diff options
Diffstat (limited to 'tools/lib/bpf/bpf_core_read.h')
| -rw-r--r-- | tools/lib/bpf/bpf_core_read.h | 169 |
1 files changed, 130 insertions, 39 deletions
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index bbcefb3ff5a5..53b3e199fb25 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -195,17 +195,22 @@ enum bpf_enum_value_kind { * (local) BTF, used to record relocation. */ #define bpf_core_read(dst, sz, src) \ - bpf_probe_read_kernel(dst, sz, \ - (const void *)__builtin_preserve_access_index(src)) + bpf_probe_read_kernel(dst, sz, (const void *)__builtin_preserve_access_index(src)) +/* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */ +#define bpf_core_read_user(dst, sz, src) \ + bpf_probe_read_user(dst, sz, (const void *)__builtin_preserve_access_index(src)) /* * bpf_core_read_str() is a thin wrapper around bpf_probe_read_str() * additionally emitting BPF CO-RE field relocation for specified source * argument. */ #define bpf_core_read_str(dst, sz, src) \ - bpf_probe_read_kernel_str(dst, sz, \ - (const void *)__builtin_preserve_access_index(src)) + bpf_probe_read_kernel_str(dst, sz, (const void *)__builtin_preserve_access_index(src)) + +/* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */ +#define bpf_core_read_user_str(dst, sz, src) \ + bpf_probe_read_user_str(dst, sz, (const void *)__builtin_preserve_access_index(src)) #define ___concat(a, b) a ## b #define ___apply(fn, n) ___concat(fn, n) @@ -264,30 +269,29 @@ enum bpf_enum_value_kind { read_fn((void *)(dst), sizeof(*(dst)), &((src_type)(src))->accessor) /* "recursively" read a sequence of inner pointers using local __t var */ -#define ___rd_first(src, a) ___read(bpf_core_read, &__t, ___type(src), src, a); -#define ___rd_last(...) \ - ___read(bpf_core_read, &__t, \ - ___type(___nolast(__VA_ARGS__)), __t, ___last(__VA_ARGS__)); -#define ___rd_p1(...) const void *__t; ___rd_first(__VA_ARGS__) -#define ___rd_p2(...) ___rd_p1(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p3(...) ___rd_p2(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p4(...) ___rd_p3(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p5(...) ___rd_p4(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p6(...) ___rd_p5(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p7(...) ___rd_p6(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p8(...) ___rd_p7(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___rd_p9(...) ___rd_p8(___nolast(__VA_ARGS__)) ___rd_last(__VA_ARGS__) -#define ___read_ptrs(src, ...) \ - ___apply(___rd_p, ___narg(__VA_ARGS__))(src, __VA_ARGS__) - -#define ___core_read0(fn, dst, src, a) \ +#define ___rd_first(fn, src, a) ___read(fn, &__t, ___type(src), src, a); +#define ___rd_last(fn, ...) \ + ___read(fn, &__t, ___type(___nolast(__VA_ARGS__)), __t, ___last(__VA_ARGS__)); +#define ___rd_p1(fn, ...) const void *__t; ___rd_first(fn, __VA_ARGS__) +#define ___rd_p2(fn, ...) ___rd_p1(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p3(fn, ...) ___rd_p2(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p4(fn, ...) ___rd_p3(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p5(fn, ...) ___rd_p4(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p6(fn, ...) ___rd_p5(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p7(fn, ...) ___rd_p6(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p8(fn, ...) ___rd_p7(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___rd_p9(fn, ...) ___rd_p8(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__) +#define ___read_ptrs(fn, src, ...) \ + ___apply(___rd_p, ___narg(__VA_ARGS__))(fn, src, __VA_ARGS__) + +#define ___core_read0(fn, fn_ptr, dst, src, a) \ ___read(fn, dst, ___type(src), src, a); -#define ___core_readN(fn, dst, src, ...) \ - ___read_ptrs(src, ___nolast(__VA_ARGS__)) \ +#define ___core_readN(fn, fn_ptr, dst, src, ...) \ + ___read_ptrs(fn_ptr, src, ___nolast(__VA_ARGS__)) \ ___read(fn, dst, ___type(src, ___nolast(__VA_ARGS__)), __t, \ ___last(__VA_ARGS__)); -#define ___core_read(fn, dst, src, a, ...) \ - ___apply(___core_read, ___empty(__VA_ARGS__))(fn, dst, \ +#define ___core_read(fn, fn_ptr, dst, src, a, ...) \ + ___apply(___core_read, ___empty(__VA_ARGS__))(fn, fn_ptr, dst, \ src, a, ##__VA_ARGS__) /* @@ -295,20 +299,73 @@ enum bpf_enum_value_kind { * BPF_CORE_READ(), in which final field is read into user-provided storage. * See