64 boot wrapper code over to arch/powerpc)"
Cc: stable@vger.kernel.org # v2.6.15+
---
arch/powerpc/boot/div64.S | 4 ++++
arch/powerpc/lib/div64.S | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/arch/powerpc/boot/div64.S b/arch/powerpc/boot/div64.S
index 4354928ed62e..39a25b9712d1 100644
--- a/arch/powerpc/boot/div64.S
+++ b/arch/powerpc/boot/div64.S
@@ -13,6 +13,9 @@
.globl __div64_32
__div64_32:
+ li r9,0
+ cmplw r4,r9 # check if divisor r4 is zero
+ beq 5f # jump to label 5 if r4(divisor) is zero
lwz r5,0(r3) # get the dividend into r5/r6
lwz r6,4(r3)
cmplw r5,r4
@@ -52,6 +55,7 @@ __div64_32:
4: stw r7,0(r3) # return the quotient in *r3
stw r8,4(r3)
mr r3,r6 # return the remainder in r3
+5: # return if divisor r4 is zero
blr
/*
diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S
index 3d5426e7dcc4..1cc9bcabf678 100644
--- a/arch/powerpc/lib/div64.S
+++ b/arch/powerpc/lib/div64.S
@@ -13,6 +13,9 @@
#include <asm/processor.h>
_GLOBAL(__div64_32)
+ li r9,0
+ cmplw r4,r9 # check if divisor r4 is zero
+ beq 5f # jump to label 5 if r4(divisor) is zero
lwz r5,0(r3) # get the dividend into r5/r6
lwz r6,4(r3)
cmplw r5,r4
@@ -52,4 +55,5 @@ _GLOBAL(__div64_32)
4: stw r7,0(r3) # return the quotient in *r3
stw r8,4(r3)
mr r3,r6 # return the remainder in r3
+5: # return if divisor r4 is zero
blr
--
2.12.3
^ permalink raw reply related
* Re: [PATCH] powerpc: Fix a bug in __div64_32 if divisor is zero
From: Christophe Leroy @ 2020-08-20 17:02 UTC (permalink / raw)
To: Guohua Zhong, paulus, mpe, benh, gregkh
Cc: linuxppc-dev, wangle6, nixiaoming, linux-kernel, stable
In-Reply-To: <20200820131049.42940-1-zhongguohua1@huawei.com>
Le 20/08/2020 à 15:10, Guohua Zhong a écrit :
> When cat /proc/pid/stat, do_task_stat will call into cputime_adjust,
> which call stack is like this:
>
> [17179954.674326]BookE Watchdog detected hard LOCKUP on cpu 0
> [17179954.674331]dCPU: 0 PID: 1262 Comm: TICK Tainted: P W O 4.4.176 #1
> [17179954.674339]dtask: dc9d7040 task.stack: d3cb4000
> [17179954.674344]NIP: c001b1a8 LR: c006a7ac CTR: 00000000
> [17179954.674349]REGS: e6fe1f10 TRAP: 3202 Tainted: P W O (4.4.176)
> [17179954.674355]MSR: 00021002 <CE,ME> CR: 28002224 XER: 00000000
> [17179954.674364]
> GPR00: 00000016 d3cb5cb0 dc9d7040 d3cb5cc0 00000000 0000025d ffe15b24 ffffffff
> GPR08: de86aead 00000000 000003ff ffffffff 28002222 0084d1c0 00000000 ffffffff
> GPR16: b5929ca0 b4bb7a48 c0863c08 0000048d 00000062 00000062 00000000 0000000f
> GPR24: 00000000 d3cb5d08 d3cb5d60 d3cb5d64 00029002 d3e9c214 fffff30e d3e9c20c
> [17179954.674410]NIP [c001b1a8] __div64_32+0x60/0xa0
> [17179954.674422]LR [c006a7ac] cputime_adjust+0x124/0x138
> [17179954.674434]Call Trace:
> [17179961.832693]Call Trace:
> [17179961.832695][d3cb5cb0] [c006a6dc] cputime_adjust+0x54/0x138 (unreliable)
> [17179961.832705][d3cb5cf0] [c006a818] task_cputime_adjusted+0x58/0x80
> [17179961.832713][d3cb5d20] [c01dab44] do_task_stat+0x298/0x870
> [17179961.832720][d3cb5de0] [c01d4948] proc_single_show+0x60/0xa4
> [17179961.832728][d3cb5e10] [c01963d8] seq_read+0x2d8/0x52c
> [17179961.832736][d3cb5e80] [c01702fc] __vfs_read+0x40/0x114
> [17179961.832744][d3cb5ef0] [c0170b1c] vfs_read+0x9c/0x10c
> [17179961.832751][d3cb5f10] [c0171440] SyS_read+0x68/0xc4
> [17179961.832759][d3cb5f40] [c0010a40] ret_from_syscall+0x0/0x3c
>
> do_task_stat->task_cputime_adjusted->cputime_adjust->scale_stime->div_u64
> ->div_u64_rem->do_div->__div64_32
>
> In some corner case, stime + utime = 0 if overflow. Even in v5.8.2 kernel
> the cputime has changed from unsigned long to u64 data type. About 200
> days, the lowwer 32 bit will be 0x00000000. Because divisor for __div64_32
> is unsigned long data type,which is 32 bit for powepc 32, the bug still
> exists.
>
> So it is also a bug in the cputime_adjust which does not check if
> stime + utime = 0
>
> time = scale_stime((__force u64)stime, (__force u64)rtime,
> (__force u64)(stime + utime));
>
> The commit 3dc167ba5729 ("sched/cputime: Improve cputime_adjust()") in
> mainline kernel may has fixed this case. But it is also better to check
> if divisor is 0 in __div64_32 for other situation.
>
> Signed-off-by: Guohua Zhong <zhongguohua1@huawei.com>
> Fixes:14cf11af6cf6 "( powerpc: Merge enough to start building in arch/powerpc.)"
