Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a8ba72bb authored by Tony Luck's avatar Tony Luck Committed by Greg Kroah-Hartman
Browse files

ACPI: APEI: Better fix to avoid spamming the console with old error logs 



commit c3481b6b75b4797657838f44028fd28226ab48e0 upstream.

The fix in commit 3f8dec116210 ("ACPI/APEI: Limit printable size of BERT
table data") does not work as intended on systems where the BIOS has a
fixed size block of memory for the BERT table, relying on s/w to quit
when it finds a record with estatus->block_status == 0. On these systems
all errors are suppressed because the check:

	if (region_len < ACPI_BERT_PRINT_MAX_LEN)

always fails.

New scheme skips individual CPER records that are too large, and also
limits the total number of records that will be printed to 5.

Fixes: 3f8dec116210 ("ACPI/APEI: Limit printable size of BERT table data")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fa829bd4

drivers/acpi/apei/bert.c

+23 −8
Original line number Diff line number Diff line
@@ -29,16 +29,26 @@ 


#undef pr_fmt

#define pr_fmt(fmt) "BERT: " fmt



#define ACPI_BERT_PRINT_MAX_RECORDS 5

#define ACPI_BERT_PRINT_MAX_LEN 1024



static int bert_disable;



/*

 * Print "all" the error records in the BERT table, but avoid huge spam to

 * the console if the BIOS included oversize records, or too many records.

 * Skipping some records here does not lose anything because the full

 * data is available to user tools in:

 *	/sys/firmware/acpi/tables/data/BERT

 */

static void __init bert_print_all(struct acpi_bert_region *region,

				  unsigned int region_len)

{

	struct acpi_hest_generic_status *estatus =

		(struct acpi_hest_generic_status *)region;

	int remain = region_len;

	int printed = 0, skipped = 0;

	u32 estatus_len;



	while (remain >= sizeof(struct acpi_bert_region)) {
@@ -46,24 +56,26 @@ static void __init bert_print_all(struct acpi_bert_region *region, 
		if (remain < estatus_len) {

			pr_err(FW_BUG "Truncated status block (length: %u).\n",

			       estatus_len);

			return;

			break;

		}



		/* No more error records. */

		if (!estatus->block_status)

			return;

			break;



		if (cper_estatus_check(estatus)) {

			pr_err(FW_BUG "Invalid error record.\n");

			return;

			break;

		}



		if (estatus_len < ACPI_BERT_PRINT_MAX_LEN &&

		    printed < ACPI_BERT_PRINT_MAX_RECORDS) {

			pr_info_once("Error records from previous boot:\n");

		if (region_len < ACPI_BERT_PRINT_MAX_LEN)

			cper_estatus_print(KERN_INFO HW_ERR, estatus);

		else

			pr_info_once("Max print length exceeded, table data is available at:\n"

				     "/sys/firmware/acpi/tables/data/BERT");

			printed++;

		} else {

			skipped++;

		}



		/*

		 * Because the boot error source is "one-time polled" type,
@@ -75,6 +87,9 @@ static void __init bert_print_all(struct acpi_bert_region *region, 
		estatus = (void *)estatus + estatus_len;

		remain -= estatus_len;

	}



	if (skipped)

		pr_info(HW_ERR "Skipped %d error records\n", skipped);

}



static int __init setup_bert_disable(char *str)