mirror of
https://github.com/tobast/libunwind-eh_elf.git
synced 2024-12-23 20:03:43 +01:00
29483327be
Currently setcontext for x86_64 restores the signal mask, even
though it is never saved anywhere. This means the signal mask
is often garbage after an unw_resume.
(changed in commit f8a15e9679
)
It looks like this was a fix for the Gtest-resume-sig function -
testing if signal masks are restored across signal frames. The
root issue looks like that x86_64 only uses sigreturn for the exact
signal frame, and not for any decedant frames as well (as i64 does).
Instead, modify Gresume to use sigreturn if *any* frame on the stack
is a signal frame, so that we correct fixup the signal mask and any
sigaltstacks. The sigreturn os-specific functions are changed slightly
to copy in the saved ucontext structure if we are jumping farther
up the stack.
This should fix sigprocmask reported issues such as
https://github.com/dropbox/pyston/blob/master/libunwind_patches/0002-pyston-stop-x86_64-setcontext-restoring-uninitialize.patch
Tests pass on freebsd, linux
192 lines
4.6 KiB
C
192 lines
4.6 KiB
C
/* libunwind - a platform-independent unwind library
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Copyright (C) 2003-2004 Hewlett-Packard Co
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Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
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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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/* Verify that unw_resume() restores the signal mask at proper time. */
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include "compiler.h"
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#include <libunwind.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#ifdef HAVE_IA64INTRIN_H
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# include <ia64intrin.h>
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#endif
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#define panic(args...) \
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do { fprintf (stderr, args); ++nerrors; } while (0)
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int verbose;
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int nerrors;
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int got_usr1, got_usr2;
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char *sigusr1_sp;
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uintptr_t
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get_bsp (void)
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{
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#if UNW_TARGET_IA64
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# ifdef __INTEL_COMPILER
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return __getReg (_IA64_REG_AR_BSP);
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# else
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return (uintptr_t) __builtin_ia64_bsp ();
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# endif
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#else
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return 0;
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#endif
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}
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#ifdef TEST_WITH_SIGINFO
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void
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handler (int sig,
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siginfo_t *si UNUSED,
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void *ucontext UNUSED)
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#else
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void
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handler (int sig)
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#endif
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{
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unw_word_t ip;
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sigset_t mask;
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unw_context_t uc;
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unw_cursor_t c;
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char foo;
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int ret;
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#if UNW_TARGET_IA64
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if (verbose)
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printf ("bsp = %llx\n", (unsigned long long) get_bsp ());
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#endif
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if (verbose)
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printf ("got signal %d\n", sig);
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if (sig == SIGUSR1)
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{
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++got_usr1;
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sigusr1_sp = &foo;
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sigemptyset (&mask);
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sigaddset (&mask, SIGUSR2);
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sigprocmask (SIG_BLOCK, &mask, NULL);
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kill (getpid (), SIGUSR2); /* pend SIGUSR2 */
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signal (SIGUSR1, SIG_IGN);
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if ((ret = unw_getcontext (&uc)) < 0)
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panic ("unw_getcontext() failed: ret=%d\n", ret);
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if ((ret = unw_init_local (&c, &uc)) < 0)
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panic ("unw_init_local() failed: ret=%d\n", ret);
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if ((ret = unw_step (&c)) < 0) /* step to signal trampoline */
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panic ("unw_step(1) failed: ret=%d\n", ret);
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if ((ret = unw_step (&c)) < 0) /* step to kill() */
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panic ("unw_step(2) failed: ret=%d\n", ret);
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#if defined(UNW_TARGET_TILEGX)
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if ((ret = unw_step (&c)) < 0) /* step to signal trampoline */
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panic ("unw_step(2) failed: ret=%d\n", ret);
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#endif
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if ((ret = unw_get_reg (&c, UNW_REG_IP, &ip)) < 0)
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panic ("unw_get_reg(IP) failed: ret=%d\n", ret);
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if (verbose)
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printf ("resuming at 0x%lx, with SIGUSR2 pending\n",
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(unsigned long) ip);
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unw_resume (&c);
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}
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else if (sig == SIGUSR2)
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{
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++got_usr2;
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if (got_usr1)
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{
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if (verbose)
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printf ("OK: stack still at %p\n", &foo);
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}
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signal (SIGUSR2, SIG_IGN);
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}
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else
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panic ("Got unexpected signal %d\n", sig);
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}
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int
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main (int argc, char **argv UNUSED)
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{
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struct sigaction sa;
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float d = 1.0;
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int n = 0;
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if (argc > 1)
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verbose = 1;
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memset (&sa, 0, sizeof(sa));
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#ifdef TEST_WITH_SIGINFO
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sa.sa_sigaction = handler;
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sa.sa_flags = SA_SIGINFO;
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#else
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sa.sa_handler = handler;
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#endif
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if (sigaction (SIGUSR1, &sa, NULL) != 0 ||
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sigaction (SIGUSR2, &sa, NULL) != 0)
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{
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fprintf (stderr, "sigaction() failed: %s\n", strerror (errno));
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return -1;
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}
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/* Use the FPU a bit; otherwise we get spurious errors should the
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signal handler need to use the FPU for any reason. This seems to
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happen on x86-64. */
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while (d > 0.0)
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{
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d /= 2.0;
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++n;
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}
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if (n > 9999)
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return -1; /* can't happen, but don't tell the compiler... */
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if (verbose)
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printf ("sending SIGUSR1\n");
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kill (getpid (), SIGUSR1);
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if (!got_usr2)
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panic ("failed to get SIGUSR2\n");
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if (nerrors)
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{
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fprintf (stderr, "FAILURE: detected %d errors\n", nerrors);
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exit (-1);
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}
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if (verbose)
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printf ("SUCCESS\n");
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return 0;
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}
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