3085e1645e
The arm64 sigreturn* syscall handlers are non-standard. Rather than taking a number of user parameters in registers as per the AAPCS, they expect the pt_regs as their sole argument. To make this work, we override the syscall definitions to invoke wrappers written in assembly, which mov the SP into x0, and branch to their respective C functions. On other architectures (such as x86), the sigreturn* functions take no argument and instead use current_pt_regs() to acquire the user registers. This requires less boilerplate code, and allows for other features such as interposing C code in this path. This patch takes the same approach for arm64. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tentatively-reviewed-by: Dave Martin <dave.martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
/*
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* AArch64-specific system calls implementation
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Catalin Marinas <catalin.marinas@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/syscalls.h>
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#include <asm/cpufeature.h>
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asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
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unsigned long prot, unsigned long flags,
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unsigned long fd, off_t off)
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{
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if (offset_in_page(off) != 0)
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return -EINVAL;
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return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
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}
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SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
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{
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if (personality(personality) == PER_LINUX32 &&
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!system_supports_32bit_el0())
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return -EINVAL;
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return sys_personality(personality);
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}
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/*
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* Wrappers to pass the pt_regs argument.
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*/
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asmlinkage long sys_rt_sigreturn(void);
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#define sys_personality sys_arm64_personality
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#undef __SYSCALL
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#define __SYSCALL(nr, sym) [nr] = sym,
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/*
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* The sys_call_table array must be 4K aligned to be accessible from
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* kernel/entry.S.
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*/
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void * const sys_call_table[__NR_syscalls] __aligned(4096) = {
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[0 ... __NR_syscalls - 1] = sys_ni_syscall,
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#include <asm/unistd.h>
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};
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