lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

powerpc,kgdb: Introduce low level trap catching

Browse Source 
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 <paulus@samba.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Jason Wessel
2010-05-20 21:04:25 -05:00
parent f503b5ae53
commit ba797b2813
2 changed files with 9 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
arch/powerpc/kernel/traps.c
View File

@ -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) {