This can help developers to analyze the cause of WARN() because the control will be transferred to debugging environment if the debugger is connected.
Signed-off-by: Vincent Chen <[email protected]> --- arch/riscv/include/asm/bug.h | 27 ++++++++++++++++++--------- arch/riscv/kernel/traps.c | 19 ++++++++++++++++--- 2 files changed, 34 insertions(+), 12 deletions(-) diff --git a/arch/riscv/include/asm/bug.h b/arch/riscv/include/asm/bug.h index 1cab7f4..b2aa88f 100644 --- a/arch/riscv/include/asm/bug.h +++ b/arch/riscv/include/asm/bug.h @@ -43,38 +43,47 @@ #define __BUG_ENTRY \ __BUG_ENTRY_ADDR "\n\t" \ __BUG_ENTRY_FILE "\n\t" \ - RISCV_SHORT " %1" + RISCV_SHORT " %1 \n\t" \ + RISCV_SHORT " %2" #else #define __BUG_ENTRY \ - __BUG_ENTRY_ADDR + __BUG_ENTRY_ADDR "\n\t" \ + RISCV_SHORT " %2" #endif -#define BUG() \ +#define __BUG_FLAGS(flags) \ do { \ __asm__ __volatile__ ( \ "1:\n\t" \ "ebreak\n" \ - ".pushsection __bug_table,\"a\"\n\t" \ + ".pushsection __bug_table,\"aw\"\n\t" \ "2:\n\t" \ __BUG_ENTRY "\n\t" \ - ".org 2b + %2\n\t" \ + ".org 2b + %3\n\t" \ ".popsection" \ : \ : "i" (__FILE__), "i" (__LINE__), \ - "i" (sizeof(struct bug_entry))); \ - unreachable(); \ + "i" (flags), \ + "i" (sizeof(struct bug_entry))); \ } while (0) + #endif /* !__ASSEMBLY__ */ #else /* CONFIG_GENERIC_BUG */ #ifndef __ASSEMBLY__ -#define BUG() \ +#define __BUG_FLAGS(flags) \ do { \ __asm__ __volatile__ ("ebreak\n"); \ - unreachable(); \ } while (0) #endif /* !__ASSEMBLY__ */ #endif /* CONFIG_GENERIC_BUG */ +#define BUG() do { \ + __BUG_FLAGS(0); \ + unreachable(); \ +} while (0) + +#define __WARN_FLAGS(flags) __BUG_FLAGS(BUGFLAG_WARNING|(flags)) + #define HAVE_ARCH_BUG #include <asm-generic/bug.h> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index dee0e5e..023208b 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -118,6 +118,17 @@ asmlinkage void name(struct pt_regs *regs) \ DO_ERROR_INFO(do_trap_ecall_m, SIGILL, ILL_ILLTRP, "environment call from M-mode"); +#ifdef CONFIG_GENERIC_BUG +static inline unsigned long get_break_insn_length(unsigned long pc) +{ + bug_insn_t insn; + + if (probe_kernel_address((bug_insn_t *)pc, insn)) + return 0; + return ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL : 2UL; +} +#endif /* CONFIG_GENERIC_BUG */ + asmlinkage void do_trap_break(struct pt_regs *regs) { #ifdef CONFIG_GENERIC_BUG @@ -129,7 +140,8 @@ asmlinkage void do_trap_break(struct pt_regs *regs) case BUG_TRAP_TYPE_NONE: break; case BUG_TRAP_TYPE_WARN: - die(regs, "Kernel BUG. Kernel got an unexpected WARN trapped by ebreak"); + regs->sepc += get_break_insn_length(regs->sepc); + break; case BUG_TRAP_TYPE_BUG: die(regs, "Kernel BUG"); } @@ -149,12 +161,13 @@ int is_valid_bugaddr(unsigned long pc) if (probe_kernel_address((bug_insn_t *)pc, insn)) return 0; if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) - return insn == __BUG_INSN_32; + return (insn == __BUG_INSN_32); else - return (insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16; + return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16); } #endif /* CONFIG_GENERIC_BUG */ + void __init trap_init(void) { /* -- 1.7.1
