Greg Ungerer <gerg@xxxxxxxxxxx> writes:
Attached is a test case - derived from the original signal.c code.
It looks like with all those trivial functions in the non-MMU case the compiler sees enough to consider the writes to the (pseudo) function arguments dead. How about this: diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index af1c4f3..3cc9eaa 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -757,6 +757,11 @@ asmlinkage int do_sigreturn(unsigned long __unused) if (restore_sigcontext(regs, &frame->sc, frame + 1)) goto badframe; + /* + * Force a barrier so that the compiler does not consider writes + * to *sw and *regs as dead. + */ + barrier(); return regs->d0; badframe: @@ -781,6 +786,11 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused) if (rt_restore_ucontext(regs, sw, &frame->uc)) goto badframe; + /* + * Force a barrier so that the compiler does not consider writes + * to *sw and *regs as dead. + */ + barrier(); return regs->d0; badframe: Andreas. -- Andreas Schwab, schwab@xxxxxxxxxxxxxx GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