> Fixes:94b212c29f68 "( powerpc: Move ppc64 boot wrapper code over to arch/powerpc)"
> Cc: stable@vger.kernel.org # v2.6.15+
> ---
> arch/powerpc/boot/div64.S | 4 ++++
> arch/powerpc/lib/div64.S | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/arch/powerpc/boot/div64.S b/arch/powerpc/boot/div64.S
> index 4354928ed62e..39a25b9712d1 100644
> --- a/arch/powerpc/boot/div64.S
> +++ b/arch/powerpc/boot/div64.S
> @@ -13,6 +13,9 @@
>
> .globl __div64_32
> __div64_32:
> + li r9,0
> + cmplw r4,r9 # check if divisor r4 is zero
> + beq 5f # jump to label 5 if r4(divisor) is zero
> lwz r5,0(r3) # get the dividend into r5/r6
> lwz r6,4(r3)
> cmplw r5,r4
> @@ -52,6 +55,7 @@ __div64_32:
> 4: stw r7,0(r3) # return the quotient in *r3
> stw r8,4(r3)
> mr r3,r6 # return the remainder in r3
> +5: # return if divisor r4 is zero
> blr
>
> /*
> diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S
> index 3d5426e7dcc4..1cc9bcabf678 100644
> --- a/arch/powerpc/lib/div64.S
> +++ b/arch/powerpc/lib/div64.S
> @@ -13,6 +13,9 @@
> #include <asm/processor.h>
>
> _GLOBAL(__div64_32)
> + li r9,0
You don't need to load r9 with 0, use cmplwi instead.
> + cmplw r4,r9 # check if divisor r4 is zero
> + beq 5f # jump to label 5 if r4(divisor) is zero
You should leave space between the compare and the branch (i.e. have
other instructions inbetween when possible), so that the processor can
prepare the branching and do a good prediction. Same as the compare
below, you see that there are two other instructions between the cmplw
are the blt. You can eventually use another cr field than cr0 in order
to nest several test/branches.
Also because on recent powerpc32, instructions are fetched and executed
two by two.
> lwz r5,0(r3) # get the dividend into r5/r6
> lwz r6,4(r3)
> cmplw r5,r4
> @@ -52,4 +55,5 @@ _GLOBAL(__div64_32)
> 4: stw r7,0(r3) # return the quotient in *r3
> stw r8,4(r3)
> mr r3,r6 # return the remainder in r3
> +5: # return if divisor r4 is zero
> blr
>
Christophe
^ permalink raw reply
* Re: [PATCH] powerpc: Fix a bug in __div64_32 if divisor is zero
From: Christophe Leroy @ 2020-08-20 18:23 UTC (permalink / raw)
To: Guohua Zhong, paulus, mpe, benh, gregkh
Cc: linuxppc-dev, wangle6, nixiaoming, linux-kernel, stable
In-Reply-To: <20200820131049.42940-1-zhongguohua1@huawei.com>
Le 20/08/2020 à 15:10, Guohua Zhong a écrit :
> When cat /proc/pid/stat, do_task_stat will call into cputime_adjust,
> which call stack is like this:
>
> [17179954.674326]BookE Watchdog detected hard LOCKUP on cpu 0
> [17179954.674331]dCPU: 0 PID: 1262 Comm: TICK Tainted: P W O 4.4.176 #1
> [17179954.674339]dtask: dc9d7040 task.stack: d3cb4000
> [17179954.674344]NIP: c001b1a8 LR: c006a7ac CTR: 00000000
> [17179954.674349]REGS: e6fe1f10 TRAP: 3202 Tainted: P W O (4.4.176)
> [17179954.674355]MSR: 00021002 <CE,ME> CR: 28002224 XER: 00000000
> [17179954.674364]
> GPR00: 00000016 d3cb5cb0 dc9d7040 d3cb5cc0 00000000 0000025d ffe15b24 ffffffff
> GPR08: de86aead 00000000 000003ff ffffffff 28002222 0084d1c0 00000000 ffffffff
> GPR16: b5929ca0 b4bb7a48 c0863c08 0000048d 00000062 00000062 00000000 0000000f
> GPR24: 00000000 d3cb5d08 d3cb5d60 d3cb5d64 00029002 d3e9c214 fffff30e d3e9c20c
> [17179954.674410]NIP [c001b1a8] __div64_32+0x60/0xa0
> [17179954.674422]LR [c006a7ac] cputime_adjust+0x124/0x138
> [17179954.674434]Call Trace:
> [17179961.832693]Call Trace:
> [17179961.832695][d3cb5cb0] [c006a6dc] cputime_adjust+0x54/0x138 (unreliable)
> [17179961.832705][d3cb5cf0] [c006a818] task_cputime_adjusted+0x58/0x80
> [17179961.832713][d3cb5d20] [c01dab44] do_task_stat+0x298/0x870
> [17179961.832720][d3cb5de0] [c01d4948] proc_single_show+0x60/0xa4
> [17179961.832728][d3cb5e10] [c01963d8] seq_read+0x2d8/0x52c
> [17179961.832736][d3cb5e80] [c01702fc] __vfs_read+0x40/0x114
> [17179961.832744][d3cb5ef0] [c0170b1c] vfs_read+0x9c/0x10c
> [17179961.832751][d3cb5f10] [c0171440] SyS_read+0x68/0xc4
> [17179961.832759][d3cb5f40] [c0010a40] ret_from_syscall+0x0/0x3c
>
> do_task_stat->task_cputime_adjusted->cputime_adjust->scale_stime->div_u64
> ->div_u64_rem->do_div->__div64_32
>
> In some corner case, stime + utime = 0 if overflow. Even in v5.8.2 kernel
> the cputime has changed from unsigned long to u64 data type. About 200
> days, the lowwer 32 bit will be 0x00000000. Because divisor for __div64_32
> is unsigned long data type,which is 32 bit for powepc 32, the bug still
> exists.
