From: Tony Luck tony.luck@intel.com
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: Tony Luck tony.luck@intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/apei/bert.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-)
--- a/drivers/acpi/apei/bert.c +++ b/drivers/acpi/apei/bert.c @@ -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 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; }
- pr_info_once("Error records from previous boot:\n"); - if (region_len < ACPI_BERT_PRINT_MAX_LEN) + if (estatus_len < ACPI_BERT_PRINT_MAX_LEN && + printed < ACPI_BERT_PRINT_MAX_RECORDS) { + pr_info_once("Error records from previous boot:\n"); 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 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)