e6f3b3c9c1
Clang 14 added support for the __builtin_function_start function,
which allows us to implement the function_nocfi macro without
architecture-specific inline assembly and in a way that also works
with static initializers.
Change CONFIG_CFI_CLANG to depend on Clang >= 14, define
function_nocfi using __builtin_function_start, and remove the arm64
inline assembly implementation.
Link: ec2e26eaf6
Link: https://github.com/ClangBuiltLinux/linux/issues/1353
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will@kernel.org> # arm64
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220405221618.633743-1-samitolvanen@google.com
27 lines
850 B
C
27 lines
850 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_COMPILER_H
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#define __ASM_COMPILER_H
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#ifdef ARM64_ASM_ARCH
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#define ARM64_ASM_PREAMBLE ".arch " ARM64_ASM_ARCH "\n"
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#else
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#define ARM64_ASM_PREAMBLE
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#endif
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/*
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* The EL0/EL1 pointer bits used by a pointer authentication code.
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* This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply.
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*/
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#define ptrauth_user_pac_mask() GENMASK_ULL(54, vabits_actual)
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#define ptrauth_kernel_pac_mask() GENMASK_ULL(63, vabits_actual)
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/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */
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#define ptrauth_clear_pac(ptr) \
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((ptr & BIT_ULL(55)) ? (ptr | ptrauth_kernel_pac_mask()) : \
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(ptr & ~ptrauth_user_pac_mask()))
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#define __builtin_return_address(val) \
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(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))
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#endif /* __ASM_COMPILER_H */
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