Is it possible to recover from SEGV?

[Romain Tartière]

Hi Yuri,

On Sat, Oct 11, 2008 at 05:41:09PM -0700, Yuri wrote:
> Is there a way to access from signal handler CPU registers as they
> were before signal, modify some of them, clear the signal and
> continue from the instruction that caused SEGV initially?

Maybe you can have a look to the development version of the
Enlightenment window manager [1]. It catches segfaults and displayed a
window to ask the user what to do (continue, abort).  I experienced a
few crashes where this helpful window was triggered a dozen times, I
asked the window manager to continue and could save my work before
everything crashed.

First moves in the svn repository [2] (basically grep SEGV):
| ./src/bin/e_exec.c:456:	else if (cfdata->event.exit_signal == SIGSEGV)
| ./src/bin/e_desklock.c:689:	sigaction(SIGSEGV, &action, NULL);
| ./src/bin/e_object.c:153:	sigaction(SIGSEGV, &act, &oact);
| ./src/bin/e_object.c:158:	     sigaction(SIGSEGV, &oact, NULL);
| ./src/bin/e_object.c:168:	     sigaction(SIGSEGV, &oact, NULL);
| ./src/bin/e_signals.c:28:   e_alert_show("This is very bad. Enlightenment SEGV'd.\n"
| ./src/bin/e_signals.c:48:   e_alert_show("This is very bad. Enlightenment SEGV'd.\n"
| ./src/bin/e_main.c:99:   sigaction(SIGSEGV, &action, NULL);
| ./src/bin/e_main.c:322:// FIXME: SEGV's on shutdown if fm2 windows up - disable for now.

Hope that helps!
Romain

References:
  1. http://enlightenment.org/
  2. http://svn.enlightenment.org/svn/e/trunk/e/

-- 
Romain Tartière <romain at blogreen.org>        http://romain.blogreen.org/
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