diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/lib/bpf/bpf_helpers.h | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index 963b1060d944..d37c4fe2849d 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -22,12 +22,25 @@ * To allow use of SEC() with externs (e.g., for extern .maps declarations), * make sure __attribute__((unused)) doesn't trigger compilation warning. */ +#if __GNUC__ && !__clang__ + +/* + * Pragma macros are broken on GCC + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55578 + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90400 + */ +#define SEC(name) __attribute__((section(name), used)) + +#else + #define SEC(name) \ _Pragma("GCC diagnostic push") \ _Pragma("GCC diagnostic ignored \"-Wignored-attributes\"") \ __attribute__((section(name), used)) \ _Pragma("GCC diagnostic pop") \ +#endif + /* Avoid 'linux/stddef.h' definition of '__always_inline'. */ #undef __always_inline #define __always_inline inline __attribute__((always_inline)) @@ -76,6 +89,30 @@ #endif /* + * Compiler (optimization) barrier. + */ +#ifndef barrier +#define barrier() asm volatile("" ::: "memory") +#endif + +/* Variable-specific compiler (optimization) barrier. It's a no-op which makes + * compiler believe that there is some black box modification of a given + * variable and thus prevents compiler from making extra assumption about its + * value and potential simplifications and optimizations on this variable. + * + * E.g., compiler might often delay or even omit 32-bit to 64-bit casting of + * a variable, making some code patterns unverifiable. Putting barrier_var() + * in place will ensure that cast is performed before the barrier_var() + * invocation, because compiler has to pessimistically assume that embedded + * asm section might perform some extra operations on that variable. + * + * This is a variable-specific variant of more global barrier(). + */ +#ifndef barrier_var +#define barrier_var(var) asm volatile("" : "=r"(var) : "0"(var)) +#endif + +/* * Helper macro to throw a compilation error if __bpf_unreachable() gets * built into the resulting code. This works given BPF back end does not * implement __builtin_trap(). This is useful to assert that certain paths @@ -123,18 +160,6 @@ bpf_tail_call_static(void *ctx, const void *map, const __u32 slot) } #endif -/* - * Helper structure used by eBPF C program - * to describe BPF map attributes to libbpf loader - */ -struct bpf_map_def { - unsigned int type; - unsigned int key_size; - unsigned int value_size; - unsigned int max_entries; - unsigned int map_flags; -}; - enum libbpf_pin_type { LIBBPF_PIN_NONE, /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */ @@ -149,6 +174,8 @@ enum libbpf_tristate { #define __kconfig __attribute__((section(".kconfig"))) #define __ksym __attribute__((section(".ksyms"))) +#define __kptr __attribute__((btf_type_tag("kptr"))) +#define __kptr_ref __attribute__((btf_type_tag("kptr_ref"))) #ifndef ___bpf_concat #define ___bpf_concat(a, b) a ## b |