>
> So it is also a bug in the cputime_adjust which does not check if
> stime + utime = 0
>
> time = scale_stime((__force u64)stime, (__force u64)rtime,
> (__force u64)(stime + utime));
>
> The commit 3dc167ba5729 ("sched/cputime: Improve cputime_adjust()") in
> mainline kernel may has fixed this case. But it is also better to check
> if divisor is 0 in __div64_32 for other situation.
>
> Signed-off-by: Guohua Zhong <zhongguohua1@huawei.com>
> Fixes:14cf11af6cf6 "( powerpc: Merge enough to start building in arch/powerpc.)"
> Fixes:94b212c29f68 "( powerpc: Move ppc64 boot wrapper code over to arch/powerpc)"
> Cc: stable@vger.kernel.org # v2.6.15+
> ---
> arch/powerpc/boot/div64.S | 4 ++++
> arch/powerpc/lib/div64.S | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/arch/powerpc/boot/div64.S b/arch/powerpc/boot/div64.S
> index 4354928ed62e..39a25b9712d1 100644
> --- a/arch/powerpc/boot/div64.S
> +++ b/arch/powerpc/boot/div64.S
> @@ -13,6 +13,9 @@
>
> .globl __div64_32
> __div64_32:
> + li r9,0
> + cmplw r4,r9 # check if divisor r4 is zero
> + beq 5f # jump to label 5 if r4(divisor) is zero
In generic version in lib/math/div64.c, there is no checking of 'base'
either.
Do we really want to add this check in the powerpc version only ?
The only user of __div64_32() is do_div() in
include/asm-generic/div64.h. Wouldn't it be better to do the check there ?
Christophe
> lwz r5,0(r3) # get the dividend into r5/r6
> lwz r6,4(r3)
> cmplw r5,r4
> @@ -52,6 +55,7 @@ __div64_32:
> 4: stw r7,0(r3) # return the quotient in *r3
> stw r8,4(r3)
> mr r3,r6 # return the remainder in r3
> +5: # return if divisor r4 is zero
> blr
>
> /*
> diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S
> index 3d5426e7dcc4..1cc9bcabf678 100644
> --- a/arch/powerpc/lib/div64.S
> +++ b/arch/powerpc/lib/div64.S
> @@ -13,6 +13,9 @@
> #include <asm/processor.h>
>
> _GLOBAL(__div64_32)
> + li r9,0
> + cmplw r4,r9 # check if divisor r4 is zero
> + beq 5f # jump to label 5 if r4(divisor) is zero
> lwz r5,0(r3) # get the dividend into r5/r6
> lwz r6,4(r3)
> cmplw r5,r4
> @@ -52,4 +55,5 @@ _GLOBAL(__div64_32)
> 4: stw r7,0(r3) # return the quotient in *r3
> stw r8,4(r3)
> mr r3,r6 # return the remainder in r3
> +5: # return if divisor r4 is zero
> blr
>
^ permalink raw reply
* Re: [PATCH v2 1/4] powerpc/drmem: Make lmb_size 64 bit
From: Nathan Lynch @ 2020-08-20 20:10 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: linuxppc-dev, stable
In-Reply-To: <20200806162329.276534-1-aneesh.kumar@linux.ibm.com>
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> Similar to commit 89c140bbaeee ("pseries: Fix 64 bit logical memory block panic")
> make sure different variables tracking lmb_size are updated to be 64 bit.
>
> This was found by code audit.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
> arch/powerpc/include/asm/drmem.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
> index 17ccc6474ab6..d719cbac34b2 100644
> --- a/arch/powerpc/include/asm/drmem.h
> +++ b/arch/powerpc/include/asm/drmem.h
> @@ -21,7 +21,7 @@ struct drmem_lmb {
> struct drmem_lmb_info {
> struct drmem_lmb *lmbs;
> int n_lmbs;
> - u32 lmb_size;
> + u64 lmb_size;
> };
>
> extern struct drmem_lmb_info *drmem_info;
> @@ -67,7 +67,7 @@ struct of_drconf_cell_v2 {
> #define DRCONF_MEM_RESERVED 0x00000080
> #define DRCONF_MEM_HOTREMOVABLE 0x00000100
>
> -static inline u32 drmem_lmb_size(void)
> +static inline u64 drmem_lmb_size(void)
> {
> return drmem_info->lmb_size;
> }
Looks fine.
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
^ permalink raw reply
* Re: [PATCH v2 3/4] powerpc/memhotplug: Make lmb size 64bit
From: Nathan Lynch @ 2020-08-20 20:20 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: linuxppc-dev, stable
In-Reply-To: <20200806162329.276534-3-aneesh.kumar@linux.ibm.com>
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> @@ -322,12 +322,16 @@ static int pseries_remove_mem_node(struct device_node *np)
> /*
> * Find the base address and size of the memblock
> */
> - regs = of_get_property(np, "reg", NULL);
> - if (!regs)
> + prop = of_get_property(np, "reg", NULL);
> + if (!prop)
> return ret;
>
> - base = be64_to_cpu(*(unsigned long *)regs);
> - lmb_size = be32_to_cpu(regs[3]);
> + /*
> + * "reg" property represents (addr,size) tuple.
> + */
> + base = of_read_number(prop, mem_addr_cells);
> + prop += mem_addr_cells;
> + lmb_size = of_read_number(prop, mem_size_cells);
Would of_n_size_cells() and of_n_addr_cells() work here?
^ permalink raw reply
* Re: [PATCH v2 3/6] powerpc/32s: Only leave NX unset on segments used for modules
From: Andreas Schwab @ 2020-08-20 22:00 UTC (permalink / raw)
To: Christophe Leroy; +Cc: Paul Mackerras, linuxppc-dev, linux-kernel
In-Reply-To: <7172c0f5253419315e434a1816ee3d6ed6505bc0.1593428200.git.christophe.leroy@csgroup.eu>
On Jun 29 2020, Christophe Leroy wrote:
> Instead of leaving NX unset on all segments above the start
> of vmalloc space, only leave NX unset on segments used for
> modules.
