72 lines
3 KiB
Diff
72 lines
3 KiB
Diff
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From c86b726c048eddc1be320c0bf64a897658bee13d Mon Sep 17 00:00:00 2001
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From: Uros Bizjak <ubizjak@gmail.com>
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Date: Wed, 18 May 2022 20:03:26 +0200
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Subject: [PATCH] x86: Fix -fsplit-stack feature detection via
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TARGET_CAN_SPLIT_STACK
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Since commit c163647ffbc9a20c8feb6e079dbecccfe016c82e -fsplit-stack
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is only supported on glibc targets. However, this original commit
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required some fixups. As part of the fixup, the changes to the
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gnu-user-common.h and gnu.h were partially reverted in commit
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60953a23d57b13a672f751bec0c6eefc059eb1ab thus causing TARGET_CAN_SPLIT_STACK
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to be defined for non-glibc targets even though -fsplit-stack is
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actually not supported and attempting to use it causes a runtime error.
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This causes gcc internal code, such as ./gcc/go/gospec.c to not
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correctly detect that -fsplit-stack is not supported and thus causes
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gccgo to fail compilation on non-glibc targets.
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This commit ensures that TARGET_CAN_SPLIT_STACK is only set if the
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default libc is glibc. It is presently unclear to me if there is a
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better way to detect glibc at pre-processor time.
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The proposed changes have been tested on x86 and x86_64 Alpine Linux
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(which uses musl libc) and fix compilation of gccgo for this target.
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Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
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gcc/ChangeLog:
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* config/i386/gnu-user-common.h (defined): Only define
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TARGET_CAN_SPLIT_STACK for glibc targets.
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* config/i386/gnu.h (defined): Ditto.
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---
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gcc/config/i386/gnu-user-common.h | 5 +++--
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gcc/config/i386/gnu.h | 5 +++--
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2 files changed, 6 insertions(+), 4 deletions(-)
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diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h
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index 23b54c5be52..cab9be2bfb7 100644
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--- a/gcc/config/i386/gnu-user-common.h
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+++ b/gcc/config/i386/gnu-user-common.h
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@@ -66,7 +66,8 @@ along with GCC; see the file COPYING3. If not see
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#define STACK_CHECK_STATIC_BUILTIN 1
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/* We only build the -fsplit-stack support in libgcc if the
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- assembler has full support for the CFI directives. */
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-#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
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+ assembler has full support for the CFI directives. Also
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+ we only support -fsplit-stack on glibc targets. */
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+#if (DEFAULT_LIBC == LIBC_GLIBC) && HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
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#define TARGET_CAN_SPLIT_STACK
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#endif
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diff --git a/gcc/config/i386/gnu.h b/gcc/config/i386/gnu.h
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index 401e60c9a02..fb8d69a97d8 100644
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--- a/gcc/config/i386/gnu.h
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+++ b/gcc/config/i386/gnu.h
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@@ -41,8 +41,9 @@ along with GCC. If not, see <http://www.gnu.org/licenses/>.
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#define TARGET_THREAD_SSP_OFFSET 0x14
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/* We only build the -fsplit-stack support in libgcc if the
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- assembler has full support for the CFI directives. */
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-#if HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
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+ assembler has full support for the CFI directives. Also
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+ we only support -fsplit-stack on glibc targets. */
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+#if (DEFAULT_LIBC == LIBC_GLIBC) && HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
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#define TARGET_CAN_SPLIT_STACK
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#endif
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/* We steal the last transactional memory word. */
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