Merge patch series "riscv: Rework the arch_kgdb_breakpoint() implementation"

WangYuli <wangyuli@uniontech.com> says:

1. 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_compiled_break
   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.

2. Remove ".option norvc/.option rvc" to fix a bug that the C extension
   would unconditionally enable even if the kernel is being built with
   CONFIG_RISCV_ISA_C=n.

* b4-shazam-merge:
  riscv: KGDB: Remove ".option norvc/.option rvc" for kgdb_compiled_break
  riscv: KGDB: Do not inline arch_kgdb_breakpoint()

Link: https://lore.kernel.org/r/D5A83DF3A06E1DF9+20250411072905.55134-1-wangyuli@uniontech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: palmer-dabbelt

arch/riscv/include/asm/kgdb.h

@@ -19,16 +19,9 @@
 
 #ifndef	__ASSEMBLY__
 
+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"

arch/riscv/kernel/kgdb.c

@@ -254,6 +254,12 @@ 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"
+	    "kgdb_compiled_break: ebreak\n");
+}
+
 void kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer,
 				char *remcom_out_buffer)
 {