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From:   guoren@kernel.org
To:     guoren@kernel.org, palmer@rivosinc.com, paul.walmsley@sifive.com,
        falcon@tinylab.org, bjorn@kernel.org, conor.dooley@microchip.com
Cc:     linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, stable@vger.kernel.org,
        Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH 0/2] riscv: stack: Fixup independent softirq/irq stack for CONFIG_FRAME_POINTER=n
Date:   Sat, 15 Jul 2023 09:45:50 -0400
Message-Id: <20230715134552.3437933-1-guoren@kernel.org>
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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>

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(-)

-- 
2.36.1