BPF_CORE_READ() below for more details on general usage. */ -#define BPF_CORE_READ_INTO(dst, src, a, ...) \ - ({ \ - ___core_read(bpf_core_read, dst, (src), a, ##__VA_ARGS__) \ - }) +#define BPF_CORE_READ_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_core_read, bpf_core_read, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* + * Variant of BPF_CORE_READ_INTO() for reading from user-space memory. + * + * NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. + */ +#define BPF_CORE_READ_USER_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_core_read_user, bpf_core_read_user, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* Non-CO-RE variant of BPF_CORE_READ_INTO() */ +#define BPF_PROBE_READ_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_probe_read, bpf_probe_read, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* Non-CO-RE variant of BPF_CORE_READ_USER_INTO(). + * + * As no CO-RE relocations are emitted, source types can be arbitrary and are + * not restricted to kernel types only. + */ +#define BPF_PROBE_READ_USER_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_probe_read_user, bpf_probe_read_user, \ + dst, (src), a, ##__VA_ARGS__) \ +}) /* * BPF_CORE_READ_STR_INTO() does same "pointer chasing" as * BPF_CORE_READ() for intermediate pointers, but then executes (and returns * corresponding error code) bpf_core_read_str() for final string read. */ -#define BPF_CORE_READ_STR_INTO(dst, src, a, ...) \ - ({ \ - ___core_read(bpf_core_read_str, dst, (src), a, ##__VA_ARGS__)\ - }) +#define BPF_CORE_READ_STR_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_core_read_str, bpf_core_read, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* + * Variant of BPF_CORE_READ_STR_INTO() for reading from user-space memory. + * + * NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. + */ +#define BPF_CORE_READ_USER_STR_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_core_read_user_str, bpf_core_read_user, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* Non-CO-RE variant of BPF_CORE_READ_STR_INTO() */ +#define BPF_PROBE_READ_STR_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_probe_read_str, bpf_probe_read, \ + dst, (src), a, ##__VA_ARGS__) \ +}) + +/* + * Non-CO-RE variant of BPF_CORE_READ_USER_STR_INTO(). + * + * As no CO-RE relocations are emitted, source types can be arbitrary and are + * not restricted to kernel types only. + */ +#define BPF_PROBE_READ_USER_STR_INTO(dst, src, a, ...) ({ \ + ___core_read(bpf_probe_read_user_str, bpf_probe_read_user, \ + dst, (src), a, ##__VA_ARGS__) \ +}) /* * BPF_CORE_READ() is used to simplify BPF CO-RE relocatable read, especially @@ -334,12 +391,46 @@ enum bpf_enum_value_kind { * N.B. Only up to 9 "field accessors" are supported, which should be more * than enough for any practical purpose. */ -#define BPF_CORE_READ(src, a, ...) \ - ({ \ - ___type((src), a, ##__VA_ARGS__) __r; \ - BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \ - __r; \ - }) +#define BPF_CORE_READ(src, a, ...) ({ \ + ___type((src), a, ##__VA_ARGS__) __r; \ + BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \ + __r; \ +}) + +/* + * Variant of BPF_CORE_READ() for reading from user-space memory. + * + * NOTE: all the source types involved are still *kernel types* and need to + * exist in kernel (or kernel module) BTF, otherwise CO-RE relocation will + * fail. Custom user types are not relocatable with CO-RE. + * The typical situation in which BPF_CORE_READ_USER() might be used is to + * read kernel UAPI types from the user-space memory passed in as a syscall + * input argument. + */ +#define BPF_CORE_READ_USER(src, a, ...) ({ \ + ___type((src), a, ##__VA_ARGS__) __r; \ + BPF_CORE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \ + __r; \ +}) + +/* Non-CO-RE variant of BPF_CORE_READ() */ +#define BPF_PROBE_READ(src, a, ...) ({ \ + ___type((src), a, ##__VA_ARGS__) __r; \ + BPF_PROBE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \ + __r; \ +}) + +/* + * Non-CO-RE variant of BPF_CORE_READ_USER(). + * + * As no CO-RE relocations are emitted, source types can be arbitrary and are + * not restricted to kernel types only. + */ +#define BPF_PROBE_READ_USER(src, a, ...) ({ \ + ___type((src), a, ##__VA_ARGS__) __r; \ + BPF_PROBE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \ + __r; \ +}) #endif |