| Message ID | ceb6ba8e70efae6f268295c0e04a4ca58c1f6d0b.1477539388.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Oct 27, 2016 at 09:09:30AM +0530, Viresh Kumar wrote: > The kernel WARNs and then crashes today if wm8994_device_init() fails > after calling devm_regulator_bulk_get(). > > That happens because there are multiple devices involved here and the > order in which resources are freed isn't correct. > > The regulators are added as children of wm8994->dev. > devm_regulator_bulk_get() receives wm8994->dev as the device, though it > gets the same regulators which were added as children of wm8994->dev > earlier. > > During failures, the children are removed first and the core eventually > calls regulator_unregister() for them. As regulator_put() was never done > for them (opposite of devm_regulator_bulk_get()), the kernel WARNs at > > WARN_ON(rdev->open_count); > > And eventually it crashes from debugfs_remove_recursive(). > > --------x------------------x---------------- The back track seems to have got really really long again. Thanks, Charles > > wm8994 3-001a: Device is not a WM8994, ID is 0 > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at /mnt/ssd/all/work/repos/devel/linux/drivers/regulator/core.c:4072 regulator_unregister+0xc8/0xd0 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [<c010e24c>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14) > [<c010af38>] (show_stack) from [<c032a1c4>] (dump_stack+0x88/0x9c) > [<c032a1c4>] (dump_stack) from [<c011a98c>] (__warn+0xe8/0x100) > [<c011a98c>] (__warn) from [<c011aa54>] (warn_slowpath_null+0x20/0x28) > [<c011aa54>] (warn_slowpath_null) from [<c0384a0c>] (regulator_unregister+0xc8/0xd0) > [<c0384a0c>] (regulator_unregister) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04039c4>] (__device_release_driver+0x8c/0x110) > [<c04039c4>] (__device_release_driver) from [<c0403a64>] (device_release_driver+0x1c/0x28) > [<c0403a64>] (device_release_driver) from [<c0402b24>] (bus_remove_device+0xd8/0x104) > [<c0402b24>] (bus_remove_device) from [<c03ffcd8>] (device_del+0x10c/0x218) > [<c03ffcd8>] (device_del) from [<c0404e4c>] (platform_device_del+0x1c/0x88) > [<c0404e4c>] (platform_device_del) from [<c0404ec4>] (platform_device_unregister+0xc/0x20) > [<c0404ec4>] (platform_device_unregister) from [<c0428bc0>] (mfd_remove_devices_fn+0x5c/0x64) > [<c0428bc0>] (mfd_remove_devices_fn) from [<c03ff9d8>] (device_for_each_child_reverse+0x4c/0x78) > [<c03ff9d8>] (device_for_each_child_reverse) from [<c04288c4>] (mfd_remove_devices+0x20/0x30) > [<c04288c4>] (mfd_remove_devices) from [<c042758c>] (wm8994_device_init+0x2ac/0x7f0) > [<c042758c>] (wm8994_device_init) from [<c04f14a8>] (i2c_device_probe+0x178/0x1fc) > [<c04f14a8>] (i2c_device_probe) from [<c04036fc>] (driver_probe_device+0x214/0x2c0) > [<c04036fc>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > ---[ end trace 0919d3d0bc998260 ]--- > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at /mnt/ssd/all/work/repos/devel/linux/drivers/regulator/core.c:4072 regulator_unregister+0xc8/0xd0 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [<c010e24c>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14) > [<c010af38>] (show_stack) from [<c032a1c4>] (dump_stack+0x88/0x9c) > [<c032a1c4>] (dump_stack) from [<c011a98c>] (__warn+0xe8/0x100) > [<c011a98c>] (__warn) from [<c011aa54>] (warn_slowpath_null+0x20/0x28) > [<c011aa54>] (warn_slowpath_null) from [<c0384a0c>] (regulator_unregister+0xc8/0xd0) > [<c0384a0c>] (regulator_unregister) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04039c4>] (__device_release_driver+0x8c/0x110) > [<c04039c4>] (__device_release_driver) from [<c0403a64>] (device_release_driver+0x1c/0x28) > [<c0403a64>] (device_release_driver) from [<c0402b24>] (bus_remove_device+0xd8/0x104) > [<c0402b24>] (bus_remove_device) from [<c03ffcd8>] (device_del+0x10c/0x218) > [<c03ffcd8>] (device_del) from [<c0404e4c>] (platform_device_del+0x1c/0x88) > wm8994 3-001a: Device is not a WM8994, ID is 0 > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at /mnt/ssd/all/work/repos/devel/linux/drivers/regulator/core.c:4072 regulator_unregister+0xc8/0xd0 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [<c010e24c>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14) > [<c010af38>] (show_stack) from [<c032a1c4>] (dump_stack+0x88/0x9c) > [<c032a1c4>] (dump_stack) from [<c011a98c>] (__warn+0xe8/0x100) > [<c011a98c>] (__warn) from [<c011aa54>] (warn_slowpath_null+0x20/0x28) > [<c011aa54>] (warn_slowpath_null) from [<c0384a0c>] (regulator_unregister+0xc8/0xd0) > [<c0384a0c>] (regulator_unregister) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04039c4>] (__device_release_driver+0x8c/0x110) > [<c04039c4>] (__device_release_driver) from [<c0403a64>] (device_release_driver+0x1c/0x28) > [<c0403a64>] (device_release_driver) from [<c0402b24>] (bus_remove_device+0xd8/0x104) > [<c0402b24>] (bus_remove_device) from [<c03ffcd8>] (device_del+0x10c/0x218) > [<c03ffcd8>] (device_del) from [<c0404e4c>] (platform_device_del+0x1c/0x88) > [<c0404e4c>] (platform_device_del) from [<c0404ec4>] (platform_device_unregister+0xc/0x20) > [<c0404ec4>] (platform_device_unregister) from [<c0428bc0>] (mfd_remove_devices_fn+0x5c/0x64) > [<c0428bc0>] (mfd_remove_devices_fn) from [<c03ff9d8>] (device_for_each_child_reverse+0x4c/0x78) > [<c03ff9d8>] (device_for_each_child_reverse) from [<c04288c4>] (mfd_remove_devices+0x20/0x30) > [<c04288c4>] (mfd_remove_devices) from [<c042758c>] (wm8994_device_init+0x2ac/0x7f0) > [<c042758c>] (wm8994_device_init) from [<c04f14a8>] (i2c_device_probe+0x178/0x1fc) > [<c04f14a8>] (i2c_device_probe) from [<c04036fc>] (driver_probe_device+0x214/0x2c0) > [<c04036fc>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > ---[ end trace 0919d3d0bc998260 ]--- > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at /mnt/ssd/all/work/repos/devel/linux/drivers/regulator/core.c:4072 regulator_unregister+0xc8/0xd0 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [<c010e24c>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14) > [<c010af38>] (show_stack) from [<c032a1c4>] (dump_stack+0x88/0x9c) > [<c032a1c4>] (dump_stack) from [<c011a98c>] (__warn+0xe8/0x100) > [<c011a98c>] (__warn) from [<c011aa54>] (warn_slowpath_null+0x20/0x28) > [<c011aa54>] (warn_slowpath_null) from [<c0384a0c>] (regulator_unregister+0xc8/0xd0) > [<c0384a0c>] (regulator_unregister) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04039c4>] (__device_release_driver+0x8c/0x110) > [<c04039c4>] (__device_release_driver) from [<c0403a64>] (device_release_driver+0x1c/0x28) > [<c0403a64>] (device_release_driver) from [<c0402b24>] (bus_remove_device+0xd8/0x104) > [<c0402b24>] (bus_remove_device) from [<c03ffcd8>] (device_del+0x10c/0x218) > [<c03ffcd8>] (device_del) from [<c0404e4c>] (platform_device_del+0x1c/0x88) > [<c0404e4c>] (platform_device_del) from [<c0404ec4>] (platform_device_unregister+0xc/0x20) > [<c0404ec4>] (platform_device_unregister) from [<c0428bc0>] (mfd_remove_devices_fn+0x5c/0x64) > [<c0428bc0>] (mfd_remove_devices_fn) from [<c03ff9d8>] (device_for_each_child_reverse+0x4c/0x78) > [<c03ff9d8>] (device_for_each_child_reverse) from [<c04288c4>] (mfd_remove_devices+0x20/0x30) > [<c04288c4>] (mfd_remove_devices) from [<c042758c>] (wm8994_device_init+0x2ac/0x7f0) > [<c042758c>] (wm8994_device_init) from [<c04f14a8>] (i2c_device_probe+0x178/0x1fc) > [<c04f14a8>] (i2c_device_probe) from [<c04036fc>] (driver_probe_device+0x214/0x2c0) > [<c04036fc>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > ---[ end trace 0919d3d0bc998261 ]--- > Unable to handle kernel NULL pointer dereference at virtual address 00000078 > pgd = c0004000 > [00000078] *pgd=00000000 > Internal error: Oops: 5 [#1] PREEMPT SMP ARM > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > task: ee874000 task.stack: ee878000 > PC is at down_write+0x14/0x54 > LR is at debugfs_remove_recursive+0x30/0x150 > pc : [<c06e489c>] lr : [<c02e9954>] psr: 80000013 > sp : ee879e18 ip : 2e575000 fp : 00000000 > r10: 00000000 r9 : c0406004 r8 : ee46f428 > r7 : ee46f4ac r6 : ee46f478 r5 : ee46f428 r4 : 00000078 > r3 : ffff0001 r2 : 00000000 r1 : 00000001 r0 : 00000078 > Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > Control: 10c5387d Table: 4000406a DAC: 00000051 > Process swapper/0 (pid: 1, stack limit = 0xee878210) > Stack: (0xee879e18 to 0xee87a000) > 9e00: ee216340 c02e9954 > 9e20: ee216340 ee12bc00 0000000d eea22220 ee879e58 c0382b78 c0b1505c ee216340 > 9e40: 0000000d c0382c1c ee216300 ee216200 0000000d c0406434 ee1e7c00 ee216700 > 9e60: eea22220 c0b81c0c c0b81c14 c0b22320 ffffffea 00000000 00000000 c04035d4 > 9e80: eea22220 c0b22320 eea22254 c0b2a950 c0b44000 000000d8 00000000 c0403854 > 9ea0: 00000000 c0b22320 c04037a8 c0401a74 ee97be74 eea153c0 c0b22320 ee16f480 > 9ec0: 00000000 c0402cf0 c08a5174 c0a1d3cc c0a34840 c0b22320 c0a1d3cc c0a34840 > 9ee0: c0b44000 c040406c c0b22304 c0a1d3cc c0a34840 c04f20a0 c0a5ff58 c0a1d3cc > 9f00: c0a34840 c01017d0 c0b0ac18 ee879f18 c0b45fe8 c06e3f40 60000000 c0b095a0 > 9f20: 00000000 c0b095a0 efffca46 c0716b00 efffca42 c01350dc 0000cccd 00000000 > 9f40: c08cdb2c 00000000 00000006 00000006 c0b0957c efffc940 c0a5ff58 00000006 > 9f60: c0a34840 c0b44000 c0b44000 000000d8 c0a34848 c0a00dbc 00000006 00000006 > 9f80: 00000000 c0a005a0 00000000 c06e07a8 00000000 00000000 00000000 00000000 > 9fa0: 00000000 c06e07b0 00000000 c0107978 00000000 00000000 00000000 00000000 > 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff > [<c06e489c>] (down_write) from [<c02e9954>] (debugfs_remove_recursive+0x30/0x150) > [<c02e9954>] (debugfs_remove_recursive) from [<c0382b78>] (_regulator_put+0x24/0xac) > [<c0382b78>] (_regulator_put) from [<c0382c1c>] (regulator_put+0x1c/0x2c) > [<c0382c1c>] (regulator_put) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04035d4>] (driver_probe_device+0xec/0x2c0) > [<c04035d4>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > Code: e1a04000 f590f000 e3a03001 