6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yuli Wang wangyuli@uniontech.com
[ Upstream commit 29c92a41c6d2879c1f62220fe4758dce191bb38f ]
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 <inline asm>: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 zhoubinbin@loongson.cn Co-developed-by: Winston Wen wentao@uniontech.com Signed-off-by: Winston Wen wentao@uniontech.com Co-developed-by: Wentao Guan guanwentao@uniontech.com Signed-off-by: Wentao Guan guanwentao@uniontech.com Signed-off-by: Yuli Wang wangyuli@uniontech.com Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Sasha Levin sashal@kernel.org --- 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 445c452d72a79..7be5b4c0c9002 100644 --- a/arch/loongarch/kernel/kgdb.c +++ b/arch/loongarch/kernel/kgdb.c @@ -8,6 +8,7 @@ #include <linux/hw_breakpoint.h> #include <linux/kdebug.h> #include <linux/kgdb.h> +#include <linux/objtool.h> #include <linux/processor.h> #include <linux/ptrace.h> #include <linux/sched.h> @@ -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,