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

guoren
2023-07-15T13:46:19Z

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>

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 | 2 +-
arch/riscv/kernel/traps.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)