I'm getting this crash:
kernel tried to execute exec-protected page (f294b000) - exploit attempt (uid: 0)
BUG: Unable to handle kernel instruction fetch
Faulting instruction address: 0xf294b000
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K MMU=Hash PowerMac
Modules linked in: pata_macio(+)
CPU: 0 PID: 87 Comm: udevd Not tainted 5.8.0-rc2-test #49
NIP: f294b000 LR: 0005c60 CTR: f294b000
REGS: f18d9cc0 TRAP: 0400 Not tainted (5.8.0-rc2-test)
MSR: 10009032 <E,ME,IR,DR,RI> CR: 84222422 XER: 20000000
GPR00: c0005c14 f18d9d78 ef30ca20 00000000 ef0000e0 c00993d0 ef6da038 0000005e
GPR08: c09050b8 c08b0000 00000000 f18d9d78 44222422 10072070 00000000 0fefaca4
GPR16: 1006a00c f294d50b 00000120 00000124 c0096ea8 0000000e ef2776c0 ef2776e4
GPR24: f18fd6e8 00000001 c086fe64 c086fe04 00000000 c08b0000 f294b000 ffffffff
NIP [f294b000] pata_macio_init+0x0/0xc0 [pata_macio]
LR [c0005c60] do_one_initcall+0x6c/0x160
Call Trace:
[f18d9d78] [c0005c14] do_one_initcall+0x20/0x160 (unreliable)
[f18d9dd8] [c009a22c] do_init_module+0x60/0x1c0
[f18d9df8] [c00993d8] load_module+0x16a8/0x1c14
[f18d9ea8] [c0099aa4] sys_finit_module+0x8c/0x94
[f18d9f38] [c0012174] ret_from_syscall+0x0/0x34
--- interrupt: c01 at 0xfdb4318
LR = 0xfeee9c0
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX <3d20c08b> 3d40c086 9421ffe0 8129106c
---[ end trace 85a98cc836109871 ]---
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
^ permalink raw reply
* [RFT][PATCH 0/7] Avoid overflow at boundary_size
From: Nicolin Chen @ 2020-08-20 23:19 UTC (permalink / raw)
To: mpe, benh, paulus, rth, ink, mattst88, tony.luck, fenghua.yu,
schnelle, gerald.schaefer, hca, gor, borntraeger, davem, tglx,
mingo, bp, x86, hpa, James.Bottomley, deller
Cc: sfr, linux-ia64, linux-parisc, linux-s390, linux-kernel,
linux-alpha, sparclinux, linuxppc-dev, hch
We are expending the default DMA segmentation boundary to its
possible maximum value (ULONG_MAX) to indicate that a device
doesn't specify a boundary limit. So all dma_get_seg_boundary
callers should take a precaution with the return values since
it would easily get overflowed.
I scanned the entire kernel tree for all the existing callers
and found that most of callers may get overflowed in two ways:
either "+ 1" or passing it to ALIGN() that does "+ mask".
According to kernel defines:
#define ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
#define ALIGN(x, a) ALIGN_MASK(x, (typeof(x))(a) - 1)
We can simplify the logic here:
ALIGN(boundary + 1, 1 << shift) >> shift
= ALIGN_MASK(b + 1, (1 << s) - 1) >> s
= {[b + 1 + (1 << s) - 1] & ~[(1 << s) - 1]} >> s
= [b + 1 + (1 << s) - 1] >> s
= [b + (1 << s)] >> s
= (b >> s) + 1
So this series of patches fix the potential overflow with this
overflow-free shortcut.
As I don't think that I have these platforms, marking RFT.
Thanks
Nic
Nicolin Chen (7):
powerpc/iommu: Avoid overflow at boundary_size
alpha: Avoid overflow at boundary_size
ia64/sba_iommu: Avoid overflow at boundary_size
s390/pci_dma: Avoid overflow at boundary_size
sparc: Avoid overflow at boundary_size
x86/amd_gart: Avoid overflow at boundary_size
parisc: Avoid overflow at boundary_size
arch/alpha/kernel/pci_iommu.c | 10 ++++------
arch/ia64/hp/common/sba_iommu.c | 4 ++--
arch/powerpc/kernel/iommu.c | 11 +++++------
arch/s390/pci/pci_dma.c | 4 ++--
arch/sparc/kernel/iommu-common.c | 9 +++------
arch/sparc/kernel/iommu.c | 4 ++--
arch/sparc/kernel/pci_sun4v.c | 4 ++--
arch/x86/kernel/amd_gart_64.c | 4 ++--
drivers/parisc/ccio-dma.c | 4 ++--
drivers/parisc/sba_iommu.c | 4 ++--
10 files changed, 26 insertions(+), 32 deletions(-)
--
2.17.1
^ permalink raw reply
* [RFT][PATCH 1/7] powerpc/iommu: Avoid overflow at boundary_size
From: Nicolin Chen @ 2020-08-20 23:19 UTC (permalink / raw)
To: mpe, benh, paulus; +Cc: sfr, linuxppc-dev, hch, linux-kernel
The boundary_size might be as large as ULONG_MAX, which means
that a device has no specific boundary limit. So either "+ 1"
or passing it to ALIGN() would potentially overflow.
