Messages in this thread |  | | Date | Wed, 13 Nov 2013 12:57:13 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] gcc4: Disable __compiletime_object_size for GCC 4.6+ |
| |
On 11/13/2013 10:39 AM, Kees Cook wrote: > Hi Guenter, > > On Fri, Apr 12, 2013 at 07:49:08PM -0700, Guenter Roeck wrote: >> __builtin_object_size is known to be broken on gcc 4.6+. >> See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48880 for details. >> >> This causes unnecssary build warnings and errors such as >> >> In function 'copy_from_user', inlined from 'sb16_copy_from_user' >> at sound/oss/sb_audio.c:878:22: >> arch/x86/include/asm/uaccess_32.h:211:26: error: call to 'copy_from_user_overflow' >> declared with attribute error: copy_from_user() buffer size is not provably correct >> make[3]: [sound/oss/sb_audio.o] Error 1 (ignored) >> >> Disable it where broken. > > Is there an alternative? This means that things like > DEBUG_STRICT_USER_COPY_CHECKS are being rendered useless. I don't think > this is _always_ broken, just under certain situations, right? >
It would be one thing to block it for, say, gcc 4.6 and 4.7 only, but without an upper cap I don't think this is at all okay.
-hpa
|  |