This is necessary to make sure that functions that can have stack
protection are not used to update the stack guard. If not, the stack
guard check would fail when it shouldn't.
guard_setup() calls elf_aux_info(), which, in turn, calls memcpy() to
update stack_chk_guard. If either elf_aux_info() or memcpy() have
stack protection enabled, __stack_chk_guard will be modified before
returning from them, causing the stack protection check to fail.
This change uses a temporary buffer to delay changing
__stack_chk_guard until elf_aux_info() returns.
Submitted by: Luis Pires
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D15173
According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).
The comment in the libc/sys symbol map referenced the generated symbols
for the syscall trampolines. Such comment was out of place in the secure
symbol map so remove the stale comment and attempt to clarify the old one
to avoid risks of confusion.
Pointed out by: kib
As part of the code refactoring to support FORTIFY_SOURCE we want
a new subdirectory "secure" to keep the files related to security.
Move the stack protector functions to this new directory.
No functional change.
Differential Review: https://reviews.freebsd.org/D3333