e34f3fff (e1902f9f) > ---[ end trace 0919d3d0bc998262 ]--- > Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > > CPU1: stopping > CPU: 1 PID: 0 Comm: swapper/1 Tainted: G D W 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [<c010e24c>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14) > [<c010af38>] (show_stack) from [<c032a1c4>] (dump_stack+0x88/0x9c) > [<c032a1c4>] (dump_stack) from [<c010d4f8>] (handle_IPI+0x198/0x1ac) > [<c010d4f8>] (handle_IPI) from [<c01014e4>] (gic_handle_irq+0x94/0x98) > [<c01014e4>] (gic_handle_irq) from [<c010ba0c>] (__irq_svc+0x6c/0xa8) > Exception stack(0xee89ff88 to 0xee89ffd0) > ff80: 00000001 00000000 00000000 c0113f40 ee89e000 c0b02454 > ffa0: 00000002 00000000 00000000 c0a65f88 c0b024c0 c0b024b8 00000000 ee89ffd8 > ffc0: c01083b8 c01083bc 60000013 ffffffff > [<c010ba0c>] (__irq_svc) from [<c01083bc>] (arch_cpu_idle+0x38/0x3c) > [<c01083bc>] (arch_cpu_idle) from [<c01531f0>] (cpu_startup_entry+0x1cc/0x250) > [<c01531f0>] (cpu_startup_entry) from [<4010158c>] (0x4010158c) > ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > [<c0404e4c>] (platform_device_del) from [<c0404ec4>] (platform_device_unregister+0xc/0x20) > [<c0404ec4>] (platform_device_unregister) from [<c0428bc0>] (mfd_remove_devices_fn+0x5c/0x64) > [<c0428bc0>] (mfd_remove_devices_fn) from [<c03ff9d8>] (device_for_each_child_reverse+0x4c/0x78) > [<c03ff9d8>] (device_for_each_child_reverse) from [<c04288c4>] (mfd_remove_devices+0x20/0x30) > [<c04288c4>] (mfd_remove_devices) from [<c042758c>] (wm8994_device_init+0x2ac/0x7f0) > [<c042758c>] (wm8994_device_init) from [<c04f14a8>] (i2c_device_probe+0x178/0x1fc) > [<c04f14a8>] (i2c_device_probe) from [<c04036fc>] (driver_probe_device+0x214/0x2c0) > [<c04036fc>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > ---[ end trace 0919d3d0bc998261 ]--- > Unable to handle kernel NULL pointer dereference at virtual address 00000078 > pgd = c0004000 > [00000078] *pgd=00000000 > Internal error: Oops: 5 [#1] PREEMPT SMP ARM > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.8.0-rc6-00154-g54fe84cbd50b #41 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > task: ee874000 task.stack: ee878000 > PC is at down_write+0x14/0x54 > LR is at debugfs_remove_recursive+0x30/0x150 > pc : [<c06e489c>] lr : [<c02e9954>] psr: 80000013 > sp : ee879e18 ip : 2e575000 fp : 00000000 > r10: 00000000 r9 : c0406004 r8 : ee46f428 > r7 : ee46f4ac r6 : ee46f478 r5 : ee46f428 r4 : 00000078 > r3 : ffff0001 r2 : 00000000 r1 : 00000001 r0 : 00000078 > Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > Control: 10c5387d Table: 4000406a DAC: 00000051 > Process swapper/0 (pid: 1, stack limit = 0xee878210) > Stack: (0xee879e18 to 0xee87a000) > 9e00: ee216340 c02e9954 > 9e20: ee216340 ee12bc00 0000000d eea22220 ee879e58 c0382b78 c0b1505c ee216340 > 9e40: 0000000d c0382c1c ee216300 ee216200 0000000d c0406434 ee1e7c00 ee216700 > 9e60: eea22220 c0b81c0c c0b81c14 c0b22320 ffffffea 00000000 00000000 c04035d4 > 9e80: eea22220 c0b22320 eea22254 c0b2a950 c0b44000 000000d8 00000000 c0403854 > 9ea0: 00000000 c0b22320 c04037a8 c0401a74 ee97be74 eea153c0 c0b22320 ee16f480 > 9ec0: 00000000 c0402cf0 c08a5174 c0a1d3cc c0a34840 c0b22320 c0a1d3cc c0a34840 > 9ee0: c0b44000 c040406c c0b22304 c0a1d3cc c0a34840 c04f20a0 c0a5ff58 c0a1d3cc > 9f00: c0a34840 c01017d0 