[PATCH 6/7] EDAC, mce_amd: Issue the decoded info through the TP or printk()

Borislav Petkov
2017-08-25T10:24:54Z

From: Borislav Petkov <bp@suse.de>

... depending on whether we have userspace consumers. Handle the HW_ERR
prefix accordingly - for printk() I need to do some strsep() monkey
business.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
drivers/edac/mce_amd.c | 106 +++++++++++++++++++++++++++++++------------------
1 file changed, 68 insertions(+), 38 deletions(-)

diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index b7c1f8f7e871..41c09d5b81f0 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -2,9 +2,12 @@
#include <linux/seq_buf.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/ras.h>

#include <asm/cpu.h>

+#include <trace/events/mce.h>
+
#include "mce_amd.h"

static struct amd_decoder_ops *fam_ops;
@@ -465,7 +468,7 @@ static void decode_mc0_mce(struct mce *m)
u16 ec = EC(m->status);
u8 xec = XEC(m->status, xec_mask);

- seq_buf_printf(&sb, HW_ERR "MC0 Error: ");
+ seq_buf_printf(&sb, "MC0 Error: ");

/* TLB error signatures are the same across families */
if (TLB_ERROR(ec)) {
@@ -575,7 +578,7 @@ static void decode_mc1_mce(struct mce *m)
u16 ec = EC(m->status);
u8 xec = XEC(m->status, xec_mask);

- seq_buf_printf(&sb, HW_ERR "MC1 Error: ");
+ seq_buf_printf(&sb, "MC1 Error: ");

if (TLB_ERROR(ec))
seq_buf_printf(&sb, "%s TLB %s.\n", LL_MSG(ec),
@@ -721,7 +724,7 @@ static void decode_mc2_mce(struct mce *m)
u16 ec = EC(m->status);
u8 xec = XEC(m->status, xec_mask);

- seq_buf_printf(&sb, HW_ERR "MC2 Error: ");
+ seq_buf_printf(&sb, "MC2 Error: ");

if (!fam_ops->mc2_mce(ec, xec))
pr_emerg(HW_ERR "Corrupted MC2 MCE info?\n");
@@ -738,7 +741,7 @@ static void decode_mc3_mce(struct mce *m)
return;
}

- seq_buf_printf(&sb, HW_ERR "MC3 Error");
+ seq_buf_printf(&sb, "MC3 Error");

if (xec == 0x0) {
u8 r4 = R4(ec);
@@ -764,7 +767,7 @@ static void decode_mc4_mce(struct mce *m)
u8 xec = XEC(m->status, 0x1f);
u8 offset = 0;

- seq_buf_printf(&sb, HW_ERR "MC4 Error (node %d): ", node_id);
+ seq_buf_printf(&sb, "MC4 Error (node %d): ", node_id);

switch (xec) {
case 0x0 ... 0xe:
@@ -823,7 +826,7 @@ static void decode_mc5_mce(struct mce *m)
if (fam == 0xf || fam == 0x11)
goto wrong_mc5_mce;

- seq_buf_printf(&sb, HW_ERR "MC5 Error: ");
+ seq_buf_printf(&sb, "MC5 Error: ");

if (INT_ERROR(ec)) {
if (xec <= 0x1f) {
@@ -850,7 +853,7 @@ static void decode_mc6_mce(struct mce *m)
{
u8 xec = XEC(m->status, xec_mask);

- seq_buf_printf(&sb, HW_ERR "MC6 Error: ");
+ seq_buf_printf(&sb, "MC6 Error: ");

if (xec > 0x5)
goto wrong_mc6_mce;
@@ -883,12 +886,12 @@ static void decode_smca_error(struct mce *m)
bank_type = hwid->bank_type;
ip_name = smca_get_long_name(bank_type);

- seq_buf_printf(&sb, HW_ERR "%s Extended Error Code: %d\n", ip_name, xec);
+ seq_buf_printf(&sb, "%s Extended Error Code: %d\n", ip_name, xec);

/* Only print the decode of valid error codes */
if (xec < smca_mce_descs[bank_type].num_descs &&
(hwid->xec_bitmap & BIT_ULL(xec))) {
- seq_buf_printf(&sb, HW_ERR "%s Error: ", ip_name);
+ seq_buf_printf(&sb, "%s Error: ", ip_name);
seq_buf_printf(&sb, "%s.\n", smca_mce_descs[bank_type].descs[xec]);
}

@@ -950,26 +953,10 @@ static const char *decode_error_status(struct mce *m)
return "Corrected error, no action required.";
}

-static int
-amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
+static void __decode_mce(struct mce *m)
{
- struct mce *m = (struct mce *)data;
unsigned int fam = x86_family(m->cpuid);
int ecc;
- char *dec_buf;
-
- if (amd_filter_mce(m))
- return NOTIFY_STOP;
-
- dec_buf = (void *)gen_pool_alloc(dec_pool, ELEM_SIZE);
- if (!dec_buf) {
- pr_warn("Decode buffer full!\n");
- return NOTIFY_STOP;
- }
-
- /* \0 terminated */
- seq_buf_init(&sb, dec_buf, ELEM_SIZE);
- seq_buf_clear_buf(&sb);

pr_emerg(HW_ERR "%s\n", decode_error_status(m));

@@ -1011,7 +998,12 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
pr_cont("]: 0x%016llx\n", m->status);

if (m->status & MCI_STATUS_ADDRV)
- pr_emerg(HW_ERR "Error Addr: 0x%016llx\n", m->addr);
+ pr_emerg(HW_ERR "Error Addr: 0x%016llx ", m->addr);
+
+ if (m->tsc)
+ pr_cont("TSC: %llu", m->tsc);
+
+ pr_cont("\n");

if (boot_cpu_has(X86_FEATURE_SMCA)) {
pr_emerg(HW_ERR "IPID: 0x%016llx", m->ipid);
@@ -1020,16 +1012,13 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
pr_cont(", Syndrome: 0x%016llx", m->synd);

pr_cont("\n");
-
- decode_smca_error(m);
- goto err_code;
}
+}

- if (m->tsc)
- pr_emerg(HW_ERR "TSC: %llu\n", m->tsc);
-
+static void decode_legacy_error(struct mce *m)
+{
if (!fam_ops)
- goto err_code;
+ return;

switch (m->bank) {
case 0:
@@ -1063,11 +1052,52 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
default:
break;
}
+}

- err_code:
- amd_decode_err_code(m->status & 0xffff);
+static int
+amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
+{
+ struct mce *m = (struct mce *)data;
+ char *dec_buf;
+
+ if (amd_filter_mce(m))
+ return NOTIFY_STOP;

- pr_emerg("%.*s\n", (int)sb.len, sb.buffer);
+ dec_buf = (void *)gen_pool_alloc(dec_pool, ELEM_SIZE);
+ if (!dec_buf) {
+ pr_warn("Decode buffer full!\n");
+ return NOTIFY_STOP;
+ }
+
+ /* \0 terminated */
+ seq_buf_init(&sb, dec_buf, ELEM_SIZE);
+ seq_buf_clear_buf(&sb);
+
+ if (!ras_userspace_consumers())
+ __decode_mce(m);
+
+ if (boot_cpu_has(X86_FEATURE_SMCA))
+ decode_smca_error(m);
+ else
+ decode_legacy_error(m);
+
+ if (ras_userspace_consumers()) {
+ trace_mce_record(m, sb.buffer);
+ } else {
+ char *l;
+
+ while ((l = strsep(&sb.buffer, "\n"))) {
+ if (!strnlen(l, ELEM_SIZE))
+ break;
+
+ pr_emerg(HW_ERR "%s\n", l);
+ }
+
+ /* Restore original address because strsep() mangles it. */
+ sb.buffer = __err_buf;
+
+ amd_decode_err_code(m->status & 0xffff);
+ }

gen_pool_free(dec_pool, (unsigned long)dec_buf, ELEM_SIZE);

@@ -1076,7 +1106,7 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)

static struct notifier_block amd_mce_dec_nb = {
.notifier_call = amd_decode_mce,
- .priority = MCE_PRIO_EDAC,
+ .priority = MCE_PRIO_DECODER,
};

static int __init mce_amd_init(void)
--
2.13.0