From: Guillaume Solignac <gsoligna@cisco.com>
Date: Thu, 23 May 2024 09:59:53 +0000 (+0200)
Subject: vppinfra: support libunwind for backtrace
X-Git-Tag: v25.02-rc0~241
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F21%2F40921%2F2;p=vpp.git

vppinfra: support libunwind for backtrace

On non-glibc systems, execinfo is the only option available, but the lib
is old and can crash when unwinding. We now can use libunwind to unroll
it instead of using execinfo.h.

Type: improvement
Signed-off-by: Guillaume Solignac <gsoligna@cisco.com>
Change-Id: I8b55f7aca97261a2efb5dca998889d5e0645939a
---

diff --git a/src/vppinfra/CMakeLists.txt b/src/vppinfra/CMakeLists.txt
index 154e3a77cb1..a8c64a36121 100644
--- a/src/vppinfra/CMakeLists.txt
+++ b/src/vppinfra/CMakeLists.txt
@@ -234,9 +234,13 @@ if("${CMAKE_SYSTEM_NAME}" STREQUAL "FreeBSD")
 else()
   option(VPP_USE_EXTERNAL_LIBEXECINFO "Use external libexecinfo (useful for non-glibc targets)." OFF)
 endif()
+option(VPP_USE_LIBUNWIND "Use libunwind for backtrace." OFF)
 
 if(VPP_USE_EXTERNAL_LIBEXECINFO)
   set(EXECINFO_LIB execinfo)
+elseif(VPP_USE_LIBUNWIND)
+  set(EXECINFO_LIB unwind)
+  add_compile_definitions(USE_LIBUNWIND)
 endif()
 add_vpp_library(vppinfra
   SOURCES ${VPPINFRA_SRCS}
diff --git a/src/vppinfra/backtrace.c b/src/vppinfra/backtrace.c
index e713bae6876..bae563d04b0 100644
--- a/src/vppinfra/backtrace.c
+++ b/src/vppinfra/backtrace.c
@@ -219,8 +219,17 @@ backtrace_done:
 #ifndef clib_backtrace_defined
 #define clib_backtrace_defined
 
+#ifndef USE_LIBUNWIND
 /* use glibc backtrace for stack trace */
 #include <execinfo.h>
+#else
+#include <libunwind.h>
+static int
+backtrace (void **buffer, int size)
+{
+  return unw_backtrace (buffer, size);
+}
+#endif
 
 __clib_export uword
 clib_backtrace (uword * callers, uword max_callers, uword n_frames_to_skip)