* [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies
@ 2016-06-07 16:52 Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector Borislav Petkov
` (3 more replies)
0 siblings, 4 replies; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 16:52 UTC (permalink / raw)
To: linux-edac; +Cc: Tony Luck, Yazen Ghannam, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
So this set cannot have a bigger "RFC" tag:
It attempts to revive the correctable errors collector. In this version,
the thing gets counters in debugfs:
(debugfs)/ras/cec/
|-- array
`-- pfn
which give some stats on the CEC like how many CEs it caught and the
number of pages it soft-offlined due to excessive amount of CEs.
$ cat ras/cec/array
{ n: 2
000: [0000000000000012|001]
001: [0000003735928559|e01]
}
Stats:
CEs: 514
offlined pages: 0
Flags: 0x0
Then, we stuck all the /dev/mcelog functionality behind a
CONFIG_X86_MCELOG which people can disable if they don't need mcelog and
are going to use the rasdaemon. This is probably going to happen sooner
or later with the distros anyway.
And then, as a result of that move, mce-inject is being made independent
from mcelog and gets the error injection debugfs nodes of mce_amd_inj
which you can echo into and don't need special tools:
$ tree --charset=ascii /sys/kernel/debug/mce-inject/
/sys/kernel/debug/mce-inject/
|-- addr
|-- bank
|-- cpu
|-- flags
|-- misc
|-- README
`-- status
0 directories, 7 files
Comments are more than welcome, Tony and will be polishing on those but
thought it would be a nice point in time to send them out to get other
people's opinions.
Thanks.
Borislav Petkov (3):
RAS: Add a Corrected Errors Collector
x86/mce: Merge mce_amd_inj into mce-inject
x86/mce-inject: Use debugfs_remove_recursive()
Tony Luck (1):
x86/mce: Deprecate /dev/mcelog
arch/x86/Kconfig | 8 +
arch/x86/kernel/cpu/mcheck/Makefile | 2 +
arch/x86/kernel/cpu/mcheck/dev-mcelog.c | 397 +++++++++++++++++++++++
arch/x86/kernel/cpu/mcheck/mce-inject.c | 519 +++++++++++++++++++++++++++++-
arch/x86/kernel/cpu/mcheck/mce-internal.h | 8 +
arch/x86/kernel/cpu/mcheck/mce.c | 513 +++++------------------------
arch/x86/ras/Kconfig | 11 +
arch/x86/ras/Makefile | 2 -
arch/x86/ras/mce_amd_inj.c | 484 ----------------------------
drivers/ras/Makefile | 3 +-
drivers/ras/cec.c | 425 ++++++++++++++++++++++++
drivers/ras/debugfs.c | 2 +-
drivers/ras/debugfs.h | 8 +
include/linux/ras.h | 12 +-
14 files changed, 1467 insertions(+), 927 deletions(-)
create mode 100644 arch/x86/kernel/cpu/mcheck/dev-mcelog.c
delete mode 100644 arch/x86/ras/mce_amd_inj.c
create mode 100644 drivers/ras/cec.c
create mode 100644 drivers/ras/debugfs.h
--
2.7.3
^ permalink raw reply [flat|nested] 8+ messages in thread
* [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector
2016-06-07 16:52 [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies Borislav Petkov
@ 2016-06-07 16:52 ` Borislav Petkov
2016-06-07 18:11 ` Luck, Tony
2016-06-07 16:52 ` [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog Borislav Petkov
` (2 subsequent siblings)
3 siblings, 1 reply; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 16:52 UTC (permalink / raw)
To: linux-edac; +Cc: Tony Luck, Yazen Ghannam, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
A simple data structure for collecting correctable errors along with
accessors. More detailed description in the code itself.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mcheck/mce.c | 120 +++++------
arch/x86/ras/Kconfig | 11 +
drivers/ras/Makefile | 3 +-
drivers/ras/cec.c | 425 +++++++++++++++++++++++++++++++++++++++
drivers/ras/debugfs.c | 2 +-
drivers/ras/debugfs.h | 8 +
include/linux/ras.h | 12 +-
7 files changed, 521 insertions(+), 60 deletions(-)
create mode 100644 drivers/ras/cec.c
create mode 100644 drivers/ras/debugfs.h
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 92e5e37d97bf..a6cc08a10cc3 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -35,6 +35,7 @@
#include <linux/poll.h>
#include <linux/nmi.h>
#include <linux/cpu.h>
+#include <linux/ras.h>
#include <linux/smp.h>
#include <linux/fs.h>
#include <linux/mm.h>
@@ -151,14 +152,71 @@ static struct mce_log mcelog = {
.recordlen = sizeof(struct mce),
};
-void mce_log(struct mce *mce)
+static bool memory_error(struct mce *m)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+
+ if (c->x86_vendor == X86_VENDOR_AMD) {
+ /* ErrCodeExt[20:16] */
+ u8 xec = (m->status >> 16) & 0x1f;
+
+ return (xec == 0x0 || xec == 0x8);
+ } else if (c->x86_vendor == X86_VENDOR_INTEL) {
+ /*
+ * Intel SDM Volume 3B - 15.9.2 Compound Error Codes
+ *
+ * Bit 7 of the MCACOD field of IA32_MCi_STATUS is used for
+ * indicating a memory error. Bit 8 is used for indicating a
+ * cache hierarchy error. The combination of bit 2 and bit 3
+ * is used for indicating a `generic' cache hierarchy error
+ * But we can't just blindly check the above bits, because if
+ * bit 11 is set, then it is a bus/interconnect error - and
+ * either way the above bits just gives more detail on what
+ * bus/interconnect error happened. Note that bit 12 can be
+ * ignored, as it's the "filter" bit.
+ */
+ return (m->status & 0xef80) == BIT(7) ||
+ (m->status & 0xef00) == BIT(8) ||
+ (m->status & 0xeffc) == 0xc;
+ }
+
+ return false;
+}
+
+/*
+ * Check if the address reported by the CPU is in a format we can parse.
+ * It would be possible to add code for most other cases, but all would
+ * be somewhat complicated (e.g. segment offset would require an instruction
+ * parser). So only support physical addresses up to page granuality for now.
+ */
+static int mce_usable_address(struct mce *m)
+{
+ if (!(m->status & MCI_STATUS_MISCV) || !(m->status & MCI_STATUS_ADDRV))
+ return 0;
+
+ /* Checks after this one are Intel-specific: */
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+ return 1;
+
+ if (MCI_MISC_ADDR_LSB(m->misc) > PAGE_SHIFT)
+ return 0;
+ if (MCI_MISC_ADDR_MODE(m->misc) != MCI_MISC_ADDR_PHYS)
+ return 0;
+ return 1;
+}
+
+void mce_log(struct mce *m)
{
unsigned next, entry;
+ if (!in_atomic() && memory_error(m) && mce_usable_address(m))
+ if (!ce_add_elem(m->addr >> PAGE_SHIFT))
+ return;
+
/* Emit the trace record: */
- trace_mce_record(mce);
+ trace_mce_record(m);
- if (!mce_gen_pool_add(mce))
+ if (!mce_gen_pool_add(m))
irq_work_queue(&mce_irq_work);
wmb();
@@ -188,7 +246,7 @@ void mce_log(struct mce *mce)
if (cmpxchg(&mcelog.next, entry, next) == entry)
break;
}
- memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
+ memcpy(mcelog.entry + entry, m, sizeof(struct mce));
wmb();
mcelog.entry[entry].finished = 1;
wmb();
@@ -518,28 +576,6 @@ static void mce_report_event(struct pt_regs *regs)
irq_work_queue(&mce_irq_work);
}
-/*
- * Check if the address reported by the CPU is in a format we can parse.
- * It would be possible to add code for most other cases, but all would
- * be somewhat complicated (e.g. segment offset would require an instruction
- * parser). So only support physical addresses up to page granuality for now.
- */
-static int mce_usable_address(struct mce *m)
-{
- if (!(m->status & MCI_STATUS_MISCV) || !(m->status & MCI_STATUS_ADDRV))
- return 0;
-
- /* Checks after this one are Intel-specific: */
- if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
- return 1;
-
- if (MCI_MISC_ADDR_LSB(m->misc) > PAGE_SHIFT)
- return 0;
- if (MCI_MISC_ADDR_MODE(m->misc) != MCI_MISC_ADDR_PHYS)
- return 0;
- return 1;
-}
-
static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
@@ -582,37 +618,6 @@ static void mce_read_aux(struct mce *m, int i)
}
}
-static bool memory_error(struct mce *m)
-{
- struct cpuinfo_x86 *c = &boot_cpu_data;
-
- if (c->x86_vendor == X86_VENDOR_AMD) {
- /* ErrCodeExt[20:16] */
- u8 xec = (m->status >> 16) & 0x1f;
-
- return (xec == 0x0 || xec == 0x8);
- } else if (c->x86_vendor == X86_VENDOR_INTEL) {
- /*
- * Intel SDM Volume 3B - 15.9.2 Compound Error Codes
- *
- * Bit 7 of the MCACOD field of IA32_MCi_STATUS is used for
- * indicating a memory error. Bit 8 is used for indicating a
- * cache hierarchy error. The combination of bit 2 and bit 3
- * is used for indicating a `generic' cache hierarchy error
- * But we can't just blindly check the above bits, because if
- * bit 11 is set, then it is a bus/interconnect error - and
- * either way the above bits just gives more detail on what
- * bus/interconnect error happened. Note that bit 12 can be
- * ignored, as it's the "filter" bit.
- */
- return (m->status & 0xef80) == BIT(7) ||
- (m->status & 0xef00) == BIT(8) ||
- (m->status & 0xeffc) == 0xc;
- }
-
- return false;
-}
-
DEFINE_PER_CPU(unsigned, mce_poll_count);
/*
@@ -2679,6 +2684,7 @@ static int __init mcheck_debugfs_init(void) { return -EINVAL; }
static int __init mcheck_late_init(void)
{
mcheck_debugfs_init();
+ ce_init();
/*
* Flush out everything that has been logged during early boot, now that
diff --git a/arch/x86/ras/Kconfig b/arch/x86/ras/Kconfig
index d957d5f21a86..513e8ffc9e08 100644
--- a/arch/x86/ras/Kconfig
+++ b/arch/x86/ras/Kconfig
@@ -7,3 +7,14 @@ config MCE_AMD_INJ
aspects of the MCE handling code.
WARNING: Do not even assume this interface is staying stable!
+
+config RAS_CEC
+ bool "Correctable Errors Collector"
+ depends on X86_MCE && MEMORY_FAILURE && DEBUG_FS
+ ---help---
+ This is a small cache which collects correctable memory errors per 4K
+ page PFN and counts their repeated occurrence. Once the counter for a
+ PFN overflows, we try to soft-offline that page as we take it to mean
+ that it has reached a relatively high error count and would probably
+ be best if we don't use it anymore.
