If specified, use __builtin_dynamic_object_size() instead of
__builtin_object_size() if supported (GCC 12.0 or later).
This enables buffer overflow checks if the buffer size is non-const
but known during runtime.
Use new macro __ssp_bos_known() instead of the (bos(p) != (size_t)-1)
checks. The latter is no longer a compile time constant in all cases.
This avoids the generation of unused code.
Signed-off-by: Christian Franke <christian.franke@t-online.de>
This is a NetBSD-specific detail which does not apply to Newlib, causing
linking issues in certain scenarios:
https://cygwin.com/ml/cygwin/2018-01/msg00189.html
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The following functions are also guarded in glibc:
fwprintf, swprintf, wprintf, vfwprintf, vswprintf, vwprintf.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The implementation is from NetBSD, with the addition of feature test macros
for readlink. glibc also wraps the following functions:
confstr, getdomainname, getgroups, gethostname, getlogin_r, getwd, pread,
readlinkat, ttyname_r.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The implementation is mostly from NetBSD, except for switching fgets to
pure inline, and the addition of fgets_unlocked, fread, and fread_unlocked
for parity with glibc. The following functions are also guarded in glibc:
asprintf, dprintf, fprintf, printf, vasprintf, vdprintf, vfprintf, vprintf.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The implementation is from NetBSD, with the addition of mempcpy (a GNU
extension) for parity with glibc and libssp.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
The Object Size Checking (-D_FORTIFY_SOURCE=*) functionality provides
wrappers around functions suspectible to buffer overflows. While
independent from Stack Smashing Protection (-fstack-protector*), they
are often used and implemented together.
While GCC also provides an implementation in libssp, it is completely
broken (CVE-2016-4973, RHBZ#1324759) and seemingly unfixable, as there
is no reliable way for a preprocessor macro to trigger a link flag.
Therefore, adding this here is necessary to make it work.
Note that this does require building gcc with --disable-libssp and
gcc_cv_libc_provides_ssp=yes.
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
Christian Franke
Yaakov Selkowitz