extlog_init() uses rdmsrl() to read an MSR, which on older CPUs provokes a error message at boot: unchecked MSR access error: RDMSR from 0x179 at rIP: 0xcd047307 (native_read_msr+0x7/0x40) Use rdmsrl_safe() instead, and return -ENODEV if it fails. Reported-by: jim@xxxxxxxxxxx References: https://bugs.debian.org/971058 Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/acpi/acpi_extlog.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c index f138e12b7b82..72f1fb77abcd 100644 --- a/drivers/acpi/acpi_extlog.c +++ b/drivers/acpi/acpi_extlog.c @@ -222,9 +222,9 @@ static int __init extlog_init(void) u64 cap; int rc; - rdmsrl(MSR_IA32_MCG_CAP, cap); - - if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr()) + if (rdmsrl_safe(MSR_IA32_MCG_CAP, &cap) || + !(cap & MCG_ELOG_P) || + !extlog_get_l1addr()) return -ENODEV; rc = -EINVAL;
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