From: Paul Mackerras This patch is from Ananth N Mavinakayanahalli . While processing a kprobe, we were currently not handling all available trap variants available on PowerPC. This lead to the breakage of BUG() handling in ppc64. Signed-off-by: Paul Mackerras Signed-off-by: Andrew Morton --- 25-akpm/arch/ppc64/kernel/kprobes.c | 11 +++++++++-- 25-akpm/include/asm-ppc64/kprobes.h | 5 +++++ 2 files changed, 14 insertions(+), 2 deletions(-) diff -puN arch/ppc64/kernel/kprobes.c~ppc64-kprobes-handle-trap-variants-while-processing-probes arch/ppc64/kernel/kprobes.c --- 25/arch/ppc64/kernel/kprobes.c~ppc64-kprobes-handle-trap-variants-while-processing-probes 2005-03-07 20:41:25.000000000 -0800 +++ 25-akpm/arch/ppc64/kernel/kprobes.c 2005-03-07 20:41:25.000000000 -0800 @@ -105,9 +105,17 @@ static inline int kprobe_handler(struct p = get_kprobe(addr); if (!p) { unlock_kprobes(); -#if 0 if (*addr != BREAKPOINT_INSTRUCTION) { /* + * PowerPC has multiple variants of the "trap" + * instruction. If the current instruction is a + * trap variant, it could belong to someone else + */ + kprobe_opcode_t cur_insn = *addr; + if (IS_TW(cur_insn) || IS_TD(cur_insn) || + IS_TWI(cur_insn) || IS_TDI(cur_insn)) + goto no_kprobe; + /* * The breakpoint instruction was removed right * after we hit it. Another cpu has removed * either a probepoint or a debugger breakpoint @@ -116,7 +124,6 @@ static inline int kprobe_handler(struct */ ret = 1; } -#endif /* Not one of ours: let kernel handle it */ goto no_kprobe; } diff -puN include/asm-ppc64/kprobes.h~ppc64-kprobes-handle-trap-variants-while-processing-probes include/asm-ppc64/kprobes.h --- 25/include/asm-ppc64/kprobes.h~ppc64-kprobes-handle-trap-variants-while-processing-probes 2005-03-07 20:41:25.000000000 -0800 +++ 25-akpm/include/asm-ppc64/kprobes.h 2005-03-07 20:41:25.000000000 -0800 @@ -35,6 +35,11 @@ typedef unsigned int kprobe_opcode_t; #define BREAKPOINT_INSTRUCTION 0x7fe00008 /* trap */ #define MAX_INSN_SIZE 1 +#define IS_TW(instr) (((instr) & 0xfc0007fe) == 0x7c000008) +#define IS_TD(instr) (((instr) & 0xfc0007fe) == 0x7c000088) +#define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000) +#define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000) + #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry) /* Architecture specific copy of original instruction */ _