From 9afa888ce0f816d0f2cfc95eebe4f49244c518af Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 3 Oct 2023 10:15:49 +0100 Subject: [PATCH] osdep: set _FORTIFY_SOURCE=2 when optimization is enabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently we set _FORTIFY_SOURCE=2 as a compiler argument when the meson 'optimization' setting is non-zero, the compiler is GCC and the target is Linux. While the default QEMU optimization level is 2, user could override this by setting CFLAGS="-O0" or --extra-cflags="-O0" when running configure and this won't be reflected in the meson 'optimization' setting. As a result we try to enable _FORTIFY_SOURCE=2 and then the user gets compile errors as it only works with optimization. Rather than trying to improve detection in meson, it is simpler to just check the __OPTIMIZE__ define from osdep.h. The comment about being incompatible with clang appears to be outdated, as compilation works fine without excluding clang. In the coroutine code we must set _FORTIFY_SOURCE=0 to stop the logic in osdep.h then enabling it. Signed-off-by: Daniel P. Berrangé Message-id: 20231003091549.223020-1-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- include/qemu/osdep.h | 4 ++++ meson.build | 10 ---------- util/coroutine-sigaltstack.c | 4 ++-- util/coroutine-ucontext.c | 4 ++-- 4 files changed, 8 insertions(+), 14 deletions(-) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 18b940db75..475a1c62ff 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -27,6 +27,10 @@ #ifndef QEMU_OSDEP_H #define QEMU_OSDEP_H +#if !defined _FORTIFY_SOURCE && defined __OPTIMIZE__ && __OPTIMIZE__ && defined __linux__ +# define _FORTIFY_SOURCE 2 +#endif + #include "config-host.h" #ifdef NEED_CPU_H #include CONFIG_TARGET diff --git a/meson.build b/meson.build index 21a1bc03f8..20ceeb8158 100644 --- a/meson.build +++ b/meson.build @@ -479,16 +479,6 @@ if 'cpp' in all_languages qemu_cxxflags = ['-D__STDC_LIMIT_MACROS', '-D__STDC_CONSTANT_MACROS', '-D__STDC_FORMAT_MACROS'] + qemu_cflags endif -# clang does not support glibc + FORTIFY_SOURCE (is it still true?) -if get_option('optimization') != '0' and targetos == 'linux' - if cc.get_id() == 'gcc' - qemu_cflags += ['-U_FORTIFY_SOURCE', '-D_FORTIFY_SOURCE=2'] - endif - if 'cpp' in all_languages and cxx.get_id() == 'gcc' - qemu_cxxflags += ['-U_FORTIFY_SOURCE', '-D_FORTIFY_SOURCE=2'] - endif -endif - add_project_arguments(qemu_cflags, native: false, language: 'c') add_project_arguments(cc.get_supported_arguments(warn_flags), native: false, language: 'c') if 'cpp' in all_languages diff --git a/util/coroutine-sigaltstack.c b/util/coroutine-sigaltstack.c index e2690c5f41..037d6416c4 100644 --- a/util/coroutine-sigaltstack.c +++ b/util/coroutine-sigaltstack.c @@ -22,9 +22,9 @@ */ /* XXX Is there a nicer way to disable glibc's stack check for longjmp? */ -#ifdef _FORTIFY_SOURCE #undef _FORTIFY_SOURCE -#endif +#define _FORTIFY_SOURCE 0 + #include "qemu/osdep.h" #include #include "qemu/coroutine_int.h" diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c index ddc98fb4f8..7b304c79d9 100644 --- a/util/coroutine-ucontext.c +++ b/util/coroutine-ucontext.c @@ -19,9 +19,9 @@ */ /* XXX Is there a nicer way to disable glibc's stack check for longjmp? */ -#ifdef _FORTIFY_SOURCE #undef _FORTIFY_SOURCE -#endif +#define _FORTIFY_SOURCE 0 + #include "qemu/osdep.h" #include #include "qemu/coroutine_int.h"