glibc/sysdeps/mips/unwind-arch.h
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

75 lines
2.4 KiB
C

/* Dynamic loading of the libgcc unwinder. MIPS customization.
Copyright (C) 2020-2022 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 Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _ARCH_UNWIND_LINK_H
#define _ARCH_UNWIND_LINK_H
#include <stdint.h>
#include <sys/syscall.h>
#define UNWIND_LINK_GETIP 1
#define UNWIND_LINK_FRAME_STATE_FOR 1
#define UNWIND_LINK_FRAME_ADJUSTMENT 1
#define UNWIND_LINK_EXTRA_FIELDS
#define UNWIND_LINK_EXTRA_INIT
/* MIPS fallback code handle a frame where its FDE can not be obtained
(for instance a signal frame) by reading the kernel allocated signal frame
and adding '2' to the value of 'sc_pc' [1]. The added value is used to
recognize an end of an EH region on mips16 [2].
The idea here is to adjust the obtained signal frame ADDR value and remove
the libgcc added value by checking if the previous frame is a signal frame
one.
[1] libgcc/config/mips/linux-unwind.h from gcc code.
[2] gcc/config/mips/mips.h from gcc code. */
static inline void *
unwind_arch_adjustment (void *prev, void *addr)
{
uint32_t *pc = (uint32_t *) prev;
if (pc == NULL)
return addr;
/* For MIPS16 or microMIPS frame libgcc makes no adjustment. */
if ((uintptr_t) pc & 0x3)
return addr;
/* The vDSO containes either
24021061 li v0, 0x1061 (rt_sigreturn)
0000000c syscall
or
24021017 li v0, 0x1017 (sigreturn)
0000000c syscall */
if (pc[1] != 0x0000000c)
return addr;
#if _MIPS_SIM == _ABIO32
if (pc[0] == (0x24020000 | __NR_sigreturn))
return (void *) ((uintptr_t) addr - 2);
#endif
if (pc[0] == (0x24020000 | __NR_rt_sigreturn))
return (void *) ((uintptr_t) addr - 2);
return addr;
}
#endif /* _ARCH_UNWIND_LINK_H */