[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 7/7] tools/kdd: mute spurious gcc warning
On Fri, Apr 06, 2018 at 09:39:50AM -0400, Boris Ostrovsky wrote: > On 04/06/2018 09:07 AM, Wei Liu wrote: > > On Fri, Apr 06, 2018 at 08:39:53AM -0400, Boris Ostrovsky wrote: > >> On 04/04/2018 09:50 PM, Marek Marczykowski-Górecki wrote: > >>> gcc-8 complains: > >>> > >>> kdd.c:698:13: error: 'memcpy' offset [-204, -717] is out of the > >>> bounds [0, 216] of object 'ctrl' with type 'kdd_ctrl' {aka 'union > >>> <anonymous>'} [-Werror=array-bounds] > >>> memcpy(buf, ((uint8_t *)&ctrl.c32) + offset, len); > >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >>> kdd.c: In function 'kdd_select_callback': > >>> kdd.c:642:14: note: 'ctrl' declared here > >>> kdd_ctrl ctrl; > >>> ^~~~ > >>> > >>> But this is impossible - 'offset' is unsigned and correctly validated > >>> few lines before. > >>> > >>> Signed-off-by: Marek Marczykowski-Górecki > >>> <marmarek@xxxxxxxxxxxxxxxxxxxxxx> > >>> --- > >>> tools/debugger/kdd/kdd.c | 3 +++ > >>> 1 file changed, 3 insertions(+) > >>> > >>> diff --git a/tools/debugger/kdd/kdd.c b/tools/debugger/kdd/kdd.c > >>> index 1bd5dd5..61d769e 100644 > >>> --- a/tools/debugger/kdd/kdd.c > >>> +++ b/tools/debugger/kdd/kdd.c > >>> @@ -695,7 +695,10 @@ static void kdd_handle_read_ctrl(kdd_state *s) > >>> KDD_LOG(s, "Request outside of known control space\n"); > >>> len = 0; > >>> } else { > >>> +#pragma GCC diagnostic push > >>> +#pragma GCC diagnostic ignored "-Warray-bounds" > >>> memcpy(buf, ((uint8_t *)&ctrl.c32) + offset, len); > >>> +#pragma GCC diagnostic pop > >>> } > >>> } > >>> > >> > >> Breaks 32-bit build, at least with my (ancient, gcc version 4.4.5 > >> 20101112 (Red Hat 4.4.5-2) (GCC)) compiler: > >> > >> > >> > >> kdd.c: In function ‘kdd_handle_read_ctrl’: > >> kdd.c:698: error: #pragma GCC diagnostic not allowed inside functions > >> kdd.c:699: error: #pragma GCC diagnostic not allowed inside functions > >> kdd.c:701: error: #pragma GCC diagnostic not allowed inside functions > >> make[5]: *** [kdd.o] Error 1 > >> > > Does moving the relevant #pragma's outside of the function fix it? > > The additional problem with these pragmas is that apparently push/pop > have been introduced in gcc 4.6.0: > > https://gcc.gnu.org/onlinedocs/gcc-4.6.0/gcc/Diagnostic-Pragmas.html#Diagnostic-Pragmas > > If you change release number to a lower one (e.g. 4.5.4) you won't see them. > > So I can move "diagnostic ignored" from inside the function and that > will clear the "GCC diagnostic not allowed inside functions" error. But > then push/pop are not recognized: > > cc1: warnings being treated as errors > kdd.c:639: error: expected [error|warning|ignored] after ‘#pragma GCC > diagnostic’ > kdd.c:714: error: expected [error|warning|ignored] after ‘#pragma GCC > diagnostic’ > > (Interestingly, my 64-bit build completed without issues) Hmm... this is messy. If you have information about which version does what we can try to enclose the #pragma's with #if __GCC__. Wei. > > -boris _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |