[PATCH] ACPI / extlog: Handle multiple records

From: Tony Luck
Date: Thu Oct 06 2022 - 12:33:12 EST


If there is no user space consumer of extlog_mem trace records, then
Linux properly handles multiple error records in an ELOG block

extlog_print()
print_extlog_rcd()
__print_extlog_rcd()
cper_estatus_print()
apei_estatus_for_each_section()

But the other code path hard codes looking for a single record to
output a trace record.

Fix by using the same apei_estatus_for_each_section() iterator
to step over all records.

Fixes: 2dfb7d51a61d ("trace, RAS: Add eMCA trace event interface")
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
drivers/acpi/acpi_extlog.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index 72f1fb77abcd..4af2cfcbbd2d 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -12,6 +12,7 @@
#include <linux/ratelimit.h>
#include <linux/edac.h>
#include <linux/ras.h>
+#include <acpi/ghes.h>
#include <asm/cpu.h>
#include <asm/mce.h>

@@ -138,8 +139,8 @@ static int extlog_print(struct notifier_block *nb, unsigned long val,
int cpu = mce->extcpu;
struct acpi_hest_generic_status *estatus, *tmp;
struct acpi_hest_generic_data *gdata;
- const guid_t *fru_id = &guid_null;
- char *fru_text = "";
+ const guid_t *fru_id;
+ char *fru_text;
guid_t *sec_type;
static u32 err_seq;

@@ -160,17 +161,23 @@ static int extlog_print(struct notifier_block *nb, unsigned long val,

/* log event via trace */
err_seq++;
- gdata = (struct acpi_hest_generic_data *)(tmp + 1);
- if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
- fru_id = (guid_t *)gdata->fru_id;
- if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
- fru_text = gdata->fru_text;
- sec_type = (guid_t *)gdata->section_type;
- if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
- struct cper_sec_mem_err *mem = (void *)(gdata + 1);
- if (gdata->error_data_length >= sizeof(*mem))
- trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
- (u8)gdata->error_severity);
+ apei_estatus_for_each_section(estatus, gdata) {
+ if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
+ fru_id = (guid_t *)gdata->fru_id;
+ else
+ fru_id = &guid_null;
+ if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
+ fru_text = gdata->fru_text;
+ else
+ fru_text = "";
+ sec_type = (guid_t *)gdata->section_type;
+ if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+ struct cper_sec_mem_err *mem = (void *)(gdata + 1);
+
+ if (gdata->error_data_length >= sizeof(*mem))
+ trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
+ (u8)gdata->error_severity);
+ }
}

out:
--
2.37.3