According to kernel defines:
#define ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
#define ALIGN(x, a) ALIGN_MASK(x, (typeof(x))(a) - 1)
We can simplify the logic here:
ALIGN(boundary + 1, 1 << shift) >> shift
= ALIGN_MASK(b + 1, (1 << s) - 1) >> s
= {[b + 1 + (1 << s) - 1] & ~[(1 << s) - 1]} >> s
= [b + 1 + (1 << s) - 1] >> s
= [b + (1 << s)] >> s
= (b >> s) + 1
So fixing a potential overflow with the safer shortcut.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/kernel/iommu.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 9704f3f76e63..c01ccbf8afdd 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -236,15 +236,14 @@ static unsigned long iommu_range_alloc(struct device *dev,
}
}
- if (dev)
- boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
- 1 << tbl->it_page_shift);
- else
- boundary_size = ALIGN(1UL << 32, 1 << tbl->it_page_shift);
/* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
+ boundary_size = dev ? dma_get_seg_boundary(dev) : U32_MAX;
+
+ /* Overflow-free shortcut for: ALIGN(b + 1, 1 << s) >> s */
+ boundary_size = (boundary_size >> tbl->it_page_shift) + 1;
n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset,
- boundary_size >> tbl->it_page_shift, align_mask);
+ boundary_size, align_mask);
if (n == -1) {
if (likely(pass == 0)) {
/* First try the pool from the start */
--
2.17.1
^ permalink raw reply related
* Re: [PATCH net-next v2 0/4] refactoring of ibmvnic code
From: David Miller @ 2020-08-20 23:36 UTC (permalink / raw)
To: ljp; +Cc: netdev, linuxppc-dev
In-Reply-To: <20200819225226.10152-1-ljp@linux.ibm.com>
From: Lijun Pan <ljp@linux.ibm.com>
Date: Wed, 19 Aug 2020 17:52:22 -0500
> This patch series refactor reset_init and init functions,
> and make some other cosmetic changes to make the code
> easier to read and debug. v2 removes __func__ and v1's 1/5.
Series applied, thank you.
^ permalink raw reply
* [PATCH] tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()
From: Tyrel Datwyler @ 2020-08-20 23:46 UTC (permalink / raw)
To: gregkh
Cc: Tyrel Datwyler, Jason Yan,
open list:HYPERVISOR VIRTUAL CONSOLE DRIVER, open list,
Joe Perches, Jiri Slaby
The code currently NULLs tty->driver_data in hvcs_close() with the
intent of informing the next call to hvcs_open() that device needs to be
reconfigured. However, when hvcs_cleanup() is called we copy hvcsd from
tty->driver_data which was previoulsy NULLed by hvcs_close() and our
call to tty_port_put(&hvcsd->port) doesn't actually do anything since
&hvcsd->port ends up translating to NULL by chance. This has the side
effect that when hvcs_remove() is called we have one too many port
references preventing hvcs_destuct_port() from ever being called. This
also prevents us from reusing the /dev/hvcsX node in a future
hvcs_probe() and we can eventually run out of /dev/hvcsX devices.
Fix this by waiting to NULL tty->driver_data in hvcs_cleanup().
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
drivers/tty/hvc/hvcs.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 55105ac38f89..509d1042825a 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1216,13 +1216,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
- /*
- * This line is important because it tells hvcs_open that this
- * device needs to be re-configured the next time hvcs_open is
- * called.
- */
- tty->driver_data = NULL;
-
free_irq(irq, hvcsd);
return;
} else if (hvcsd->port.count < 0) {
@@ -1237,6 +1230,13 @@ static void hvcs_cleanup(struct tty_struct * tty)
{
struct hvcs_struct *hvcsd = tty->driver_data;
+ /*
+ * This line is important because it tells hvcs_open that this
+ * device needs to be re-configured the next time hvcs_open is
+ * called.
+ */
+ tty->driver_data = NULL;
+
tty_port_put(&hvcsd->port);
}
--
2.27.0
^ permalink raw reply related
* [PATCH 0/2] Reintroduce PROT_SAO
From: Shawn Anastasio @ 2020-08-21 1:08 UTC (permalink / raw)
To: linuxppc-dev; +Cc: npiggin
This set re-introduces the PROT_SAO prot flag removed in
Commit 5c9fa16e8abd ("powerpc/64s: Remove PROT_SAO support").
To address concerns regarding live migration of guests using SAO
to P10 hosts without SAO support, the flag is disabled by default
in LPARs. A new config option, PPC_PROT_SAO_LPAR was added to
allow users to explicitly enable it if they will not be running
in an environment where this is a conern.
Shawn Anastasio (2):
Revert "powerpc/64s: Remove PROT_SAO support"
powerpc/64s: Disallow PROT_SAO in LPARs by default
arch/powerpc/Kconfig | 12 ++++++
arch/powerpc/include/asm/book3s/64/pgtable.h | 8 ++--
arch/powerpc/include/asm/cputable.h | 10 ++---
arch/powerpc/include/asm/mman.h | 31 ++++++++++++--
arch/powerpc/include/asm/nohash/64/pgtable.h | 2 +
arch/powerpc/include/uapi/asm/mman.h | 2 +-
arch/powerpc/kernel/dt_cpu_ftrs.c | 2 +-
arch/powerpc/mm/book3s64/hash_utils.c | 2 +
include/linux/mm.h | 2 +
include/trace/events/mmflags.h | 2 +
mm/ksm.c | 4 ++
tools/testing/selftests/powerpc/mm/.gitignore | 1 +
tools/testing/selftests/powerpc/mm/Makefile | 4 +-
tools/testing/selftests/powerpc/mm/prot_sao.c | 42 +++++++++++++++++++
14 files changed, 107 insertions(+), 17 deletions(-)
create mode 100644 tools/testing/selftests/powerpc/mm/prot_sao.c
--
2.28.0
^ permalink raw reply
* [PATCH 1/2] Revert "powerpc/64s: Remove PROT_SAO support"
From: Shawn Anastasio @ 2020-08-21 1:08 UTC (permalink / raw)
To: linuxppc-dev; +Cc: npiggin
In-Reply-To: <20200821010837.4079-1-shawn@anastas.io>
This reverts commit 5c9fa16e8abd342ce04dc830c1ebb2a03abf6c05.
Since PROT_SAO can still be useful for certain classes of software,
reintroduce it. Concerns about guest migration for LPARs using SAO
will be addressed next.