+
diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile
index d7f73341ced3..7b26dd3aa5d0 100644
--- a/drivers/ras/Makefile
+++ b/drivers/ras/Makefile
@@ -1 +1,2 @@
-obj-$(CONFIG_RAS) += ras.o debugfs.o
+obj-$(CONFIG_RAS) += ras.o debugfs.o
+obj-$(CONFIG_RAS_CEC) += cec.o
diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
new file mode 100644
index 000000000000..846155124598
--- /dev/null
+++ b/drivers/ras/cec.c
@@ -0,0 +1,425 @@
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+
+#include <asm/bug.h>
+
+#include "debugfs.h"
+
+/*
+ * RAS Correctable Errors Collector
+ *
+ * This is a simple gadget which collects correctable errors and counts their
+ * occurrence per physical page address.
+ *
+ * We've opted for possibly the simplest data structure to collect those - an
+ * array of the size of a memory page. It stores 512 u64's with the following
+ * structure:
+ *
+ * [63 ... PFN ... 12 | 11 ... generation ... 10 | 9 ... count ... 0]
+ *
+ * The generation in the two highest order bits is two bits which are set to 11b
+ * on every insertion. During the course of each entry's existence, the
+ * generation field gets decremented during spring cleaning to 10b, then 01b and
+ * then 00b.
+ *
+ * This way we're employing the natural numeric ordering to make sure that newly
+ * inserted/touched elements have higher 12-bit counts (which we've manufactured)
+ * and thus iterating over the array initially won't kick out those elements
+ * which were inserted last.
+ *
+ * Spring cleaning is what we do when we reach a certain number CLEAN_ELEMS of
+ * elements entered into the array, during which, we're decaying all elements.
+ * If, after decay, an element gets inserted again, its generation is set to 11b
+ * to make sure it has higher numerical count than other, older elements and
+ * thus emulate an an LRU-like behavior when deleting elements to free up space
+ * in the page.
+ *
+ * When an element reaches it's max count of COUNT_MASK, we try to poison it by
+ * assuming that errors triggered COUNT_MASK times in a single page are
+ * excessive and that page shouldn't be used anymore.
+ *
+ * To the question why we've chosen a page and moving elements around with
+ * memmove(), it is because it is a very simple structure to handle and max data
+ * movement is 4K which on highly optimized modern CPUs is almost unnoticeable.
+ * We wanted to avoid the pointer traversal of more complex structures like a
+ * linked list or some sort of a balancing search tree.
+ *
+ * Deleting an element takes O(n) but since it is only a single page, it should
+ * be fast enough and it shouldn't happen all too often depending on error
+ * patterns.
+ */
+
+#undef pr_fmt
+#define pr_fmt(fmt) "RAS: " fmt
+
+/*
+ * We use DECAY_BITS bits of PAGE_SHIFT bits for counting decay, i.e., how long
+ * elements have stayed in the array without having been accessed again.
+ */
+#define DECAY_BITS 2
+#define DECAY_MASK ((1ULL << DECAY_BITS) - 1)
+#define MAX_ELEMS (PAGE_SIZE / sizeof(u64))
+
+/*
+ * Threshold amount of inserted elements after which we start spring
+ * cleaning.
+ */
+#define CLEAN_ELEMS (MAX_ELEMS >> DECAY_BITS)
+
+/* Bits which count the number of errors happened in this 4K page. */
+#define COUNT_BITS (PAGE_SHIFT - DECAY_BITS)
+#define COUNT_MASK ((1ULL << COUNT_BITS) - 1)
+#define FULL_COUNT_MASK (PAGE_SIZE - 1)
+
+/*
+ * u64: [ 63 ... 12 | DECAY_BITS | COUNT_BITS ]
+ */
+
+#define PFN(e) ((e) >> PAGE_SHIFT)
+#define DECAY(e) (((e) >> COUNT_BITS) & DECAY_MASK)
+#define COUNT(e) ((unsigned int)(e) & COUNT_MASK)
+#define FULL_COUNT(e) ((e) & (PAGE_SIZE - 1))
+
+static struct ce_array {
+ u64 *array; /* container page */
+ unsigned n; /* number of elements in the array */
+
+ unsigned int decay_count; /*
+ * number of element insertions/increments
+ * since the last spring cleaning.
+ */
+
+ u64 pfns_poisoned; /*
+ * number of PFNs which got poisoned.
+ */
+
+ u64 ces_entered; /*
+ * The number of correctable errors
+ * entered into the collector.
+ */
+ union {
+ struct {
+ __u32 disabled : 1, /* cmdline disabled */
+ __resv : 31;
+ };
+ __u32 flags;
+ };
+} ce_arr;
+
+static DEFINE_MUTEX(ce_mutex);
+
+static u64 dfs_pfn;
+
+/*
+ * Decrement decay value. We're using DECAY_BITS bits to denote decay of an
+ * element in the array. On insertion and any access, it gets reset to max.
+ */
+static void do_spring_cleaning(struct ce_array *ca)
+{
+ int i;
+
+ for (i = 0; i < ca->n; i++) {
+ u8 decay = DECAY(ca->array[i]);
+
+ if (!decay)
+ continue;
+
+ decay--;
+
+ ca->array[i] &= ~(DECAY_MASK << COUNT_BITS);
+ ca->array[i] |= (decay << COUNT_BITS);
+ }
+ ca->decay_count = 0;
+}
+
+/*
+ * @to: index of the smallest element which is >= then @pfn.
+ *
+ * Return the index of the pfn if found, otherwise negative value.
+ */
+static int __find_elem(struct ce_array *ca, u64 pfn, unsigned *to)
+{
+ u64 this_pfn;
+ int min = 0, max = ca->n;
+
+ while (min < max) {
+ int tmp = (max + min) >> 1;
+
+ this_pfn = PFN(ca->array[tmp]);
+
+ if (this_pfn < pfn)
+ min = tmp + 1;
+ else if (this_pfn > pfn)
+ max = tmp;
+ else {
+ min = tmp;
+ break;
+ }
+ }
+
+ if (to)
+ *to = min;
+
+ this_pfn = PFN(ca->array[min]);
+
+ if (this_pfn == pfn)
+ return min;
+
+ return -ENOKEY;
+}
+
+static int find_elem(struct ce_array *ca, u64 pfn, unsigned *to)
+{
+ WARN_ON(!to);
+
+ if (!ca->n) {
+ *to = 0;
+ return -ENOKEY;
+ }
+ return __find_elem(ca, pfn, to);
+}
+
+static void del_elem(struct ce_array *ca, int idx)
+{
+ /* Save us a function call when deleting the last element. */
+ if (ca->n - (idx + 1))
+ memmove((void *)&ca->array[idx],
+ (void *)&ca->array[idx + 1],
+ (ca->n - (idx + 1)) * sizeof(u64));
+
+ ca->n--;
+}
+
+static u64 del_lru_elem_unlocked(struct ce_array *ca)
+{
+ unsigned int min = FULL_COUNT_MASK;
+ int i, min_idx = 0;
+
+ for (i = 0; i < ca->n; i++) {
+ unsigned int this = FULL_COUNT(ca->array[i]);
+ if (min > this) {
+ min = this;
+ min_idx = i;
+ }
+ }
+
+ del_elem(ca, min_idx);
+
+ return PFN(ca->array[min_idx]);
+}
+
+/*
+ * We return the 0th pfn in the error case under the assumption that it cannot
+ * be poisoned and excessive CEs in there are a serious deal anyway.
+ */
+static u64 __maybe_unused del_lru_elem(void)
+{
+ struct ce_array *ca = &ce_arr;
+ u64 pfn;
+
+ if (!ca->n)
+ return 0;
+
+ mutex_lock(&ce_mutex);
+ pfn = del_lru_elem_unlocked(ca);
+ mutex_unlock(&ce_mutex);
+
+ return pfn;
+}
+
+
+int ce_add_elem(u64 pfn)
+{
+ struct ce_array *ca = &ce_arr;
+ unsigned to;
+ int count, ret;
+
+ /*
+ * We can be called very early on the identify_cpu() path where we are
+ * not initialized yet. We ignore the error for simplicity.
+ */
+ if (!ce_arr.array)
+ return -ENODEV;
+
+ ca->ces_entered++;
+
+ mutex_lock(&ce_mutex);
+
+ if (ca->n == MAX_ELEMS)
+ WARN_ON(!del_lru_elem_unlocked(ca));
+
+ ret = find_elem(ca, pfn, &to);
+ if (ret < 0) {
+ /*
+ * Shift range [to-end] to make room for one more element.
+ */
+ memmove((void *)&ca->array[to + 1],
+ (void *)&ca->array[to],
+ (ca->n - to) * sizeof(u64));
+
+ ca->array[to] = (pfn << PAGE_SHIFT) |
+ (DECAY_MASK << COUNT_BITS) | 1;
+
+ ca->n++;
+
+ goto decay;
+ }
+
+ count = COUNT(ca->array[to]);
+
+ if (count < COUNT_MASK) {
+ ca->array[to] |= (DECAY_MASK << COUNT_BITS);
+ ca->array[to]++;
+ } else {
+ u64 pfn = ca->array[to] >> PAGE_SHIFT;
+
+ /*
+ * We have reached max count for this page, soft-offline it.
