7bc9b9d25b
With non-canonical CFI, the compiler rewrites function references to point to the CFI jump table for indirect call checking. This won't happen when the address is taken in assembly, and will result in a CFI failure if we jump to the address later in C code. This change adds the __cficanonical attribute, which tells the compiler to switch to a canonical jump table for the function. With canonical CFI, the compiler appends a .cfi postfix to the function name, and points the original symbol to the jump table. This allows addresses taken in assembly code to be used for indirect calls without tripping CFI checks. Bug: 145210207 Change-Id: Iaca9d1d95f59d7169168d89bc10bf71420487a67 Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
71 lines
2.2 KiB
C
71 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_COMPILER_TYPES_H
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#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
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#endif
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#define CLANG_VERSION (__clang_major__ * 10000 \
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+ __clang_minor__ * 100 \
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+ __clang_patchlevel__)
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#if CLANG_VERSION < 100001
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#ifndef __BPF_TRACING__
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# error Sorry, your version of Clang is too old - please use 10.0.1 or newer.
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#endif
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#endif
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/* Compiler specific definitions for Clang compiler */
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/* same as gcc, this was present in clang-2.6 so we can assume it works
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* with any version that can compile the kernel
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*/
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#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
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/* all clang versions usable with the kernel support KASAN ABI version 5 */
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#define KASAN_ABI_VERSION 5
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#if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
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/* Emulate GCC's __SANITIZE_ADDRESS__ flag */
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#define __SANITIZE_ADDRESS__
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#define __no_sanitize_address \
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__attribute__((no_sanitize("address", "hwaddress")))
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#else
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#define __no_sanitize_address
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#endif
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#if __has_feature(thread_sanitizer)
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/* emulate gcc's __SANITIZE_THREAD__ flag */
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#define __SANITIZE_THREAD__
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#define __no_sanitize_thread \
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__attribute__((no_sanitize("thread")))
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#else
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#define __no_sanitize_thread
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#endif
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#if __has_feature(undefined_behavior_sanitizer)
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/* GCC does not have __SANITIZE_UNDEFINED__ */
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#define __no_sanitize_undefined \
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__attribute__((no_sanitize("undefined")))
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#else
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#define __no_sanitize_undefined
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#endif
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/*
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* Not all versions of clang implement the type-generic versions
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* of the builtin overflow checkers. Fortunately, clang implements
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* __has_builtin allowing us to avoid awkward version
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* checks. Unfortunately, we don't know which version of gcc clang
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* pretends to be, so the macro may or may not be defined.
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*/
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#if __has_builtin(__builtin_mul_overflow) && \
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__has_builtin(__builtin_add_overflow) && \
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__has_builtin(__builtin_sub_overflow)
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#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
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#endif
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#if __has_feature(shadow_call_stack)
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# define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
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#endif
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#define __nocfi __attribute__((__no_sanitize__("cfi")))
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#define __cficanonical __attribute__((__cfi_canonical_jump_table__))
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