Signed-off-by: Shawn Anastasio <shawn@anastas.io>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 8 ++--
arch/powerpc/include/asm/cputable.h | 10 ++---
arch/powerpc/include/asm/mman.h | 26 ++++++++++--
arch/powerpc/include/asm/nohash/64/pgtable.h | 2 +
arch/powerpc/include/uapi/asm/mman.h | 2 +-
arch/powerpc/kernel/dt_cpu_ftrs.c | 2 +-
arch/powerpc/mm/book3s64/hash_utils.c | 2 +
include/linux/mm.h | 2 +
include/trace/events/mmflags.h | 2 +
mm/ksm.c | 4 ++
tools/testing/selftests/powerpc/mm/.gitignore | 1 +
tools/testing/selftests/powerpc/mm/Makefile | 4 +-
tools/testing/selftests/powerpc/mm/prot_sao.c | 42 +++++++++++++++++++
13 files changed, 90 insertions(+), 17 deletions(-)
create mode 100644 tools/testing/selftests/powerpc/mm/prot_sao.c
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 6de56c3b33c4..495fc0ccb453 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -20,13 +20,9 @@
#define _PAGE_RW (_PAGE_READ | _PAGE_WRITE)
#define _PAGE_RWX (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
#define _PAGE_PRIVILEGED 0x00008 /* kernel access only */
-
-#define _PAGE_CACHE_CTL 0x00030 /* Bits for the folowing cache modes */
- /* No bits set is normal cacheable memory */
- /* 0x00010 unused, is SAO bit on radix POWER9 */
+#define _PAGE_SAO 0x00010 /* Strong access order */
#define _PAGE_NON_IDEMPOTENT 0x00020 /* non idempotent memory */
#define _PAGE_TOLERANT 0x00030 /* tolerant memory, cache inhibited */
-
#define _PAGE_DIRTY 0x00080 /* C: page changed */
#define _PAGE_ACCESSED 0x00100 /* R: page referenced */
/*
@@ -828,6 +824,8 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
return hash__set_pte_at(mm, addr, ptep, pte, percpu);
}
+#define _PAGE_CACHE_CTL (_PAGE_SAO | _PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)
+
#define pgprot_noncached pgprot_noncached
static inline pgprot_t pgprot_noncached(pgprot_t prot)
{
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index fdddb822d564..f89205eff691 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -191,7 +191,7 @@ static inline void cpu_feature_keys_init(void) { }
#define CPU_FTR_SPURR LONG_ASM_CONST(0x0000000001000000)
#define CPU_FTR_DSCR LONG_ASM_CONST(0x0000000002000000)
#define CPU_FTR_VSX LONG_ASM_CONST(0x0000000004000000)
-// Free LONG_ASM_CONST(0x0000000008000000)
+#define CPU_FTR_SAO LONG_ASM_CONST(0x0000000008000000)
#define CPU_FTR_CP_USE_DCBTZ LONG_ASM_CONST(0x0000000010000000)
#define CPU_FTR_UNALIGNED_LD_STD LONG_ASM_CONST(0x0000000020000000)
#define CPU_FTR_ASYM_SMT LONG_ASM_CONST(0x0000000040000000)
@@ -436,7 +436,7 @@ static inline void cpu_feature_keys_init(void) { }
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
- CPU_FTR_DSCR | CPU_FTR_ASYM_SMT | \
+ CPU_FTR_DSCR | CPU_FTR_SAO | CPU_FTR_ASYM_SMT | \
CPU_FTR_STCX_CHECKS_ADDRESS | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
CPU_FTR_CFAR | CPU_FTR_HVMODE | \
CPU_FTR_VMX_COPY | CPU_FTR_HAS_PPR | CPU_FTR_DABRX )
@@ -445,7 +445,7 @@ static inline void cpu_feature_keys_init(void) { }
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
- CPU_FTR_DSCR | \
+ CPU_FTR_DSCR | CPU_FTR_SAO | \
CPU_FTR_STCX_CHECKS_ADDRESS | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_DAWR | \
@@ -456,7 +456,7 @@ static inline void cpu_feature_keys_init(void) { }
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
- CPU_FTR_DSCR | \
+ CPU_FTR_DSCR | CPU_FTR_SAO | \
CPU_FTR_STCX_CHECKS_ADDRESS | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_ARCH_207S | \
@@ -474,7 +474,7 @@ static inline void cpu_feature_keys_init(void) { }
CPU_FTR_MMCRA | CPU_FTR_SMT | \
CPU_FTR_COHERENT_ICACHE | \
CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
- CPU_FTR_DSCR | \
+ CPU_FTR_DSCR | CPU_FTR_SAO | \
CPU_FTR_STCX_CHECKS_ADDRESS | CPU_FTR_POPCNTB | CPU_FTR_POPCNTD | \
CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_ARCH_207S | \
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 7c07728af300..4ba303ea27f5 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -13,20 +13,38 @@
#include <linux/pkeys.h>
#include <asm/cpu_has_feature.h>
-#ifdef CONFIG_PPC_MEM_KEYS
static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
unsigned long pkey)
{
- return pkey_to_vmflag_bits(pkey);
+#ifdef CONFIG_PPC_MEM_KEYS
+ return (((prot & PROT_SAO) ? VM_SAO : 0) | pkey_to_vmflag_bits(pkey));
+#else
+ return ((prot & PROT_SAO) ? VM_SAO : 0);
+#endif
}
#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
{
- return __pgprot(vmflag_to_pte_pkey_bits(vm_flags));
+#ifdef CONFIG_PPC_MEM_KEYS
+ return (vm_flags & VM_SAO) ?