+ */
+ pr_err("Soft-offlining pfn: 0x%llx\n", pfn);
+ memory_failure_queue(pfn, 0, MF_SOFT_OFFLINE);
+ ca->pfns_poisoned++;
+ del_elem(ca, to);
+
+ ret = 0;
+
+ goto unlock;
+ }
+
+decay:
+ ca->decay_count++;
+
+ if (ca->decay_count >= CLEAN_ELEMS)
+ do_spring_cleaning(ca);
+
+unlock:
+ mutex_unlock(&ce_mutex);
+
+ return 0;
+}
+
+static int pfn_get(void *data, u64 *val)
+{
+ *val = *(u64 *)data;
+
+ return 0;
+}
+
+static int pfn_set(void *data, u64 val)
+{
+ *(u64 *)data = val;
+
+ return ce_add_elem(val);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(pfn_ops, pfn_get, pfn_set, "0x%llx\n");
+
+static int array_dump(struct seq_file *m, void *v)
+{
+ struct ce_array *ca = &ce_arr;
+ u64 prev = 0;
+ int i;
+
+ mutex_lock(&ce_mutex);
+
+ seq_printf(m, "{ n: %d\n", ca->n);
+ for (i = 0; i < ca->n; i++) {
+ u64 this = PFN(ca->array[i]);
+
+ seq_printf(m, " %03d: [%016llu|%03llx]\n", i, this, FULL_COUNT(ca->array[i]));
+
+ WARN_ON(prev > this);
+
+ prev = this;
+ }
+
+ seq_printf(m, "}\n");
+
+ seq_printf(m, "Stats:\n CEs: %llu\n offlined pages: %llu\n",
+ ca->ces_entered, ca->pfns_poisoned);
+
+ seq_printf(m, "Flags: 0x%x\n", ca->flags);
+
+ mutex_unlock(&ce_mutex);
+
+ return 0;
+}
+
+static int array_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, array_dump, NULL);
+}
+
+static const struct file_operations array_ops = {
+ .owner = THIS_MODULE,
+ .open = array_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init create_debugfs_nodes(void)
+{
+ struct dentry *d, *pfn, *array;
+
+ d = debugfs_create_dir("cec", ras_debugfs_dir);
+ if (!d) {
+ pr_warn("Error creating cec debugfs node!\n");
+ return -1;
+ }
+
+ pfn = debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops);
+ if (!pfn) {
+ pr_warn("Error creating pfn debugfs node!\n");
+ goto err;
+ }
+
+ array = debugfs_create_file("array", S_IRUSR, d, NULL, &array_ops);
+ if (!array) {
+ pr_warn("Error creating array debugfs node!\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ debugfs_remove_recursive(d);
+
+ return 1;
+}
+
+void __init ce_init(void)
+{
+ if (ce_arr.disabled)
+ return;
+
+ ce_arr.array = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!ce_arr.array) {
+ pr_err("Error allocating CE array page!\n");
+ return;
+ }
+
+ if (create_debugfs_nodes())
+ return;
+
+ pr_info("Correctable Errors collector initialized.\n");
+}
+
+static int __init cec_param(char *str)
+{
+ if (!str)
+ return 0;
+
+ if (*str == '=')
+ str++;
+
+ if (!strncmp(str, "disable", 7))
+ ce_arr.disabled = 1;
+ else
+ return 0;
+
+ return 1;
+}
+
+__setup("cec", cec_param);
diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c
index 0322acf67ea5..501603057dff 100644
--- a/drivers/ras/debugfs.c
+++ b/drivers/ras/debugfs.c
@@ -1,6 +1,6 @@
#include <linux/debugfs.h>
-static struct dentry *ras_debugfs_dir;
+struct dentry *ras_debugfs_dir;
static atomic_t trace_count = ATOMIC_INIT(0);
diff --git a/drivers/ras/debugfs.h b/drivers/ras/debugfs.h
new file mode 100644
index 000000000000..db72e4513191
--- /dev/null
+++ b/drivers/ras/debugfs.h
@@ -0,0 +1,8 @@
+#ifndef __RAS_DEBUGFS_H__
+#define __RAS_DEBUGFS_H__
+
+#include <linux/debugfs.h>
+
+extern struct dentry *ras_debugfs_dir;
+
+#endif /* __RAS_DEBUGFS_H__ */
diff --git a/include/linux/ras.h b/include/linux/ras.h
index 2aceeafd6fe5..a96762a10100 100644
--- a/include/linux/ras.h
+++ b/include/linux/ras.h
@@ -1,14 +1,24 @@
#ifndef __RAS_H__
#define __RAS_H__
+#include <asm/errno.h>
+
#ifdef CONFIG_DEBUG_FS
int ras_userspace_consumers(void);
void ras_debugfs_init(void);
int ras_add_daemon_trace(void);
#else
static inline int ras_userspace_consumers(void) { return 0; }
-static inline void ras_debugfs_init(void) { return; }
+static inline void ras_debugfs_init(void) { }
static inline int ras_add_daemon_trace(void) { return 0; }
#endif
+#ifdef CONFIG_RAS_CEC
+void __init ce_init(void);
+int ce_add_elem(u64 pfn);
+#else
+static inline void __init ce_init(void) { }
+static inline int ce_add_elem(u64 pfn) { return -ENODEV; }
#endif
+
+#endif /* __RAS_H__ */
--
2.7.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog
2016-06-07 16:52 [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector Borislav Petkov
@ 2016-06-07 16:52 ` Borislav Petkov
2016-06-13 9:00 ` Thomas Gleixner
2016-06-07 16:52 ` [RFC PATCH 3/4] x86/mce: Merge mce_amd_inj into mce-inject Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 4/4] x86/mce-inject: Use debugfs_remove_recursive() Borislav Petkov
3 siblings, 1 reply; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 16:52 UTC (permalink / raw)
To: linux-edac; +Cc: Tony Luck, Yazen Ghannam, X86 ML, LKML
From: Tony Luck <tony.luck@intel.com>
Move all code relating to /dev/mcelog to own source file. /dev/mcelog
driver can now operate from the machine check notifier with lowest prio.
Boris:
* Move the mce_helper and trigger functionality behind
CONFIG_X86_MCELOG.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/Kconfig | 10 +-
arch/x86/kernel/cpu/mcheck/Makefile | 2 +
arch/x86/kernel/cpu/mcheck/dev-mcelog.c | 397 +++++++++++++++++++++++++++++
arch/x86/kernel/cpu/mcheck/mce-internal.h | 8 +
arch/x86/kernel/cpu/mcheck/mce.c | 405 +++---------------------------
5 files changed, 445 insertions(+), 377 deletions(-)
create mode 100644 arch/x86/kernel/cpu/mcheck/dev-mcelog.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0a7b885964ba..0bb289520207 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1004,6 +1004,14 @@ config X86_MCE
The action the kernel takes depends on the severity of the problem,
ranging from warning messages to halting the machine.
+config X86_MCELOG
+ bool "Support for deprecated /dev/mcelog character device"
+ depends on X86_MCE
+ ---help---
+ Enable support for /dev/mcelog which is needed by the old mcelog
+ userspace logging daemon. Consider switching to the new generation
+ rasdaemon solution.
+
config X86_MCE_INTEL
def_bool y
prompt "Intel MCE features"
@@ -1033,7 +1041,7 @@ config X86_MCE_THRESHOLD
def_bool y
config X86_MCE_INJECT
- depends on X86_MCE
+ depends on X86_MCE && X86_MCELOG
tristate "Machine check injector support"
---help---
Provide support for injecting machine checks for testing purposes.
diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile
index a3311c886194..950e9ff602ea 100644
--- a/arch/x86/kernel/cpu/mcheck/Makefile
+++ b/arch/x86/kernel/cpu/mcheck/Makefile
@@ -9,3 +9,5 @@ obj-$(CONFIG_X86_MCE_INJECT) += mce-inject.o
obj-$(CONFIG_X86_THERMAL_VECTOR) += therm_throt.o
obj-$(CONFIG_ACPI_APEI) += mce-apei.o
+
+obj-$(CONFIG_X86_MCELOG) += dev-mcelog.o
diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
new file mode 100644
index 000000000000..798bff750e35
--- /dev/null
+++ b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
@@ -0,0 +1,397 @@
+/*
+ * /dev/mcelog driver
+ *
+ * K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs.
+ * Rest from unknown author(s).
+ * 2004 Andi Kleen. Rewrote most of it.
+ * Copyright 2008 Intel Corporation
+ * Author: Andi Kleen
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/miscdevice.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/poll.h>
+
+#include "mce-internal.h"
+
+static DEFINE_MUTEX(mce_chrdev_read_mutex);
+
+static char mce_helper[128];
+static char *mce_helper_argv[2] = { mce_helper, NULL };
+
+#define mce_log_get_idx_check(p) \
+({ \
+ RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \
+ !lockdep_is_held(&mce_chrdev_read_mutex), \
+ "suspicious mce_log_get_idx_check() usage"); \
+ smp_load_acquire(&(p)); \
+})
+
+/*
+ * Lockless MCE logging infrastructure.
+ * This avoids deadlocks on printk locks without having to break locks. Also
+ * separate MCEs from kernel messages to avoid bogus bug reports.
+ */
+
+static struct mce_log mcelog = {
+ .signature = MCE_LOG_SIGNATURE,
+ .len = MCE_LOG_LEN,
+ .recordlen = sizeof(struct mce),
+};
+
+static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
+
+/* User mode helper program triggered by machine check event */
+extern char mce_helper[128];
+
+static int dev_mce_log(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct mce *mce = (struct mce *)data;
+ unsigned next, entry;
+
+ wmb();
+ for (;;) {
+ entry = mce_log_get_idx_check(mcelog.next);
+ for (;;) {
+
+ /*
+ * When the buffer fills up discard new entries.
+ * Assume that the earlier errors are the more
+ * interesting ones:
+ */
+ if (entry >= MCE_LOG_LEN) {
+ set_bit(MCE_OVERFLOW,
+ (unsigned long *)&mcelog.flags);
+ return NOTIFY_OK;
+ }
+ /* Old left over entry. Skip: */
+ if (mcelog.entry[entry].finished) {
+ entry++;
+ continue;
+ }
+ break;
+ }
+ smp_rmb();
+ next = entry + 1;
+ if (cmpxchg(&mcelog.next, entry, next) == entry)
+ break;
+ }
+ memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
+ wmb();
+ mcelog.entry[entry].finished = 1;
+ wmb();
+
+ /* wake processes polling /dev/mcelog */
+ wake_up_interruptible(&mce_chrdev_wait);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block dev_mcelog_nb = {
+ .notifier_call = dev_mce_log,
+ .priority = 0,
+};
+
+static void mce_do_trigger(struct work_struct *work)
+{
+ call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT);
+}
+
+static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
+
+
+void mce_work_trigger(void)
+{
+ if (mce_helper[0])
+ schedule_work(&mce_trigger_work);
+}
+
+static ssize_t
+show_trigger(struct device *s, struct device_attribute *attr, char *buf)
+{
+ strcpy(buf, mce_helper);
+ strcat(buf, "\n");
+ return strlen(mce_helper) + 1;
+}
+
+static ssize_t set_trigger(struct device *s, struct device_attribute *attr,
+ const char *buf, size_t siz)
+{
+ char *p;
+
+ strncpy(mce_helper, buf, sizeof(mce_helper));
+ mce_helper[sizeof(mce_helper)-1] = 0;
+ p = strchr(mce_helper, '\n');
+
+ if (p)
+ *p = 0;
+
+ return strlen(mce_helper) + !!p;
+}
+
+DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger);
+
+/*
+ * mce_chrdev: Character device /dev/mcelog to read and clear the MCE log.
+ */
+
+static DEFINE_SPINLOCK(mce_chrdev_state_lock);
+static int mce_chrdev_open_count; /* #times opened */
+static int mce_chrdev_open_exclu; /* already open exclusive? */
+
+static int mce_chrdev_open(struct inode *inode, struct file *file)
+{
+ spin_lock(&mce_chrdev_state_lock);
+
+ if (mce_chrdev_open_exclu ||
+ (mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
+ spin_unlock(&mce_chrdev_state_lock);
+
+ return -EBUSY;
+ }
+
+ if (file->f_flags & O_EXCL)
+ mce_chrdev_open_exclu = 1;
+ mce_chrdev_open_count++;
+
+ spin_unlock(&mce_chrdev_state_lock);
+
+ return nonseekable_open(inode, file);
+}
+
+static int mce_chrdev_release(struct inode *inode, struct file *file)
+{
+ spin_lock(&mce_chrdev_state_lock);
+
+ mce_chrdev_open_count--;
+ mce_chrdev_open_exclu = 0;
+
+ spin_unlock(&mce_chrdev_state_lock);
+
+ return 0;
+}
+
+static void collect_tscs(void *data)
+{
+ unsigned long *cpu_tsc = (unsigned long *)data;
+
+ cpu_tsc[smp_processor_id()] = rdtsc();
+}
+
+static int mce_apei_read_done;
+
+/* Collect MCE record of previous boot in persistent storage via APEI ERST. */
+static int __mce_read_apei(char __user **ubuf, size_t usize)
+{
+ int rc;
+ u64 record_id;
+ struct mce m;
+
+ if (usize < sizeof(struct mce))
+ return -EINVAL;
+
+ rc = apei_read_mce(&m, &record_id);
+ /* Error or no more MCE record */
+ if (rc <= 0) {
+ mce_apei_read_done = 1;
+ /*
+ * When ERST is disabled, mce_chrdev_read() should return
+ * "no record" instead of "no device."
