From 29c92a41c6d2879c1f62220fe4758dce191bb38f Mon Sep 17 00:00:00 2001 From: Yuli Wang Date: Sun, 30 Mar 2025 16:31:09 +0800 Subject: [PATCH] LoongArch: Rework the arch_kgdb_breakpoint() implementation The arch_kgdb_breakpoint() function defines the kgdb_breakinst symbol using inline assembly. 1. There's a potential issue where the compiler might inline arch_kgdb_breakpoint(), which would then define the kgdb_breakinst symbol multiple times, leading to a linker error. To prevent this, declare arch_kgdb_breakpoint() as noinline. Fix follow error with LLVM-19 *only* when LTO_CLANG_FULL: LD vmlinux.o ld.lld-19: error: ld-temp.o :3:1: symbol 'kgdb_breakinst' is already defined kgdb_breakinst: break 2 ^ 2. Remove "nop" in the inline assembly because it's meaningless for LoongArch here. 3. Add "STACK_FRAME_NON_STANDARD" for arch_kgdb_breakpoint() to avoid the objtool warning. Fixes: e14dd076964e ("LoongArch: Add basic KGDB & KDB support") Tested-by: Binbin Zhou Co-developed-by: Winston Wen Signed-off-by: Winston Wen Co-developed-by: Wentao Guan Signed-off-by: Wentao Guan Signed-off-by: Yuli Wang Signed-off-by: Huacai Chen --- arch/loongarch/kernel/kgdb.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/kernel/kgdb.c b/arch/loongarch/kernel/kgdb.c index 445c452d72a7..7be5b4c0c900 100644 --- a/arch/loongarch/kernel/kgdb.c +++ b/arch/loongarch/kernel/kgdb.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -224,13 +225,13 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) regs->csr_era = pc; } -void arch_kgdb_breakpoint(void) +noinline void arch_kgdb_breakpoint(void) { __asm__ __volatile__ ( \ ".globl kgdb_breakinst\n\t" \ - "nop\n" \ "kgdb_breakinst:\tbreak 2\n\t"); /* BRK_KDB = 2 */ } +STACK_FRAME_NON_STANDARD(arch_kgdb_breakpoint); /* * Calls linux_debug_hook before the kernel dies. If KGDB is enabled, -- 2.50.1