ARM: signal: sigreturn_codes should be endian neutral to work in BE8 (574e2b51) · Commits · 戴 / test

arch/arm/kernel/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -17,7 +17,8 @@ CFLAGS_REMOVE_return_address.o = -pg

		obj-y := elf.o entry-common.o irq.o opcodes.o \
		process.o ptrace.o return_address.o \
		setup.o signal.o stacktrace.o sys_arm.o time.o traps.o
		setup.o signal.o sigreturn_codes.o \
		stacktrace.o sys_arm.o time.o traps.o

		obj-$(CONFIG_ATAGS) += atags_parse.o
		obj-$(CONFIG_ATAGS_PROC) += atags_proc.o

arch/arm/kernel/signal.c

+1 −23

Original line number	Diff line number	Diff line
		@@ -21,29 +21,7 @@
		#include <asm/unistd.h>
		#include <asm/vfp.h>

		/*
		* For ARM syscalls, we encode the syscall number into the instruction.
		*/
		#define SWI_SYS_SIGRETURN (0xef000000\|(__NR_sigreturn)\|(__NR_OABI_SYSCALL_BASE))
		#define SWI_SYS_RT_SIGRETURN (0xef000000\|(__NR_rt_sigreturn)\|(__NR_OABI_SYSCALL_BASE))

		/*
		* With EABI, the syscall number has to be loaded into r7.
		*/
		#define MOV_R7_NR_SIGRETURN (0xe3a07000 \| (__NR_sigreturn - __NR_SYSCALL_BASE))
		#define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 \| (__NR_rt_sigreturn - __NR_SYSCALL_BASE))

		/*
		* For Thumb syscalls, we pass the syscall number via r7. We therefore
		* need two 16-bit instructions.
		*/
		#define SWI_THUMB_SIGRETURN (0xdf00 << 16 \| 0x2700 \| (__NR_sigreturn - __NR_SYSCALL_BASE))
		#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 \| 0x2700 \| (__NR_rt_sigreturn - __NR_SYSCALL_BASE))

		static const unsigned long sigreturn_codes[7] = {
		MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
		MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
		};
		extern const unsigned long sigreturn_codes[7];

		static unsigned long signal_return_offset;

arch/arm/kernel/sigreturn_codes.S

0 → 100644

+80 −0

Original line number	Diff line number	Diff line
		/*
		* sigreturn_codes.S - code sinpets for sigreturn syscalls
		*
		* Created by: Victor Kamensky, 2013-08-13
		* Copyright: (C) 2013 Linaro Limited
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 as
		* published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*/

		#include <asm/unistd.h>

		/*
		* For ARM syscalls, we encode the syscall number into the instruction.
		* With EABI, the syscall number has to be loaded into r7. As result
		* ARM syscall sequence snippet will have move and svc in .arm encoding
		*
		* For Thumb syscalls, we pass the syscall number via r7. We therefore
		* need two 16-bit instructions in .thumb encoding
		*
		* Please note sigreturn_codes code are not executed in place. Instead
		* they just copied by kernel into appropriate places. Code inside of
		* arch/arm/kernel/signal.c is very sensitive to layout of these code
		* snippets.
		*/

		#if __LINUX_ARM_ARCH__ <= 4
		/*
		* Note we manually set minimally required arch that supports
		* required thumb opcodes for early arch versions. It is OK
		* for this file to be used in combination with other
		* lower arch variants, since these code snippets are only
		* used as input data.
		*/
		.arch armv4t
		#endif

		.section .rodata
		.global sigreturn_codes
		.type sigreturn_codes, #object

		.arm

		sigreturn_codes:

		/* ARM sigreturn syscall code snippet */
		mov r7, #(__NR_sigreturn - __NR_SYSCALL_BASE)
		swi #(__NR_sigreturn)\|(__NR_OABI_SYSCALL_BASE)

		/* Thumb sigreturn syscall code snippet */
		.thumb
		movs r7, #(__NR_sigreturn - __NR_SYSCALL_BASE)
		swi #0

		/* ARM sigreturn_rt syscall code snippet */
		.arm
		mov r7, #(__NR_rt_sigreturn - __NR_SYSCALL_BASE)
		swi #(__NR_rt_sigreturn)\|(__NR_OABI_SYSCALL_BASE)

		/* Thumb sigreturn_rt syscall code snippet */
		.thumb
		movs r7, #(__NR_rt_sigreturn - __NR_SYSCALL_BASE)
		swi #0

		/*
		* Note on addtional space: setup_return in signal.c
		* algorithm uses two words copy regardless whether
		* it is thumb case or not, so we need additional
		* word after real last entry.
		*/
		.arm
		.space 4

		.size sigreturn_codes, . - sigreturn_codes

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