+ */
+ if (rc == -ENODEV)
+ return 0;
+ return rc;
+ }
+ rc = -EFAULT;
+ if (copy_to_user(*ubuf, &m, sizeof(struct mce)))
+ return rc;
+ /*
+ * In fact, we should have cleared the record after that has
+ * been flushed to the disk or sent to network in
+ * /sbin/mcelog, but we have no interface to support that now,
+ * so just clear it to avoid duplication.
+ */
+ rc = apei_clear_mce(record_id);
+ if (rc) {
+ mce_apei_read_done = 1;
+ return rc;
+ }
+ *ubuf += sizeof(struct mce);
+
+ return 0;
+}
+
+static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
+ size_t usize, loff_t *off)
+{
+ char __user *buf = ubuf;
+ unsigned long *cpu_tsc;
+ unsigned prev, next;
+ int i, err;
+
+ cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
+ if (!cpu_tsc)
+ return -ENOMEM;
+
+ mutex_lock(&mce_chrdev_read_mutex);
+
+ if (!mce_apei_read_done) {
+ err = __mce_read_apei(&buf, usize);
+ if (err || buf != ubuf)
+ goto out;
+ }
+
+ next = mce_log_get_idx_check(mcelog.next);
+
+ /* Only supports full reads right now */
+ err = -EINVAL;
+ if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce))
+ goto out;
+
+ err = 0;
+ prev = 0;
+ do {
+ for (i = prev; i < next; i++) {
+ unsigned long start = jiffies;
+ struct mce *m = &mcelog.entry[i];
+
+ while (!m->finished) {
+ if (time_after_eq(jiffies, start + 2)) {
+ memset(m, 0, sizeof(*m));
+ goto timeout;
+ }
+ cpu_relax();
+ }
+ smp_rmb();
+ err |= copy_to_user(buf, m, sizeof(*m));
+ buf += sizeof(*m);
+timeout:
+ ;
+ }
+
+ memset(mcelog.entry + prev, 0,
+ (next - prev) * sizeof(struct mce));
+ prev = next;
+ next = cmpxchg(&mcelog.next, prev, 0);
+ } while (next != prev);
+
+ synchronize_sched();
+
+ /*
+ * Collect entries that were still getting written before the
+ * synchronize.
+ */
+ on_each_cpu(collect_tscs, cpu_tsc, 1);
+
+ for (i = next; i < MCE_LOG_LEN; i++) {
+ struct mce *m = &mcelog.entry[i];
+
+ if (m->finished && m->tsc < cpu_tsc[m->cpu]) {
+ err |= copy_to_user(buf, m, sizeof(*m));
+ smp_rmb();
+ buf += sizeof(*m);
+ memset(m, 0, sizeof(*m));
+ }
+ }
+
+ if (err)
+ err = -EFAULT;
+
+out:
+ mutex_unlock(&mce_chrdev_read_mutex);
+ kfree(cpu_tsc);
+
+ return err ? err : buf - ubuf;
+}
+
+static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait)
+{
+ poll_wait(file, &mce_chrdev_wait, wait);
+ if (READ_ONCE(mcelog.next))
+ return POLLIN | POLLRDNORM;
+ if (!mce_apei_read_done && apei_check_mce())
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+
+static long mce_chrdev_ioctl(struct file *f, unsigned int cmd,
+ unsigned long arg)
+{
+ int __user *p = (int __user *)arg;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case MCE_GET_RECORD_LEN:
+ return put_user(sizeof(struct mce), p);
+ case MCE_GET_LOG_LEN:
+ return put_user(MCE_LOG_LEN, p);
+ case MCE_GETCLEAR_FLAGS: {
+ unsigned flags;
+
+ do {
+ flags = mcelog.flags;
+ } while (cmpxchg(&mcelog.flags, flags, 0) != flags);
+
+ return put_user(flags, p);
+ }
+ default:
+ return -ENOTTY;
+ }
+}
+
+static ssize_t (*mce_write)(struct file *filp, const char __user *ubuf,
+ size_t usize, loff_t *off);
+
+void register_mce_write_callback(ssize_t (*fn)(struct file *filp,
+ const char __user *ubuf,
+ size_t usize, loff_t *off))
+{
+ mce_write = fn;
+}
+EXPORT_SYMBOL_GPL(register_mce_write_callback);
+
+static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
+ size_t usize, loff_t *off)
+{
+ if (mce_write)
+ return mce_write(filp, ubuf, usize, off);
+ else
+ return -EINVAL;
+}
+
+static const struct file_operations mce_chrdev_ops = {
+ .open = mce_chrdev_open,
+ .release = mce_chrdev_release,
+ .read = mce_chrdev_read,
+ .write = mce_chrdev_write,
+ .poll = mce_chrdev_poll,
+ .unlocked_ioctl = mce_chrdev_ioctl,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice mce_chrdev_device = {
+ MISC_MCELOG_MINOR,
+ "mcelog",
+ &mce_chrdev_ops,
+};
+
+static __init int dev_mcelog_init_device(void)
+{
+ int err;
+
+ /* register character device /dev/mcelog */
+ err = misc_register(&mce_chrdev_device);
+ if (err) {
+ pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
+ return err;
+ }
+ mce_register_decode_chain(&dev_mcelog_nb);
+ return 0;
+}
+device_initcall_sync(dev_mcelog_init_device);
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index cd74a3f00aea..aa0deeb8bb69 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -96,3 +96,11 @@ static inline bool mce_cmp(struct mce *m1, struct mce *m2)
m1->addr != m2->addr ||
m1->misc != m2->misc;
}
+
+extern struct device_attribute dev_attr_trigger;
+
+#ifdef CONFIG_X86_MCELOG
+extern void mce_work_trigger(void);
+#else
+static inline void mce_work_trigger(void) { }
+#endif
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index a6cc08a10cc3..f8efd8569694 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -51,16 +51,6 @@
#include "mce-internal.h"
-static DEFINE_MUTEX(mce_chrdev_read_mutex);
-
-#define mce_log_get_idx_check(p) \
-({ \
- RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \
- !lockdep_is_held(&mce_chrdev_read_mutex), \
- "suspicious mce_log_get_idx_check() usage"); \
- smp_load_acquire(&(p)); \
-})
-
#define CREATE_TRACE_POINTS
#include <trace/events/mce.h>
@@ -84,12 +74,7 @@ struct mca_config mca_cfg __read_mostly = {
.monarch_timeout = -1
};
-/* User mode helper program triggered by machine check event */
static unsigned long mce_need_notify;
-static char mce_helper[128];
-static char *mce_helper_argv[2] = { mce_helper, NULL };
-
-static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait);
static DEFINE_PER_CPU(struct mce, mces_seen);
static int cpu_missing;
@@ -140,18 +125,6 @@ void mce_setup(struct mce *m)
DEFINE_PER_CPU(struct mce, injectm);
EXPORT_PER_CPU_SYMBOL_GPL(injectm);
-/*
- * Lockless MCE logging infrastructure.
- * This avoids deadlocks on printk locks without having to break locks. Also
- * separate MCEs from kernel messages to avoid bogus bug reports.
- */
-
-static struct mce_log mcelog = {
- .signature = MCE_LOG_SIGNATURE,
- .len = MCE_LOG_LEN,
- .recordlen = sizeof(struct mce),
-};
-
static bool memory_error(struct mce *m)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
@@ -207,8 +180,6 @@ static int mce_usable_address(struct mce *m)
void mce_log(struct mce *m)
{
- unsigned next, entry;
-
if (!in_atomic() && memory_error(m) && mce_usable_address(m))
if (!ce_add_elem(m->addr >> PAGE_SHIFT))
return;
@@ -218,50 +189,41 @@ void mce_log(struct mce *m)
if (!mce_gen_pool_add(m))
irq_work_queue(&mce_irq_work);
-
- wmb();
- for (;;) {
- entry = mce_log_get_idx_check(mcelog.next);
- for (;;) {
-
- /*
- * When the buffer fills up discard new entries.
- * Assume that the earlier errors are the more
- * interesting ones:
- */
- if (entry >= MCE_LOG_LEN) {
- set_bit(MCE_OVERFLOW,
- (unsigned long *)&mcelog.flags);
- return;
- }
- /* Old left over entry. Skip: */
- if (mcelog.entry[entry].finished) {
- entry++;
- continue;
- }
- break;
- }
- smp_rmb();
- next = entry + 1;
- if (cmpxchg(&mcelog.next, entry, next) == entry)
- break;
- }
- memcpy(mcelog.entry + entry, m, sizeof(struct mce));
- wmb();
- mcelog.entry[entry].finished = 1;
- wmb();
-
set_bit(0, &mce_need_notify);
}
+static DEFINE_MUTEX(mce_log_mutex);
+
void mce_inject_log(struct mce *m)
{
- mutex_lock(&mce_chrdev_read_mutex);
+ mutex_lock(&mce_log_mutex);
mce_log(m);
- mutex_unlock(&mce_chrdev_read_mutex);
+ mutex_unlock(&mce_log_mutex);
}
EXPORT_SYMBOL_GPL(mce_inject_log);
+/*
+ * Notify the user(s) about new machine check events.
+ * Can be called from interrupt context, but not from machine check/NMI
+ * context.
+ */
+int mce_notify_irq(void)
+{
+ /* Not more than two messages every minute */
+ static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
+
+ if (test_and_clear_bit(0, &mce_need_notify)) {
+ mce_work_trigger();
+
+ if (__ratelimit(&ratelimit))
+ pr_info(HW_ERR "Machine check events logged\n");
+
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mce_notify_irq);
+
static struct notifier_block mce_srao_nb;
void mce_register_decode_chain(struct notifier_block *nb)
@@ -1379,39 +1341,6 @@ static void mce_timer_delete_all(void)
del_timer_sync(&per_cpu(mce_timer, cpu));
}
-static void mce_do_trigger(struct work_struct *work)
-{
- call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT);
-}
-
-static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
-
-/*
- * Notify the user(s) about new machine check events.
- * Can be called from interrupt context, but not from machine check/NMI
- * context.
- */
-int mce_notify_irq(void)
-{
- /* Not more than two messages every minute */
- static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
-
- if (test_and_clear_bit(0, &mce_need_notify)) {
- /* wake processes polling /dev/mcelog */
- wake_up_interruptible(&mce_chrdev_wait);
-
- if (mce_helper[0])
- schedule_work(&mce_trigger_work);
-
- if (__ratelimit(&ratelimit))
- pr_info(HW_ERR "Machine check events logged\n");
-
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL_GPL(mce_notify_irq);
-
static int __mcheck_cpu_mce_banks_init(void)
{
int i;
@@ -1808,252 +1737,6 @@ void mcheck_cpu_clear(struct cpuinfo_x86 *c)
}
-/*
- * mce_chrdev: Character device /dev/mcelog to read and clear the MCE log.
