diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-29 08:46:28 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-29 08:46:28 -0700 |
| commit | 94b086b243e112030b815b76e61de6523e6fc700 (patch) | |
| tree | 3c7f2308e7e5afdb276a858c4960754168a92d8c /arch/x86/kernel/cpu/perf_event.c | |
| parent | 967857dfd990081f6702daebc6c9bc6f4ba7a39e (diff) | |
| parent | 8f0d8163b50e01f398b14bcd4dc039ac5ab18d64 (diff) | |
Merge 3.7-rc3 into driver-core-next
This pulls in the various driver core changes that were in 3.7-rc3 into the
driver-core-next branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 3373f84d139..4a3374e61a9 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -208,12 +208,14 @@ static bool check_hw_exists(void) } /* - * Now write a value and read it back to see if it matches, - * this is needed to detect certain hardware emulators (qemu/kvm) - * that don't trap on the MSR access and always return 0s. + * Read the current value, change it and read it back to see if it + * matches, this is needed to detect certain hardware emulators + * (qemu/kvm) that don't trap on the MSR access and always return 0s. */ - val = 0xabcdUL; reg = x86_pmu_event_addr(0); + if (rdmsrl_safe(reg, &val)) + goto msr_fail; + val ^= 0xffffUL; ret = wrmsrl_safe(reg, val); ret |= rdmsrl_safe(reg, &val_new); if (ret || val != val_new) |