[PATCH] riscv: KGDB: Do not inline arch_kgdb_breakpoint()
WangYuli
wangyuli at uniontech.com
Fri Mar 21 23:28:36 PDT 2025
The arch_kgdb_breakpoint() function defines the kgdb_compiled_break
symbol using inline assembly.
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 fail to link vmlinux.o.
This isn't merely a potential compilation problem. The intent here
is to determine the global symbol address of kgdb_compiled_break,
and if this function is inlined multiple times, it would logically
be a grave error.
Fixes: fe89bd2be866 ("riscv: Add KGDB support")
Co-developed-by: Huacai Chen <chenhuacai at loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai at loongson.cn>
Signed-off-by: WangYuli <wangyuli at uniontech.com>
---
arch/riscv/include/asm/kgdb.h | 13 +------------
arch/riscv/kernel/kgdb.c | 8 ++++++++
2 files changed, 9 insertions(+), 12 deletions(-)
diff --git a/arch/riscv/include/asm/kgdb.h b/arch/riscv/include/asm/kgdb.h
index 46677daf708b..566ab1bc66fa 100644
--- a/arch/riscv/include/asm/kgdb.h
+++ b/arch/riscv/include/asm/kgdb.h
@@ -17,20 +17,9 @@
#define BREAK_INSTR_SIZE 4
#endif
-#ifndef __ASSEMBLY__
-
+extern void arch_kgdb_breakpoint(void);
extern unsigned long kgdb_compiled_break;
-static inline void arch_kgdb_breakpoint(void)
-{
- asm(".global kgdb_compiled_break\n"
- ".option norvc\n"
- "kgdb_compiled_break: ebreak\n"
- ".option rvc\n");
-}
-
-#endif /* !__ASSEMBLY__ */
-
#define DBG_REG_ZERO "zero"
#define DBG_REG_RA "ra"
#define DBG_REG_SP "sp"
diff --git a/arch/riscv/kernel/kgdb.c b/arch/riscv/kernel/kgdb.c
index 2e0266ae6bd7..5d1ce8dacaf5 100644
--- a/arch/riscv/kernel/kgdb.c
+++ b/arch/riscv/kernel/kgdb.c
@@ -254,6 +254,14 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
regs->epc = pc;
}
+noinline void arch_kgdb_breakpoint(void)
+{
+ asm(".global kgdb_compiled_break\n"
+ ".option norvc\n"
+ "kgdb_compiled_break: ebreak\n"
+ ".option rvc\n");
+}
+
void kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer,
char *remcom_out_buffer)
{
--
2.49.0
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