- */
-
-static DEFINE_SPINLOCK(mce_chrdev_state_lock);
-static int mce_chrdev_open_count; /* #times opened */
-static int mce_chrdev_open_exclu; /* already open exclusive? */
-
-static int mce_chrdev_open(struct inode *inode, struct file *file)
-{
- spin_lock(&mce_chrdev_state_lock);
-
- if (mce_chrdev_open_exclu ||
- (mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
- spin_unlock(&mce_chrdev_state_lock);
-
- return -EBUSY;
- }
-
- if (file->f_flags & O_EXCL)
- mce_chrdev_open_exclu = 1;
- mce_chrdev_open_count++;
-
- spin_unlock(&mce_chrdev_state_lock);
-
- return nonseekable_open(inode, file);
-}
-
-static int mce_chrdev_release(struct inode *inode, struct file *file)
-{
- spin_lock(&mce_chrdev_state_lock);
-
- mce_chrdev_open_count--;
- mce_chrdev_open_exclu = 0;
-
- spin_unlock(&mce_chrdev_state_lock);
-
- return 0;
-}
-
-static void collect_tscs(void *data)
-{
- unsigned long *cpu_tsc = (unsigned long *)data;
-
- cpu_tsc[smp_processor_id()] = rdtsc();
-}
-
-static int mce_apei_read_done;
-
-/* Collect MCE record of previous boot in persistent storage via APEI ERST. */
-static int __mce_read_apei(char __user **ubuf, size_t usize)
-{
- int rc;
- u64 record_id;
- struct mce m;
-
- if (usize < sizeof(struct mce))
- return -EINVAL;
-
- rc = apei_read_mce(&m, &record_id);
- /* Error or no more MCE record */
- if (rc <= 0) {
- mce_apei_read_done = 1;
- /*
- * When ERST is disabled, mce_chrdev_read() should return
- * "no record" instead of "no device."
- */
- if (rc == -ENODEV)
- return 0;
- return rc;
- }
- rc = -EFAULT;
- if (copy_to_user(*ubuf, &m, sizeof(struct mce)))
- return rc;
- /*
- * In fact, we should have cleared the record after that has
- * been flushed to the disk or sent to network in
- * /sbin/mcelog, but we have no interface to support that now,
- * so just clear it to avoid duplication.
- */
- rc = apei_clear_mce(record_id);
- if (rc) {
- mce_apei_read_done = 1;
- return rc;
- }
- *ubuf += sizeof(struct mce);
-
- return 0;
-}
-
-static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
- size_t usize, loff_t *off)
-{
- char __user *buf = ubuf;
- unsigned long *cpu_tsc;
- unsigned prev, next;
- int i, err;
-
- cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
- if (!cpu_tsc)
- return -ENOMEM;
-
- mutex_lock(&mce_chrdev_read_mutex);
-
- if (!mce_apei_read_done) {
- err = __mce_read_apei(&buf, usize);
- if (err || buf != ubuf)
- goto out;
- }
-
- next = mce_log_get_idx_check(mcelog.next);
-
- /* Only supports full reads right now */
- err = -EINVAL;
- if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce))
- goto out;
-
- err = 0;
- prev = 0;
- do {
- for (i = prev; i < next; i++) {
- unsigned long start = jiffies;
- struct mce *m = &mcelog.entry[i];
-
- while (!m->finished) {
- if (time_after_eq(jiffies, start + 2)) {
- memset(m, 0, sizeof(*m));
- goto timeout;
- }
- cpu_relax();
- }
- smp_rmb();
- err |= copy_to_user(buf, m, sizeof(*m));
- buf += sizeof(*m);
-timeout:
- ;
- }
-
- memset(mcelog.entry + prev, 0,
- (next - prev) * sizeof(struct mce));
- prev = next;
- next = cmpxchg(&mcelog.next, prev, 0);
- } while (next != prev);
-
- synchronize_sched();
-
- /*
- * Collect entries that were still getting written before the
- * synchronize.
- */
- on_each_cpu(collect_tscs, cpu_tsc, 1);
-
- for (i = next; i < MCE_LOG_LEN; i++) {
- struct mce *m = &mcelog.entry[i];
-
- if (m->finished && m->tsc < cpu_tsc[m->cpu]) {
- err |= copy_to_user(buf, m, sizeof(*m));
- smp_rmb();
- buf += sizeof(*m);
- memset(m, 0, sizeof(*m));
- }
- }
-
- if (err)
- err = -EFAULT;
-
-out:
- mutex_unlock(&mce_chrdev_read_mutex);
- kfree(cpu_tsc);
-
- return err ? err : buf - ubuf;
-}
-
-static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait)
-{
- poll_wait(file, &mce_chrdev_wait, wait);
- if (READ_ONCE(mcelog.next))
- return POLLIN | POLLRDNORM;
- if (!mce_apei_read_done && apei_check_mce())
- return POLLIN | POLLRDNORM;
- return 0;
-}
-
-static long mce_chrdev_ioctl(struct file *f, unsigned int cmd,
- unsigned long arg)
-{
- int __user *p = (int __user *)arg;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- switch (cmd) {
- case MCE_GET_RECORD_LEN:
- return put_user(sizeof(struct mce), p);
- case MCE_GET_LOG_LEN:
- return put_user(MCE_LOG_LEN, p);
- case MCE_GETCLEAR_FLAGS: {
- unsigned flags;
-
- do {
- flags = mcelog.flags;
- } while (cmpxchg(&mcelog.flags, flags, 0) != flags);
-
- return put_user(flags, p);
- }
- default:
- return -ENOTTY;
- }
-}
-
-static ssize_t (*mce_write)(struct file *filp, const char __user *ubuf,
- size_t usize, loff_t *off);
-
-void register_mce_write_callback(ssize_t (*fn)(struct file *filp,
- const char __user *ubuf,
- size_t usize, loff_t *off))
-{
- mce_write = fn;
-}
-EXPORT_SYMBOL_GPL(register_mce_write_callback);
-
-static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
- size_t usize, loff_t *off)
-{
- if (mce_write)
- return mce_write(filp, ubuf, usize, off);
- else
- return -EINVAL;
-}
-
-static const struct file_operations mce_chrdev_ops = {
- .open = mce_chrdev_open,
- .release = mce_chrdev_release,
- .read = mce_chrdev_read,
- .write = mce_chrdev_write,
- .poll = mce_chrdev_poll,
- .unlocked_ioctl = mce_chrdev_ioctl,
- .llseek = no_llseek,
-};
-
-static struct miscdevice mce_chrdev_device = {
- MISC_MCELOG_MINOR,
- "mcelog",
- &mce_chrdev_ops,
-};
-
static void __mce_disable_bank(void *arg)
{
int bank = *((int *)arg);
@@ -2271,29 +1954,6 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr,
return size;
}
-static ssize_t
-show_trigger(struct device *s, struct device_attribute *attr, char *buf)
-{
- strcpy(buf, mce_helper);
- strcat(buf, "\n");
- return strlen(mce_helper) + 1;
-}
-
-static ssize_t set_trigger(struct device *s, struct device_attribute *attr,
- const char *buf, size_t siz)
-{
- char *p;
-
- strncpy(mce_helper, buf, sizeof(mce_helper));
- mce_helper[sizeof(mce_helper)-1] = 0;
- p = strchr(mce_helper, '\n');
-
- if (p)
- *p = 0;
-
- return strlen(mce_helper) + !!p;
-}
-
static ssize_t set_ignore_ce(struct device *s,
struct device_attribute *attr,
const char *buf, size_t size)
@@ -2350,7 +2010,6 @@ static ssize_t store_int_with_restart(struct device *s,
return ret;
}
-static DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger);
static DEVICE_INT_ATTR(tolerant, 0644, mca_cfg.tolerant);
static DEVICE_INT_ATTR(monarch_timeout, 0644, mca_cfg.monarch_timeout);
static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce);
@@ -2373,7 +2032,9 @@ static struct dev_ext_attribute dev_attr_cmci_disabled = {
static struct device_attribute *mce_device_attrs[] = {
&dev_attr_tolerant.attr,
&dev_attr_check_interval.attr,
+#ifdef CONFIG_X86_MCELOG
&dev_attr_trigger,
+#endif
&dev_attr_monarch_timeout.attr,
&dev_attr_dont_log_ce.attr,
&dev_attr_ignore_ce.attr,
@@ -2587,16 +2248,8 @@ static __init int mcheck_init_device(void)
register_syscore_ops(&mce_syscore_ops);
- /* register character device /dev/mcelog */
- err = misc_register(&mce_chrdev_device);
- if (err)
- goto err_register;
-
return 0;
-err_register:
- unregister_syscore_ops(&mce_syscore_ops);
-
err_device_create:
/*
* We didn't keep track of which devices were created above, but
@@ -2611,7 +2264,7 @@ err_out_mem:
free_cpumask_var(mce_device_initialized);
err_out:
- pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
+ pr_err("Unable to init mce devices (rc: %d)\n", err);
return err;
}
--
2.7.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RFC PATCH 3/4] x86/mce: Merge mce_amd_inj into mce-inject
2016-06-07 16:52 [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog Borislav Petkov
@ 2016-06-07 16:52 ` Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 4/4] x86/mce-inject: Use debugfs_remove_recursive() Borislav Petkov
3 siblings, 0 replies; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 16:52 UTC (permalink / raw)
To: linux-edac; +Cc: Tony Luck, Yazen Ghannam, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
We're reusing mce_amd_inj's debugfs interface so that mce-inject can
benefit from it too. The old functionality is still preserved under
CONFIG_X86_MCELOG.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/Kconfig | 2 +-
arch/x86/kernel/cpu/mcheck/mce-inject.c | 525 +++++++++++++++++++++++++++++++-
arch/x86/ras/Makefile | 2 -
arch/x86/ras/mce_amd_inj.c | 484 -----------------------------
4 files changed, 515 insertions(+), 498 deletions(-)
delete mode 100644 arch/x86/ras/mce_amd_inj.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0bb289520207..c34e0fe23cf2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1041,7 +1041,7 @@ config X86_MCE_THRESHOLD
def_bool y
config X86_MCE_INJECT
- depends on X86_MCE && X86_MCELOG
+ depends on X86_MCE
tristate "Machine check injector support"
---help---
Provide support for injecting machine checks for testing purposes.
diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
index 517619ea6498..f1d8d3f9ec1d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -10,23 +10,106 @@
* Authors:
* Andi Kleen
* Ying Huang
+ *
+ * The AMD part (former mce_amd_inj.c): a simple MCE injection facility
+ * for testing different aspects of the RAS code. This driver should be
+ * built as module so that it can be loaded on production kernels for
+ * testing purposes.
+ *
+ * This file may be distributed under the terms of the GNU General Public
+ * License version 2.
+ *
+ * Copyright (c) 2010-15: Borislav Petkov <bp@alien8.de>
+ * Advanced Micro Devices Inc.
