From d8ecca4043f2d9d89daab7915eca8c2ec6254d0f Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Tue, 18 Feb 2020 10:44:08 -0800 Subject: x86/mce/dev-mcelog: Dynamically allocate space for machine check records We have had a hard coded limit of 32 machine check records since the dawn of time. But as numbers of cores increase, it is possible for more than 32 errors to be reported before a user process reads from /dev/mcelog. In this case the additional errors are lost. Keep 32 as the minimum. But tune the maximum value up based on the number of processors. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200218184408.GA23048@agluck-desk2.amr.corp.intel.com --- arch/x86/include/asm/mce.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 4359b955e0b7..9d5b09913ef3 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -102,7 +102,7 @@ #define MCE_OVERFLOW 0 /* bit 0 in flags means overflow */ -#define MCE_LOG_LEN 32 +#define MCE_LOG_MIN_LEN 32U #define MCE_LOG_SIGNATURE "MACHINECHECK" /* AMD Scalable MCA */ @@ -135,11 +135,11 @@ */ struct mce_log_buffer { char signature[12]; /* "MACHINECHECK" */ - unsigned len; /* = MCE_LOG_LEN */ + unsigned len; /* = elements in .mce_entry[] */ unsigned next; unsigned flags; unsigned recordlen; /* length of struct mce */ - struct mce entry[MCE_LOG_LEN]; + struct mce entry[]; }; enum mce_notifier_prios { -- cgit v1.2.3