mirror of
https://github.com/tobast/libunwind-eh_elf.git
synced 2024-11-16 21:27:38 +01:00
795529eee3
This improves the performance of Lperf-simple from 500ns to 195ns on the avg. Signed-off-by: Arun Sharma <arun.sharma@google.com>
69 lines
2.2 KiB
C
69 lines
2.2 KiB
C
/* libunwind - a platform-independent unwind library
|
|
Copyright (C) 2002-2003 Hewlett-Packard Co
|
|
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
|
|
|
|
Modified for x86_64 by Max Asbock <masbock@us.ibm.com>
|
|
|
|
This file is part of libunwind.
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
|
a copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so, subject to
|
|
the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be
|
|
included in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
|
|
|
#include "unwind_i.h"
|
|
|
|
#ifdef __linux__
|
|
PROTECTED int
|
|
unw_is_signal_frame (unw_cursor_t *cursor)
|
|
{
|
|
struct cursor *c = (struct cursor *) cursor;
|
|
unw_word_t w0, w1, ip;
|
|
unw_addr_space_t as;
|
|
unw_accessors_t *a;
|
|
void *arg;
|
|
int ret;
|
|
|
|
as = c->dwarf.as;
|
|
a = unw_get_accessors (as);
|
|
as->validate = 1; /* Don't trust the ip */
|
|
arg = c->dwarf.as_arg;
|
|
|
|
/* Check if RIP points at sigreturn sequence.
|
|
on x86_64 Linux that is (see libc.so):
|
|
48 c7 c0 0f 00 00 00 mov $0xf,%rax
|
|
0f 05 syscall
|
|
66 data16
|
|
*/
|
|
|
|
ip = c->dwarf.ip;
|
|
if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0
|
|
|| (ret = (*a->access_mem) (as, ip + 8, &w1, 0, arg)) < 0)
|
|
return 0;
|
|
w1 &= 0xffffffff;
|
|
return (w0 == 0x0f0000000fc0c748 && w1 == 0x66666605);
|
|
}
|
|
|
|
#else /* __linux__ */
|
|
|
|
PROTECTED int
|
|
unw_is_signal_frame (unw_cursor_t *cursor)
|
|
{
|
|
printf ("%s: implement me\n", __FUNCTION__);
|
|
return -UNW_ENOINFO;
|
|
}
|
|
#endif /* __linux__ */
|