This is the mail archive of the newlib@sourceware.org mailing list for the newlib project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
// gcc test.c -o test.exe -g -O2 -Wp,-D_FORTIFY_SOURCE=2 // // extracted from InputLineAddChar in xserver/xkb/maprules.c // #include <stdio.h> #include <stdlib.h> #include <string.h> int main() { const char *buf[128]; char *line = reallocarray(NULL, 128, 2); // size of line is 128*2 = 256 printf("%zu\n", __builtin_object_size(line, 0)); memcpy(line, buf, 128); // __mempcy_chk tests against size 2, and terminates }reallocarray() is annotated in stdlib.h with '__alloc_size(2) __alloc_size(3)'
per [1], this doesn't seem to be the correct syntax when the size is the product of the arguments, and the last alloc_size seems to be silently winning.
If I change this to '__alloc_size((2,3))' (as in the patch attached), __builtin_object_size doesn't seem to be a compile-time constant anymore, and so memcpy() evaluates differently, so it's hard to be sure that's actually correct...
[1] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Attachment:
0001-Correct-alloc_size-annotation-on-reallocarray.patch
Description: Text document
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |