This is a note to let you know that I've just added the patch titled
spmi: Add a check for remove callback when removing a SPMI driver
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spmi-add-a-check-for-remove-callback-when-removing-a.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3e725bd9cf70e8f60f3d2990d13b31569fda723d
Author: Jishnu Prakash <quic_jprakash@xxxxxxxxxxx>
Date: Thu Apr 13 15:38:34 2023 -0700
spmi: Add a check for remove callback when removing a SPMI driver
[ Upstream commit b56eef3e16d888883fefab47425036de80dd38fc ]
When removing a SPMI driver, there can be a crash due to NULL pointer
dereference if it does not have a remove callback defined. This is
one such call trace observed when removing the QCOM SPMI PMIC driver:
dump_backtrace.cfi_jt+0x0/0x8
dump_stack_lvl+0xd8/0x16c
panic+0x188/0x498
__cfi_slowpath+0x0/0x214
__cfi_slowpath+0x1dc/0x214
spmi_drv_remove+0x16c/0x1e0
device_release_driver_internal+0x468/0x79c
driver_detach+0x11c/0x1a0
bus_remove_driver+0xc4/0x124
driver_unregister+0x58/0x84
cleanup_module+0x1c/0xc24 [qcom_spmi_pmic]
__do_sys_delete_module+0x3ec/0x53c
__arm64_sys_delete_module+0x18/0x28
el0_svc_common+0xdc/0x294
el0_svc+0x38/0x9c
el0_sync_handler+0x8c/0xf0
el0_sync+0x1b4/0x1c0
If a driver has all its resources allocated through devm_() APIs and
does not need any other explicit cleanup, it would not require a
remove callback to be defined. Hence, add a check for remove callback
presence before calling it when removing a SPMI driver.
Link: https://lore.kernel.org/r/1671601032-18397-2-git-send-email-quic_jprakash@xxxxxxxxxxx
Fixes: 6f00f8c8635f ("mfd: qcom-spmi-pmic: Use devm_of_platform_populate()")
Fixes: 5a86bf343976 ("spmi: Linux driver framework for SPMI")
Signed-off-by: Jishnu Prakash <quic_jprakash@xxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230413223834.4084793-7-sboyd@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c
index c16b60f645a4d..8ca7e004a53dc 100644
--- a/drivers/spmi/spmi.c
+++ b/drivers/spmi/spmi.c
@@ -348,7 +348,8 @@ static int spmi_drv_remove(struct device *dev)
const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
pm_runtime_get_sync(dev);
- sdrv->remove(to_spmi_device(dev));
+ if (sdrv->remove)
+ sdrv->remove(to_spmi_device(dev));
pm_runtime_put_noidle(dev);
pm_runtime_disable(dev);
