diff options
| author |   Balbir Singh <bsingharora@gmail.com> | 2016-02-18 13:48:01 +1100 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2016-02-24 20:09:04 +1100 |
| commit | a4c3f909b4d9bb9430bf42ad583661df6dfa86c6 (patch) | |
| tree | 298c791fd82de132ae1ec3c0fa4144290287507d /arch | |
| parent | powerpc: Use BUILD_BUG_ON_MSG() for unsupported {cmp}xchg sizes (diff) | |
| download | linux-dev-a4c3f909b4d9bb9430bf42ad583661df6dfa86c6.tar.xz linux-dev-a4c3f909b4d9bb9430bf42ad583661df6dfa86c6.zip | |
powerpc: Fix BUG_ON() reporting in real mode
I ran into this issue while debugging an early boot problem. The system
hit a BUG_ON() but report bug failed to print the line number and file
name. The reason being that the system was running in real mode and
report_bug() searches for addresses in the PAGE_OFFSET+ region.
Suggested-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index b6becc795bb5..4e5c11d4d19d 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1148,6 +1148,7 @@ void __kprobes program_check_exception(struct pt_regs *regs) goto bail; } if (reason & REASON_TRAP) { + unsigned long bugaddr; /* Debugger is first in line to stop recursive faults in * rcu_lock, notify_die, or atomic_notifier_call_chain */ if (debugger_bpt(regs)) @@ -1158,8 +1159,15 @@ void __kprobes program_check_exception(struct pt_regs *regs) == NOTIFY_STOP) goto bail; + bugaddr = regs->nip; + /* + * Fixup bugaddr for BUG_ON() in real mode + */ + if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR)) + bugaddr += PAGE_OFFSET; + if (!(regs->msr & MSR_PR) && /* not user-mode */ - report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) { + report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) { regs->nip += 4; goto bail; } |