On 07/23/2013 09:58 PM, Michael Ellerman wrote: > On Mon, Jul 22, 2013 at 03:02:53PM +0800, Chen Gang wrote: >> Hello Maintainers: >> >> With allmodconfig and EXTRA_CFLAGS=-W", it reports warnings below: > >> >> arch/powerpc/xmon/xmon.c:3027:6: warning: variable ‘i’ might be clobbered by >> ‘longjmp’ or ‘vfork’ [-Wclobbered] >> arch/powerpc/xmon/xmon.c:3068:6: warning: variable ‘i’ might be clobbered by >> ‘longjmp’ or ‘vfork’ [-Wclobbered] > > In both these cases we are inside the body of a for loop and we do a > if (setjmp) / else block. Although looking at the source the value of i > is not modified by the setjmp, I guess it's possible that the compiler > might reorder the increment of i inside the setjmp and loose the value > when we longjmp. >
I should continue to confirm the details based on your valuable information, thanks. >> arch/powerpc/xmon/xmon.c:352:48: warning: argument ‘fromipi’ might be >> clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered] > > This one I can't see, but I assume it's a similar case. > OK, I should continue for it. >> Excuse me, I am not quite sure about it whether can cause issue or not. > > I've never seen it get stuck in those loops or anything, but I guess > it's possible. > OK, I should make the confirmation. > The first thing to do would be to analyse the generated assembler code > to determine if there really is any possiblity of the value being > clobbered, or if it's just a theoretical bug. > Thank you for your valuable information again. Excuse me, I have to do another things within this month, so I should provide the confirmation within next month (2013-08-31), is it OK (no reply means OK). Welcome any suggestions or completions. Thanks. -- Chen Gang _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
