![Mark Rutland](/assets/img/avatar_default.png)
We currently set x27 in compat_sys_sigreturn_wrapper and compat_sys_rt_sigreturn_wrapper, similarly to what we do with r8/why on 32-bit ARM, in an attempt to prevent sigreturns from being restarted. However, on arm64 we have always used pt_regs::syscallno for syscall restarting (for both native and compat tasks), and x27 is never inspected again before being overwritten in kernel_exit. This patch removes the pointless register assignments. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
122 lines
3 KiB
ArmAsm
122 lines
3 KiB
ArmAsm
/*
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* Compat system call wrappers
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*
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* Copyright (C) 2012 ARM Ltd.
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* Authors: Will Deacon <will.deacon@arm.com>
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* 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/linkage.h>
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#include <linux/const.h>
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#include <asm/assembler.h>
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#include <asm/asm-offsets.h>
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#include <asm/errno.h>
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#include <asm/page.h>
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/*
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* System call wrappers for the AArch32 compatibility layer.
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*/
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ENTRY(compat_sys_sigreturn_wrapper)
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mov x0, sp
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b compat_sys_sigreturn
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ENDPROC(compat_sys_sigreturn_wrapper)
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ENTRY(compat_sys_rt_sigreturn_wrapper)
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mov x0, sp
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b compat_sys_rt_sigreturn
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ENDPROC(compat_sys_rt_sigreturn_wrapper)
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ENTRY(compat_sys_statfs64_wrapper)
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mov w3, #84
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cmp w1, #88
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csel w1, w3, w1, eq
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b compat_sys_statfs64
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ENDPROC(compat_sys_statfs64_wrapper)
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ENTRY(compat_sys_fstatfs64_wrapper)
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mov w3, #84
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cmp w1, #88
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csel w1, w3, w1, eq
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b compat_sys_fstatfs64
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ENDPROC(compat_sys_fstatfs64_wrapper)
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/*
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* Note: off_4k (w5) is always in units of 4K. If we can't do the
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* requested offset because it is not page-aligned, we return -EINVAL.
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*/
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ENTRY(compat_sys_mmap2_wrapper)
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#if PAGE_SHIFT > 12
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tst w5, #~PAGE_MASK >> 12
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b.ne 1f
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lsr w5, w5, #PAGE_SHIFT - 12
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#endif
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b sys_mmap_pgoff
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1: mov x0, #-EINVAL
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ret
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ENDPROC(compat_sys_mmap2_wrapper)
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/*
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* Wrappers for AArch32 syscalls that either take 64-bit parameters
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* in registers or that take 32-bit parameters which require sign
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* extension.
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*/
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ENTRY(compat_sys_pread64_wrapper)
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regs_to_64 x3, x4, x5
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b sys_pread64
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ENDPROC(compat_sys_pread64_wrapper)
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ENTRY(compat_sys_pwrite64_wrapper)
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regs_to_64 x3, x4, x5
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b sys_pwrite64
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ENDPROC(compat_sys_pwrite64_wrapper)
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ENTRY(compat_sys_truncate64_wrapper)
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regs_to_64 x1, x2, x3
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b sys_truncate
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ENDPROC(compat_sys_truncate64_wrapper)
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ENTRY(compat_sys_ftruncate64_wrapper)
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regs_to_64 x1, x2, x3
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b sys_ftruncate
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ENDPROC(compat_sys_ftruncate64_wrapper)
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ENTRY(compat_sys_readahead_wrapper)
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regs_to_64 x1, x2, x3
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mov w2, w4
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b sys_readahead
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ENDPROC(compat_sys_readahead_wrapper)
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ENTRY(compat_sys_fadvise64_64_wrapper)
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mov w6, w1
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regs_to_64 x1, x2, x3
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regs_to_64 x2, x4, x5
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mov w3, w6
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b sys_fadvise64_64
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ENDPROC(compat_sys_fadvise64_64_wrapper)
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ENTRY(compat_sys_sync_file_range2_wrapper)
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regs_to_64 x2, x2, x3
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regs_to_64 x3, x4, x5
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b sys_sync_file_range2
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ENDPROC(compat_sys_sync_file_range2_wrapper)
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ENTRY(compat_sys_fallocate_wrapper)
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regs_to_64 x2, x2, x3
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regs_to_64 x3, x4, x5
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b sys_fallocate
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ENDPROC(compat_sys_fallocate_wrapper)
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