2007-08-02 17:59:43 +02:00
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/* libunwind - a platform-independent unwind library
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Copyright (C) 2006-2007 IBM
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Contributed by
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Corey Ashford <cjashfor@us.ibm.com>
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Jose Flavio Aguilar Paulino <jflavio@br.ibm.com> <joseflavio@gmail.com>
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This file is part of libunwind.
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Permission is hereby granted, free of charge, to any person obtaining
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a copy of this software and associated documentation files (the
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"Software"), to deal in the Software without restriction, including
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without limitation the rights to use, copy, modify, merge, publish,
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distribute, sublicense, and/or sell copies of the Software, and to
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permit persons to whom the Software is furnished to do so, subject to
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the following conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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2007-09-13 05:52:25 +02:00
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#include <libunwind_i.h>
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2007-08-02 17:59:43 +02:00
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PROTECTED int
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unw_is_signal_frame (unw_cursor_t * cursor)
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{
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struct cursor *c = (struct cursor *) cursor;
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unw_word_t w0, w1, ip;
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unw_addr_space_t as;
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unw_accessors_t *a;
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void *arg;
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int ret;
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as = c->dwarf.as;
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as->validate = 1; /* Don't trust the ip */
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arg = c->dwarf.as_arg;
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/* Check if return address points at sigreturn sequence.
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on ppc64 Linux that is (see libc.so):
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0x38210080 addi r1, r1, 128 // pop the stack
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0x380000ac li r0, 172 // invoke system service 172
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0x44000002 sc
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*/
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ip = c->dwarf.ip;
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if (ip == 0)
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return 0;
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/* Read up two 8-byte words at the IP. We are only looking at 3
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consecutive 32-bit words, so the second 8-byte word needs to be
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shifted right by 32 bits (think big-endian) */
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a = unw_get_accessors (as);
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if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0
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|| (ret = (*a->access_mem) (as, ip + 8, &w1, 0, arg)) < 0)
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return 0;
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w1 >>= 32;
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return (w0 == 0x38210080380000ac && w1 == 0x44000002);
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}
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