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[V2,0/2] riscv: stack: Fixup independent softirq/irq stack for CONFIG_FRAME_POINTER=n

Message ID 20230716001506.3506041-1-guoren@kernel.org
Headers
Series riscv: stack: Fixup independent softirq/irq stack for CONFIG_FRAME_POINTER=n |

Message

Guo Ren July 16, 2023, 12:15 a.m. UTC 
  From: Guo Ren <guoren@linux.alibaba.com>

The independent softirq/irq stack uses s0 to save & restore sp, but s0
would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber
list to fix the problem.

<+0>:     addi    sp,sp,-32
<+2>:     sd      s0,16(sp)
<+4>:     sd      s1,8(sp)
<+6>:     sd      ra,24(sp)
<+8>:     sd      s2,0(sp)
<+10>:    mv      s0,a0		--> compiler allocate s0 for a0 when CONFIG_FRAME_POINTER=n
<+12>:    jal     ra,0xffffffff800bc0ce <irqentry_enter>
<+16>:    ld      a5,56(tp) # 0x38
<+20>:    lui     a4,0x4
<+22>:    mv      s1,a0
<+24>:    xor     a5,a5,sp
<+28>:    bgeu    a5,a4,0xffffffff800bc092 <do_irq+88>
<+32>:    auipc   s2,0x5d
<+36>:    ld      s2,1118(s2) # 0xffffffff801194b8 <irq_stack_ptr>
<+40>:    add     s2,s2,a4
<+42>:    addi    sp,sp,-8
<+44>:    sd      ra,0(sp)
<+46>:    addi    sp,sp,-8
<+48>:    sd      s0,0(sp)
<+50>:    addi    s0,sp,16	--> our code clobber the s0
<+52>:    mv      sp,s2
<+54>:    mv      a0,s0		--> a0 got wrong value for handle_riscv_irq 
<+56>:    jal     ra,0xffffffff800bbb3a <handle_riscv_irq>

Changelog:
V2
 - Fixup compile error with CONFIG_FRAME_POINTER=y
 - FIxup stable@vger.kernel.org tag

Guo Ren (2):
  riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=n
  riscv: stack: Fixup independent softirq stack for
    CONFIG_FRAME_POINTER=n

 arch/riscv/kernel/irq.c   | 3 +++
 arch/riscv/kernel/traps.c | 3 +++
 2 files changed, 6 insertions(+)

Comments

Drew Fustini July 29, 2023, 12:33 a.m. UTC | #1 
On Sat, Jul 15, 2023 at 08:15:04PM -0400, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> The independent softirq/irq stack uses s0 to save & restore sp, but s0
> would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber
> list to fix the problem.
> 
> <+0>:     addi    sp,sp,-32
> <+2>:     sd      s0,16(sp)
> <+4>:     sd      s1,8(sp)
> <+6>:     sd      ra,24(sp)
> <+8>:     sd      s2,0(sp)
> <+10>:    mv      s0,a0		--> compiler allocate s0 for a0 when CONFIG_FRAME_POINTER=n
> <+12>:    jal     ra,0xffffffff800bc0ce <irqentry_enter>
> <+16>:    ld      a5,56(tp) # 0x38
> <+20>:    lui     a4,0x4
> <+22>:    mv      s1,a0
> <+24>:    xor     a5,a5,sp
> <+28>:    bgeu    a5,a4,0xffffffff800bc092 <do_irq+88>
> <+32>:    auipc   s2,0x5d
> <+36>:    ld      s2,1118(s2) # 0xffffffff801194b8 <irq_stack_ptr>
> <+40>:    add     s2,s2,a4
> <+42>:    addi    sp,sp,-8
> <+44>:    sd      ra,0(sp)
> <+46>:    addi    sp,sp,-8
> <+48>:    sd      s0,0(sp)
> <+50>:    addi    s0,sp,16	--> our code clobber the s0
> <+52>:    mv      sp,s2
> <+54>:    mv      a0,s0		--> a0 got wrong value for handle_riscv_irq 
> <+56>:    jal     ra,0xffffffff800bbb3a <handle_riscv_irq>
> 
> Changelog:
> V2
>  - Fixup compile error with CONFIG_FRAME_POINTER=y
>  - FIxup stable@vger.kernel.org tag
> 
> Guo Ren (2):
>   riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=n
>   riscv: stack: Fixup independent softirq stack for
>     CONFIG_FRAME_POINTER=n
> 
>  arch/riscv/kernel/irq.c   | 3 +++
>  arch/riscv/kernel/traps.c | 3 +++
>  2 files changed, 6 insertions(+)
> 
> -- 
> 2.36.1
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Tested-by: Drew Fustini <dfustini@baylibre.com>

Xi Ruoyao noticed that the mainline kernel crashed when using a kernel
config with CONFIG_FRAME_POINTER=n. I was able to reproduce this [1].
Emil suggested I trying this patche series. I can confirm that this
resolves the kernel crash on the Sipeed Lichee Pi4a [2].

Thanks,
Drew

[1] https://lore.kernel.org/linux-riscv/ZMNojqwLxcG8FcHN@x1/
[2] https://lore.kernel.org/linux-riscv/ZMQAqUfb0y%2FigQs2@x1/
patchwork-bot+linux-riscv@kernel.org Aug. 17, 2023, 3:20 p.m. UTC | #2 
Hello:

This series was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Sat, 15 Jul 2023 20:15:04 -0400 you wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> The independent softirq/irq stack uses s0 to save & restore sp, but s0
> would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber
> list to fix the problem.
> 
> <+0>:     addi    sp,sp,-32
> <+2>:     sd      s0,16(sp)
> <+4>:     sd      s1,8(sp)
> <+6>:     sd      ra,24(sp)
> <+8>:     sd      s2,0(sp)
> <+10>:    mv      s0,a0		--> compiler allocate s0 for a0 when CONFIG_FRAME_POINTER=n
> <+12>:    jal     ra,0xffffffff800bc0ce <irqentry_enter>
> <+16>:    ld      a5,56(tp) # 0x38
> <+20>:    lui     a4,0x4
> <+22>:    mv      s1,a0
> <+24>:    xor     a5,a5,sp
> <+28>:    bgeu    a5,a4,0xffffffff800bc092 <do_irq+88>
> <+32>:    auipc   s2,0x5d
> <+36>:    ld      s2,1118(s2) # 0xffffffff801194b8 <irq_stack_ptr>
> <+40>:    add     s2,s2,a4
> <+42>:    addi    sp,sp,-8
> <+44>:    sd      ra,0(sp)
> <+46>:    addi    sp,sp,-8
> <+48>:    sd      s0,0(sp)
> <+50>:    addi    s0,sp,16	--> our code clobber the s0
> <+52>:    mv      sp,s2
> <+54>:    mv      a0,s0		--> a0 got wrong value for handle_riscv_irq
> <+56>:    jal     ra,0xffffffff800bbb3a <handle_riscv_irq>
> 
> [...]

Here is the summary with links:
  - [V2,1/2] riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=n
    https://git.kernel.org/riscv/c/8d0be64154cf
  - [V2,2/2] riscv: stack: Fixup independent softirq stack for CONFIG_FRAME_POINTER=n
    https://git.kernel.org/riscv/c/ebc9cb03b21e

You are awesome, thank you!