[PATCH v2] ACPI / extlog: Handle multiple records

[Tony Luck <tony.luck@xxxxxxxxx>]

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>
---

Changes since v1: Oops. Cut & pasted the apei_estatus_for_each_section()
line, but forgot to change the argument from "estatus" to "tmp". Need to
walk the *copy* that was made, not the original because BIOS is allowed to
stomp on it as soon as it sees block_status has been cleared.

 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..e648158368a7 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(tmp, 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