+ __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+ __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+ return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
}
#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-#endif
+
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
+{
+ if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
+ return false;
+ if ((prot & PROT_SAO) && !cpu_has_feature(CPU_FTR_SAO))
+ return false;
+ return true;
+}
+#define arch_validate_prot arch_validate_prot
#endif /* CONFIG_PPC64 */
#endif /* _ASM_POWERPC_MMAN_H */
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index 59ee9fa4ae09..6cb8aa357191 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -82,6 +82,8 @@
*/
#include <asm/nohash/pte-book3e.h>
+#define _PAGE_SAO 0
+
#define PTE_RPN_MASK (~((1UL << PTE_RPN_SHIFT) - 1))
/*
diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h
index 3a700351feca..c0c737215b00 100644
--- a/arch/powerpc/include/uapi/asm/mman.h
+++ b/arch/powerpc/include/uapi/asm/mman.h
@@ -11,7 +11,7 @@
#include <asm-generic/mman-common.h>
-#define PROT_SAO 0x10 /* Unsupported since v5.9 */
+#define PROT_SAO 0x10 /* Strong Access Ordering */
#define MAP_RENAME MAP_ANONYMOUS /* In SunOS terminology */
#define MAP_NORESERVE 0x40 /* don't reserve swap pages */
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 6f8c0c6b937a..231f92248140 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -657,7 +657,7 @@ static struct dt_cpu_feature_match __initdata
{"processor-control-facility-v3", feat_enable_dbell, CPU_FTR_DBELL},
{"processor-utilization-of-resources-register", feat_enable_purr, 0},
{"no-execute", feat_enable, 0},
- /* strong-access-ordering is unused */
+ {"strong-access-ordering", feat_enable, CPU_FTR_SAO},
{"cache-inhibited-large-page", feat_enable_large_ci, 0},
{"coprocessor-icswx", feat_enable, 0},
{"hypervisor-virtualization-interrupt", feat_enable_hvi, 0},
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 1da9dbba9217..c1ea93b368b6 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -232,6 +232,8 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags)
rflags |= HPTE_R_I;
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
rflags |= (HPTE_R_I | HPTE_R_G);
+ else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
+ rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
else
/*
* Add memory coherence if cache inhibited is not set
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1983e08f5906..5abe6df4247e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -321,6 +321,8 @@ extern unsigned int kobjsize(const void *objp);
#if defined(CONFIG_X86)
# define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */
+#elif defined(CONFIG_PPC)
+# define VM_SAO VM_ARCH_1 /* Strong Access Ordering (powerpc) */
#elif defined(CONFIG_PARISC)
# define VM_GROWSUP VM_ARCH_1
#elif defined(CONFIG_IA64)
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 939092dbcb8b..5fb752034386 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -114,6 +114,8 @@ IF_HAVE_PG_IDLE(PG_idle, "idle" )
#if defined(CONFIG_X86)
#define __VM_ARCH_SPECIFIC_1 {VM_PAT, "pat" }
+#elif defined(CONFIG_PPC)
+#define __VM_ARCH_SPECIFIC_1 {VM_SAO, "sao" }
#elif defined(CONFIG_PARISC) || defined(CONFIG_IA64)
#define __VM_ARCH_SPECIFIC_1 {VM_GROWSUP, "growsup" }
#elif !defined(CONFIG_MMU)
diff --git a/mm/ksm.c b/mm/ksm.c
index 0aa2247bddd7..90a625b02a1d 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2453,6 +2453,10 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
if (vma_is_dax(vma))
return 0;
+#ifdef VM_SAO
+ if (*vm_flags & VM_SAO)
+ return 0;
+#endif
#ifdef VM_SPARC_ADI
if (*vm_flags & VM_SPARC_ADI)
return 0;
diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore
index 91c775c23c66..aac4a59f9e28 100644
--- a/tools/testing/selftests/powerpc/mm/.gitignore
+++ b/tools/testing/selftests/powerpc/mm/.gitignore
@@ -2,6 +2,7 @@
hugetlb_vs_thp_test
subpage_prot
tempfile
+prot_sao
segv_errors
wild_bctr
large_vm_fork_separation
diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile
index 250ce172e0da..defe488d6bf1 100644
--- a/tools/testing/selftests/powerpc/mm/Makefile
+++ b/tools/testing/selftests/powerpc/mm/Makefile
@@ -2,7 +2,7 @@
noarg:
$(MAKE) -C ../
-TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot segv_errors wild_bctr \
+TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors wild_bctr \
large_vm_fork_separation bad_accesses pkey_exec_prot \
pkey_siginfo stack_expansion_signal stack_expansion_ldst
@@ -14,6 +14,8 @@ include ../../lib.mk
$(TEST_GEN_PROGS): ../harness.c ../utils.c
+$(OUTPUT)/prot_sao: ../utils.c
+
$(OUTPUT)/wild_bctr: CFLAGS += -m64
$(OUTPUT)/large_vm_fork_separation: CFLAGS += -m64
$(OUTPUT)/bad_accesses: CFLAGS += -m64
diff --git a/tools/testing/selftests/powerpc/mm/prot_sao.c b/tools/testing/selftests/powerpc/mm/prot_sao.c
new file mode 100644
index 000000000000..e2eed65b7735
--- /dev/null
+++ b/tools/testing/selftests/powerpc/mm/prot_sao.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2016, Michael Ellerman, IBM Corp.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <asm/cputable.h>
+
+#include "utils.h"
+
+#define SIZE (64 * 1024)
+
+int test_prot_sao(void)
+{
+ char *p;
+
+ /* 2.06 or later should support SAO */
+ SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
+
+ /*
+ * Ensure we can ask for PROT_SAO.
+ * We can't really verify that it does the right thing, but at least we
+ * confirm the kernel will accept it.
+ */
+ p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE | PROT_SAO,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ FAIL_IF(p == MAP_FAILED);
+
+ /* Write to the mapping, to at least cause a fault */
+ memset(p, 0xaa, SIZE);
+
+ return 0;
+}
+
+int main(void)
+{
+ return test_harness(test_prot_sao, "prot-sao");
+}
--
2.28.0
^ permalink raw reply related
* [PATCH 2/2] powerpc/64s: Disallow PROT_SAO in LPARs by default
From: Shawn Anastasio @ 2020-08-21 1:08 UTC (permalink / raw)
To: linuxppc-dev; +Cc: npiggin
In-Reply-To: <20200821010837.4079-1-shawn@anastas.io>
Since migration of guests using SAO to ISA 3.1 hosts may cause issues,
disable PROT_SAO in LPARs by default and introduce a new Kconfig option
PPC_PROT_SAO_LPAR to allow users to enable it if desired.
