From e7b451941b92e2bdbb9c08bb4283c9a39d5571c6 Mon Sep 17 00:00:00 2001
From: Rob Norris <rob.norris@klarasystems.com>
Date: Fri, 10 May 2024 10:19:48 +1000
Subject: [PATCH] zdb/ztest: use libspl backtrace for crashes

We can show much nicer backtraces these days, lets use them.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16181
---
 cmd/zdb/zdb.c               | 12 +-----------
 cmd/ztest.c                 | 12 +-----------
 lib/libspl/assert.c         |  9 ++++++---
 lib/libspl/include/assert.h |  2 ++
 4 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index f3274a65d..908e4e0ab 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -85,9 +85,6 @@
 #include <sys/brt_impl.h>
 #include <zfs_comutil.h>
 #include <sys/zstd/zstd.h>
-#if (__GLIBC__ && !__UCLIBC__)
-#include <execinfo.h> /* for backtrace() */
-#endif
 
 #include <libnvpair.h>
 #include <libzutil.h>
@@ -843,18 +840,11 @@ dump_debug_buffer(void)
 	zfs_dbgmsg_print("zdb");
 }
 
-#define	BACKTRACE_SZ	100
-
 static void sig_handler(int signo)
 {
 	struct sigaction action;
-#if (__GLIBC__ && !__UCLIBC__) /* backtrace() is a GNU extension */
-	int nptrs;
-	void *buffer[BACKTRACE_SZ];
 
-	nptrs = backtrace(buffer, BACKTRACE_SZ);
-	backtrace_symbols_fd(buffer, nptrs, STDERR_FILENO);
-#endif
+	libspl_dump_backtrace();
 	dump_debug_buffer();
 
 	/*
diff --git a/cmd/ztest.c b/cmd/ztest.c
index 56eb01618..ccfe71c29 100644
--- a/cmd/ztest.c
+++ b/cmd/ztest.c
@@ -136,9 +136,6 @@
 #include <libzutil.h>
 #include <sys/crypto/icp.h>
 #include <sys/zfs_impl.h>
-#if (__GLIBC__ && !__UCLIBC__)
-#include <execinfo.h> /* for backtrace() */
-#endif
 
 static int ztest_fd_data = -1;
 static int ztest_fd_rand = -1;
@@ -621,18 +618,11 @@ dump_debug_buffer(void)
 	zfs_dbgmsg_print("ztest");
 }
 
-#define	BACKTRACE_SZ	100
-
 static void sig_handler(int signo)
 {
 	struct sigaction action;
-#if (__GLIBC__ && !__UCLIBC__) /* backtrace() is a GNU extension */
-	int nptrs;
-	void *buffer[BACKTRACE_SZ];
 
-	nptrs = backtrace(buffer, BACKTRACE_SZ);
-	backtrace_symbols_fd(buffer, nptrs, STDERR_FILENO);
-#endif
+	libspl_dump_backtrace();
 	dump_debug_buffer();
 
 	/*
diff --git a/lib/libspl/assert.c b/lib/libspl/assert.c
index 5b12c14ac..79b640d89 100644
--- a/lib/libspl/assert.c
+++ b/lib/libspl/assert.c
@@ -55,7 +55,7 @@
 #define	UNW_LOCAL_ONLY
 #include <libunwind.h>
 
-static inline void
+void
 libspl_dump_backtrace(void)
 {
 	unw_context_t uc;
@@ -85,7 +85,7 @@ libspl_dump_backtrace(void)
 #elif defined(HAVE_BACKTRACE)
 #include <execinfo.h>
 
-static inline void
+void
 libspl_dump_backtrace(void)
 {
 	void *btptrs[100];
@@ -97,7 +97,10 @@ libspl_dump_backtrace(void)
 	free(bt);
 }
 #else
-#define	libspl_dump_backtrace()
+void
+libspl_dump_backtrace(void)
+{
+}
 #endif
 
 #if defined(__APPLE__)
diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index 155bbab30..126f2db24 100644
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -60,6 +60,8 @@ libspl_assert(const char *buf, const char *file, const char *func, int line)
 	return (0);
 }
 
+extern void libspl_dump_backtrace(void);
+
 #ifdef verify
 #undef verify
 #endif