The patch regulator: core: fix crash in error path of regulator_register
has been applied to the regulator tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 32165230eb6e629d7f88e66e0bd90a201549de53 Mon Sep 17 00:00:00 2001 From: Krzysztof Adamski <[email protected]> Date: Wed, 24 Feb 2016 11:52:50 +0100 Subject: [PATCH] regulator: core: fix crash in error path of regulator_register This problem was introduced by: commit daad134d6649 ("regulator: core: Request GPIO before creating sysfs entries") The error path was not updated correctly after moving GPIO registration code and in case regulator_ena_gpio_free failed, device_unregister() was called even though device_register() was not yet called. This problem breaks the boot at least on all Tegra 32-bit devices. It will also crash each device that specifices GPIO that is unavaiable at regulator_register call. Here's error log I've got when forced GPIO to be invalid: [ 1.116612] usb-otg-vbus-reg: Failed to request enable GPIO10: -22 [ 1.122794] Unable to handle kernel NULL pointer dereference at virtual address 00000044 [ 1.130894] pgd = c0004000 [ 1.133598] [00000044] *pgd=00000000 [ 1.137205] Internal error: Oops: 5 [#1] SMP ARM and here's backtrace from KDB: Exception stack(0xef11fbd0 to 0xef11fc18) fbc0: 00000000 c0738a14 00000000 00000000 fbe0: c0b2a0b0 00000000 00000000 c0738a14 c0b5fdf8 00000001 ef7f6074 ef11fc4c fc00: ef11fc50 ef11fc20 c02a8344 c02a7f1c 60000013 ffffffff [<c010cee0>] (__dabt_svc) from [<c02a7f1c>] (kernfs_find_ns+0x18/0xf8) [<c02a7f1c>] (kernfs_find_ns) from [<c02a8344>] (kernfs_find_and_get_ns+0x40/0x58) [<c02a8344>] (kernfs_find_and_get_ns) from [<c02ac4a4>] (sysfs_unmerge_group+0x28/0x68) [<c02ac4a4>] (sysfs_unmerge_group) from [<c044389c>] (dpm_sysfs_remove+0x30/0x5c) [<c044389c>] (dpm_sysfs_remove) from [<c0436ba8>] (device_del+0x48/0x1f4) [<c0436ba8>] (device_del) from [<c0436d84>] (device_unregister+0x30/0x6c) [<c0436d84>] (device_unregister) from [<c0403910>] (regulator_register+0x6d0/0xdac) [<c0403910>] (regulator_register) from [<c04052d4>] (devm_regulator_register+0x50/0x84) [<c04052d4>] (devm_regulator_register) from [<c0406298>] (reg_fixed_voltage_probe+0x25c/0x3c0) [<c0406298>] (reg_fixed_voltage_probe) from [<c043d21c>] (platform_drv_probe+0x60/0xb0) [<c043d21c>] (platform_drv_probe) from [<c043b078>] (driver_probe_device+0x24c/0x440) [<c043b078>] (driver_probe_device) from [<c043b5e8>] (__device_attach_driver+0xc0/0x120) [<c043b5e8>] (__device_attach_driver) from [<c043901c>] (bus_for_each_drv+0x6c/0x98) [<c043901c>] (bus_for_each_drv) from [<c043ad20>] (__device_attach+0xac/0x138) [<c043ad20>] (__device_attach) from [<c043b664>] (device_initial_probe+0x1c/0x20) [<c043b664>] (device_initial_probe) from [<c043a074>] (bus_probe_device+0x94/0x9c) [<c043a074>] (bus_probe_device) from [<c043a610>] (deferred_probe_work_func+0x80/0xcc) [<c043a610>] (deferred_probe_work_func) from [<c01381d0>] (process_one_work+0x158/0x454) [<c01381d0>] (process_one_work) from [<c013854c>] (worker_thread+0x38/0x510) [<c013854c>] (worker_thread) from [<c013e154>] (kthread+0xe8/0x104) [<c013e154>] (kthread) from [<c0108638>] (ret_from_fork+0x14/0x3c) Signed-off-by: Krzysztof Adamski <[email protected]> Reported-by: Jon Hunter <[email protected]> Acked-by: Jon Hunter <[email protected]> Tested-by: Jon Hunter <[email protected]> Signed-off-by: Mark Brown <[email protected]> --- drivers/regulator/core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 6ee9ba43fa8f..055f8c1a83a8 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -3919,7 +3919,7 @@ regulator_register(const struct regulator_desc *regulator_desc, if (ret != 0) { rdev_err(rdev, "Failed to request enable GPIO%d: %d\n", config->ena_gpio, ret); - goto wash; + goto clean; } } @@ -3931,7 +3931,7 @@ regulator_register(const struct regulator_desc *regulator_desc, ret = device_register(&rdev->dev); if (ret != 0) { put_device(&rdev->dev); - goto clean; + goto wash; } dev_set_drvdata(&rdev->dev, rdev); @@ -3974,13 +3974,13 @@ unset_supplies: scrub: regulator_ena_gpio_free(rdev); - -wash: device_unregister(&rdev->dev); /* device core frees rdev */ rdev = ERR_PTR(ret); goto out; +wash: + regulator_ena_gpio_free(rdev); clean: kfree(rdev); rdev = ERR_PTR(ret); -- 2.7.0
