[v8,05/20] aarch64: Add GCS support to vfork

Message ID	20250114160328.2031684-6-yury.khrustalev@arm.com
State	New
Headers	show Return-Path: <libc-alpha-bounces~incoming=patchwork.ozlabs.org@sourceware.org> DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 50A913856259 From: Yury Khrustalev <yury.khrustalev@arm.com> To: libc-alpha@sourceware.org Cc: fweimer@redhat.com, adhemerval.zanella@linaro.org, codonell@redhat.com, nsz@gcc.gnu.org, schwab@suse.de, wilco.dijkstra@arm.com Subject: [PATCH v8 05/20] aarch64: Add GCS support to vfork Date: Tue, 14 Jan 2025 16:03:13 +0000 Message-Id: <20250114160328.2031684-6-yury.khrustalev@arm.com> In-Reply-To: <20250114160328.2031684-1-yury.khrustalev@arm.com> References: <20250114160328.2031684-1-yury.khrustalev@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: list Errors-To: libc-alpha-bounces~incoming=patchwork.ozlabs.org@sourceware.org
Series	aarch64: Add support for Guarded Control Stack extension \| expand [v8,00/20] aarch64: Add support for Guarded Control Stack extension [v8,01/20] aarch64: Add asm helpers for GCS [v8,02/20] elf.h: Define GNU_PROPERTY_AARCH64_FEATURE_1_GCS [v8,03/20] aarch64: Define jmp_buf offset for GCS [v8,04/20] aarch64: Add GCS support to longjmp [v8,05/20] aarch64: Add GCS support to vfork [v8,06/20] aarch64: Add GCS support for setcontext [v8,07/20] aarch64: Mark swapcontext with indirect_return [v8,08/20] aarch64: Add GCS support for makecontext [v8,09/20] aarch64: Add glibc.cpu.aarch64_gcs tunable [v8,10/20] aarch64: Enable GCS in static linked exe [v8,11/20] aarch64: Enable GCS in dynamic linked exe [v8,12/20] aarch64: Mark objects with GCS property note [v8,13/20] aarch64: Add glibc.cpu.aarch64_gcs_policy tunable [v8,14/20] aarch64: Use l_searchlist.r_list for bti [v8,15/20] aarch64: Handle GCS marking [v8,16/20] aarch64: Ignore GCS property of ld.so [v8,17/20] aarch64: Process gnu properties in static exe [v8,18/20] aarch64: Add GCS user-space allocation logic [v8,19/20] aarch64: Use __alloc_gcs in makecontext [v8,20/20] aarch64: Fix tests not compatible with targets supporting GCS

Message ID

20250114160328.2031684-6-yury.khrustalev@arm.com

State

New

Headers

DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 50A913856259
From: Yury Khrustalev <yury.khrustalev@arm.com>
To: libc-alpha@sourceware.org
Cc: fweimer@redhat.com, adhemerval.zanella@linaro.org, codonell@redhat.com,
 nsz@gcc.gnu.org, schwab@suse.de, wilco.dijkstra@arm.com
Subject: [PATCH v8 05/20] aarch64: Add GCS support to vfork
Date: Tue, 14 Jan 2025 16:03:13 +0000
Message-Id: <20250114160328.2031684-6-yury.khrustalev@arm.com>
In-Reply-To: <20250114160328.2031684-1-yury.khrustalev@arm.com>
References: <20250114160328.2031684-1-yury.khrustalev@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: list
Errors-To: libc-alpha-bounces~incoming=patchwork.ozlabs.org@sourceware.org

Series

aarch64: Add support for Guarded Control Stack extension | expand

Commit Message

Yury Khrustalev Jan. 14, 2025, 4:03 p.m. UTC

From: Szabolcs Nagy <szabolcs.nagy@arm.com>

Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
---
 sysdeps/unix/sysv/linux/aarch64/vfork.S | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sysdeps/unix/sysv/linux/aarch64/vfork.S b/sysdeps/unix/sysv/linux/aarch64/vfork.S
index 27618567f1..d5943a7485 100644
--- a/sysdeps/unix/sysv/linux/aarch64/vfork.S
+++ b/sysdeps/unix/sysv/linux/aarch64/vfork.S
@@ -33,8 +33,13 @@  ENTRY (__vfork)
 
 	cmn	x0, #4095
 	b.cs    .Lsyscall_error
+	cbz	x0, L(child)
 	RET
-
+L(child):
+	/* Return with indirect branch in the child to support GCS.
+	   Compilers insert BTI instruction after vfork() to make
+	   sure return via BR works on systems with BTI.  */
+	br	x30
 PSEUDO_END (__vfork)
 libc_hidden_def (__vfork)

[v8,05/20] aarch64: Add GCS support to vfork

Commit Message

Patch