Fix null pointer deference in clk_core_enable() when driver unbind is run
when there is an application has an active pipeline playing.
s5p_mfc_release() gets called after s5p_mfc_final_pm() disables and does
clk_put() and s5p_mfc_release() attempts to enable clock and runs into
null pointer deference accessing invalid pointer.
[ 4869.434709] Unable to handle kernel NULL pointer dereference at virtual addr0
[ 4869.441312] pgd = e91ac000
[ 4869.443996] [00000010] *pgd=ba4f7835
[ 4869.447552] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 4869.452921] Modules linked in: cpufreq_userspace cpufreq_powersave cpufreq_ca
[ 4869.471728] CPU: 4 PID: 2965 Comm: lt-gst-launch-1 Not tainted 4.7.0-rc2-nex0
[ 4869.481778] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 4869.487844] task: e91f1e00 ti: ed650000 task.ti: ed650000
[ 4869.493227] PC is at clk_core_enable+0x4c/0x98
[ 4869.497637] LR is at clk_core_enable+0x40/0x98
[ 4869.502056] pc : [<c0559714>] lr : [<c0559708>] psr: 60060093
[ 4869.502056] sp : ed651f18 ip : 00000000 fp : 002641b4
[ 4869.513493] r10: e9088c08 r9 : 00000008 r8 : ed676d68
[ 4869.518692] r7 : ee3ac000 r6 : bf16b3c0 r5 : a0060013 r4 : ee37a8c0
[ 4869.525191] r3 : 00000000 r2 : 00000001 r1 : 00000004 r0 : 00000000
[ 4869.531692] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment noe
[ 4869.538883] Control: 10c5387d Table: 691ac06a DAC: 00000051
[ 4869.544603] Process lt-gst-launch-1 (pid: 2965, stack limit = 0xed650210)
[ 4869.551361] Stack: (0xed651f18 to 0xed652000)
[ 4869.555694] 1f00: ee373
[ 4869.563841] 1f20: bf16b3c0 c055a0e0 ee3ac004 ed676c10 bf16b3c0 bf1558e0 e9080
[ 4869.571986] 1f40: 00000000 ee98a510 ee502e40 bf047344 e9088c00 ee986938 00004
[ 4869.580132] 1f60: 00000000 00000000 e91f2204 00000000 c0b4658c e91f1e00 c0100
[ 4869.588277] 1f80: 00000000 c0135c58 ed650000 c0107904 ed651fb0 00000006 c0104
[ 4869.596423] 1fa0: 00229500 b6581000 b6f7b544 c0107794 00000000 00000002 b6f90
[ 4869.604568] 1fc0: 00229500 b6581000 b6f7b544 00000006 0017b600 0002c038 00264
[ 4869.612714] 1fe0: 00000000 bee56ef0 00000000 b6d49612 00060030 00000006 00000
[ 4869.620865] [<c0559714>] (clk_core_enable) from [<c055a0e0>] (clk_enable+0x2)
[ 4869.628509] [<c055a0e0>] (clk_enable) from [<bf1558e0>] (s5p_mfc_release+0x3)
[ 4869.637111] [<bf1558e0>] (s5p_mfc_release [s5p_mfc]) from [<bf047344>] (v4l2)
[ 4869.646706] [<bf047344>] (v4l2_release [videodev]) from [<c01e4274>] (__fput)
[ 4869.654745] [<c01e4274>] (__fput) from [<c0135c58>] (task_work_run+0x94/0xc8)
[ 4869.661852] [<c0135c58>] (task_work_run) from [<c010a9d4>] (do_work_pending+)
[ 4869.669735] [<c010a9d4>] (do_work_pending) from [<c0107794>] (slow_work_pend)
[ 4869.677878] Code: ebffffef e3500000 18bd8070 e5943004 (e5933010)
Signed-off-by: Shuah Khan <shua...@osg.samsung.com>
---
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
index 9f75221..930dc2d 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
@@ -77,8 +77,10 @@ int s5p_mfc_init_pm(struct s5p_mfc_dev *dev)
err_s_clk:
clk_put(pm->clock);
+ pm->clock = NULL;
err_p_ip_clk:
clk_put(pm->clock_gate);
+ pm->clock_gate = NULL;
err_g_ip_clk:
return ret;
}
@@ -89,9 +91,11 @@ void s5p_mfc_final_pm(struct s5p_mfc_dev *dev)
pm->clock) {
clk_disable_unprepare(pm->clock);
clk_put(pm->clock);
+ pm->clock = NULL;
}
clk_unprepare(pm->clock_gate);
clk_put(pm->clock_gate);
+ pm->clock_gate = NULL;
#ifdef CONFIG_PM
pm_runtime_disable(pm->device);
#endif
@@ -99,12 +103,13 @@ void s5p_mfc_final_pm(struct s5p_mfc_dev *dev)
int s5p_mfc_clock_on(void)
{
- int ret;
+ int ret = 0;
#ifdef CLK_DEBUG
atomic_inc(&clk_ref);
mfc_debug(3, "+ %d\n", atomic_read(&clk_ref));
#endif
- ret = clk_enable(pm->clock_gate);
+ if (!IS_ERR_OR_NULL(pm->clock_gate))
+ ret = clk_enable(pm->clock_gate);
return ret;
}
@@ -114,7 +119,8 @@ void s5p_mfc_clock_off(void)
atomic_dec(&clk_ref);
mfc_debug(3, "- %d\n", atomic_read(&clk_ref));
#endif
- clk_disable(pm->clock_gate);
+ if (!IS_ERR_OR_NULL(pm->clock_gate))
+ clk_disable(pm->clock_gate);
}
int s5p_mfc_power_on(void)
--
2.7.4
