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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/arm64/kernel/reloc_test_syms.S

86 строки
1.4 KiB
ArmAsm
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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 Based on 2 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 11:11:33 +03:00
/* SPDX-License-Identifier: GPL-2.0-only */
arm64: relocation testing module This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-31 10:55:33 +03:00
/*
* Copyright (C) 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
*/
#include <linux/linkage.h>
ENTRY(absolute_data64)
ldr x0, 0f
ret
0: .quad sym64_abs
ENDPROC(absolute_data64)
ENTRY(absolute_data32)
ldr w0, 0f
ret
0: .long sym32_abs
ENDPROC(absolute_data32)
ENTRY(absolute_data16)
adr x0, 0f
ldrh w0, [x0]
ret
0: .short sym16_abs, 0
ENDPROC(absolute_data16)
ENTRY(signed_movw)
movz x0, #:abs_g2_s:sym64_abs
movk x0, #:abs_g1_nc:sym64_abs
movk x0, #:abs_g0_nc:sym64_abs
ret
ENDPROC(signed_movw)
ENTRY(unsigned_movw)
movz x0, #:abs_g3:sym64_abs
movk x0, #:abs_g2_nc:sym64_abs
movk x0, #:abs_g1_nc:sym64_abs
movk x0, #:abs_g0_nc:sym64_abs
ret
ENDPROC(unsigned_movw)
arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419 Working around Cortex-A53 erratum #843419 involves special handling of ADRP instructions that end up in the last two instruction slots of a 4k page, or whose output register gets overwritten without having been read. (Note that the latter instruction sequence is never emitted by a properly functioning compiler, which is why it is disregarded by the handling of the same erratum in the bfd.ld linker which we rely on for the core kernel) Normally, this gets taken care of by the linker, which can spot such sequences at final link time, and insert a veneer if the ADRP ends up at a vulnerable offset. However, linux kernel modules are partially linked ELF objects, and so there is no 'final link time' other than the runtime loading of the module, at which time all the static relocations are resolved. For this reason, we have implemented the #843419 workaround for modules by avoiding ADRP instructions altogether, by using the large C model, and by passing -mpc-relative-literal-loads to recent versions of GCC that may emit adrp/ldr pairs to perform literal loads. However, this workaround forces us to keep literal data mixed with the instructions in the executable .text segment, and literal data may inadvertently turn into an exploitable speculative gadget depending on the relative offsets of arbitrary symbols. So let's reimplement this workaround in a way that allows us to switch back to the small C model, and to drop the -mpc-relative-literal-loads GCC switch, by patching affected ADRP instructions at runtime: - ADRP instructions that do not appear at 4k relative offset 0xff8 or 0xffc are ignored - ADRP instructions that are within 1 MB of their target symbol are converted into ADR instructions - remaining ADRP instructions are redirected via a veneer that performs the load using an unaffected movn/movk sequence. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: tidied up ADRP -> ADR instruction patching.] [will: use ULL suffix for 64-bit immediate] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 20:15:33 +03:00
.align 12
.space 0xff8
arm64: relocation testing module This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-31 10:55:33 +03:00
ENTRY(relative_adrp)
adrp x0, sym64_rel
add x0, x0, #:lo12:sym64_rel
ret
ENDPROC(relative_adrp)
arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419 Working around Cortex-A53 erratum #843419 involves special handling of ADRP instructions that end up in the last two instruction slots of a 4k page, or whose output register gets overwritten without having been read. (Note that the latter instruction sequence is never emitted by a properly functioning compiler, which is why it is disregarded by the handling of the same erratum in the bfd.ld linker which we rely on for the core kernel) Normally, this gets taken care of by the linker, which can spot such sequences at final link time, and insert a veneer if the ADRP ends up at a vulnerable offset. However, linux kernel modules are partially linked ELF objects, and so there is no 'final link time' other than the runtime loading of the module, at which time all the static relocations are resolved. For this reason, we have implemented the #843419 workaround for