diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2025-08-01 03:10:07 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-08-01 04:23:53 +0300 |
| commit | f1befc82addda926c8301436123d041bf3249505 (patch) | |
| tree | a3162e0378828eeb67248d6061473e16566fdf8b /include/linux | |
| parent | 5ccaeedb489b41ce6cb857d0de488992746be282 (diff) | |
| download | linux-f1befc82addda926c8301436123d041bf3249505.tar.xz | |
cfi: Move BPF CFI types and helpers to generic code
Instead of duplicating the same code for each architecture, move
the CFI type hash variables for BPF function types and related
helper functions to generic CFI code, and allow architectures to
override the function definitions if needed.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20250801001004.1859976-7-samitolvanen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cfi.h | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/include/linux/cfi.h b/include/linux/cfi.h index 1db17ecbb86c..52a98886a455 100644 --- a/include/linux/cfi.h +++ b/include/linux/cfi.h @@ -11,16 +11,9 @@ #include <linux/module.h> #include <asm/cfi.h> +#ifdef CONFIG_CFI_CLANG extern bool cfi_warn; -#ifndef cfi_get_offset -static inline int cfi_get_offset(void) -{ - return 0; -} -#endif - -#ifdef CONFIG_CFI_CLANG enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr, unsigned long *target, u32 type); @@ -29,6 +22,44 @@ static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs, { return report_cfi_failure(regs, addr, NULL, 0); } + +#ifndef cfi_get_offset +/* + * Returns the CFI prefix offset. By default, the compiler emits only + * a 4-byte CFI type hash before the function. If an architecture + * uses -fpatchable-function-entry=N,M where M>0 to change the prefix + * offset, they must override this function. + */ +static inline int cfi_get_offset(void) +{ + return 4; +} +#endif + +#ifndef cfi_get_func_hash +static inline u32 cfi_get_func_hash(void *func) +{ + u32 hash; + + if (get_kernel_nofault(hash, func - cfi_get_offset())) + return 0; + + return hash; +} +#endif + +/* CFI type hashes for BPF function types */ +extern u32 cfi_bpf_hash; +extern u32 cfi_bpf_subprog_hash; + +#else /* CONFIG_CFI_CLANG */ + +static inline int cfi_get_offset(void) { return 0; } +static inline u32 cfi_get_func_hash(void *func) { return 0; } + +#define cfi_bpf_hash 0U +#define cfi_bpf_subprog_hash 0U + #endif /* CONFIG_CFI_CLANG */ #ifdef CONFIG_ARCH_USES_CFI_TRAPS |