*/
-#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/timer.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
+
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
#include <linux/fs.h>
-#include <linux/preempt.h>
-#include <linux/smp.h>
-#include <linux/notifier.h>
+#include <linux/gfp.h>
#include <linux/kdebug.h>
-#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/pci.h>
+#include <linux/preempt.h>
#include <linux/sched.h>
-#include <linux/gfp.h>
-#include <asm/mce.h>
+#include <linux/smp.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/uaccess.h>
+
+#include <asm/amd_nb.h>
#include <asm/apic.h>
+#include <asm/irq_vectors.h>
+#include <asm/mce.h>
#include <asm/nmi.h>
+#include <asm/smp.h>
+
+#include "mce-internal.h"
+
+/*
+ * Collect all the MCi_XXX settings
+ */
+static struct mce i_mce;
+static struct dentry *dfs_inj;
+
+static u8 n_banks;
+
+#define MAX_FLAG_OPT_SIZE 3
+#define NBCFG 0x44
+
+enum injection_type {
+ SW_INJ = 0, /* SW injection, simply decode the error */
+ HW_INJ, /* Trigger a #MC */
+ DFR_INT_INJ, /* Trigger Deferred error interrupt */
+ THR_INT_INJ, /* Trigger threshold interrupt */
+ N_INJ_TYPES,
+};
+
+static const char * const flags_options[] = {
+ [SW_INJ] = "sw",
+ [HW_INJ] = "hw",
+ [DFR_INT_INJ] = "df",
+ [THR_INT_INJ] = "th",
+ NULL
+};
+
+/* Set default injection to SW_INJ */
+static enum injection_type inj_type = SW_INJ;
+
+#define MCE_INJECT_SET(reg) \
+static int inj_##reg##_set(void *data, u64 val) \
+{ \
+ struct mce *m = (struct mce *)data; \
+ \
+ m->reg = val; \
+ return 0; \
+}
+
+MCE_INJECT_SET(status);
+MCE_INJECT_SET(misc);
+MCE_INJECT_SET(addr);
+
+#define MCE_INJECT_GET(reg) \
+static int inj_##reg##_get(void *data, u64 *val) \
+{ \
+ struct mce *m = (struct mce *)data; \
+ \
+ *val = m->reg; \
+ return 0; \
+}
+
+MCE_INJECT_GET(status);
+MCE_INJECT_GET(misc);
+MCE_INJECT_GET(addr);
+
+DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
+
/* Update fake mce registers on current CPU. */
static void inject_mce(struct mce *m)
@@ -201,6 +284,7 @@ static void raise_mce(struct mce *m)
}
}
+#ifdef CONFIG_X86_MCELOG
/* Error injection interface */
static ssize_t mce_write(struct file *filp, const char __user *ubuf,
size_t usize, loff_t *off)
@@ -235,21 +319,440 @@ static ssize_t mce_write(struct file *filp, const char __user *ubuf,
mutex_unlock(&mce_inject_mutex);
return usize;
}
+#endif
+
+/*
+ * Caller needs to be make sure this cpu doesn't disappear
+ * from under us, i.e.: get_cpu/put_cpu.
+ */
+static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
+{
+ u32 l, h;
+ int err;
+
+ err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
+ if (err) {
+ pr_err("%s: error reading HWCR\n", __func__);
+ return err;
+ }
+
+ enable ? (l |= BIT(18)) : (l &= ~BIT(18));
+
+ err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
+ if (err)
+ pr_err("%s: error writing HWCR\n", __func__);
+
+ return err;
+}
+
+static int __set_inj(const char *buf)
+{
+ int i;
+
+ for (i = 0; i < N_INJ_TYPES; i++) {
+ if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
+ inj_type = i;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static ssize_t flags_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[MAX_FLAG_OPT_SIZE];
+ int n;
+
+ n = sprintf(buf, "%s\n", flags_options[inj_type]);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
+}
+
+static ssize_t flags_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[MAX_FLAG_OPT_SIZE], *__buf;
+ int err;
+
+ if (cnt > MAX_FLAG_OPT_SIZE)
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt - 1] = 0;
+
+ /* strip whitespace */
+ __buf = strstrip(buf);
+
+ err = __set_inj(__buf);
+ if (err) {
+ pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
+ return err;
+ }
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static const struct file_operations flags_fops = {
+ .read = flags_read,
+ .write = flags_write,
+ .llseek = generic_file_llseek,
+};
+
+/*
+ * On which CPU to inject?
+ */
+MCE_INJECT_GET(extcpu);
+
+static int inj_extcpu_set(void *data, u64 val)
+{
+ struct mce *m = (struct mce *)data;
+
+ if (val >= nr_cpu_ids || !cpu_online(val)) {
+ pr_err("%s: Invalid CPU: %llu\n", __func__, val);
+ return -EINVAL;
+ }
+ m->extcpu = val;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(extcpu_fops, inj_extcpu_get, inj_extcpu_set, "%llu\n");
+
+static void trigger_mce(void *info)
+{
+ asm volatile("int $18");
+}
+
+static void trigger_dfr_int(void *info)
+{
+ asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
+}
+
+static void trigger_thr_int(void *info)
+{
+ asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
+}
+
+static u32 get_nbc_for_node(int node_id)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+ u32 cores_per_node;
+
+ cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
+
+ return cores_per_node * node_id;
+}
+
+static void toggle_nb_mca_mst_cpu(u16 nid)
+{
+ struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
+ u32 val;
+ int err;
+
+ if (!F3)
+ return;
+
+ err = pci_read_config_dword(F3, NBCFG, &val);
+ if (err) {
+ pr_err("%s: Error reading F%dx%03x.\n",
+ __func__, PCI_FUNC(F3->devfn), NBCFG);
+ return;
+ }
+
+ if (val & BIT(27))
+ return;
+
+ pr_err("%s: Set D18F3x44[NbMcaToMstCpuEn] which BIOS hasn't done.\n",
+ __func__);
+
+ val |= BIT(27);
+ err = pci_write_config_dword(F3, NBCFG, val);
+ if (err)
+ pr_err("%s: Error writing F%dx%03x.\n",
+ __func__, PCI_FUNC(F3->devfn), NBCFG);
+}
+
+static void do_inject(void)
+{
+ u64 mcg_status = 0;
+ unsigned int cpu = i_mce.extcpu;
+ u8 b = i_mce.bank;
+
+ if (i_mce.misc)
+ i_mce.status |= MCI_STATUS_MISCV;
+
+ if (inj_type == SW_INJ) {
+ mce_inject_log(&i_mce);
+ return;
+ }
+
+ /* prep MCE global settings for the injection */
+ mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
+
+ if (!(i_mce.status & MCI_STATUS_PCC))
+ mcg_status |= MCG_STATUS_RIPV;
+
+ /*
+ * Ensure necessary status bits for deferred errors:
+ * - MCx_STATUS[Deferred]: make sure it is a deferred error
+ * - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
+ */
+ if (inj_type == DFR_INT_INJ) {
+ i_mce.status |= MCI_STATUS_DEFERRED;
+ i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
+ }
+
+ /*
+ * Intel injection:
+ */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+ mutex_lock(&mce_inject_mutex);
+ raise_mce(&i_mce);
+ mutex_unlock(&mce_inject_mutex);
+ return;
+ }
+
+ /*
+ * For multi node CPUs, logging and reporting of bank 4 errors happens
+ * only on the node base core. Refer to D18F3x44[NbMcaToMstCpuEn] for
+ * Fam10h and later BKDGs.
+ */
+ if (static_cpu_has(X86_FEATURE_AMD_DCM) && b == 4) {
+ toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
+ cpu = get_nbc_for_node(amd_get_nb_id(cpu));
+ }
+
+ get_online_cpus();
+ if (!cpu_online(cpu))
+ goto err;
+
+ toggle_hw_mce_inject(cpu, true);
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCG_STATUS,
+ (u32)mcg_status, (u32)(mcg_status >> 32));
+
+ if (boot_cpu_has(X86_FEATURE_SMCA)) {
+ if (inj_type == DFR_INT_INJ) {
+ wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_DESTAT(b),
+ (u32)i_mce.status, (u32)(i_mce.status >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_DEADDR(b),
+ (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
+ } else {
+ wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_STATUS(b),
+ (u32)i_mce.status, (u32)(i_mce.status >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_ADDR(b),
+ (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
+ }
+
+ wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_MISC(b),
+ (u32)i_mce.misc, (u32)(i_mce.misc >> 32));
+ } else {
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_STATUS(b),
+ (u32)i_mce.status, (u32)(i_mce.status >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_ADDR(b),
+ (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_MISC(b),
+ (u32)i_mce.misc, (u32)(i_mce.misc >> 32));
+ }
+
+ toggle_hw_mce_inject(cpu, false);
+
+ switch (inj_type) {
+ case DFR_INT_INJ:
+ smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
+ break;
+ case THR_INT_INJ:
+ smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
+ break;
+ default:
+ smp_call_function_single(cpu, trigger_mce, NULL, 0);
+ }
+
+err:
+ put_online_cpus();
+
+}
+
+/*
+ * This denotes into which bank we're injecting and triggers
+ * the injection, at the same time.
+ */
+static int inj_bank_set(void *data, u64 val)
+{
+ struct mce *m = (struct mce *)data;
+
+ if (val >= n_banks) {
+ pr_err("Non-existent MCE bank: %llu\n", val);
+ return -EINVAL;
+ }
+
+ m->bank = val;
+ do_inject();
+
+ return 0;
+}
+
+MCE_INJECT_GET(bank);
+
+DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
+
+static const char readme_msg[] =
+"Description of the files and their usages:\n"
+"\n"
+"Note1: i refers to the bank number below.\n"
+"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
+"as they mirror the hardware registers.\n"
+"\n"
+"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
+"\t attributes of the error which caused the MCE.\n"
+"\n"
+"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
+"\t used for error thresholding purposes and its validity is indicated by\n"
+"\t MCi_STATUS[MiscV].\n"
+"\n"
+"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
+"\t associated with the error.\n"
+"\n"
+"cpu:\t The CPU to inject the error on.\n"
+"\n"
+"bank:\t Specify the bank you want to inject the error into: the number of\n"
+"\t banks in a processor varies and is family/model-specific, therefore, the\n"
+"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
+"\t injection.\n"
+"\n"
+"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
+"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
+"\t for AMD processors.\n"
+"\n"
+"\t Allowed error injection types:\n"
+"\t - \"sw\": Software error injection. Decode error to a human-readable \n"
+"\t format only. Safe to use.\n"
+"\t - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
+"\t handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
+"\t is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
+"\t before injecting.\n"
+"\t - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
+"\t error APIC interrupt handler to handle the error if the feature is \n"
+"\t is present in hardware. \n"
+"\t - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
+"\t APIC interrupt handler to handle the error. \n"
+"\n";
+
+static ssize_t
+inj_readme_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ readme_msg, strlen(readme_msg));
+}
+
+static const struct file_operations readme_fops = {
+ .read = inj_readme_read,
+};
+
+static struct dfs_node {
+ char *name;
+ struct dentry *d;
+ const struct file_operations *fops;
+ umode_t perm;
+} dfs_fls[] = {
+ { .name = "status", .fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
+};
+
+
+static int __init debugfs_init(void)
+{
+ int i;
+ u64 cap;
+
+ rdmsrl(MSR_IA32_MCG_CAP, cap);
+ n_banks = cap & MCG_BANKCNT_MASK;
+
+ dfs_inj = debugfs_create_dir("mce-inject", NULL);
+ if (!dfs_inj)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
+ dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
+ dfs_fls[i].perm,
+ dfs_inj,
+ &i_mce,
+ dfs_fls[i].fops);
+
+ if (!dfs_fls[i].d)
+ goto err_dfs_add;
+ }
+
+ return 0;
+
+err_dfs_add:
+ while (--i >= 0)
+ debugfs_remove(dfs_fls[i].d);
+
+ debugfs_remove(dfs_inj);
+ dfs_inj = NULL;
+
+ return -ENOMEM;
+}
+
+static void __exit debugfs_exit(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dfs_fls); i++)
+ debugfs_remove(dfs_fls[i].d);
+
+ memset(&dfs_fls, 0, sizeof(dfs_fls));
+
+ debugfs_remove(dfs_inj);
+ dfs_inj = NULL;
+}
static int inject_init(void)
{
+ int err;
+
if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
return -ENOMEM;
+
pr_info("Machine check injector initialized\n");
+
+#ifdef CONFIG_X86_MCELOG
register_mce_write_callback(mce_write);
+#endif
+
register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
"mce_notify");
+
+ err = debugfs_init();
+ if (err)
+ return err;
+
return 0;
}
module_init(inject_init);
+
/*
* Cannot tolerate unloading currently because we cannot
* guarantee all openers of mce_chrdev will get a reference to us.
