From: Ben Hutchings ben@decadent.org.uk
commit 7cecb47f55e00282f972a1e0b09136c8cd938221 upstream.
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@photojim.ca Cc: All applicable stable@vger.kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/acpi/acpi_extlog.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- 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;