Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
cfi: add C CFI type macro
Currently x86 and riscv open-code 4 instances of the same logic to
define a u32 variable with the KCFI typeid of a given function.
Replace the duplicate logic with a common macro.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Co-developed-by: Maxwell Bland <mbland@motorola.com>
Signed-off-by: Maxwell Bland <mbland@motorola.com>
Co-developed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Dao Huang <huangdao1@oppo.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250801001004.1859976-6-samitolvanen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
authored by
Mark Rutland
and committed by
Alexei Starovoitov
5ccaeedb
13cb7573
+29
-60
+3
-32
arch/riscv/kernel/cfi.c
+3
-32
arch/riscv/kernel/cfi.c
···
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*
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* Copyright (C) 2023 Google LLC
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*/
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#include <linux/cfi_types.h>
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#include <linux/cfi.h>
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#include <asm/insn.h>
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···
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/* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
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extern unsigned int __bpf_prog_runX(const void *ctx,
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const struct bpf_insn *insn);
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/*
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* Force a reference to the external symbol so the compiler generates
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* __kcfi_typid.
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*/
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__ADDRESSABLE(__bpf_prog_runX);
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/* u32 __ro_after_init cfi_bpf_hash = __kcfi_typeid___bpf_prog_runX; */
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asm (
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" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
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" .type cfi_bpf_hash,@object \n"
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" .globl cfi_bpf_hash \n"
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" .p2align 2, 0x0 \n"
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"cfi_bpf_hash: \n"
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" .word __kcfi_typeid___bpf_prog_runX \n"
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" .size cfi_bpf_hash, 4 \n"
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" .popsection \n"
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);
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DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
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/* Must match bpf_callback_t */
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extern u64 __bpf_callback_fn(u64, u64, u64, u64, u64);
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__ADDRESSABLE(__bpf_callback_fn);
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/* u32 __ro_after_init cfi_bpf_subprog_hash = __kcfi_typeid___bpf_callback_fn; */
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asm (
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" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
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" .type cfi_bpf_subprog_hash,@object \n"
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" .globl cfi_bpf_subprog_hash \n"
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" .p2align 2, 0x0 \n"
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"cfi_bpf_subprog_hash: \n"
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" .word __kcfi_typeid___bpf_callback_fn \n"
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" .size cfi_bpf_subprog_hash, 4 \n"
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" .popsection \n"
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);
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DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
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u32 cfi_get_func_hash(void *func)
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{
+3
-28
arch/x86/kernel/alternative.c
+3
-28
arch/x86/kernel/alternative.c
···
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#define pr_fmt(fmt) "SMP alternatives: " fmt
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#include <linux/mmu_context.h>
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#include <linux/cfi_types.h>
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#include <linux/perf_event.h>
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#include <linux/vmalloc.h>
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#include <linux/memory.h>
···
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/* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
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extern unsigned int __bpf_prog_runX(const void *ctx,
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const struct bpf_insn *insn);
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KCFI_REFERENCE(__bpf_prog_runX);
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/* u32 __ro_after_init cfi_bpf_hash = __kcfi_typeid___bpf_prog_runX; */
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asm (
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" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
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" .type cfi_bpf_hash,@object \n"
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" .globl cfi_bpf_hash \n"
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" .p2align 2, 0x0 \n"
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"cfi_bpf_hash: \n"
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" .long __kcfi_typeid___bpf_prog_runX \n"
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" .size cfi_bpf_hash, 4 \n"
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" .popsection \n"
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);
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DEFINE_CFI_TYPE(cfi_bpf_hash, __bpf_prog_runX);
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/* Must match bpf_callback_t */
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extern u64 __bpf_callback_fn(u64, u64, u64, u64, u64);
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KCFI_REFERENCE(__bpf_callback_fn);
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/* u32 __ro_after_init cfi_bpf_subprog_hash = __kcfi_typeid___bpf_callback_fn; */
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asm (
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" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
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" .type cfi_bpf_subprog_hash,@object \n"
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" .globl cfi_bpf_subprog_hash \n"
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" .p2align 2, 0x0 \n"
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"cfi_bpf_subprog_hash: \n"
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" .long __kcfi_typeid___bpf_callback_fn \n"
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" .size cfi_bpf_subprog_hash, 4 \n"
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" .popsection \n"
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);
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DEFINE_CFI_TYPE(cfi_bpf_subprog_hash, __bpf_callback_fn);
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u32 cfi_get_func_hash(void *func)
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{
+23
include/linux/cfi_types.h
+23
include/linux/cfi_types.h
···
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SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
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#endif
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#else /* __ASSEMBLY__ */
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#ifdef CONFIG_CFI_CLANG
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#define DEFINE_CFI_TYPE(name, func) \
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/* \
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* Force a reference to the function so the compiler generates \
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* __kcfi_typeid_<func>. \
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*/ \
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__ADDRESSABLE(func); \
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/* u32 name __ro_after_init = __kcfi_typeid_<func> */ \
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extern u32 name; \
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asm ( \
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" .pushsection .data..ro_after_init,\"aw\",\%progbits \n" \
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" .type " #name ",\%object \n" \
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" .globl " #name " \n" \
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" .p2align 2, 0x0 \n" \
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#name ": \n" \
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" .4byte __kcfi_typeid_" #func " \n" \
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" .size " #name ", 4 \n" \
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" .popsection \n" \
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);
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#endif
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#endif /* __ASSEMBLY__ */
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#endif /* _LINUX_CFI_TYPES_H */