cpufreq: Avoid crash in resume on SMP without OPP
When resuming from s2ram on an SMP system without cpufreq operating
points (e.g. there's no "operating-points" property for the CPU node in
DT, or the platform doesn't use DT yet), the kernel crashes when
bringing CPU 1 online:
Enabling non-boot CPUs ...
CPU1: Booted secondary processor
Unable to handle kernel NULL pointer dereference at virtual address
0000003c
pgd =
ee5e6b00
[
0000003c] *pgd=
6e579003, *pmd=
6e588003, *pte=
00000000
Internal error: Oops: a07 [#1] SMP ARM
Modules linked in:
CPU: 0 PID: 1246 Comm: s2ram Tainted: G W
3.18.0-rc3-koelsch-01614-g0377af242bb175c8-dirty #589
task:
eeec5240 ti:
ee704000 task.ti:
ee704000
PC is at __cpufreq_add_dev.isra.24+0x24c/0x77c
LR is at __cpufreq_add_dev.isra.24+0x244/0x77c
pc : [<
c0298efc>] lr : [<
c0298ef4>] psr:
60000153
sp :
ee705d48 ip :
ee705d48 fp :
ee705d84
r10:
c04e0450 r9 :
00000000 r8 :
00000001
r7 :
c05426a8 r6 :
00000001 r5 :
00000001 r4 :
00000000
r3 :
00000000 r2 :
00000000 r1 :
20000153 r0 :
c0542734
Verify that policy is not NULL before dereferencing it to fix this.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes:
8414809c6a1e (cpufreq: Preserve policy structure across suspend/resume)
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>