Launchpad has imported 3 comments from the remote bug at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=35948.
If you reply to an imported comment from within Launchpad, your comment will be sent to the remote bug automatically. Read more about Launchpad's inter-bugtracker facilities at https://documentation.ubuntu.com/launchpad/user/reference/bugs/multi-project-bugs/about-multi-project-bugs/#bugs-in-external-trackers. ------------------------------------------------------------------------ On 2008-04-15T16:28:40+00:00 Kees Cook wrote: The following source, without the "(void*)" overrides, will throw an warning (as expected), when compiled with -Wall: $ gcc -o memcpy-fortify -Wall memcpy-fortify.c memcpy-fortify.c: In function 'main': memcpy-fortify.c:21: warning: passing argument 1 of 'memcpy' discards qualifiers from pointer target type memcpy-fortify.c:22: warning: passing argument 1 of 'strcpy' discards qualifiers from pointer target type With "(void*)" it is (as expected) silent. With -O2, it is silent, but with -D_FORTIFY_SOURCE != 0, the qualifier override is ignored: $ gcc -o memcpy-fortify -Wall -O2 -D_FORTIFY_SOURCE=2 memcpy-fortify.c memcpy-fortify.c: In function 'main': memcpy-fortify.c:21: warning: passing argument 1 of 'memcpy' discards qualifiers from pointer target type memcpy-fortify.c:22: warning: passing argument 1 of 'strcpy' discards qualifiers from pointer target type This will cause problems for builds that run with -Werror. /* * gcc -o memcpy-fortify -Wall -Werror -O2 -D_FORTIFY_SOURCE=2 memcpy-fortify.c * */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <stdint.h> #include <string.h> #include <stdint.h> #include <inttypes.h> int main(int argc, char * argv[]) { char *foo = strdup("string one"); char *bar = strdup("string two"); const char *baz = (const char *)foo; printf("%s\n", foo); memcpy((void*)baz, bar, strlen(bar)+1); strcpy((void*)baz, bar); printf("%s\n", foo); return 0; } Reply at: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/217481/comments/1 ------------------------------------------------------------------------ On 2008-04-15T16:35:26+00:00 Pinskia wrote: This is not a GCC bug but rather a glibc issue. Reply at: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/217481/comments/2 ------------------------------------------------------------------------ On 2008-04-15T16:44:12+00:00 Kees Cook wrote: Erk, right. Sorry for the noise. Reply at: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/217481/comments/3 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/217481 Title: -D_FORTIFY_SOURCE discards qualifier overrides in {mem,str}cpy To manage notifications about this bug go to: https://bugs.launchpad.net/gcc/+bug/217481/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
