[PATCH v2 0/2] arm: Replace this_cpu_* with raw_cpu_* in panic_bad_stack()

[Russell King (Oracle)]

Please distinguish your patches/patch series between arch/arm and
arch/arm64. The two are maintained separately, and it gets quite
annoying to read messages nd then realise that they're not for 32-bit
ARM, but are for arm64/aarch64.

Thanks.

On Fri, Aug 26, 2022 at 05:51:10PM +0800, Zhen Lei wrote:
> v1 --> v2:
> Update commit message of two patches.
> 
> v1:
> I'm analyzing a strange problem these days, and I find that there are some areas in
> panic_bad_stack() that can be optimized. That is, replace this_cpu_* with raw_cpu_* .
> 
> Just optimization, it is unlikely to cause the following exception nesting, because of
> "lr : __bad_stack+0x88/0x8c".
> 
> [20220819163739]Unable to handle kernel paging request at virtual address f7ffff94901b8048
> [20220819163739]Mem abort info:
> [20220819163739]  ESR = 0x96000004
> [20220819163739]  EC = 0x25: DABT (current EL), IL = 32 bits
> [20220819163739]  SET = 0, FnV = 0
> [20220819163739]  EA = 0, S1PTW = 0
> [20220819163739]Data abort info:
> [20220819163739]  ISV = 0, ISS = 0x00000004
> [20220819163739]  CM = 0, WnR = 0
> [20220819163739][f7ffff94901b8048] address between user and kernel address ranges
> [20220819163739]Internal error: Oops: 96000004 [#1] PREEMPT SMP
> [20220819163739]Modules linked in: ...
> [20220819163740]CPU: 2 PID: 1272 Comm: 00002SWDLMain Tainted: G        W  O      5.10.0 #1
> [20220819163740]Hardware name: hisilicon,hi1213-fpga (DT)
> [20220819163740]pstate: 000003c5 (nzcv DAIF -PAN -UAO -TCO BTYPE=--)
> [20220819163740]pc : __bad_stack+0x4c/0x8c
> [20220819163740]lr : __bad_stack+0x88/0x8c
> [20220819163740]sp : ffffff953ffa8160
> [20220819163740]x29: f7ffff953ffa8120 x28: f7ffff94901b8040 
> [20220819163740]x27: ffffffeb72ea6940 x26: ffffffebeee6cf10 
> [20220819163740]x25: ffffffebef627000 x24: 0000000000000000 
> [20220819163740]x23: 00000000600003c5 x22: f7ffffebeee11904 
> [20220819163740]x21: ffffff953ffa82b0 x20: 0000007fffffffff 
> [20220819163740]x19: f7ffffc0133ab898 x18: 0000000000000000 
> [20220819163740]x17: 0000000000000000 x16: ffffffebef32f0a0 
> [20220819163740]x15: 00000000624057a0 x14: 953325a7da350fb3 
> [20220819163740]x13: 09bbbe32ce2b3c11 x12: c15a0e2d1991997b 
> [20220819163740]x11: 0bc8be839e7850d0 x10: cafa1cb223203045 
> [20220819163740]x9 : f36bed299e5840dc x8 : ffffffc0133aba48 
> [20220819163740]x7 : ffffff953b1b0480 x6 : ffffffebef3e1000 
> [20220819163740]x5 : 0000000000000000 x4 : 0000000000000001 
> [20220819163740]x3 : f7ffffc0133ab750 x2 : 0000000000000025 
> [20220819163740]x1 : 0000000096000004 x0 : ffffff953ffa8160 
> [20220819163740]Call trace:
> [20220819163740] __bad_stack+0x4c/0x8c
> [20220819163740]Code: a90d6ffa a90e77fc 910543f5 d538411c (f9400794) 
> [20220819163740]---[ end trace 07532bfa2c24851c ]---
> [20220819163740]Kernel panic - not syncing: Oops: Fatal exception
> 
> Zhen Lei (2):
>   arm64/traps: Replace this_cpu_* with raw_cpu_* in panic_bad_stack()
>   ARM: replace this_cpu_* with raw_cpu_* in panic_bad_stack()
> 
>  arch/arm/kernel/traps.c   | 4 ++--
>  arch/arm64/kernel/traps.c | 4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> -- 
> 2.25.1
> 
> 

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