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authorVincenzo Frascino <vincenzo.frascino@arm.com>2019-06-21 10:52:37 +0100
committerThomas Gleixner <tglx@linutronix.de>2019-06-22 21:21:08 +0200
commita7f71a2c8903f8599312f75233946287c558d9f6 (patch)
tree5461a5b76b05685bd53ab621b087b1a65635b184 /arch/arm64/kernel/vdso32/sigreturn.S
parentf14d8025d263f3c8236775df724a7c1f14e0dc94 (diff)
arm64: compat: Add vDSO
Provide the arm64 compat (AArch32) vDSO in kernel/vdso32 in a similar way to what happens in kernel/vdso. The compat vDSO leverages on an adaptation of the arm architecture code with few changes: - Use of lib/vdso for gettimeofday - Implement a syscall based fallback - Introduce clock_getres() for the compat library - Implement trampolines - Implement elf note To build the compat vDSO a 32 bit compiler is required and needs to be specified via CONFIG_CROSS_COMPILE_COMPAT_VDSO. The code is not yet enabled as other prerequisites are missing. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-11-vincenzo.frascino@arm.com
Diffstat (limited to 'arch/arm64/kernel/vdso32/sigreturn.S')
-rw-r--r--arch/arm64/kernel/vdso32/sigreturn.S62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/arm64/kernel/vdso32/sigreturn.S b/arch/arm64/kernel/vdso32/sigreturn.S
new file mode 100644
index 000000000000..1a81277c2d09
--- /dev/null
+++ b/arch/arm64/kernel/vdso32/sigreturn.S
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file provides both A32 and T32 versions, in accordance with the
+ * arm sigreturn code.
+ *
+ * Copyright (C) 2018 ARM Limited
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+#define ARM_ENTRY(name) \
+ ENTRY(name)
+
+#define ARM_ENDPROC(name) \
+ .type name, %function; \
+ END(name)
+
+ .text
+
+ .arm
+ .fnstart
+ .save {r0-r15}
+ .pad #COMPAT_SIGFRAME_REGS_OFFSET
+ nop
+ARM_ENTRY(__kernel_sigreturn_arm)
+ mov r7, #__NR_compat_sigreturn
+ svc #0
+ .fnend
+ARM_ENDPROC(__kernel_sigreturn_arm)
+
+ .fnstart
+ .save {r0-r15}
+ .pad #COMPAT_RT_SIGFRAME_REGS_OFFSET
+ nop
+ARM_ENTRY(__kernel_rt_sigreturn_arm)
+ mov r7, #__NR_compat_rt_sigreturn
+ svc #0
+ .fnend
+ARM_ENDPROC(__kernel_rt_sigreturn_arm)
+
+ .thumb
+ .fnstart
+ .save {r0-r15}
+ .pad #COMPAT_SIGFRAME_REGS_OFFSET
+ nop
+ARM_ENTRY(__kernel_sigreturn_thumb)
+ mov r7, #__NR_compat_sigreturn
+ svc #0
+ .fnend
+ARM_ENDPROC(__kernel_sigreturn_thumb)
+
+ .fnstart
+ .save {r0-r15}
+ .pad #COMPAT_RT_SIGFRAME_REGS_OFFSET
+ nop
+ARM_ENTRY(__kernel_rt_sigreturn_thumb)
+ mov r7, #__NR_compat_rt_sigreturn
+ svc #0
+ .fnend
+ARM_ENDPROC(__kernel_rt_sigreturn_thumb)