[patch] generic bug: use show_regs() instead of dump_stack()
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
The current generic bug implementation has a call to dump_stack() in
case a WARN_ON(whatever) gets hit. Since report_bug(), which calls
dump_stack(), gets called from an exception handler we can do better:
just pass the pt_regs structure to report_bug() and pass it to
show_regs() in case of a warning. This will give more debug informations
like register contents, etc... In addition this avoids some pointless
lines that dump_stack() emits, since it includes a stack backtrace of
the exception handler which is of no interest in case of a warning.
E.g. on s390 the following lines are currently always present in a stack
backtrace if dump_stack() gets called from report_bug():