On the sh architecture, kprobes and gdb/gdbserver use different breakpoint opcodes. Without this fix, kprobes doesn't recognize the gdb traps, and the resulting NOTIFY_STOP prevents ptrace and gdb from being notified. The result is that if kprobes is configured, a gdb-traced process hangs when its gdb breakpoint is hit.
Signed-off-by: Jim Keniston <[email protected]> Signed-off-by: Reza Arbab <[email protected]> Reported-by: Vijay Kumar <[email protected]> Tested-by: Vijay Kumar <[email protected]> --- arch/sh/include/asm/kprobes.h | 2 ++ arch/sh/kernel/kprobes.c | 5 ++++- 2 files changed, 6 insertions(+), 1 deletions(-) diff --git a/arch/sh/include/asm/kprobes.h b/arch/sh/include/asm/kprobes.h index 134f398..f22a3cb 100644 --- a/arch/sh/include/asm/kprobes.h +++ b/arch/sh/include/asm/kprobes.h @@ -8,6 +8,8 @@ typedef insn_size_t kprobe_opcode_t; #define BREAKPOINT_INSTRUCTION 0xc33a +#define GDB_BREAKPOINT_INSTRUCTION 0xc3c3 +#define GDBSERVER_BREAKPOINT_INSTRUCTION 0xc320 #define MAX_INSN_SIZE 16 #define MAX_STACK_SIZE 64 diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index 83acbf3..bcaa072 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -260,7 +260,10 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) p = get_kprobe(addr); if (!p) { /* Not one of ours: let kernel handle it */ - if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) { + kprobe_opcode_t opcode = *(kprobe_opcode_t *)addr; + if (opcode != BREAKPOINT_INSTRUCTION && + opcode != GDB_BREAKPOINT_INSTRUCTION && + opcode != GDBSERVER_BREAKPOINT_INSTRUCTION) { /* * The breakpoint instruction was removed right * after we hit it. Another cpu has removed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
