Re: [PATCH] pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On Tue, Jun 02, 2020 at 10:06:26PM +0200, Christophe JAILLET wrote:
> Use 'devm_of_iomap()' instead 'of_iomap()' to avoid a resource leak in
> case of error.
> 
> Update the error handling code accordingly.
> 
> Fixes: 26d8cde5260b ("pinctrl: freescale: imx: add shared input select reg support")
> Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

When booting mcimx7d-sabre in qemu, his patch results in:

[    1.835341] imx7d-pinctrl 302c0000.iomuxc-lpsr: initialized IMX pinctrl driver
[    1.839702] imx7d-pinctrl 30330000.pinctrl: can't request region for resource [mem 0x30330000-0x3033ffff]
[    1.840261] imx7d-pinctrl: probe of 30330000.pinctrl failed with error -16

This is followed by:

[   21.589169] sdhci-esdhc-imx 30b40000.usdhc: could not get pinctrl
[   21.589569] 8<--- cut here ---
[   21.589683] Unable to handle kernel paging request at virtual address ffffff9e
[   21.589830] pgd = (ptrval)
[   21.589905] [ffffff9e] *pgd=8bfde841, *pte=00000000, *ppte=00000000
[   21.590404] Internal error: Oops: 27 [#1] SMP ARM
[   21.590595] Modules linked in:
[   21.590792] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.7.0-14530-g464c47191c90-dirty #4
[   21.590926] Hardware name: Freescale i.MX7 Dual (Device Tree)
[   21.591402] Workqueue: events deferred_probe_work_func
[   21.591547] PC is at pinctrl_lookup_state+0x8/0x78
[   21.591626] LR is at sdhci_esdhc_imx_probe+0x5e4/0x6c4
[   21.591731] pc : [<c091e884>]    lr : [<c0f9c84c>]    psr: 20000013
[   21.591874] sp : cb1b5df8  ip : 00000001  fp : c1fee723
[   21.591993] r10: 00000009  r9 : 00000000  r8 : 00000000
[   21.592120] r7 : cb4c5810  r6 : cb4c5800  r5 : ffffff92  r4 : cbdd338c
[   21.592263] r3 : 00014368  r2 : d8f46c35  r1 : c1a1e710  r0 : ffffff92
[   21.592441] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   21.592610] Control: 10c5387d  Table: 8020406a  DAC: 00000051
[   21.592762] Process kworker/0:0 (pid: 5, stack limit = 0x(ptrval))
[   21.592935] Stack: (0xcb1b5df8 to 0xcb1b6000)
[   21.593129] 5de0:                                                       cbdd338c c9744540
[   21.593404] 5e00: cb4c5800 cb4c5810 00000000 c0f9c84c 00000000 d8f46c35 cb4c5810 00000000
[   21.593649] 5e20: cb4c5810 c1fc55b4 c2652ab0 00000000 c1fc55b4 c0bb98a4 cb4c5810 c2652aa8
[   21.593937] 5e40: 00000000 c2652ab0 00000000 c0bb73f8 cb4c5810 c1fc55b4 c0bb776c cb1b4000
[   21.594209] 5e60: c1f8b2e8 cb1b4000 c1e08eec c0bb766c 00000000 cb1b5eac c0bb776c c0bb55d0
[   21.594460] 5e80: cb4a7124 cb0bb8e4 c94af4d8 d8f46c35 00000004 cb4c5810 cb1b4000 00000001
[   21.594702] 5ea0: cb4c58a0 c0bb71a4 cb1b4000 cb4c5810 00000001 d8f46c35 00000000 cb4bbaf4
[   21.594973] 5ec0: cb4c5810 c1f8b750 c1f8b29c c0bb6470 cb4bbaf4 cb4c5810 c1f8b29c c0bb692c
[   21.595187] 5ee0: c1f8b340 cb0b4c80 cbd95c00 cbd98f00 c1fefbd0 c036885c 00000001 00000000
[   21.595457] 5f00: c03687a8 c120d364 00000000 00000000 00000000 cbd95c00 c1f8b340 c24673d8
[   21.595727] 5f20: 00000000 c19af744 00000000 d8f46c35 cbd95c00 cb0b4c80 cbd95c00 cb0b4c94
[   21.596023] 5f40: cbd95c38 c1e05d00 00000008 cb1b4000 cbd95c00 c0368f94 cb19a164 c1fef34a
[   21.596284] 5f60: cb1b4000 cb0b5280 cb17a7c0 cb1b4000 00000000 c0368d7c cb0b4c80 cb183e7c
[   21.596519] 5f80: cb0b52c4 c03714c8 cb1b4000 cb17a7c0 c0371388 00000000 00000000 00000000
[   21.596742] 5fa0: 00000000 00000000 00000000 c0300174 00000000 00000000 00000000 00000000
[   21.596976] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   21.597196] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[   21.597442] [<c091e884>] (pinctrl_lookup_state) from [<c0f9c84c>] (sdhci_esdhc_imx_probe+0x5e4/0x6c4)
[   21.597651] [<c0f9c84c>] (sdhci_esdhc_imx_probe) from [<c0bb98a4>] (platform_drv_probe+0x48/0x98)
[   21.597838] [<c0bb98a4>] (platform_drv_probe) from [<c0bb73f8>] (really_probe+0x1e0/0x348)
[   21.598016] [<c0bb73f8>] (really_probe) from [<c0bb766c>] (driver_probe_device+0x5c/0xb4)
[   21.598188] [<c0bb766c>] (driver_probe_device) from [<c0bb55d0>] (bus_for_each_drv+0x84/0xc8)
[   21.598367] [<c0bb55d0>] (bus_for_each_drv) from [<c0bb71a4>] (__device_attach+0xdc/0x148)
[   21.598545] [<c0bb71a4>] (__device_attach) from [<c0bb6470>] (bus_probe_device+0x88/0x90)
[   21.598720] [<c0bb6470>] (bus_probe_device) from [<c0bb692c>] (deferred_probe_work_func+0x74/0xa4)
[   21.598906] [<c0bb692c>] (deferred_probe_work_func) from [<c036885c>] (process_one_work+0x274/0x794)
[   21.599105] [<c036885c>] (process_one_work) from [<c0368f94>] (worker_thread+0x218/0x4f4)
[   21.599275] [<c0368f94>] (worker_thread) from [<c03714c8>] (kthread+0x140/0x174)
[   21.599441] [<c03714c8>] (kthread) from [<c0300174>] (ret_from_fork+0x14/0x20)
[   21.599606] Exception stack(0xcb1b5fb0 to 0xcb1b5ff8)
[   21.599782] 5fa0:                                     00000000 00000000 00000000 00000000
[   21.600042] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   21.600290] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[   21.600582] Code: e8bd81f0 c138c66c e92d41f0 e1a05000 (e5b5400c)
[   21.601140] ---[ end trace a236f1b24b2698e6 ]---