c0b0ac18 ee879f18 c0b45fe8 c06e3f40 60000000 c0b095a0 > 9f20: 00000000 c0b095a0 efffca46 c0716b00 efffca42 c01350dc 0000cccd 00000000 > 9f40: c08cdb2c 00000000 00000006 00000006 c0b0957c efffc940 c0a5ff58 00000006 > 9f60: c0a34840 c0b44000 c0b44000 000000d8 c0a34848 c0a00dbc 00000006 00000006 > 9f80: 00000000 c0a005a0 00000000 c06e07a8 00000000 00000000 00000000 00000000 > 9fa0: 00000000 c06e07b0 00000000 c0107978 00000000 00000000 00000000 00000000 > 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff > [<c06e489c>] (down_write) from [<c02e9954>] (debugfs_remove_recursive+0x30/0x150) > [<c02e9954>] (debugfs_remove_recursive) from [<c0382b78>] (_regulator_put+0x24/0xac) > [<c0382b78>] (_regulator_put) from [<c0382c1c>] (regulator_put+0x1c/0x2c) > [<c0382c1c>] (regulator_put) from [<c0406434>] (release_nodes+0x16c/0x1dc) > [<c0406434>] (release_nodes) from [<c04035d4>] (driver_probe_device+0xec/0x2c0) > [<c04035d4>] (driver_probe_device) from [<c0403854>] (__driver_attach+0xac/0xb0) > [<c0403854>] (__driver_attach) from [<c0401a74>] (bus_for_each_dev+0x68/0x9c) > [<c0401a74>] (bus_for_each_dev) from [<c0402cf0>] (bus_add_driver+0x1a0/0x218) > [<c0402cf0>] (bus_add_driver) from [<c040406c>] (driver_register+0x78/0xf8) > [<c040406c>] (driver_register) from [<c04f20a0>] (i2c_register_driver+0x34/0x84) > [<c04f20a0>] (i2c_register_driver) from [<c01017d0>] (do_one_initcall+0x40/0x170) > [<c01017d0>] (do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc) > [<c0a00dbc>] (kernel_init_freeable) from [<c06e07b0>] (kernel_init+0x8/0x114) > [<c06e07b0>] (kernel_init) from [<c0107978>] (ret_from_fork+0x14/0x3c) > Code: e1a04000 f590f000 e3a03001 e34f3fff (e1902f9f) > ---[ end trace 0919d3d0bc998262 ]--- > Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > > --------x------------------x---------------- > > Fix the kernel warnings and crashes by moving away from managed > regulator bulk get API by using regulator_bulk_get() and explicitly > calling regulator_put() for all the supplies in exit paths. > > Tested on Exynos 5250, dual core ARM A15 machine. > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> > --- > V2->V3: > - Fixed a rebase conflict > - sending only one patch with Charles Ack > > V1->V2: > - Use regulator_bulk_free() instead of open coding it. > - Shorter backtrace > - Reworded the last paragraph to make it more clear > - Added a comment in code > > drivers/mfd/wm8994-core.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c > index 95e6bc55adbb..87e9309c5f92 100644 > --- a/drivers/mfd/wm8994-core.c > +++ b/drivers/mfd/wm8994-core.c > @@ -394,7 +394,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) > goto err; > } > > - ret = devm_regulator_bulk_get(wm8994->dev, wm8994->num_supplies, > + ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies, > wm8994->supplies); > if (ret != 0) { > dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret); > @@ -404,7 +404,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) > ret = regulator_bulk_enable(wm8994->num_supplies, wm8994->supplies); > if (ret != 0) { > dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret); > - goto err; > + goto err_regulator_put; > } > > ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET); > @@ -595,6 +595,9 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) > err_enable: > regulator_bulk_disable(wm8994->num_supplies, > wm8994->supplies); > +err_regulator_put: > + for (i = wm8994->num_supplies - 1; i >= 0; i--) > + regulator_put(wm8994->supplies[i].consumer); > err: > mfd_remove_devices(wm8994->dev); > return ret; > @@ -602,9 +605,12 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) > > static void wm8994_device_exit(struct wm8994 *wm8994) > { > + int i; > pm_runtime_disable(wm8994->dev); > wm8994_irq_exit(wm8994); > regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies); > + for (i = wm8994->num_supplies - 1; i >= 0; i--) > + regulator_put(wm8994->supplies[i].consumer); > mfd_remove_devices(wm8994->dev); > } > > -- > 2.7.1.410.g6faf27b
On 27-10-16, 10:14, Charles Keepax wrote: > On Thu, Oct 27, 2016 at 09:09:30AM +0530, Viresh Kumar wrote: > > The kernel WARNs and then crashes today if wm8994_device_init() fails > > after calling devm_regulator_bulk_get(). > > > > That happens because there are multiple devices involved here and the > > order in which resources are freed isn't correct. > > > > The regulators are added as children of wm8994->dev. > > devm_regulator_bulk_get() receives wm8994->dev as the device, though it > > gets the same regulators which were added as children of wm8994->dev > > earlier. > > > > During failures, the children are removed first and the core eventually > > calls regulator_unregister() for them. As regulator_put() was never done > > for them (opposite of devm_regulator_bulk_get()), the kernel WARNs at > > > > WARN_ON(rdev->open_count); > > > > And eventually it crashes from debugfs_remove_recursive(). > > > > --------x------------------x---------------- > > The back track seems to have got really really long again. Not just that, even the code moved a version back. Sorry for the noise, the right version is sent now :( -- viresh
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c index 95e6bc55adbb..87e9309c5f92 100644 --- a/drivers/mfd/wm8994-core.c +++ b/drivers/mfd/wm8994-core.c @@ -394,7 +394,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) goto err; } - ret = devm_regulator_bulk_get(wm8994->dev, wm8994->num_supplies, + ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies, wm8994->supplies); if (ret != 0) { dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret); @@ -404,7 +404,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) ret = regulator_bulk_enable(wm8994->num_supplies, wm8994->supplies); if (ret != 0) { dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret); - goto err; + goto err_regulator_put; } ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET); @@ -595,6 +595,9 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) err_enable: regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies); +err_regulator_put: + for (i = wm8994->num_supplies - 1; i >= 0; i--) + regulator_put(wm8994->supplies[i].consumer); err: mfd_remove_devices(wm8994->dev); return ret; @@ -602,9 +605,12 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq) static void wm8994_device_exit(struct wm8994 *wm8994) { + int i; pm_runtime_disable(wm8994->dev); wm8994_irq_exit(wm8994); regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies); + for (i = wm8994->num_supplies - 1; i >= 0; i--) + regulator_put(wm8994->supplies[i].consumer); mfd_remove_devices(wm8994->dev); }