http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55739
--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> 2013-01-14 22:11:16 UTC --- Created attachment 29165 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29165 A prototype If as, ld and ld.so provide size info via "symbol@size", we can do .LASAN0: # __beg: .quad common_data # __size: .quad common_data@size # __size_with_redzone: .quad common_data@size + 40 # __name: .quad .LC0 # __has_dynamic_init: .quad 0 [hjl@gnu-6 pr55739]$ make /export/build/gnu/gcc/build-x86_64-linux/gcc/../../release/usr/gcc-4.8.0/bin/gcc -fsanitize=address -O -static-libasan -c -o m.o m.c /export/build/gnu/gcc/build-x86_64-linux/gcc/../../release/usr/gcc-4.8.0/bin/gcc -fsanitize=address -O -static-libasan -c -o c.o c.c /export/build/gnu/gcc/build-x86_64-linux/gcc/../../release/usr/gcc-4.8.0/bin/gcc -fsanitize=address -O -static-libasan -c size.S /export/build/gnu/gcc/build-x86_64-linux/gcc/../../release/usr/gcc-4.8.0/bin/gcc -fsanitize=address -O -static-libasan -o x m.o c.o size.o ./x 10: 0 29: 1 ================================================================= ==1454== ERROR: AddressSanitizer: global-buffer-overflow on address 0x000002e70a18 at pc 0x401dc5 bp 0x7fffffffde90 sp 0x7fffffffde70 WRITE of size 4 at 0x000002e70a18 thread T0 #0 0x401dc4 (/export/home/hjl/bugs/gcc/pr55739/x+0x401dc4) 0x000002e70a18 is located 0 bytes to the right of global variable 'c (d.c)' (0x2e709a0) of size 120 'c (d.c)' is ascii string '' Shadow bytes around the buggy address: 0x1000005ce0f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x1000005ce140: 00 00 00[f9]f9 f9 f9 f9 00 00 00 00 00 00 00 00 0x1000005ce150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000005ce190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap righ redzone: fb Freed Heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 ASan internal: fe Stats: 0M malloced (0M for red zones) by 0 calls Stats: 0M realloced by 0 calls Stats: 0M freed by 0 calls Stats: 0M really freed by 0 calls Stats: 0M (0M-0M) mmaped; 0 maps, 0 unmaps mmaps by size class: mallocs by size class: frees by size class: rfrees by size class: Stats: malloc large: 0 small slow: 0 Stats: StackDepot: 0 ids; 0M mapped ==1454== ABORTING make: *** [all] Error 1 [hjl@gnu-6 pr55739]$ readelf -s c.o | grep common_data 17: 0000000000000020 120 OBJECT GLOBAL DEFAULT COM common_data [hjl@gnu-6 pr55739]$
