tree 7b17fd7408b47892e391604c6791674f03109e1c parent ece90303ec7e2e8d8610eb03ee7648755dd8efe7 author Andi Kleen <[EMAIL PROTECTED]> Sun, 17 Apr 2005 05:25:13 -0700 committer Linus Torvalds <[EMAIL PROTECTED]> Sun, 17 Apr 2005 05:25:13 -0700
[PATCH] x86_64: Keep only a single debug notifier chain Calling a notifier three times in the debug handler does not make much sense, because a debugger can figure out the various conditions by itself. Remove the additional calls to DIE_DEBUG and DIE_DEBUGSTEP completely. This matches what i386 does now. This also makes sure interrupts are always still disabled when calling a debugger, which prevents: BUG: using smp_processor_id() in preemptible [00000001] code: tpopf/1470 caller is post_kprobe_handler+0x9/0x70 Call Trace:<ffffffff8024f10f>{smp_processor_id+191} <ffffffff80120e69>{post_kpro be_handler+9} <ffffffff80120f7a>{kprobe_exceptions_notify+58} <ffffffff80144fc0>{notifier_call_chain+32} <ffffffff80110daf>{do_debug+335} <ffffffff8010f513>{debug+127} <EOE> on preemptible debug kernels with kprobes when single stepping in user space. This was probably a bug even on non preempt kernels, this function was supposed to be running with interrupts off according to a comment there. Note to third part debugger maintainers: please double check your debugger can still single step. Cc: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Signed-off-by: Andi Kleen <[EMAIL PROTECTED]> Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]> x86_64/kernel/traps.c | 14 +++----------- asm-x86_64/kdebug.h | 1 - 2 files changed, 3 insertions(+), 12 deletions(-) Index: arch/x86_64/kernel/traps.c =================================================================== --- 1a6b38b4afd5dae194c93a79152c3bb18460c38f/arch/x86_64/kernel/traps.c (mode:100644 sha1:2f42fd5c075ffaf56788f66222a1f917c4ea6810) +++ 7b17fd7408b47892e391604c6791674f03109e1c/arch/x86_64/kernel/traps.c (mode:100644 sha1:f6ccf155e3e5851a9819e6014400f093b0803246) @@ -659,9 +659,9 @@ asm("movq %%db6,%0" : "=r" (condition)); if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, - SIGTRAP) == NOTIFY_STOP) { + SIGTRAP) == NOTIFY_STOP) return; - } + conditional_sti(regs); /* Mask out spurious debug traps due to lazy DR7 setting */ @@ -674,9 +674,7 @@ tsk->thread.debugreg6 = condition; /* Mask out spurious TF errors due to lazy TF clearing */ - if ((condition & DR_STEP) && - (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition, - 1, SIGTRAP) != NOTIFY_STOP)) { + if (condition & DR_STEP) { /* * The TF error should be masked out only if the current * process is not traced and if the TRAP flag has been set @@ -711,16 +709,10 @@ force_sig_info(SIGTRAP, &info, tsk); clear_dr7: asm volatile("movq %0,%%db7"::"r"(0UL)); - notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP); return; clear_TF_reenable: set_tsk_thread_flag(tsk, TIF_SINGLESTEP); - -clear_TF: - /* RED-PEN could cause spurious errors */ - if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP) - != NOTIFY_STOP) regs->eflags &= ~TF_MASK; } Index: include/asm-x86_64/kdebug.h =================================================================== --- 1a6b38b4afd5dae194c93a79152c3bb18460c38f/include/asm-x86_64/kdebug.h (mode:100644 sha1:adb6f918d3ad719600c034a04b33ce1a5d32b29e) +++ 7b17fd7408b47892e391604c6791674f03109e1c/include/asm-x86_64/kdebug.h (mode:100644 sha1:6277f75cbb4b3f1a25330cf80280e9118f63f8a3) @@ -23,7 +23,6 @@ DIE_OOPS = 1, DIE_INT3, DIE_DEBUG, - DIE_DEBUGSTEP, DIE_PANIC, DIE_NMI, DIE_DIE, - To unsubscribe from this list: send the line "unsubscribe bk-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html