[RFC PATCH V3 13/43] rv64ilp32_abi: riscv: Correct stackframe layout
From: guoren@kernel.org
Date: 2025-03-25 12:19:51
Also in:
bpf, kvm, kvm-riscv, linux-arch, linux-btrfs, linux-crypto, linux-fsdevel, linux-input, linux-media, linux-mm, linux-nfs, linux-perf-users, linux-riscv, linux-sctp, linux-serial, linux-trace-kernel, linux-usb, lkml, netfilter-devel
Subsystem:
risc-v architecture, the rest · Maintainers:
Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
From: "Guo Ren (Alibaba DAMO Academy)" <guoren@kernel.org> In RV64ILP32 ABI, the callee saved fp & ra are 64-bit width, not long size. This patch corrects the layout for the struct stackframe. echo c > /proc/sysrq-trigger Before the patch: sysrq: Trigger a crash Kernel panic - not syncing: sysrq triggered crash CPU: 0 PID: 102 Comm: sh Not tainted ... Hardware name: riscv-virtio,qemu (DT) Call Trace: ---[ end Kernel panic - not syncing: sysrq triggered crash ]--- After the patch: sysrq: Trigger a crash Kernel panic - not syncing: sysrq triggered crash CPU: 0 PID: 102 Comm: sh Not tainted ... Hardware name: riscv-virtio,qemu (DT) Call Trace: [<c00050c8>] dump_backtrace+0x1e/0x26 [<c086dcae>] show_stack+0x2e/0x3c [<c0878e00>] dump_stack_lvl+0x40/0x5a [<c0878e30>] dump_stack+0x16/0x1e [<c086df7c>] panic+0x10c/0x2a8 [<c04f4c1e>] sysrq_reset_seq_param_set+0x0/0x76 [<c04f52cc>] __handle_sysrq+0x9c/0x19c [<c04f5946>] write_sysrq_trigger+0x64/0x78 [<c020c7f6>] proc_reg_write+0x4a/0xa2 [<c01acf0a>] vfs_write+0xac/0x308 [<c01ad2b8>] ksys_write+0x62/0xda [<c01ad33e>] sys_write+0xe/0x16 [<c0879860>] do_trap_ecall_u+0xd8/0xda [<c00037de>] ret_from_exception+0x0/0x66 ---[ end Kernel panic - not syncing: sysrq triggered crash ]--- Signed-off-by: Guo Ren (Alibaba DAMO Academy) <guoren@kernel.org> --- arch/riscv/include/asm/stacktrace.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/riscv/include/asm/stacktrace.h b/arch/riscv/include/asm/stacktrace.h
index b1495a7e06ce..556655cab09d 100644
--- a/arch/riscv/include/asm/stacktrace.h
+++ b/arch/riscv/include/asm/stacktrace.h@@ -8,7 +8,13 @@ struct stackframe { unsigned long fp; +#if IS_ENABLED(CONFIG_64BIT) && (BITS_PER_LONG == 32) + unsigned long __fp; +#endif unsigned long ra; +#if IS_ENABLED(CONFIG_64BIT) && (BITS_PER_LONG == 32) + unsigned long __ra; +#endif }; extern void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
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2.40.1