x86: mce: Use safer ways to access MCE registers
Use rdmsrl_safe() when accessing MCE registers. While in theory we always 'know' which ones are safe to access from the capability bits, there's a lot of hardware variations and reality might differ from theory, as it did in this case: http://bugzilla.kernel.org/show_bug.cgi?id=14204 [ 0.010016] mce: CPU supports 5 MCE banks [ 0.011029] general protection fault: 0000 [#1] [ 0.011998] last sysfs file: [ 0.011998] Modules linked in: [ 0.011998] [ 0.011998] Pid: 0, comm: swapper Not tainted (2.6.31_router #1) HP Vectra [ 0.011998] EIP: 0060:[<c100d9b9>] EFLAGS: 00010246 CPU: 0 [ 0.011998] EIP is at mce_rdmsrl+0x19/0x60 [ 0.011998] EAX: 00000000 EBX: 00000001 ECX: 00000407 EDX: 08000000 [ 0.011998] ESI: 00000000 EDI: 8c000000 EBP: 00000405 ESP: c17d5eac So WARN_ONCE() instead of crashing the box. ( also fix a number of stylistic inconsistencies in the code. ) Note, we might still crash in wrmsrl() if we get that far, but we shouldnt if the registers are truly inaccessible. Reported-by: GNUtoo <GNUtoo@no-log.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Andi Kleen <ak@linux.intel.com> LKML-Reference: <bug-14204-5438@http.bugzilla.kernel.org/> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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