From 4ea687132408a7c662706c4a7eb3c61b7773d735 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 21 Jan 2022 13:24:00 -0800 Subject: [PATCH] x86: Properly disable -fsplit-stack support on non-glibc targets Revert x86 changes in commit c163647ffbc9a20c8feb6e079dbecccfe016c82e Author: Soren Tempel Date: Fri Jan 21 19:22:46 2022 +0000 Disable -fsplit-stack support on non-glibc targets and change ix86_supports_split_stack to return true only on glibc. PR bootstrap/104170 * common/config/i386/i386-common.c (ix86_supports_split_stack): Return true only on glibc. * config/i386/gnu-user-common.h (STACK_CHECK_STATIC_BUILTIN): Revert commit c163647ffbc. * config/i386/gnu.h (TARGET_LIBC_PROVIDES_SSP): Likewise. --- gcc/common/config/i386/i386-common.c | 17 +++++++++++------ gcc/config/i386/gnu-user-common.h | 5 ++--- gcc/config/i386/gnu.h | 5 +---- 3 files changed, 14 insertions(+), 13 deletions(-) diff --git a/gcc/common/config/i386/i386-common.c b/gcc/common/config/i386/i386-common.c index 96549aa7d7e..a3b5258e828 100644 --- a/gcc/common/config/i386/i386-common.c +++ b/gcc/common/config/i386/i386-common.c @@ -1696,16 +1696,21 @@ ix86_option_init_struct (struct gcc_options *opts) field in the TCB, so they cannot be used together. */ static bool -ix86_supports_split_stack (bool report ATTRIBUTE_UNUSED, +ix86_supports_split_stack (bool report, struct gcc_options *opts ATTRIBUTE_UNUSED) { +#ifdef TARGET_THREAD_SPLIT_STACK_OFFSET + if (opts->x_linux_libc != LIBC_GLIBC) +#endif + { + if (report) + error ("%<-fsplit-stack%> currently only supported on GNU/Linux"); + return false; + } + bool ret = true; -#ifndef TARGET_THREAD_SPLIT_STACK_OFFSET - if (report) - error ("%<-fsplit-stack%> currently only supported on GNU/Linux"); - ret = false; -#else +#ifdef TARGET_THREAD_SPLIT_STACK_OFFSET if (!HAVE_GAS_CFI_PERSONALITY_DIRECTIVE) { if (report) diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h index 6e13315b5a3..00226f5a455 100644 --- a/gcc/config/i386/gnu-user-common.h +++ b/gcc/config/i386/gnu-user-common.h @@ -66,8 +66,7 @@ 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 and - targets glibc. */ -#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE && OPTION_GLIBC + assembler has full support for the CFI directives. */ +#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE #define TARGET_CAN_SPLIT_STACK #endif diff --git a/gcc/config/i386/gnu.h b/gcc/config/i386/gnu.h index afd3e8e8841..25fbc07f58c 100644 --- a/gcc/config/i386/gnu.h +++ b/gcc/config/i386/gnu.h @@ -35,10 +35,7 @@ along with GCC. If not, see . crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}" #endif -/* -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 +#ifdef TARGET_LIBC_PROVIDES_SSP /* i386 glibc provides __stack_chk_guard in %gs:0x14. */ #define TARGET_THREAD_SSP_OFFSET 0x14 -- 2.35.1