diff options
| author | Samuel Holland <samuel.holland@sifive.com> | 2026-06-24 19:31:48 +0800 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2026-06-25 13:44:27 -0600 |
| commit | c4c7756a81b5baef286bf9be1ea404f3e4dd7a3c (patch) | |
| tree | b93f139c874fe87f08e64b190a07a2d9df091ce3 | |
| parent | 57ad674d032baf5426a38b0d6b2ddd60cbd3913f (diff) | |
riscv: Fix 32-bit call_on_irq_stack() frame pointer ABI
call_on_irq_stack() uses struct member offsets to set up its link in the
frame record list. On riscv32, struct stackframe is the wrong size to
maintain stack pointer alignment, so STACKFRAME_SIZE_ON_STACK includes
padding. However, the ABI requires the frame record to be placed
immediately below the address stored in s0, so the padding must come
before the struct members.
Fix the layout by making STACKFRAME_FP and STACKFRAME_RA the negative
offsets from s0, instead of the positive offsets from sp.
Fixes: 82982fdd5133 ("riscv: Deduplicate IRQ stack switching")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Matthew Bystrin <dev.mbstr@gmail.com>
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Link: https://lore.kernel.org/all/20240530001733.1407654-2-samuel.holland@sifive.com/
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://patch.msgid.link/20260624113148.3723541-1-qirui.001@bytedance.com
[pjw@kernel.org: cleaned up the patch tags and added Matthew's Reviewed-by]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
| -rw-r--r-- | arch/riscv/kernel/asm-offsets.c | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/entry.S | 8 |
2 files changed, 6 insertions, 6 deletions
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c index af827448a609..a75f0cfea1e9 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -501,8 +501,8 @@ void asm_offsets(void) OFFSET(SBI_HART_BOOT_STACK_PTR_OFFSET, sbi_hart_boot_data, stack_ptr); DEFINE(STACKFRAME_SIZE_ON_STACK, ALIGN(sizeof(struct stackframe), STACK_ALIGN)); - OFFSET(STACKFRAME_FP, stackframe, fp); - OFFSET(STACKFRAME_RA, stackframe, ra); + DEFINE(STACKFRAME_FP, offsetof(struct stackframe, fp) - sizeof(struct stackframe)); + DEFINE(STACKFRAME_RA, offsetof(struct stackframe, ra) - sizeof(struct stackframe)); #ifdef CONFIG_FUNCTION_TRACER DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func)); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index c6988983cdf7..08df724e13b9 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -386,8 +386,8 @@ SYM_CODE_END(ret_from_fork_user_asm) SYM_FUNC_START(call_on_irq_stack) /* Create a frame record to save ra and s0 (fp) */ addi sp, sp, -STACKFRAME_SIZE_ON_STACK - REG_S ra, STACKFRAME_RA(sp) - REG_S s0, STACKFRAME_FP(sp) + REG_S ra, (STACKFRAME_SIZE_ON_STACK + STACKFRAME_RA)(sp) + REG_S s0, (STACKFRAME_SIZE_ON_STACK + STACKFRAME_FP)(sp) addi s0, sp, STACKFRAME_SIZE_ON_STACK /* Switch to the per-CPU shadow call stack */ @@ -405,8 +405,8 @@ SYM_FUNC_START(call_on_irq_stack) /* Switch back to the thread stack and restore ra and s0 */ addi sp, s0, -STACKFRAME_SIZE_ON_STACK - REG_L ra, STACKFRAME_RA(sp) - REG_L s0, STACKFRAME_FP(sp) + REG_L ra, (STACKFRAME_SIZE_ON_STACK + STACKFRAME_RA)(sp) + REG_L s0, (STACKFRAME_SIZE_ON_STACK + STACKFRAME_FP)(sp) addi sp, sp, STACKFRAME_SIZE_ON_STACK ret |