2022-09-22 06:14:58

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v8 2/2 RESEND] mwifiex: fix sleep in atomic context bugs caused by dev_coredumpv

Duoming Zhou <[email protected]> wrote:

> There are sleep in atomic context bugs when uploading device dump
> data in mwifiex. The root cause is that dev_coredumpv could not
> be used in atomic contexts, because it calls dev_set_name which
> include operations that may sleep. The call tree shows execution
> paths that could lead to bugs:
>
> (Interrupt context)
> fw_dump_timer_fn
> mwifiex_upload_device_dump
> dev_coredumpv(..., GFP_KERNEL)
> dev_coredumpm()
> kzalloc(sizeof(*devcd), gfp); //may sleep
> dev_set_name
> kobject_set_name_vargs
> kvasprintf_const(GFP_KERNEL, ...); //may sleep
> kstrdup(s, GFP_KERNEL); //may sleep
>
> The corresponding fail log is shown below:
>
> [ 135.275938] usb 1-1: == mwifiex dump information to /sys/class/devcoredump start
> [ 135.281029] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
> ...
> [ 135.293613] Call Trace:
> [ 135.293613] <IRQ>
> [ 135.293613] dump_stack_lvl+0x57/0x7d
> [ 135.293613] __might_resched.cold+0x138/0x173
> [ 135.293613] ? dev_coredumpm+0xca/0x2e0
> [ 135.293613] kmem_cache_alloc_trace+0x189/0x1f0
> [ 135.293613] ? devcd_match_failing+0x30/0x30
> [ 135.293613] dev_coredumpm+0xca/0x2e0
> [ 135.293613] ? devcd_freev+0x10/0x10
> [ 135.293613] dev_coredumpv+0x1c/0x20
> [ 135.293613] ? devcd_match_failing+0x30/0x30
> [ 135.293613] mwifiex_upload_device_dump+0x65/0xb0
> [ 135.293613] ? mwifiex_dnld_fw+0x1b0/0x1b0
> [ 135.293613] call_timer_fn+0x122/0x3d0
> [ 135.293613] ? msleep_interruptible+0xb0/0xb0
> [ 135.293613] ? lock_downgrade+0x3c0/0x3c0
> [ 135.293613] ? __next_timer_interrupt+0x13c/0x160
> [ 135.293613] ? lockdep_hardirqs_on_prepare+0xe/0x220
> [ 135.293613] ? mwifiex_dnld_fw+0x1b0/0x1b0
> [ 135.293613] __run_timers.part.0+0x3f8/0x540
> [ 135.293613] ? call_timer_fn+0x3d0/0x3d0
> [ 135.293613] ? arch_restore_msi_irqs+0x10/0x10
> [ 135.293613] ? lapic_next_event+0x31/0x40
> [ 135.293613] run_timer_softirq+0x4f/0xb0
> [ 135.293613] __do_softirq+0x1c2/0x651
> ...
> [ 135.293613] RIP: 0010:default_idle+0xb/0x10
> [ 135.293613] RSP: 0018:ffff888006317e68 EFLAGS: 00000246
> [ 135.293613] RAX: ffffffff82ad8d10 RBX: ffff888006301cc0 RCX: ffffffff82ac90e1
> [ 135.293613] RDX: ffffed100d9ff1b4 RSI: ffffffff831ad140 RDI: ffffffff82ad8f20
> [ 135.293613] RBP: 0000000000000003 R08: 0000000000000000 R09: ffff88806cff8d9b
> [ 135.293613] R10: ffffed100d9ff1b3 R11: 0000000000000001 R12: ffffffff84593410
> [ 135.293613] R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff11000c62fd2
> ...
> [ 135.389205] usb 1-1: == mwifiex dump information to /sys/class/devcoredump end
>
> This patch uses delayed work to replace timer and moves the operations
> that may sleep into a delayed work in order to mitigate bugs, it was
> tested on Marvell 88W8801 chip whose port is usb and the firmware is
> usb8801_uapsta.bin. The following is the result after using delayed
> work to replace timer.
>
> [ 134.936453] usb 1-1: == mwifiex dump information to /sys/class/devcoredump start
> [ 135.043344] usb 1-1: == mwifiex dump information to /sys/class/devcoredump end
>
> As we can see, there is no bug now.
>
> Fixes: f5ecd02a8b20 ("mwifiex: device dump support for usb interface")
> Signed-off-by: Duoming Zhou <[email protected]>
> Reviewed-by: Brian Norris <[email protected]>
> Acked-by: Greg Kroah-Hartman <[email protected]>

Patch applied to wireless-next.git, thanks.

551e4745c7f2 mwifiex: fix sleep in atomic context bugs caused by dev_coredumpv

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]zju.edu.cn/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches