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(+)