From: Bernd Schubert <bschubert@ddn.com>
Date: Wed, 20 Mar 2024 10:33:46 +0000 (+0100)
Subject: Add glibc backtrace to signal handler
X-Git-Tag: fuse-3.17.1-rc0~144^2~2
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e48c71d445f8b5557f45974eb0fcf5130b1e7b20;p=qemu-gpiodev%2Flibfuse.git

Add glibc backtrace to signal handler

It is very hard to see in github tests what is actually failing
with signals - add the gnu-libc backtrace handler.
---

diff --git a/lib/fuse_signals.c b/lib/fuse_signals.c
index 048d047..4c1d172 100644
--- a/lib/fuse_signals.c
+++ b/lib/fuse_signals.c
@@ -16,15 +16,30 @@
 #include <string.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <execinfo.h>
 
 static struct fuse_session *fuse_instance;
 
+static void dump_stack(void)
+{
+#ifdef HAVE_BACKTRACE
+	const size_t backtrace_sz = 1024 * 1024;
+	void* backtrace_buffer[backtrace_sz];
+
+	int err_fd = fileno(stderr);
+
+	int trace_len = backtrace(backtrace_buffer, backtrace_sz);
+	backtrace_symbols_fd(backtrace_buffer, trace_len, err_fd);
+#endif
+}
+
 static void exit_handler(int sig)
 {
 	if (fuse_instance) {
 		fuse_session_exit(fuse_instance);
 		if(sig <= 0) {
 			fuse_log(FUSE_LOG_ERR, "assertion error: signal value <= 0\n");
+			dump_stack();
 			abort();
 		}
 		fuse_instance->error = sig;
diff --git a/meson.build b/meson.build
index 7d62dcf..7d8db7f 100644
--- a/meson.build
+++ b/meson.build
@@ -61,6 +61,8 @@ private_cfg.set('HAVE_SETXATTR',
         cc.has_function('setxattr', prefix: '#include <sys/xattr.h>'))
 private_cfg.set('HAVE_ICONV', 
         cc.has_function('iconv', prefix: '#include <iconv.h>'))
+private_cfg.set('HAVE_BACKTRACE',
+        cc.has_function('backtrace', prefix: '#include <execinfo.h>'))
 
 # Test if structs have specific member
 private_cfg.set('HAVE_STRUCT_STAT_ST_ATIM',