| Message ID | 1455763681-13663-1-git-send-email-bsingharora@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Thu, 2016-18-02 at 02:48:01 UTC, Balbir Singh wrote: > Changelog: > Don't use REGION_ID, breaks on some platforms > Don't blindly add PAGE_OFFSET to bugaddr > > 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> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/a4c3f909b4d9bb9430bf42ad58 cheers
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index b6becc7..4e5c11d 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; }
Changelog: Don't use REGION_ID, breaks on some platforms Don't blindly add PAGE_OFFSET to bugaddr 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> --- arch/powerpc/kernel/traps.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)