Re: Bus error
Eric Blake <[email protected]>
| Newsgroups | gmane.comp.gnu.m4.patches,gmane.comp.gnu.m4.bugs |
|---|---|
| Message-ID | <[email protected]> |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 [dropping bug-gnulib, adding m4-patches] According to Bruno Haible on 12/6/2008 8:45 AM: > Eric Blake wrote: >> maybe swapping the order will help, where I install the >> SIGBUS handler first, and then c_stack_action can optionally install an >> alternate handler on platforms where it is needed for stack overflow? > > Yes, I was going to propose this too. I'm installing this on the stackovf branch (which I still need to merge into both branch-1.6 and master). I'm also debating whether to release m4 1.4.13 (it depends on how long it takes me to get m4 1.6 in nice shape); but if I do end up releasing 1.4.13, this patch is on the list for inclusion on branch-1.4. - -- Don't work too hard, make some time for fun as well! Eric Blake [email protected] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkk6vSkACgkQ84KuGfSFAYBDcgCeOXmBpVawBbrW71yG1xTUrSAd TTEAoM7ReoUIjGejRZBqMuuPWN8yNhar =ATor -----END PGP SIGNATURE----- _______________________________________________ M4-patches mailing list [email protected] http://lists.gnu.org/mailman/listinfo/m4-patches
m4.patch386
(text/plain, 2.5 KB)
From f66f95f60436fe3c8e805268338fbfb1087a385d Mon Sep 17 00:00:00 2001 From: Eric Blake <[email protected]> Date: Sat, 6 Dec 2008 10:53:22 -0700 Subject: [PATCH] Don't override signal handlers installed by c-stack. * src/m4.c (main): Reorder installation of signal handlers, so we don't trash a SIGBUS handler installed by c-stack. Also provide a SIGSEGV fallback, for platforms where c-stack combined with libsigsegv uses something lower level than SIGSEGV. Signed-off-by: Eric Blake <[email protected]> --- ChangeLog | 8 ++++++++ src/m4.c | 10 +++++++--- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index f13b710..0dab381 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,13 @@ 2008-12-06 Eric Blake <[email protected]> + Don't override signal handlers installed by c-stack. + * src/m4.c (main): Reorder installation of signal handlers, so we + don't trash a SIGBUS handler installed by c-stack. Also provide a + SIGSEGV fallback, for platforms where c-stack combined with + libsigsegv uses something lower level than SIGSEGV. + +2008-12-06 Eric Blake <[email protected]> + Upgrade to FDL 1.3, keep COPYING in repository. * Makefile.am (MAINTAINERCLEANFILES): Don't remove COPYING. * .cvsignore: Don't ignore it. diff --git a/src/m4.c b/src/m4.c index a24f82d..6031797 100644 --- a/src/m4.c +++ b/src/m4.c @@ -466,9 +466,10 @@ main (int argc, char *const *argv, char *const *envp) /* Stack overflow and program error handling. Ignore failure to install a handler, since this is merely for improved output on - crash, and we should never crash ;). */ - if (c_stack_action (fault_handler) == 0) - nesting_limit = 0; + crash, and we should never crash ;). We install SIGBUS and + SIGSEGV handlers prior to using the c-stack module; depending on + the platform, c-stack will then override none, SIGSEGV, or both + handlers. */ program_error_message = xasprintf (_("internal error detected; please report this bug to <%s>"), PACKAGE_BUGREPORT); @@ -483,10 +484,13 @@ main (int argc, char *const *argv, char *const *envp) to default signal behavior. */ act.sa_flags = SA_NODEFER | SA_RESETHAND; act.sa_handler = fault_handler; + sigaction (SIGSEGV, &act, NULL); sigaction (SIGABRT, &act, NULL); sigaction (SIGILL, &act, NULL); sigaction (SIGFPE, &act, NULL); sigaction (SIGBUS, &act, NULL); + if (c_stack_action (fault_handler) == 0) + nesting_limit = 0; #ifdef DEBUG_STKOVF /* Make it easier to test our fault handlers. Exporting M4_CRASH=0 -- 1.6.0.4