glibc/sysdeps/unix/sysv/linux/hppa/____longjmp_chk.c
Joseph Myers 7553131847 Fix struct sigaltstack namespace (bug 21517).
glibc defines the stack_t type with the tag struct sigaltstack.  This
is not permitted by POSIX; sigaltstack is only reserved with file
scope in the namespace of ordinary identifiers, not the tag namespace,
and in the case where stack_t is obtained from ucontext.h rather than
signal.h, it's not reserved with file scope at all.

This patch removes the tag accordingly and updates uses in glibc of
struct sigaltstack.  This is similar to the removal of the "struct
siginfo" tag a few years ago: C++ name mangling changes are an
unavoidable consequence.  A NEWS item is added to note the changed
mangling.  There is inevitably some risk of breaking builds of
anything that relies on the struct sigaltstack name (though the first
few hits I looked at from codesearch.debian.net generally seemed to
involve code that could use the stack_t name conditionally, so
depending on how they determine the conditionals they may work with
glibc not defining the struct tag anyway).

Tested for x86_64 and x86, and with build-many-glibcs.py.

	[BZ #21517]
	* bits/types/stack_t.h (stack_t): Remove struct tag.
	* sysdeps/unix/sysv/linux/bits/types/stack_t.h (stack_t):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h (stack_t):
	Likewise.
	* debug/segfault.c (install_handler): Use stack_t instead of
	struct sigaltstack.
	* hurd/hurd/signal.h (struct hurd_sigstate): Likewise.
	* hurd/trampoline.c (_hurd_setup_sighandler): Likewise.
	* include/signal.h (__sigaltstack): Likwise.
	* signal/sigaltstack.c (__sigaltstack): Likewise.
	* signal/signal.h (sigaltstack): Likewise.
	* sysdeps/mach/hurd/i386/signal-defines.sym
	(SIGALTSTACK__SS_SP__OFFSET): Likewise.
	(SIGALTSTACK__SS_SIZE__OFFSET): Likewise.
	(SIGALTSTACK__SS_FLAGS__OFFSET): Likewise.
	* sysdeps/mach/hurd/sigaltstack.c (__sigaltstack): Likewise.
	* sysdeps/mach/hurd/sigstack.c (sigstack): Likewise.
	* sysdeps/unix/sysv/linux/alpha/sys/procfs.h (struct
	elf_prstatus): Likewise.
	* sysdeps/unix/sysv/linux/hppa/____longjmp_chk.c (CHECK_SP):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/sys/procfs.h (struct elf_prstatus):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/____longjmp_chk.c (CHECK_SP):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/sys/procfs.h (struct
	elf_prstatus): Likewise.
	* sysdeps/unix/sysv/linux/sh/sys/procfs.h (struct elf_prstatus):
	Likewise.
	* sysdeps/unix/sysv/linux/sys/procfs.h (struct elf_prstatus):
	Likewise.
2017-06-05 10:17:46 +00:00

48 lines
2.1 KiB
C

/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include <stdio.h>
#include <signal.h>
#include <sysdep.h>
#define __longjmp ____longjmp_chk
#define CHECK_SP(sp) \
do { \
register unsigned long this_sp asm ("r30"); \
/* The stack grows up, therefore frames that were created and then \
destroyed must all have stack values higher than ours. */ \
if ((unsigned long) (sp) > this_sp) \
{ \
stack_t oss; \
INTERNAL_SYSCALL_DECL (err); \
int result = INTERNAL_SYSCALL (sigaltstack, err, 2, NULL, &oss);\
/* If we aren't using an alternate stack then we have already \
shown that we are jumping to a frame that doesn't exist so \
error out. If we are using an alternate stack we must prove \
that we are jumping *out* of the alternate stack. Note that \
the check for that is the same as that for _STACK_GROWS_UP \
as for _STACK_GROWS_DOWN. */ \
if (!INTERNAL_SYSCALL_ERROR_P (result, err) \
&& ((oss.ss_flags & SS_ONSTACK) == 0 \
|| ((unsigned long) oss.ss_sp + oss.ss_size \
- (unsigned long) (sp)) < oss.ss_size)) \
__fortify_fail ("longjmp causes uninitialized stack frame"); \
} \
} while (0)
#include <__longjmp.c>