On Sat, Jul 15, 2023 at 08:15:04PM -0400, guoren@xxxxxxxxxx wrote: > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > 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@xxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv Tested-by: Drew Fustini <dfustini@xxxxxxxxxxxx> 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/