After reverting the patch, the log is:

[    1.829261] imx7d-pinctrl 302c0000.iomuxc-lpsr: initialized IMX pinctrl driver
[    1.841358] imx7d-pinctrl 30330000.pinctrl: initialized IMX pinctrl driver

and there is no subsequent error/crash.

Guenter

---
bisect log:

# bad: [af7b4801030c07637840191c69eb666917e4135d] Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
# good: [3b69e8b4571125bec1f77f886174fe6cab6b9d75] Merge tag 'sh-for-5.8' of git://git.libc.org/linux-sh
git bisect start 'af7b4801030c' '3b69e8b45711'
# good: [77f55d1305c11fb729b88f2c3f7881ba0831fa6f] staging: rtl8723bs: Use common packet header constants
git bisect good 77f55d1305c11fb729b88f2c3f7881ba0831fa6f
# good: [f558b8364e19f9222e7976c64e9367f66bab02cc] Merge tag 'driver-core-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
git bisect good f558b8364e19f9222e7976c64e9367f66bab02cc
# good: [57343d51613227373759f5b0f2eede257fd4b82e] misc: xilinx-sdfec: improve get_user_pages_fast() error handling
git bisect good 57343d51613227373759f5b0f2eede257fd4b82e
# good: [e8dff03aef6a76c5c9184ed1dd3c770d4ce9c885] Merge tag 'rtc-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
git bisect good e8dff03aef6a76c5c9184ed1dd3c770d4ce9c885
# good: [920fecc1aa4591da27ef9dcb338fc5da86b404d7] pinctrl: bcm2835: Add support for wake-up interrupts
git bisect good 920fecc1aa4591da27ef9dcb338fc5da86b404d7
# good: [4e2905adac9f0fdc25154ac83719a986c2367a14] net: dp83869: Reset return variable if PHY strap is read
git bisect good 4e2905adac9f0fdc25154ac83719a986c2367a14
# good: [9049a40c858f49c141e12924b77b91cce4c46617] Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
git bisect good 9049a40c858f49c141e12924b77b91cce4c46617
# bad: [cf0c97f148e9e50aa5a7ddd1984a604dd2bde4af] Merge tag 'pinctrl-v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
git bisect bad cf0c97f148e9e50aa5a7ddd1984a604dd2bde4af
# good: [11d8da5cabf7c6c3263ba2cd9c00260395867048] pinctrl: freescale: imx: Fix an error handling path in 'imx_pinctrl_probe()'
git bisect good 11d8da5cabf7c6c3263ba2cd9c00260395867048
# bad: [08acc963190a3a0eb491efa9cc466b2c18d59f22] pinctrl: pxa: pxa2xx: Remove 'pxa2xx_pinctrl_exit()' which is unused and broken
git bisect bad 08acc963190a3a0eb491efa9cc466b2c18d59f22
# bad: [ba403242615c2c99e27af7984b1650771a2cc2c9] pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'
git bisect bad ba403242615c2c99e27af7984b1650771a2cc2c9
# first bad commit: [ba403242615c2c99e27af7984b1650771a2cc2c9] pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'

---
qemu command line:

qemu-system-arm -M mcimx7d-sabre \
	-kernel arch/arm/boot/zImage -no-reboot \
	-initrd rootfs-armv7a.cpio \
	-m 256 -display none \
	--append "rdinit=/sbin/init earlycon=ec_imx6q,mmio,0x30860000,115200n8 console=ttymxc0,115200" \
	-dtb arch/arm/boot/dts/imx7d-sdb.dtb \
	-nographic -monitor null -serial stdio