diff options
Diffstat (limited to 'main/gcc/0046-Disable-fsplit-stack-support-on-non-glibc-targets.patch')
-rw-r--r-- | main/gcc/0046-Disable-fsplit-stack-support-on-non-glibc-targets.patch | 115 |
1 files changed, 0 insertions, 115 deletions
diff --git a/main/gcc/0046-Disable-fsplit-stack-support-on-non-glibc-targets.patch b/main/gcc/0046-Disable-fsplit-stack-support-on-non-glibc-targets.patch deleted file mode 100644 index ffd7ab045a0..00000000000 --- a/main/gcc/0046-Disable-fsplit-stack-support-on-non-glibc-targets.patch +++ /dev/null @@ -1,115 +0,0 @@ -From 2c6bf28619c9b3bf713f7f5319c5d750a6c297ae Mon Sep 17 00:00:00 2001 -From: =?UTF-8?q?S=C3=B6ren=20Tempel?= <soeren@soeren-tempel.net> -Date: Fri, 21 Jan 2022 19:22:46 +0000 -Subject: [PATCH] Disable -fsplit-stack support on non-glibc targets -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -The -fsplit-stack option requires the pthread_t TCB definition in the -libc to provide certain struct fields at specific hardcoded offsets. As -far as I know, only glibc provides these fields at the required offsets. -Most notably, musl libc does not have these fields. However, since gcc -accesses the fields using a fixed offset, this does not cause a -compile-time error, but instead results in a silent memory corruption at -run-time with musl libc. For example, on s390x libgcc's -__stack_split_initialize CTOR will overwrite the cancel field in the -pthread_t TCB on musl. - -The -fsplit-stack option is used within the gcc code base itself by -gcc-go (if available). On musl-based systems with split-stack support -(i.e. s390x or x86) this causes Go programs compiled with gcc-go to -misbehave at run-time. - -This patch fixes gcc-go on musl by disabling -fsplit-stack in gcc itself -since it is not supported on non-glibc targets anyhow. This is achieved -by checking if gcc targets a glibc-based system. This check has been -added for x86 and s390x, the rs6000 config already checks for -TARGET_GLIBC_MAJOR. Other architectures do not have split-stack -support. With this patch applied, the gcc-go configure script will -detect that -fsplit-stack support is not available and will not use it. - -See https://www.openwall.com/lists/musl/2012/10/16/12 - -This patch was written under the assumption that glibc is the only libc -implementation which supports the required fields at the required -offsets in the pthread_t TCB. The patch has been tested on Alpine Linux -Edge on the s390x and x86 architectures by bootstrapping Google's Go -implementation with gcc-go. - -Signed-off-by: Sören Tempel <soeren@soeren-tempel.net> - -gcc/ChangeLog: - - * common/config/s390/s390-common.c (s390_supports_split_stack): - Only support split-stack on glibc targets. - * config/i386/gnu-user-common.h (STACK_CHECK_STATIC_BUILTIN): Ditto. - * config/i386/gnu.h (defined): Ditto. ---- - gcc/common/config/s390/s390-common.c | 14 ++++++++++---- - gcc/config/i386/gnu-user-common.h | 5 +++-- - gcc/config/i386/gnu.h | 5 ++++- - 3 files changed, 17 insertions(+), 7 deletions(-) - -diff --git a/gcc/common/config/s390/s390-common.c b/gcc/common/config/s390/s390-common.c -index b6bc8501742..8c1e590322d 100644 ---- a/gcc/common/config/s390/s390-common.c -+++ b/gcc/common/config/s390/s390-common.c -@@ -116,13 +116,19 @@ s390_handle_option (struct gcc_options *opts ATTRIBUTE_UNUSED, - - /* -fsplit-stack uses a field in the TCB, available with glibc-2.23. - We don't verify it, since earlier versions just have padding at -- its place, which works just as well. */ -+ its place, which works just as well. For other libc implementations -+ we disable the feature entirely to avoid corrupting the TCB. */ - - static bool --s390_supports_split_stack (bool report ATTRIBUTE_UNUSED, -- struct gcc_options *opts ATTRIBUTE_UNUSED) -+s390_supports_split_stack (bool report, -+ struct gcc_options *opts) - { -- return true; -+ if (opts->x_linux_libc == LIBC_GLIBC) -+ return true; -+ -+ if (report) -+ error ("%<-fsplit-stack%> currently only supported on GNU/Linux"); -+ return false; - } - - #undef TARGET_DEFAULT_TARGET_FLAGS -diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h -index 00226f5a455..6e13315b5a3 100644 ---- a/gcc/config/i386/gnu-user-common.h -+++ b/gcc/config/i386/gnu-user-common.h -@@ -66,7 +66,8 @@ along with GCC; see the file COPYING3. If not see - #define STACK_CHECK_STATIC_BUILTIN 1 - - /* We only build the -fsplit-stack support in libgcc if the -- assembler has full support for the CFI directives. */ --#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE -+ assembler has full support for the CFI directives and -+ targets glibc. */ -+#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE && OPTION_GLIBC - #define TARGET_CAN_SPLIT_STACK - #endif -diff --git a/gcc/config/i386/gnu.h b/gcc/config/i386/gnu.h -index 25fbc07f58c..afd3e8e8841 100644 ---- a/gcc/config/i386/gnu.h -+++ b/gcc/config/i386/gnu.h -@@ -35,7 +35,10 @@ along with GCC. If not, see <http://www.gnu.org/licenses/>. - crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}" - #endif - --#ifdef TARGET_LIBC_PROVIDES_SSP -+/* -fsplit-stack uses a field in the TCB at a fixed offset. This -+ field is only available for glibc. Disable -fsplit-stack for -+ other libc implementations to avoid silent TCB corruptions. */ -+#if defined (TARGET_LIBC_PROVIDES_SSP) && OPTION_GLIBC - - /* i386 glibc provides __stack_chk_guard in %gs:0x14. */ - #define TARGET_THREAD_SSP_OFFSET 0x14 --- -2.35.1 - |