From: Samuel Holland Date: Wed, 24 Jun 2026 11:31:48 +0000 (+0800) Subject: riscv: Fix 32-bit call_on_irq_stack() frame pointer ABI X-Git-Tag: v7.2-rc2~12^2~1 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=c4c7756a81b5baef286bf9be1ea404f3e4dd7a3c;p=thirdparty%2Flinux.git 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 Reviewed-by: Matthew Bystrin Signed-off-by: Rui Qi Link: https://lore.kernel.org/all/20240530001733.1407654-2-samuel.holland@sifive.com/ Reviewed-by: Nam Cao 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 --- 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