dev_set_drvdata() needs to be called before device_register() exposes device to userspace. Otherwise kernel crashes after it gets null pointer from dev_get_drvdata() when userspace tries to access sysfs entries.
[ 25.566073] general protection fault: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 25.621976] gsmi: Log Shutdown Reason 0x03 <snipped> [ 25.747085] Call Trace: [ 25.749532] name_show+0x51/0x6f [ 25.752760] dev_attr_show+0x59/0xa0 [ 25.756333] ? device_namespace+0x9e/0x9e [ 25.760339] sysfs_kf_seq_show+0x228/0x33b [ 25.764434] seq_read+0x74f/0xd58 [ 25.767747] ? set_track+0x63/0xfa [ 25.771148] ? kzalloc+0xf/0xf [ 25.774200] ? _copy_to_user+0x87/0x9a [ 25.777947] __vfs_read+0x106/0x320 [ 25.781433] ? mandatory_lock+0x94/0x94 [ 25.785267] ? fsnotify_unmount_inodes+0x17d/0x17d [ 25.790053] ? inode_security+0x17/0x40 [ 25.793885] ? selinux_file_permission+0x176/0x342 [ 25.798670] ? security_file_permission+0x77/0x98 [ 25.803369] vfs_read+0xf3/0x197 [ 25.806595] SyS_read+0xfa/0x19b [ 25.809822] ? file_end_write+0x91/0x91 [ 25.813653] ? filp_close+0xdb/0x100 [ 25.817225] ? file_end_write+0x91/0x91 [ 25.821057] do_syscall_64+0x184/0x1bb [ 25.824804] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 <snipped> [ 25.895502] RIP: rdev_get_name+0x29/0xa5 RSP: ffff8801d45779f0 [ 26.550863] ---[ end trace fb2a7bb4f63aeba5 ]--- Signed-off-by: Yu Zhao <[email protected]> --- drivers/regulator/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 5f2218c67edf..69565ff65800 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4404,13 +4404,13 @@ regulator_register(const struct regulator_desc *regulator_desc, !rdev->desc->fixed_uV) rdev->is_switch = true; + dev_set_drvdata(&rdev->dev, rdev); ret = device_register(&rdev->dev); if (ret != 0) { put_device(&rdev->dev); goto unset_supplies; } - dev_set_drvdata(&rdev->dev, rdev); rdev_init_debugfs(rdev); /* try to resolve regulators supply since a new one was registered */ -- 2.19.0.397.gdd90340f6a-goog
