diff options
| author | Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com> | 2009-04-15 10:37:33 -0700 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-04-19 22:47:20 -0400 |
| commit | 093f13e23137b9e5f7629dd5932ceea1419e2b61 (patch) | |
| tree | c9dac5a692824358484df522c88bc28ea6c5c515 /arch/x86/kernel | |
| parent | d91dfbb41bb2e9bdbfbd2cc7078ed7436eab027a (diff) | |
x86, acpi_cpufreq: Fix the NULL pointer dereference in get_measured_perf
Fix for a regression that was introduced by earlier commit
18b2646fe3babeb40b34a0c1751e0bf5adfdc64c on Mon Apr 6 11:26:08 2009
Regression resulted in the below error happened on systems with
software coordination where per_cpu acpi data will not be initiated for
secondary CPUs in a P-state domain.
On Tue, 2009-04-14 at 23:01 -0700, Zhang, Yanmin wrote:
My machine hanged with kernel 2.6.30-rc2 when script read
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor.
>
> opps happens in get_measured_perf:
>
> cur.aperf.whole = readin.aperf.whole -
> per_cpu(drv_data, cpu)->saved_aperf;
>
> Because per_cpu(drv_data, cpu)=NULL.
>
> So function get_measured_perf should check if (per_cpu(drv_data,
> cpu)==NULL)
> and return 0 if it's NULL.
--------------sys log------------------
BUG: unable to handle kernel NULL pointer dereference at
0000000000000020
IP: [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
PGD a7dd88067 PUD a7ccf5067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
CPU 0
Modules linked in: video output
Pid: 2091, comm: kondemand/0 Not tainted 2.6.30-rc2 #1 MP Server
RIP: 0010:[<ffffffff8021af75>] [<ffffffff8021af75>]
get_measured_perf+0x4a/0xf9
RSP: 0018:ffff880a7d56de20 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000046241a42b6 RCX: ffff88004d219000
RDX: 000000000000b660 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff880a7f052000 R08: 00000046241a42b6 R09: ffffffff807639f0
R10: 00000000ffffffea R11: ffffffff802207f4 R12: ffff880a7f052000
R13: ffff88004d20e460 R14: 0000000000ddd5a6 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88004d200000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000020 CR3: 0000000a7f1bf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kondemand/0 (pid: 2091, threadinfo ffff880a7d56c000, task
ffff880a7d4d18c0)
Stack:
ffff880a7f052078 ffffffff803efd54 00000046241a42b6 000000462ffa9e95
0000000000000001 0000000000000001 00000000ffffffea ffffffff8064f41a
0000000000000012 0000000000000012 ffff880a7f052000 ffffffff80650547
Call Trace:
[<ffffffff803efd54>] ? kobject_get+0x12/0x17
[<ffffffff8064f41a>] ? __cpufreq_driver_getavg+0x42/0x57
[<ffffffff80650547>] ? do_dbs_timer+0x147/0x272
[<ffffffff80650400>] ? do_dbs_timer+0x0/0x272
[<ffffffff802474ca>] ? worker_thread+0x15b/0x1f5
[<ffffffff8024a02c>] ? autoremove_wake_function+0x0/0x2e
[<ffffffff8024736f>] ? worker_thread+0x0/0x1f5
[<ffffffff80249f0d>] ? kthread+0x54/0x83
[<ffffffff8020c87a>] ? child_rip+0xa/0x20
[<ffffffff80249eb9>] ? kthread+0x0/0x83
[<ffffffff8020c870>] ? child_rip+0x0/0x20
Code: 99 a6 03 00 31 c9 85 c0 0f 85 c3 00 00 00 89 df 4c 8b 44 24 10 48
c7 c2 60 b6 00 00 48 8b 0c fd e0 30 a5 80 4c 89 c3 48 8b 04 0a <48> 2b
58 20 48 8b 44 24 18 48 89 1c 24 48 8b 34 0a 48 2b 46 28
RIP [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
RSP <ffff880a7d56de20>
CR2: 0000000000000020
---[ end trace 2b8fac9a49e19ad4 ]---
Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index ecdb682ab51..dd0bd76d14c 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -68,11 +68,16 @@ struct acpi_cpufreq_data { unsigned int max_freq; unsigned int resume; unsigned int cpu_feature; - u64 saved_aperf, saved_mperf; }; static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data); +struct acpi_msr_data { + u64 saved_aperf, saved_mperf; +}; + +static DEFINE_PER_CPU(struct acpi_msr_data, msr_data); + DEFINE_TRACE(power_mark); /* acpi_perf_data is a pointer to percpu data. */ @@ -287,11 +292,11 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, return 0; cur.aperf.whole = readin.aperf.whole - - per_cpu(drv_data, cpu)->saved_aperf; + per_cpu(msr_data, cpu).saved_aperf; cur.mperf.whole = readin.mperf.whole - - per_cpu(drv_data, cpu)->saved_mperf; - per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole; - per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole; + per_cpu(msr_data, cpu).saved_mperf; + per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole; + per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole; #ifdef __i386__ /* |