mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![]() While debugging a cpufreq-related hardware failure on a system I saw the
following lockdep warning:
=========================
[ BUG: held lock freed! ] 3.17.0-rc4+ #1 Tainted: G E
-------------------------
insmod/2247 is freeing memory ffff88006e1b1400-ffff88006e1b17ff, with a lock still held there!
(&policy->rwsem){+.+...}, at: [<ffffffff8156d37d>] __cpufreq_add_dev.isra.21+0x47d/0xb80
3 locks held by insmod/2247:
#0: (subsys mutex#5){+.+.+.}, at: [<ffffffff81485579>] subsys_interface_register+0x69/0x120
#1: (cpufreq_rwsem){.+.+.+}, at: [<ffffffff8156cf73>] __cpufreq_add_dev.isra.21+0x73/0xb80
#2: (&policy->rwsem){+.+...}, at: [<ffffffff8156d37d>] __cpufreq_add_dev.isra.21+0x47d/0xb80
stack backtrace:
CPU: 0 PID: 2247 Comm: insmod Tainted: G E 3.17.0-rc4+ #1
Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 08/24/2013
0000000000000000 000000008f3063c4 ffff88006f87bb30 ffffffff8171b358
ffff88006bcf3750 ffff88006f87bb68 ffffffff810e09e1 ffff88006e1b1400
ffffea0001b86c00 ffffffff8156d327 ffff880073003500 0000000000000246
Call Trace:
[<ffffffff8171b358>] dump_stack+0x4d/0x66
[<ffffffff810e09e1>] debug_check_no_locks_freed+0x171/0x180
[<ffffffff8156d327>] ? __cpufreq_add_dev.isra.21+0x427/0xb80
[<ffffffff8121412b>] kfree+0xab/0x2b0
[<ffffffff8156d327>] __cpufreq_add_dev.isra.21+0x427/0xb80
[<ffffffff81724cf7>] ? _raw_spin_unlock+0x27/0x40
[<ffffffffa003517f>] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
[<ffffffff8156da8e>] cpufreq_add_dev+0xe/0x10
[<ffffffff814855d1>] subsys_interface_register+0xc1/0x120
[<ffffffff8156bcf2>] cpufreq_register_driver+0x112/0x340
[<ffffffff8121415a>] ? kfree+0xda/0x2b0
[<ffffffffa003517f>] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
[<ffffffffa003562e>] pcc_cpufreq_init+0x4af/0xe81 [pcc_cpufreq]
[<ffffffffa003517f>] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
[<ffffffff81002144>] do_one_initcall+0xd4/0x210
[<ffffffff811f7472>] ? __vunmap+0xd2/0x120
[<ffffffff81127155>] load_module+0x1315/0x1b70
[<ffffffff811222a0>] ? store_uevent+0x70/0x70
[<ffffffff811229d9>] ? copy_module_from_fd.isra.44+0x129/0x180
[<ffffffff81127b86>] SyS_finit_module+0xa6/0xd0
[<ffffffff81725b69>] system_call_fastpath+0x16/0x1b
cpufreq: __cpufreq_add_dev: ->get() failed
insmod: ERROR: could not insert module pcc-cpufreq.ko: No such device
The warning occurs in the __cpufreq_add_dev() code which does
down_write(&policy->rwsem);
...
if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
policy->cur = cpufreq_driver->get(policy->cpu);
if (!policy->cur) {
pr_err("%s: ->get() failed\n", __func__);
goto err_get_freq;
}
If cpufreq_driver->get(policy->cpu) returns an error we execute the
code at err_get_freq, which does not up the policy->rwsem. This causes
the lockdep warning.
Trivial patch to up the policy->rwsem in the error path.
After the patch has been applied, and an error occurs in the
cpufreq_driver->get(policy->cpu) call we will now see
cpufreq: __cpufreq_add_dev: ->get() failed
cpufreq: __cpufreq_add_dev: ->get() failed
modprobe: ERROR: could not insert 'pcc_cpufreq': No such device
Fixes:
|
||
---|---|---|
.. | ||
acpi-cpufreq.c | ||
amd_freq_sensitivity.c | ||
arm_big_little.c | ||
arm_big_little.h | ||
arm_big_little_dt.c | ||
at32ap-cpufreq.c | ||
blackfin-cpufreq.c | ||
cpufreq-cpu0.c | ||
cpufreq-nforce2.c | ||
cpufreq.c | ||
cpufreq_conservative.c | ||
cpufreq_governor.c | ||
cpufreq_governor.h | ||
cpufreq_ondemand.c | ||
cpufreq_opp.c | ||
cpufreq_performance.c | ||
cpufreq_powersave.c | ||
cpufreq_stats.c | ||
cpufreq_userspace.c | ||
cris-artpec3-cpufreq.c | ||
cris-etraxfs-cpufreq.c | ||
davinci-cpufreq.c | ||
dbx500-cpufreq.c | ||
e_powersaver.c | ||
elanfreq.c | ||
exynos-cpufreq.c | ||
exynos-cpufreq.h | ||
exynos4x12-cpufreq.c | ||
exynos4210-cpufreq.c | ||
exynos5250-cpufreq.c | ||
exynos5440-cpufreq.c | ||
freq_table.c | ||
gx-suspmod.c | ||
highbank-cpufreq.c | ||
ia64-acpi-cpufreq.c | ||
imx6q-cpufreq.c | ||
integrator-cpufreq.c | ||
intel_pstate.c | ||
Kconfig | ||
Kconfig.arm | ||
Kconfig.powerpc | ||
Kconfig.x86 | ||
kirkwood-cpufreq.c | ||
longhaul.c | ||
longhaul.h | ||
longrun.c | ||
loongson2_cpufreq.c | ||
Makefile | ||
maple-cpufreq.c | ||
omap-cpufreq.c | ||
p4-clockmod.c | ||
pasemi-cpufreq.c | ||
pcc-cpufreq.c | ||
pmac32-cpufreq.c | ||
pmac64-cpufreq.c | ||
powernow-k6.c | ||
powernow-k7.c | ||
powernow-k7.h | ||
powernow-k8.c | ||
powernow-k8.h | ||
powernv-cpufreq.c | ||
ppc-corenet-cpufreq.c | ||
ppc_cbe_cpufreq.c | ||
ppc_cbe_cpufreq.h | ||
ppc_cbe_cpufreq_pervasive.c | ||
ppc_cbe_cpufreq_pmi.c | ||
pxa2xx-cpufreq.c | ||
pxa3xx-cpufreq.c | ||
s3c24xx-cpufreq-debugfs.c | ||
s3c24xx-cpufreq.c | ||
s3c64xx-cpufreq.c | ||
s3c2410-cpufreq.c | ||
s3c2412-cpufreq.c | ||
s3c2416-cpufreq.c | ||
s3c2440-cpufreq.c | ||
s5pv210-cpufreq.c | ||
sa1100-cpufreq.c | ||
sa1110-cpufreq.c | ||
sc520_freq.c | ||
sh-cpufreq.c | ||
sparc-us2e-cpufreq.c | ||
sparc-us3-cpufreq.c | ||
spear-cpufreq.c | ||
speedstep-centrino.c | ||
speedstep-ich.c | ||
speedstep-lib.c | ||
speedstep-lib.h | ||
speedstep-smi.c | ||
tegra-cpufreq.c | ||
unicore2-cpufreq.c | ||
vexpress-spc-cpufreq.c |