[PATCH V2 0/2] riscv: stack: Fixup independent softirq/irq stack for CONFIG_FRAME_POINTER=n
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(+)
From: Guo Ren guoren@linux.alibaba.com
The independent 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.
Fixes: 163e76cc6ef4 ("riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK") Cc: stable@vger.kernel.org Reported-by: Zhangjin Wu falcon@tinylab.org Signed-off-by: Guo Ren guoren@linux.alibaba.com Signed-off-by: Guo Ren guoren@kernel.org --- arch/riscv/kernel/traps.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index f910dfccbf5d..927347a19847 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -372,6 +372,9 @@ asmlinkage void noinstr do_irq(struct pt_regs *regs) : [sp] "r" (sp), [regs] "r" (regs) : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "t0", "t1", "t2", "t3", "t4", "t5", "t6", +#ifndef CONFIG_FRAME_POINTER + "s0", +#endif "memory"); } else #endif
From: Guo Ren guoren@linux.alibaba.com
The independent softirq 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.
Fixes: dd69d07a5a6c ("riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK") Cc: stable@vger.kernel.org Reported-by: Zhangjin Wu falcon@tinylab.org Signed-off-by: Guo Ren guoren@linux.alibaba.com Signed-off-by: Guo Ren guoren@kernel.org --- arch/riscv/kernel/irq.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index d0577cc6a081..a8efa053c4a5 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -84,6 +84,9 @@ void do_softirq_own_stack(void) : [sp] "r" (sp) : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "t0", "t1", "t2", "t3", "t4", "t5", "t6", +#ifndef CONFIG_FRAME_POINTER + "s0", +#endif "memory"); } else #endif
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/
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!
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