*/
+#ifndef CONFIG_X86_MCELOG
+module_exit(debugfs_exit);
+#endif
+
MODULE_LICENSE("GPL");
diff --git a/arch/x86/ras/Makefile b/arch/x86/ras/Makefile
index 5f94546db280..e69de29bb2d1 100644
--- a/arch/x86/ras/Makefile
+++ b/arch/x86/ras/Makefile
@@ -1,2 +0,0 @@
-obj-$(CONFIG_MCE_AMD_INJ) += mce_amd_inj.o
-
diff --git a/arch/x86/ras/mce_amd_inj.c b/arch/x86/ras/mce_amd_inj.c
deleted file mode 100644
index e69f4701a076..000000000000
--- a/arch/x86/ras/mce_amd_inj.c
+++ /dev/null
@@ -1,484 +0,0 @@
-/*
- * A simple MCE injection facility for testing different aspects of the RAS
- * code. This driver should be built as module so that it can be loaded
- * on production kernels for testing purposes.
- *
- * This file may be distributed under the terms of the GNU General Public
- * License version 2.
- *
- * Copyright (c) 2010-15: Borislav Petkov <bp@alien8.de>
- * Advanced Micro Devices Inc.
- */
-
-#include <linux/kobject.h>
-#include <linux/debugfs.h>
-#include <linux/device.h>
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/string.h>
-#include <linux/uaccess.h>
-#include <linux/pci.h>
-
-#include <asm/mce.h>
-#include <asm/smp.h>
-#include <asm/amd_nb.h>
-#include <asm/irq_vectors.h>
-
-#include "../kernel/cpu/mcheck/mce-internal.h"
-
-/*
- * Collect all the MCi_XXX settings
- */
-static struct mce i_mce;
-static struct dentry *dfs_inj;
-
-static u8 n_banks;
-
-#define MAX_FLAG_OPT_SIZE 3
-#define NBCFG 0x44
-
-enum injection_type {
- SW_INJ = 0, /* SW injection, simply decode the error */
- HW_INJ, /* Trigger a #MC */
- DFR_INT_INJ, /* Trigger Deferred error interrupt */
- THR_INT_INJ, /* Trigger threshold interrupt */
- N_INJ_TYPES,
-};
-
-static const char * const flags_options[] = {
- [SW_INJ] = "sw",
- [HW_INJ] = "hw",
- [DFR_INT_INJ] = "df",
- [THR_INT_INJ] = "th",
- NULL
-};
-
-/* Set default injection to SW_INJ */
-static enum injection_type inj_type = SW_INJ;
-
-#define MCE_INJECT_SET(reg) \
-static int inj_##reg##_set(void *data, u64 val) \
-{ \
- struct mce *m = (struct mce *)data; \
- \
- m->reg = val; \
- return 0; \
-}
-
-MCE_INJECT_SET(status);
-MCE_INJECT_SET(misc);
-MCE_INJECT_SET(addr);
-
-#define MCE_INJECT_GET(reg) \
-static int inj_##reg##_get(void *data, u64 *val) \
-{ \
- struct mce *m = (struct mce *)data; \
- \
- *val = m->reg; \
- return 0; \
-}
-
-MCE_INJECT_GET(status);
-MCE_INJECT_GET(misc);
-MCE_INJECT_GET(addr);
-
-DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
-
-/*
- * Caller needs to be make sure this cpu doesn't disappear
- * from under us, i.e.: get_cpu/put_cpu.
- */
-static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
-{
- u32 l, h;
- int err;
-
- err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
- if (err) {
- pr_err("%s: error reading HWCR\n", __func__);
- return err;
- }
-
- enable ? (l |= BIT(18)) : (l &= ~BIT(18));
-
- err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
- if (err)
- pr_err("%s: error writing HWCR\n", __func__);
-
- return err;
-}
-
-static int __set_inj(const char *buf)
-{
- int i;
-
- for (i = 0; i < N_INJ_TYPES; i++) {
- if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
- inj_type = i;
- return 0;
- }
- }
- return -EINVAL;
-}
-
-static ssize_t flags_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[MAX_FLAG_OPT_SIZE];
- int n;
-
- n = sprintf(buf, "%s\n", flags_options[inj_type]);
-
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
-}
-
-static ssize_t flags_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[MAX_FLAG_OPT_SIZE], *__buf;
- int err;
-
- if (cnt > MAX_FLAG_OPT_SIZE)
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt - 1] = 0;
-
- /* strip whitespace */
- __buf = strstrip(buf);
-
- err = __set_inj(__buf);
- if (err) {
- pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
- return err;
- }
-
- *ppos += cnt;
-
- return cnt;
-}
-
-static const struct file_operations flags_fops = {
- .read = flags_read,
- .write = flags_write,
- .llseek = generic_file_llseek,
-};
-
-/*
- * On which CPU to inject?
- */
-MCE_INJECT_GET(extcpu);
-
-static int inj_extcpu_set(void *data, u64 val)
-{
- struct mce *m = (struct mce *)data;
-
- if (val >= nr_cpu_ids || !cpu_online(val)) {
- pr_err("%s: Invalid CPU: %llu\n", __func__, val);
- return -EINVAL;
- }
- m->extcpu = val;
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(extcpu_fops, inj_extcpu_get, inj_extcpu_set, "%llu\n");
-
-static void trigger_mce(void *info)
-{
- asm volatile("int $18");
-}
-
-static void trigger_dfr_int(void *info)
-{
- asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
-}
-
-static void trigger_thr_int(void *info)
-{
- asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
-}
-
-static u32 get_nbc_for_node(int node_id)
-{
- struct cpuinfo_x86 *c = &boot_cpu_data;
- u32 cores_per_node;
-
- cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
-
- return cores_per_node * node_id;
-}
-
-static void toggle_nb_mca_mst_cpu(u16 nid)
-{
- struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
- u32 val;
- int err;
-
- if (!F3)
- return;
-
- err = pci_read_config_dword(F3, NBCFG, &val);
- if (err) {
- pr_err("%s: Error reading F%dx%03x.\n",
- __func__, PCI_FUNC(F3->devfn), NBCFG);
- return;
- }
-
- if (val & BIT(27))
- return;
-
- pr_err("%s: Set D18F3x44[NbMcaToMstCpuEn] which BIOS hasn't done.\n",
- __func__);
-
- val |= BIT(27);
- err = pci_write_config_dword(F3, NBCFG, val);
- if (err)
- pr_err("%s: Error writing F%dx%03x.\n",
- __func__, PCI_FUNC(F3->devfn), NBCFG);
-}
-
-static void do_inject(void)
-{
- u64 mcg_status = 0;
- unsigned int cpu = i_mce.extcpu;
- u8 b = i_mce.bank;
-
- if (i_mce.misc)
- i_mce.status |= MCI_STATUS_MISCV;
-
- if (inj_type == SW_INJ) {
- mce_inject_log(&i_mce);
- return;
- }
-
- /* prep MCE global settings for the injection */
- mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
-
- if (!(i_mce.status & MCI_STATUS_PCC))
- mcg_status |= MCG_STATUS_RIPV;
-
- /*
- * Ensure necessary status bits for deferred errors:
- * - MCx_STATUS[Deferred]: make sure it is a deferred error
- * - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
- */
- if (inj_type == DFR_INT_INJ) {
- i_mce.status |= MCI_STATUS_DEFERRED;
- i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
- }
-
- /*
- * For multi node CPUs, logging and reporting of bank 4 errors happens
- * only on the node base core. Refer to D18F3x44[NbMcaToMstCpuEn] for
- * Fam10h and later BKDGs.
- */
- if (static_cpu_has(X86_FEATURE_AMD_DCM) && b == 4) {
- toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
- cpu = get_nbc_for_node(amd_get_nb_id(cpu));
- }
-
- get_online_cpus();
- if (!cpu_online(cpu))
- goto err;
-
- toggle_hw_mce_inject(cpu, true);
-
- wrmsr_on_cpu(cpu, MSR_IA32_MCG_STATUS,
- (u32)mcg_status, (u32)(mcg_status >> 32));
-
- if (boot_cpu_has(X86_FEATURE_SMCA)) {
- if (inj_type == DFR_INT_INJ) {
- wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_DESTAT(b),
- (u32)i_mce.status, (u32)(i_mce.status >> 32));
-
- wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_DEADDR(b),
- (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
- } else {
- wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_STATUS(b),
- (u32)i_mce.status, (u32)(i_mce.status >> 32));
-
- wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_ADDR(b),
- (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
- }
-
- wrmsr_on_cpu(cpu, MSR_AMD64_SMCA_MCx_MISC(b),
- (u32)i_mce.misc, (u32)(i_mce.misc >> 32));
- } else {
- wrmsr_on_cpu(cpu, MSR_IA32_MCx_STATUS(b),
- (u32)i_mce.status, (u32)(i_mce.status >> 32));
-
- wrmsr_on_cpu(cpu, MSR_IA32_MCx_ADDR(b),
- (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
-
- wrmsr_on_cpu(cpu, MSR_IA32_MCx_MISC(b),
- (u32)i_mce.misc, (u32)(i_mce.misc >> 32));
- }
-
- toggle_hw_mce_inject(cpu, false);
-
- switch (inj_type) {
- case DFR_INT_INJ:
- smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
- break;
- case THR_INT_INJ:
- smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
- break;
- default:
- smp_call_function_single(cpu, trigger_mce, NULL, 0);
- }
-
-err:
- put_online_cpus();
-
-}
-
-/*
- * This denotes into which bank we're injecting and triggers
- * the injection, at the same time.
