[PATCH v4] acpi: apei: fix the wrong iteration of generic error status block

[Dongjiu Geng]

The revision 0x300 generic error data entry is different
from the old version, but currently iterating through the
GHES estatus blocks does not take into account this difference.
This will lead to failure to get the right data entry if GHES
has revision 0x300 error data entry.

Update the GHES estatus iteration to properly increment using
iteration macro, and correct the iteration termination condition
because the status block data length only includes error data
length.

Convert the CPER estatus checking and printing iteration logic
to use same macro.

Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx>
CC: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>
Tested-by: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
---
change since v3:
1. update the commit message 

---
 drivers/acpi/apei/apei-internal.h |  5 -----
 drivers/firmware/efi/cper.c       | 12 ++----------
 include/acpi/ghes.h               |  5 +++++
 3 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/acpi/apei/apei-internal.h b/drivers/acpi/apei/apei-internal.h
index 6e9f14c0a71b..cb4126051f62 100644
--- a/drivers/acpi/apei/apei-internal.h
+++ b/drivers/acpi/apei/apei-internal.h
@@ -120,11 +120,6 @@ int apei_exec_collect_resources(struct apei_exec_context *ctx,
 struct dentry;
 struct dentry *apei_get_debugfs_dir(void);
 
-#define apei_estatus_for_each_section(estatus, section)			\
-	for (section = (struct acpi_hest_generic_data *)(estatus + 1);	\
-	     (void *)section - (void *)estatus < estatus->data_length;	\
-	     section = (void *)(section+1) + section->error_data_length)
-
 static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
 {
 	if (estatus->raw_data_length)
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 48a8f69da42a..bf3672a81e49 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -606,7 +606,6 @@ void cper_estatus_print(const char *pfx,
 			const struct acpi_hest_generic_status *estatus)
 {
 	struct acpi_hest_generic_data *gdata;
-	unsigned int data_len;
 	int sec_no = 0;
 	char newpfx[64];
 	__u16 severity;
@@ -617,14 +616,10 @@ void cper_estatus_print(const char *pfx,
 		       "It has been corrected by h/w "
 		       "and requires no further action");
 	printk("%s""event severity: %s\n", pfx, cper_severity_str(severity));
-	data_len = estatus->data_length;
-	gdata = (struct acpi_hest_generic_data *)(estatus + 1);
 	snprintf(newpfx, sizeof(newpfx), "%s%s", pfx, INDENT_SP);
 
-	while (data_len >= acpi_hest_get_size(gdata)) {
+	apei_estatus_for_each_section(estatus, gdata) {
 		cper_estatus_print_section(newpfx, gdata, sec_no);
-		data_len -= acpi_hest_get_record_size(gdata);
-		gdata = acpi_hest_get_next(gdata);
 		sec_no++;
 	}
 }
@@ -653,15 +648,12 @@ int cper_estatus_check(const struct acpi_hest_generic_status *estatus)
 	if (rc)
 		return rc;
 	data_len = estatus->data_length;
-	gdata = (struct acpi_hest_generic_data *)(estatus + 1);
 
-	while (data_len >= acpi_hest_get_size(gdata)) {
+	apei_estatus_for_each_section(estatus, gdata) {
 		gedata_len = acpi_hest_get_error_length(gdata);
 		if (gedata_len > data_len - acpi_hest_get_size(gdata))
 			return -EINVAL;
-
 		data_len -= acpi_hest_get_record_size(gdata);
-		gdata = acpi_hest_get_next(gdata);
 	}
 	if (data_len)
 		return -EINVAL;
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 9f26e01186ae..9061c5c743b3 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -113,6 +113,11 @@ static inline void *acpi_hest_get_next(struct acpi_hest_generic_data *gdata)
 	return (void *)(gdata) + acpi_hest_get_record_size(gdata);
 }
 
+#define apei_estatus_for_each_section(estatus, section)			\
+	for (section = (struct acpi_hest_generic_data *)(estatus + 1);	\
+	     (void *)section - (void *)(estatus + 1) < estatus->data_length; \
+	     section = acpi_hest_get_next(section))
+
 int ghes_notify_sea(void);
 
 #endif /* GHES_H */
-- 
2.14.0