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linux/arch/arm64/lib/copy_from_user.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 normalized pattern(s): 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 you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 07:44:50 +02:00
/* SPDX-License-Identifier: GPL-2.0-only */
arm64: User access library functions This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:32 +00:00
/*
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/linkage.h>
arm64: kernel: Add support for Privileged Access Never 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-22 19:05:54 +01:00
arm64: don't pull uaccess.h into *.S Split asm-only parts of arm64 uaccess.h into a new header and use that from *.S. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-26 04:10:19 -05:00
#include <asm/asm-uaccess.h>
arm64: uaccess: use asm EXPORT_SYMBOL() For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the uaccess exports to the assembly files the functions are defined in. As we have to include <asm/assembler.h>, the existing includes are fixed to follow the usual ordering conventions. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-07 18:08:20 +00:00
#include <asm/assembler.h>
#include <asm/cache.h>
arm64: User access library functions This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:32 +00:00
/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
*
* Parameters:
* x0 - to
* x1 - from
* x2 - n
* Returns:
* x0 - bytes not copied
*/
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro ldrb1 reg, ptr, val
arm64: uaccess cleanup macro naming Now the uaccess primitives use LDTR/STTR unconditionally, the uao_{ldp,stp,user_alternative} asm macros are misnamed, and have a redundant argument. Let's remove the redundant argument and rename these to user_{ldp,stp,ldst} respectively to clean this up. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Robin Murohy <robin.murphy@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201202131558.39270-9-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-02 13:15:54 +00:00
user_ldst 9998f, ldtrb, \reg, \ptr, \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro strb1 reg, ptr, val
strb \reg, [\ptr], \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro ldrh1 reg, ptr, val
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
user_ldst 9997f, ldtrh, \reg, \ptr, \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro strh1 reg, ptr, val
strh \reg, [\ptr], \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro ldr1 reg, ptr, val
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
user_ldst 9997f, ldtr, \reg, \ptr, \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro str1 reg, ptr, val
str \reg, [\ptr], \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro ldp1 reg1, reg2, ptr, val
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
user_ldp 9997f, \reg1, \reg2, \ptr, \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
arm64: Reorder the macro arguments in the copy routines The current argument order is obviously buggy (memcpy.S): macro strb1 ptr, regB, val strb \ptr, [\regB], \val endm However, it cancels out as the calling sites in copy_template.S pass the address as the regB argument. Mechanically reorder the arguments to match the instruction mnemonics. There is no difference in objdump before and after this patch. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200429183702.28445-1-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-04-29 19:37:02 +01:00
.macro stp1 reg1, reg2, ptr, val
stp \reg1, \reg2, [\ptr], \val
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
.endm
end .req x5
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
srcin .req x15
arm64: lib: Use modern annotations for assembly functions In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC and also add a new annotation for static functions which previously had no ENTRY equivalent. Update the annotations in the library code to the new macros. Signed-off-by: Mark Brown <broonie@kernel.org> [will: Use SYM_FUNC_START_WEAK_PI] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-06 19:58:17 +00:00
SYM_FUNC_START(__arch_copy_from_user)
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
add end, x0, x2
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
mov srcin, x1
arm64: copy_to-from-in_user optimization using copy template This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-09-23 11:55:39 -07:00
#include "copy_template.S"
mov x0, #0 // Nothing to copy
arm64: User access library functions This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:32 +00:00
ret
arm64: lib: Use modern annotations for assembly functions In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC and also add a new annotation for static functions which previously had no ENTRY equivalent. Update the annotations in the library code to the new macros. Signed-off-by: Mark Brown <broonie@kernel.org> [will: Use SYM_FUNC_START_WEAK_PI] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-06 19:58:17 +00:00
SYM_FUNC_END(__arch_copy_from_user)
arm64: uaccess: use asm EXPORT_SYMBOL() For a while now it's been possible to use EXPORT_SYMBOL() in assembly files, which allows us to place exports immediately after assembly functions, as we do for C functions. As a step towards removing arm64ksyms.c, let's move the uaccess exports to the assembly files the functions are defined in. As we have to include <asm/assembler.h>, the existing includes are fixed to follow the usual ordering conventions. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-07 18:08:20 +00:00
EXPORT_SYMBOL(__arch_copy_from_user)
arm64: User access library functions This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:32 +00:00
.section .fixup,"ax"
.align 2
arm64: Avoid premature usercopy failure Al reminds us that the usercopy API must only return complete failure if absolutely nothing could be copied. Currently, if userspace does something silly like giving us an unaligned pointer to Device memory, or a size which overruns MTE tag bounds, we may fail to honour that requirement when faulting on a multi-byte access even though a smaller access could have succeeded. Add a mitigation to the fixup routines to fall back to a single-byte copy if we faulted on a larger access before anything has been written to the destination, to guarantee making *some* forward progress. We needn't be too concerned about the overall performance since this should only occur when callers are doing something a bit dodgy in the first place. Particularly broken userspace might still be able to trick generic_perform_write() into an infinite loop by targeting write() at an mmap() of some read-only device register where the fault-in load succeeds but any store synchronously aborts such that copy_to_user() is genuinely unable to make progress, but, well, don't do that... CC: stable@vger.kernel.org Reported-by: Chen Huang <chenhuang5@huawei.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/dc03d5c675731a1f24a62417dba5429ad744234e.1626098433.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-07-12 15:27:46 +01:00
9997: cmp dst, dstin
b.ne 9998f
// Before being absolutely sure we couldn't copy anything, try harder
USER(9998f, ldtrb tmp1w, [srcin])
strb tmp1w, [dst], #1
arm64: don't zero in __copy_from_user{,_inatomic} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-10 16:50:00 -04:00
9998: sub x0, end, dst // bytes not copied
arm64: User access library functions This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:32 +00:00
ret
.previous
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