Signed-off-by: Shawn Anastasio <shawn@anastas.io>
---
arch/powerpc/Kconfig | 12 ++++++++++++
arch/powerpc/include/asm/mman.h | 9 +++++++--
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1f48bbfb3ce9..65bed1fdeaad 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -860,6 +860,18 @@ config PPC_SUBPAGE_PROT
If unsure, say N here.
+config PPC_PROT_SAO_LPAR
+ bool "Support PROT_SAO mappings in LPARs"
+ depends on PPC_BOOK3S_64
+ help
+ This option adds support for PROT_SAO mappings from userspace
+ inside LPARs on supported CPUs.
+
+ This may cause issues when performing guest migration from
+ a CPU that supports SAO to one that does not.
+
+ If unsure, say N here.
+
config PPC_COPRO_BASE
bool
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 4ba303ea27f5..7cb6d18f5cd6 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -40,8 +40,13 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
{
if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
return false;
- if ((prot & PROT_SAO) && !cpu_has_feature(CPU_FTR_SAO))
- return false;
+ if (prot & PROT_SAO) {
+ if (!cpu_has_feature(CPU_FTR_SAO))
+ return false;
+ if (firmware_has_feature(FW_FEATURE_LPAR) &&
+ !IS_ENABLED(CONFIG_PPC_PROT_SAO_LPAR))
+ return false;
+ }
return true;
}
#define arch_validate_prot arch_validate_prot
--
2.28.0
^ permalink raw reply related
* Re: [PATCH v2 00/13] mm/debug_vm_pgtable fixes
From: Anshuman Khandual @ 2020-08-21 3:33 UTC (permalink / raw)
To: Aneesh Kumar K.V, linux-mm, akpm; +Cc: linuxppc-dev
In-Reply-To: <87tuwyvjei.fsf@linux.ibm.com>
On 08/19/2020 07:15 PM, Aneesh Kumar K.V wrote:
> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
>
>> This patch series includes fixes for debug_vm_pgtable test code so that
>> they follow page table updates rules correctly. The first two patches introduce
>> changes w.r.t ppc64. The patches are included in this series for completeness. We can
>> merge them via ppc64 tree if required.
>>
>> Hugetlb test is disabled on ppc64 because that needs larger change to satisfy
>> page table update rules.
>>
>> Changes from V1:
>> * Address review feedback
>> * drop test specific pfn_pte and pfn_pmd.
>> * Update ppc64 page table helper to add _PAGE_PTE
>>
>> Aneesh Kumar K.V (13):
>> powerpc/mm: Add DEBUG_VM WARN for pmd_clear
>> powerpc/mm: Move setting pte specific flags to pfn_pte
>> mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value
>> mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge
>> vmap support.
>> mm/debug_vm_pgtable/savedwrite: Enable savedwrite test with
>> CONFIG_NUMA_BALANCING
>> mm/debug_vm_pgtable/THP: Mark the pte entry huge before using
>> set_pmd/pud_at
>> mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an
>> existing pte entry
>> mm/debug_vm_pgtable/thp: Use page table depost/withdraw with THP
>> mm/debug_vm_pgtable/locks: Move non page table modifying test together
>> mm/debug_vm_pgtable/locks: Take correct page table lock
>> mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries
>> mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64
>> mm/debug_vm_pgtable: populate a pte entry before fetching it
>>
>> arch/powerpc/include/asm/book3s/64/pgtable.h | 29 +++-
>> arch/powerpc/include/asm/nohash/pgtable.h | 5 -
>> arch/powerpc/mm/book3s64/pgtable.c | 2 +-
>> arch/powerpc/mm/pgtable.c | 5 -
>> include/linux/io.h | 12 ++
>> mm/debug_vm_pgtable.c | 151 +++++++++++--------
>> 6 files changed, 127 insertions(+), 77 deletions(-)
>>
>
> BTW I picked a wrong branch when sending this. Attaching the diff
> against what I want to send. pfn_pmd() no more updates _PAGE_PTE
> because that is handled by pmd_mkhuge().
>
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> index 3b4da7c63e28..e18ae50a275c 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -141,7 +141,7 @@ pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
> unsigned long pmdv;
>
> pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
> - return __pmd(pmdv | pgprot_val(pgprot) | _PAGE_PTE);
> + return pmd_set_protbits(__pmd(pmdv), pgprot);
> }
>
> pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 7d9f8e1d790f..cad61d22f33a 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -229,7 +229,7 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
>
> static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
> {
> - pmd_t pmd = pfn_pmd(pfn, prot);
> + pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
>
> if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
> return;
>
Cover letter does not mention which branch or tag this series applies on.
Just assumed it to be 5.9-rc1. Should the above changes be captured as a
pre-requisite patch ?
Anyways, the series fails to be build on arm64.
A) Without CONFIG_TRANSPARENT_HUGEPAGE
mm/debug_vm_pgtable.c: In function ‘debug_vm_pgtable’:
mm/debug_vm_pgtable.c:1045:2: error: too many arguments to function ‘pmd_advanced_tests’
pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
^~~~~~~~~~~~~~~~~~
mm/debug_vm_pgtable.c:366:20: note: declared here
static void __init pmd_advanced_tests(struct mm_struct *mm,
^~~~~~~~~~~~~~~~~~
B) As mentioned previously, this should be solved by including <linux/io.h>
mm/debug_vm_pgtable.c: In function ‘pmd_huge_tests’:
mm/debug_vm_pgtable.c:215:7: error: implicit declaration of function ‘arch_ioremap_pmd_supported’; did you mean ‘arch_disable_smp_support’? [-Werror=implicit-function-declaration]
if (!arch_ioremap_pmd_supported())
^~~~~~~~~~~~~~~~~~~~~~~~~~
Please make sure that the series builds on all enabled platforms i.e x86,
arm64, ppc32, ppc64, arc, s390 along with selectively enabling/disabling
all the features that make various #ifdefs in the test.
- Anshuman
^ permalink raw reply
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