[PATCH] thermal/core: Add a check before calling set_trip_temp()
From: Lad Prabhakar
Date: Thu Sep 08 2022 - 13:47:11 EST
The thermal driver [0] for Renesas RZ/G2L SoC does not implement
set_trip_temp() callback but has trips commit 9326167058e8
("thermal/core: Move set_trip_temp ops to the sysfs code") changed
the behaviour which causes the below panic when trying to set the
trip temperature:
root@smarc-rzg2l:~# echo 51000 > /sys/class/thermal/thermal_zone0/trip_point_0_temp
[ 92.461521] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 92.470958] Mem abort info:
[ 92.474311] ESR = 0x0000000086000004
[ 92.478546] EC = 0x21: IABT (current EL), IL = 32 bits
[ 92.484290] SET = 0, FnV = 0
[ 92.487693] EA = 0, S1PTW = 0
[ 92.491153] FSC = 0x04: level 0 translation fault
[ 92.496461] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004e885000
[ 92.503736] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[ 92.510869] Internal error: Oops: 86000004 [#3] PREEMPT SMP
[ 92.516556] CPU: 0 PID: 290 Comm: sh Tainted: G D 6.0.0-rc4-next-20220906-arm64-renesas-00124-g84633c87c5f6-dirty #509
[ 92.528814] Hardware name: Renesas SMARC EVK based on r9a07g044l2 (DT)
[ 92.535441] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 92.542516] pc : 0x0
[ 92.544764] lr : trip_point_temp_store+0x84/0x140
[ 92.549582] sp : ffff80000a92bc10
[ 92.552961] x29: ffff80000a92bc10 x28: ffff00000d8a45c0 x27: 0000000000000000
[ 92.560249] x26: 0000000000000000 x25: ffff8000082b53e8 x24: ffff00000eaffc20
[ 92.567532] x23: ffff80000a92bd68 x22: ffff00000d3e0f80 x21: 0000000000000006
[ 92.574814] x20: ffff800009149000 x19: ffff00000b8ab000 x18: 0000000000000000
[ 92.582097] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaab028cdee0
[ 92.589378] x14: 0000000000000000 x13: 0000000000000000 x12: ffff80000a92bbd0
[ 92.596659] x11: ffff00000d3e0f80 x10: ffff800009149eb8 x9 : 000000000000000a
[ 92.603940] x8 : 00000000ffffffc9 x7 : 0000000000000005 x6 : 000000000000002a
[ 92.611220] x5 : 000000000000c738 x4 : 00000000ffffffd3 x3 : 0000000000000000
[ 92.618500] x2 : 000000000000c738 x1 : 0000000000000000 x0 : ffff00000b8ab000
[ 92.625781] Call trace:
[ 92.628282] 0x0
[ 92.630176] dev_attr_store+0x14/0x28
[ 92.633935] sysfs_kf_write+0x4c/0x70
[ 92.637681] kernfs_fop_write_iter+0x160/0x1e0
[ 92.642213] vfs_write+0x474/0x540
[ 92.645703] ksys_write+0x68/0xf8
[ 92.649100] __arm64_sys_write+0x18/0x20
[ 92.653111] invoke_syscall+0x40/0xf8
[ 92.656866] el0_svc_common.constprop.3+0x88/0x110
[ 92.661758] do_el0_svc+0x20/0x78
[ 92.665158] el0_svc+0x3c/0x90
[ 92.668291] el0t_64_sync_handler+0x90/0xb8
[ 92.672563] el0t_64_sync+0x148/0x14c
[ 92.676322] Code: bad PC value
[ 92.679453] ---[ end trace 0000000000000000 ]---
/bin/start_getty: line 40: 290 Segmentation fault ${setsid:-} ${getty} -L $1 $2 $3
Poky (Yocto Project Reference Distro) 3.2.1 smarc-rzg2l ttySC0
smarc-rzg2l login:
This patch fixes the above issue by adding a check to see if
set_trip_temp() callback is implemented before calling it.
[0] drivers/thermal/rzg2l_thermal.c
Fixes: 9326167058e8 ("thermal/core: Move set_trip_temp ops to the sysfs code")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
Note: Patch applies on top of [0].
[0] https://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git/log/?h=thermal/linux-next
---
drivers/thermal/thermal_sysfs.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 78c5841bdfae..ec495c7dff03 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -128,9 +128,11 @@ trip_point_temp_store(struct device *dev, struct device_attribute *attr,
if (kstrtoint(buf, 10, &temperature))
return -EINVAL;
- ret = tz->ops->set_trip_temp(tz, trip, temperature);
- if (ret)
- return ret;
+ if (tz->ops->set_trip_temp) {
+ ret = tz->ops->set_trip_temp(tz, trip, temperature);
+ if (ret)
+ return ret;
+ }
if (tz->trips)
tz->trips[trip].temperature = temperature;
--
2.25.1