From: Andy Lutomirski <luto@amacapital.net>
To: "musl@lists.openwall.com" <musl@lists.openwall.com>
Subject: _Unwind_Backtrace crashes
Date: Thu, 27 Aug 2015 11:55:24 -0700 [thread overview]
Message-ID: <CALCETrV9y=DN4TyKo7H-FrH0JD+xUze9H9fqkeHdxAo+3vivHw@mail.gmail.com> (raw)
This works on glibc. It aborts on musl on i386 using the latest git version.
I suspect it's because whatever calls main isn't properly annotated,
but I don't know how to debug this without rebuilding gcc, which is
kind of a mess.
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unwind.h>
#include <err.h>
#include <string.h>
static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
int flags)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = handler;
sa.sa_flags = SA_SIGINFO | flags;
sigemptyset(&sa.sa_mask);
if (sigaction(sig, &sa, 0))
err(1, "sigaction");
}
_Unwind_Reason_Code trace_fn(struct _Unwind_Context * ctx, void *opaque)
{
return _URC_NO_REASON;
}
static void sigusr1(int sig, siginfo_t *info, void *ctx_void)
{
printf("In signal handler. Trying to unwind.\n");
_Unwind_Backtrace(trace_fn, 0);
}
int main()
{
printf("Unwind directly\n");
_Unwind_Backtrace(trace_fn, 0);
printf("Unwind from signal handler\n");
sethandler(SIGUSR1, sigusr1, 0);
raise(SIGUSR1);
printf("OK\n");
}
--
Andy Lutomirski
AMA Capital Management, LLC
next reply other threads:[~2015-08-27 18:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-27 18:55 Andy Lutomirski [this message]
2015-08-27 19:14 ` Rich Felker
2015-08-27 20:00 ` Szabolcs Nagy
2015-08-28 13:21 ` Alexander Monakov
2015-08-28 14:16 ` Szabolcs Nagy
2015-08-28 14:46 ` Alexander Monakov
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