modules by avoiding ADRP instructions altogether, by using the large C model, and by passing -mpc-relative-literal-loads to recent versions of GCC that may emit adrp/ldr pairs to perform literal loads. However, this workaround forces us to keep literal data mixed with the instructions in the executable .text segment, and literal data may inadvertently turn into an exploitable speculative gadget depending on the relative offsets of arbitrary symbols. So let's reimplement this workaround in a way that allows us to switch back to the small C model, and to drop the -mpc-relative-literal-loads GCC switch, by patching affected ADRP instructions at runtime: - ADRP instructions that do not appear at 4k relative offset 0xff8 or 0xffc are ignored - ADRP instructions that are within 1 MB of their target symbol are converted into ADR instructions - remaining ADRP instructions are redirected via a veneer that performs the load using an unaffected movn/movk sequence. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: tidied up ADRP -> ADR instruction patching.] [will: use ULL suffix for 64-bit immediate] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 20:15:33 +03:00
.align 12
.space 0xffc
ENTRY(relative_adrp_far)
arm64: fix undefined reference to 'printk' The printk symbol was intended as a generic address that is always exported, however that turned out to be false with CONFIG_PRINTK=n: ERROR: "printk" [arch/arm64/kernel/arm64-reloc-test.ko] undefined! This changes the references to memstart_addr, which should be there regardless of configuration. Fixes: a257e02579e4 ("arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419") Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-13 14:41:41 +03:00
adrp x0, memstart_addr
add x0, x0, #:lo12:memstart_addr
arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419 Working around Cortex-A53 erratum #843419 involves special handling of ADRP instructions that end up in the last two instruction slots of a 4k page, or whose output register gets overwritten without having been read. (Note that the latter instruction sequence is never emitted by a properly functioning compiler, which is why it is disregarded by the handling of the same erratum in the bfd.ld linker which we rely on for the core kernel) Normally, this gets taken care of by the linker, which can spot such sequences at final link time, and insert a veneer if the ADRP ends up at a vulnerable offset. However, linux kernel modules are partially linked ELF objects, and so there is no 'final link time' other than the runtime loading of the module, at which time all the static relocations are resolved. For this reason, we have implemented the #843419 workaround for modules by avoiding ADRP instructions altogether, by using the large C model, and by passing -mpc-relative-literal-loads to recent versions of GCC that may emit adrp/ldr pairs to perform literal loads. However, this workaround forces us to keep literal data mixed with the instructions in the executable .text segment, and literal data may inadvertently turn into an exploitable speculative gadget depending on the relative offsets of arbitrary symbols. So let's reimplement this workaround in a way that allows us to switch back to the small C model, and to drop the -mpc-relative-literal-loads GCC switch, by patching affected ADRP instructions at runtime: - ADRP instructions that do not appear at 4k relative offset 0xff8 or 0xffc are ignored - ADRP instructions that are within 1 MB of their target symbol are converted into ADR instructions - remaining ADRP instructions are redirected via a veneer that performs the load using an unaffected movn/movk sequence. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: tidied up ADRP -> ADR instruction patching.] [will: use ULL suffix for 64-bit immediate] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 20:15:33 +03:00
ret
ENDPROC(relative_adrp_far)
arm64: relocation testing module This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-31 10:55:33 +03:00
ENTRY(relative_adr)
adr x0, sym64_rel
ret
ENDPROC(relative_adr)
ENTRY(relative_data64)
adr x1, 0f
ldr x0, [x1]
add x0, x0, x1
ret
0: .quad sym64_rel - .
ENDPROC(relative_data64)
ENTRY(relative_data32)
adr x1, 0f
ldr w0, [x1]
add x0, x0, x1
ret
0: .long sym64_rel - .
ENDPROC(relative_data32)
ENTRY(relative_data16)
adr x1, 0f
ldrsh w0, [x1]
add x0, x0, x1
ret
0: .short sym64_rel - ., 0
ENDPROC(relative_data16)