Detect the use of FORTIFY_SOURCE

[prabhu]

https://www.redhat.com/en/blog/enhance-application-security-fortifysource

We need to collect the various _chk functions from libc. This can be done with blint or commands such as readelf. The data can be stored under annotations.

readelf -s /usr/lib64/libc.so.6| grep "_chk"

1457: 0000000000121e6e    25 FUNC    GLOBAL DEFAULT   17 __recv_chk@@GLIBC_2.4
  2095: 0000000000121b7e    22 FUNC    GLOBAL DEFAULT   17 __read_chk@@GLIBC_2.4
  1058: 0000000000029c7e    82 FUNC    LOCAL  DEFAULT   17 __fgets_chk.cold
  1059: 0000000000029cd0    82 FUNC    LOCAL  DEFAULT   17 __fgetws_chk.cold
  1060: 0000000000029d22    84 FUNC    LOCAL  DEFAULT   17 __fread_chk.cold
  1061: 0000000000029d76    84 FUNC    LOCAL  DEFAULT   17 __gets_chk.cold
  1064: 000000000012145e   275 FUNC    LOCAL  DEFAULT   17 __memcpy_chk_ifunc
  1065: 000000000012158e   275 FUNC    LOCAL  DEFAULT   17 __memmove_chk_ifunc
  1066: 00000000001216be   275 FUNC    LOCAL  DEFAULT   17 __mempcpy_chk_ifunc
  1067: 00000000001217ee   239 FUNC    LOCAL  DEFAULT   17 __memset_chk_ifunc
  1068: 0000000000122c4e   104 FUNC    LOCAL  DEFAULT   17 __wmemset_chk_ifunc
  1752: 000000000018594e    15 FUNC    LOCAL  DEFAULT   17 __mempcpy_chk_av[...]
  1855: 000000000016c64e    15 FUNC    LOCAL  DEFAULT   17 __memmove_chk_av[...]
  1936: 000000000016d0ce    15 FUNC    LOCAL  DEFAULT   17 __wmemset_chk_av[...]
  1944: 000000000017cc8e    15 FUNC    LOCAL  DEFAULT   17 __memmove_chk_ev[...]
  1995: 000000000018598e    15 FUNC    LOCAL  DEFAULT   17 __memcpy_chk_avx[...]
  2061: 000000000018598e    15 FUNC    LOCAL  DEFAULT   17 __memmove_chk_av[...]
  2073: 000000000018624e    15 FUNC    LOCAL  DEFAULT   17 __wmemset_chk_av[...]
  2076: 000000000017cd3e    15 FUNC    LOCAL  DEFAULT   17 __memcpy_chk_eve[...]

At level 3, even the memory management functions from the list below would use their _chk equivalents.

memmove(),  memcpy(), snprintf(), vsnprintf(), strtok() and strncat()