On 2014-02-25 15:26, Paolo Bonzini wrote: > Il 24/02/2014 16:58, Jan Kiszka ha scritto: >> On 2014-02-24 16:25, Marius Vlad wrote: >>> Commit 3b1274463fa8d074dd3bc77efe25b59a4ddd491e uses GCCs extension >>> labels as values to handle exceptions, but GCC 4.8 ``mistakingly'' >>> uses the next body function as a jump label, for functions which >>> do not return. Fixed by returning a int value for those functions. >>> >>> See http://thread.gmane.org/gmane.comp.emulators.kvm.devel/119186 >>> >>> Signed-off-by: Marius Vlad <mv@xxxxxxxxxxxxxxxxx> >>> --- >>> x86/vmx.c | 10 +++++----- >>> 1 file changed, 5 insertions(+), 5 deletions(-) >>> >>> diff --git a/x86/vmx.c b/x86/vmx.c >>> index fe950e6..0c895af 100644 >>> --- a/x86/vmx.c >>> +++ b/x86/vmx.c >>> @@ -548,7 +548,7 @@ static void exception_handler(struct ex_regs *regs) >>> regs->rip = (u64)exception_return; >>> } >>> >>> -static int test_for_exception(unsigned int ex, void (*func)(void)) >>> +static int test_for_exception(unsigned int ex, int (*func)(void)) >>> { >>> handle_exception(ex, exception_handler); >>> exception = false; >>> @@ -557,23 +557,23 @@ static int test_for_exception(unsigned int ex, >>> void (*func)(void)) >>> return exception; >>> } >>> >>> -static void do_vmxon_off(void) >>> +static int do_vmxon_off(void) >>> { >>> exception_return = &&resume; >>> barrier(); >>> vmx_on(); >>> vmx_off(); >>> resume: >>> - return; >>> + return 0; >>> } >>> >>> -static void do_write_feature_control(void) >>> +static int do_write_feature_control(void) >>> { >>> exception_return = &&resume; >>> barrier(); >>> wrmsr(MSR_IA32_FEATURE_CONTROL, 0); >>> resume: >>> - return; >>> + return 0; >>> } >>> >>> static int test_vmx_feature_control(void) >>> >> >> Argh, getting old. I remembered that issue but forgot that I already had >> a fix for this queued: >> >> http://thread.gmane.org/gmane.comp.emulators.kvm.devel/117866 >> >> I don't mind which version to pick, but maybe Paolo has mine already in >> his queue. > > Yeah (I hadn't, but now I have). According to GCC developers this is > invalid code. > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28581 Oh - how nicely intuitive. > > Perhaps we should rewrite this using something more similar to "normal" > C setjmp/longjmp. Hmm, maybe. If barrier workaround wouldn't work already... Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