- */
-static int inj_bank_set(void *data, u64 val)
-{
- struct mce *m = (struct mce *)data;
-
- if (val >= n_banks) {
- pr_err("Non-existent MCE bank: %llu\n", val);
- return -EINVAL;
- }
-
- m->bank = val;
- do_inject();
-
- return 0;
-}
-
-MCE_INJECT_GET(bank);
-
-DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
-
-static const char readme_msg[] =
-"Description of the files and their usages:\n"
-"\n"
-"Note1: i refers to the bank number below.\n"
-"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
-"as they mirror the hardware registers.\n"
-"\n"
-"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
-"\t attributes of the error which caused the MCE.\n"
-"\n"
-"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
-"\t used for error thresholding purposes and its validity is indicated by\n"
-"\t MCi_STATUS[MiscV].\n"
-"\n"
-"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
-"\t associated with the error.\n"
-"\n"
-"cpu:\t The CPU to inject the error on.\n"
-"\n"
-"bank:\t Specify the bank you want to inject the error into: the number of\n"
-"\t banks in a processor varies and is family/model-specific, therefore, the\n"
-"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
-"\t injection.\n"
-"\n"
-"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
-"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
-"\t for AMD processors.\n"
-"\n"
-"\t Allowed error injection types:\n"
-"\t - \"sw\": Software error injection. Decode error to a human-readable \n"
-"\t format only. Safe to use.\n"
-"\t - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
-"\t handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
-"\t is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
-"\t before injecting.\n"
-"\t - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
-"\t error APIC interrupt handler to handle the error if the feature is \n"
-"\t is present in hardware. \n"
-"\t - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
-"\t APIC interrupt handler to handle the error. \n"
-"\n";
-
-static ssize_t
-inj_readme_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- return simple_read_from_buffer(ubuf, cnt, ppos,
- readme_msg, strlen(readme_msg));
-}
-
-static const struct file_operations readme_fops = {
- .read = inj_readme_read,
-};
-
-static struct dfs_node {
- char *name;
- struct dentry *d;
- const struct file_operations *fops;
- umode_t perm;
-} dfs_fls[] = {
- { .name = "status", .fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
- { .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
-};
-
-static int __init init_mce_inject(void)
-{
- int i;
- u64 cap;
-
- rdmsrl(MSR_IA32_MCG_CAP, cap);
- n_banks = cap & MCG_BANKCNT_MASK;
-
- dfs_inj = debugfs_create_dir("mce-inject", NULL);
- if (!dfs_inj)
- return -EINVAL;
-
- for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
- dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
- dfs_fls[i].perm,
- dfs_inj,
- &i_mce,
- dfs_fls[i].fops);
-
- if (!dfs_fls[i].d)
- goto err_dfs_add;
- }
-
- return 0;
-
-err_dfs_add:
- while (--i >= 0)
- debugfs_remove(dfs_fls[i].d);
-
- debugfs_remove(dfs_inj);
- dfs_inj = NULL;
-
- return -ENOMEM;
-}
-
-static void __exit exit_mce_inject(void)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(dfs_fls); i++)
- debugfs_remove(dfs_fls[i].d);
-
- memset(&dfs_fls, 0, sizeof(dfs_fls));
-
- debugfs_remove(dfs_inj);
- dfs_inj = NULL;
-}
-module_init(init_mce_inject);
-module_exit(exit_mce_inject);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Borislav Petkov <bp@alien8.de>");
-MODULE_AUTHOR("AMD Inc.");
-MODULE_DESCRIPTION("MCE injection facility for RAS testing");
--
2.7.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RFC PATCH 4/4] x86/mce-inject: Use debugfs_remove_recursive()
2016-06-07 16:52 [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies Borislav Petkov
` (2 preceding siblings ...)
2016-06-07 16:52 ` [RFC PATCH 3/4] x86/mce: Merge mce_amd_inj into mce-inject Borislav Petkov
@ 2016-06-07 16:52 ` Borislav Petkov
3 siblings, 0 replies; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 16:52 UTC (permalink / raw)
To: linux-edac; +Cc: Tony Luck, Yazen Ghannam, X86 ML, LKML
From: Borislav Petkov <bp@suse.de>
... and simplify a bit.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mcheck/mce-inject.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
index f1d8d3f9ec1d..675d2da3d31f 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -676,8 +676,8 @@ static struct dfs_node {
static int __init debugfs_init(void)
{
- int i;
u64 cap;
+ int i;
rdmsrl(MSR_IA32_MCG_CAP, cap);
n_banks = cap & MCG_BANKCNT_MASK;
@@ -700,28 +700,12 @@ static int __init debugfs_init(void)
return 0;
err_dfs_add:
- while (--i >= 0)
- debugfs_remove(dfs_fls[i].d);
-
- debugfs_remove(dfs_inj);
+ debugfs_remove_recursive(dfs_inj);
dfs_inj = NULL;
return -ENOMEM;
}
-static void __exit debugfs_exit(void)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(dfs_fls); i++)
- debugfs_remove(dfs_fls[i].d);
-
- memset(&dfs_fls, 0, sizeof(dfs_fls));
-
- debugfs_remove(dfs_inj);
- dfs_inj = NULL;
-}
-
static int inject_init(void)
{
int err;
@@ -752,6 +736,16 @@ module_init(inject_init);
* guarantee all openers of mce_chrdev will get a reference to us.
*/
#ifndef CONFIG_X86_MCELOG
+static void __exit debugfs_exit(void)
+{
+ debugfs_remove_recursive(dfs_inj);
+ dfs_inj = NULL;
+
+ unregister_nmi_handler(NMI_LOCAL, "mce_notify");
+
+ free_cpumask_var(mce_inject_cpumask);
+}
+
module_exit(debugfs_exit);
#endif
--
2.7.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector
2016-06-07 16:52 ` [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector Borislav Petkov
@ 2016-06-07 18:11 ` Luck, Tony
2016-06-07 21:04 ` Borislav Petkov
0 siblings, 1 reply; 8+ messages in thread
From: Luck, Tony @ 2016-06-07 18:11 UTC (permalink / raw)
To: Borislav Petkov; +Cc: linux-edac, Yazen Ghannam, X86 ML, LKML
On Tue, Jun 07, 2016 at 06:52:22PM +0200, Borislav Petkov wrote:
> +void mce_log(struct mce *m)
> {
> unsigned next, entry;
>
> + if (!in_atomic() && memory_error(m) && mce_usable_address(m))
> + if (!ce_add_elem(m->addr >> PAGE_SHIFT))
> + return;
> +
> /* Emit the trace record: */
> - trace_mce_record(mce);
> + trace_mce_record(m);
>
> - if (!mce_gen_pool_add(mce))
> + if (!mce_gen_pool_add(m))
> irq_work_queue(&mce_irq_work);
Is there a reason that we need to call the ce_add_elem() inline
here instead of having it just register on the mce_notifier chain?
This series just cleaned out all the /dev/mcelog special code from
here, and you are adding something back before the ink is dry on
that change.
I'm also strongly divided about whether this corrected error
handler should be allowed to preempt anything else even seeing
the error.
Argument for:
Lonely corrected errors are "No Big Deal"(TM). Just counting them
and moving on is a good thing.
Arguments against:
1) We may miss out on a one-time opportunity to get extra information
(from acpi_extlog.c).
2) I think this subverts our CMCI storm detection and mitigation code?
We could make the chain more caller friendly by adding a filter
argument so users could say "just tell me about memory errors"
(currently each of the EDAC drivers has inline code to do the same
as "memory_error(m) && mce_usable_address(m)")
-Tony
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector
2016-06-07 18:11 ` Luck, Tony
@ 2016-06-07 21:04 ` Borislav Petkov
0 siblings, 0 replies; 8+ messages in thread
From: Borislav Petkov @ 2016-06-07 21:04 UTC (permalink / raw)
To: Luck, Tony; +Cc: linux-edac, Yazen Ghannam, X86 ML, LKML
On Tue, Jun 07, 2016 at 11:11:09AM -0700, Luck, Tony wrote:
> Is there a reason that we need to call the ce_add_elem() inline
> here instead of having it just register on the mce_notifier chain?
> This series just cleaned out all the /dev/mcelog special code from
> here, and you are adding something back before the ink is dry on
> that change.
>
> I'm also strongly divided about whether this corrected error
> handler should be allowed to preempt anything else even seeing
> the error.
Well, so this is the main reason for adding the CEC: not to disturb
users with random CECC errors which might happen a couple of times
due to alpha particles and then never again. I.e., address all those
sporadic bursts of correctable errors which don't mean that the hw is
going faulty.
If the CEC consumes the error and does the leaky bucket of "forgetting"
about it after a while and after no more of that same PFN triggers
errors, then we do that silently and do not scare users. Yeah, they
think their hw is broken and whether they should start swapping things.
And then there's the aspect of soft-offlining PFNs when the error
threshold has been reached. I don't think we have had any automatic
recovery actions wrt errors so far without external agents.
> Argument for:
> Lonely corrected errors are "No Big Deal"(TM). Just counting them
> and moving on is a good thing.
Yap, exactly.
> Arguments against:
> 1) We may miss out on a one-time opportunity to get extra information
> (from acpi_extlog.c).
> 2) I think this subverts our CMCI storm detection and mitigation code?
...and we can address that by adding "ras=cec_doesnt_consume_errors" or
somesuch so that the rest of the chain sees them too.
I think we can be pretty flexible about it. And again, my main angle is
the "do not disturb users unnecessarily".
> We could make the chain more caller friendly by adding a filter
> argument so users could say "just tell me about memory errors"
> (currently each of the EDAC drivers has inline code to do the same
> as "memory_error(m) && mce_usable_address(m)")
Sure, that too.
And it can work on any system without the need for an EDAC driver.
Thanks.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog
2016-06-07 16:52 ` [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog Borislav Petkov
@ 2016-06-13 9:00 ` Thomas Gleixner
0 siblings, 0 replies; 8+ messages in thread
From: Thomas Gleixner @ 2016-06-13 9:00 UTC (permalink / raw)
To: Borislav Petkov; +Cc: linux-edac, Tony Luck, Yazen Ghannam, X86 ML, LKML
On Tue, 7 Jun 2016, Borislav Petkov wrote:
> From: Tony Luck <tony.luck@intel.com>
>
> Move all code relating to /dev/mcelog to own source file. /dev/mcelog
> driver can now operate from the machine check notifier with lowest prio.
>
> Boris:
> * Move the mce_helper and trigger functionality behind
> CONFIG_X86_MCELOG.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-06-13 9:02 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-06-07 16:52 [R-F-C PATCH 0/4] RFC: x86/mce: Deprecate mcelog and other funsies Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 1/4] RAS: Add a Corrected Errors Collector Borislav Petkov
2016-06-07 18:11 ` Luck, Tony
2016-06-07 21:04 ` Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 2/4] x86/mce: Deprecate /dev/mcelog Borislav Petkov
2016-06-13 9:00 ` Thomas Gleixner
2016-06-07 16:52 ` [RFC PATCH 3/4] x86/mce: Merge mce_amd_inj into mce-inject Borislav Petkov
2016-06-07 16:52 ` [RFC PATCH 4/4] x86/mce-inject: Use debugfs_remove_recursive() Borislav Petkov
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).