From ba797b28131b1f1367b662936ea370239d603cff Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:25 -0500 Subject: powerpc,kgdb: Introduce low level trap catching The only way the debugger can handle a trap in inside rcu_lock, notify_die, or atomic_notifier_call_chain without a recursive fault is to allow the kernel debugger to handle the exception first in program_check_exception(). The other change here is to make sure that kgdb_handle_exception() is called with correct parameters when catching an oops, because kdb needs to know if the entry was an oops, single step, or breakpoint exception. [benh@kernel.crashing.org: move debugger_bpt instead of #ifdef] CC: Paul Mackerras Signed-off-by: Jason Wessel Acked-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/traps.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel/traps.c') diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 29d128eb6c4..b6859aade9c 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -815,12 +815,15 @@ void __kprobes program_check_exception(struct pt_regs *regs) return; } if (reason & REASON_TRAP) { + /* Debugger is first in line to stop recursive faults in + * rcu_lock, notify_die, or atomic_notifier_call_chain */ + if (debugger_bpt(regs)) + return; + /* trap exception */ if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) return; - if (debugger_bpt(regs)) - return; if (!(regs->msr & MSR_PR) && /* not user-mode */ report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) { -- cgit v1.2.3-18-g5258