Since the _FORTIFY_SOURCE feature uses some routines of Glibc, they need to
be excluded from the fortification.

On top of that:
 - some tests explicitly verify that some level of fortification works
   appropriately, we therefore shouldn't modify the level set for them.
 - some objects need to be build with optimization disabled, which
   prevents _FORTIFY_SOURCE to be used for them.

Assembler files that implement architecture specific versions of the
fortified routines were not excluded from _FORTIFY_SOURCE as there is no
C header included that would impact their behavior.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

These functions are about to be added to POSIX, under Austin Group
issue 986.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

These functions are about to be added to POSIX, under Austin Group
issue 986.

The fortified strlcat implementation does not raise SIGABRT if the
destination buffer does not contain a null terminator, it just
inherits the non-failing regular strlcat behavior.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

Fix list terminator whitspace.
Sort using scripts/sort-makefile-lines.py.

No code generation changes observed in binary artifacts.
No regressions on x86_64 and i686.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

This shows up as an assertion failure when sprintf is called with
a specifier like "%.8g" and libquadmath is linked in:

Fatal glibc error: printf_buffer_as_file.c:31
  (__printf_buffer_as_file_commit): assertion failed:
  file->stream._IO_write_ptr <= file->next->write_end

Fix this by detecting pointer wraparound in __vsprintf_internal
and saturate the addition to the end of the address space instead.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

From commit 2e274cd8c1ebd0bd0c43a7f2e5433685740938ca.

Similar to ppoll, the poll.h header needs to redirect the poll call
to a proper fortified ppoll with 64 bit time_t support.

The implementation is straightforward, just need to add a similar
check as __poll_chk and call the 64 bit time_t ppoll version.  The
debug fortify tests are also extended to cover 64 bit time_t for
affected ABIs.

Unfortunately it requires an aditional symbol, which makes backport
tricky.  One possibility is to add a static inline version if compiler
supports is and call abort instead of __chk_fail, so fortified version
will call __poll64 in the end.

Another possibility is to just remove the fortify support for
_TIME_BITS=64.

Checked on i686-linux-gnu.

Generalize the test for cancellation point in __read_chk to also test
the other fortified functions with required cancellation points.

Since there is not easy way to force some syscalls to block (for
instance pread) the test tests two modes: cancellation on blocked
syscalls and early cancellation on pending request.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.

Co-authored-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>