diff options
Diffstat (limited to 'kernel/bpf/helpers.c')
-rw-r--r-- | kernel/bpf/helpers.c | 164 |
1 files changed, 149 insertions, 15 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 3243c83ef3e3..b5f0adae8293 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2498,7 +2498,7 @@ __bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid) /** * bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data. - * @ptr: The dynptr whose data slice to retrieve + * @p: The dynptr whose data slice to retrieve * @offset: Offset into the dynptr * @buffer__opt: User-provided buffer to copy contents into. May be NULL * @buffer__szk: Size (in bytes) of the buffer if present. This is the @@ -2524,9 +2524,10 @@ __bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid) * provided buffer, with its contents containing the data, if unable to obtain * direct pointer) */ -__bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset, +__bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr *p, u32 offset, void *buffer__opt, u32 buffer__szk) { + const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; enum bpf_dynptr_type type; u32 len = buffer__szk; int err; @@ -2568,7 +2569,7 @@ __bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset /** * bpf_dynptr_slice_rdwr() - Obtain a writable pointer to the dynptr data. - * @ptr: The dynptr whose data slice to retrieve + * @p: The dynptr whose data slice to retrieve * @offset: Offset into the dynptr * @buffer__opt: User-provided buffer to copy contents into. May be NULL * @buffer__szk: Size (in bytes) of the buffer if present. This is the @@ -2608,9 +2609,11 @@ __bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset * provided buffer, with its contents containing the data, if unable to obtain * direct pointer) */ -__bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr_kern *ptr, u32 offset, +__bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *p, u32 offset, void *buffer__opt, u32 buffer__szk) { + const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; + if (!ptr->data || __bpf_dynptr_is_rdonly(ptr)) return NULL; @@ -2636,11 +2639,12 @@ __bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr_kern *ptr, u32 o * will be copied out into the buffer and the user will need to call * bpf_dynptr_write() to commit changes. */ - return bpf_dynptr_slice(ptr, offset, buffer__opt, buffer__szk); + return bpf_dynptr_slice(p, offset, buffer__opt, buffer__szk); } -__bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 end) +__bpf_kfunc int bpf_dynptr_adjust(const struct bpf_dynptr *p, u32 start, u32 end) { + struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; u32 size; if (!ptr->data || start > end) @@ -2657,36 +2661,45 @@ __bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 en return 0; } -__bpf_kfunc bool bpf_dynptr_is_null(struct bpf_dynptr_kern *ptr) +__bpf_kfunc bool bpf_dynptr_is_null(const struct bpf_dynptr *p) { + struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; + return !ptr->data; } -__bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr) +__bpf_kfunc bool bpf_dynptr_is_rdonly(const struct bpf_dynptr *p) { + struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; + if (!ptr->data) return false; return __bpf_dynptr_is_rdonly(ptr); } -__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr_kern *ptr) +__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr *p) { + struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; + if (!ptr->data) return -EINVAL; return __bpf_dynptr_size(ptr); } -__bpf_kfunc int bpf_dynptr_clone(struct bpf_dynptr_kern *ptr, - struct bpf_dynptr_kern *clone__uninit) +__bpf_kfunc int bpf_dynptr_clone(const struct bpf_dynptr *p, + struct bpf_dynptr *clone__uninit) { + struct bpf_dynptr_kern *clone = (struct bpf_dynptr_kern *)clone__uninit; + struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p; + if (!ptr->data) { - bpf_dynptr_set_null(clone__uninit); + bpf_dynptr_set_null(clone); return -EINVAL; } - *clone__uninit = *ptr; + *clone = *ptr; return 0; } @@ -2786,7 +2799,7 @@ __bpf_kfunc int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) } __bpf_kfunc int bpf_wq_set_callback_impl(struct bpf_wq *wq, - int (callback_fn)(void *map, int *key, struct bpf_wq *wq), + int (callback_fn)(void *map, int *key, void *value), unsigned int flags, void *aux__ign) { @@ -2809,6 +2822,122 @@ __bpf_kfunc void bpf_preempt_enable(void) preempt_enable(); } +struct bpf_iter_bits { + __u64 __opaque[2]; +} __aligned(8); + +struct bpf_iter_bits_kern { + union { + unsigned long *bits; + unsigned long bits_copy; + }; + u32 nr_bits; + int bit; +} __aligned(8); + +/** + * bpf_iter_bits_new() - Initialize a new bits iterator for a given memory area + * @it: The new bpf_iter_bits to be created + * @unsafe_ptr__ign: A pointer pointing to a memory area to be iterated over + * @nr_words: The size of the specified memory area, measured in 8-byte units. + * Due to the limitation of memalloc, it can't be greater than 512. + * + * This function initializes a new bpf_iter_bits structure for iterating over + * a memory area which is specified by the @unsafe_ptr__ign and @nr_words. It + * copies the data of the memory area to the newly created bpf_iter_bits @it for + * subsequent iteration operations. + * + * On success, 0 is returned. On failure, ERR is returned. + */ +__bpf_kfunc int +bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, u32 nr_words) +{ + struct bpf_iter_bits_kern *kit = (void *)it; + u32 nr_bytes = nr_words * sizeof(u64); + u32 nr_bits = BYTES_TO_BITS(nr_bytes); + int err; + + BUILD_BUG_ON(sizeof(struct bpf_iter_bits_kern) != sizeof(struct bpf_iter_bits)); + BUILD_BUG_ON(__alignof__(struct bpf_iter_bits_kern) != + __alignof__(struct bpf_iter_bits)); + + kit->nr_bits = 0; + kit->bits_copy = 0; + kit->bit = -1; + + if (!unsafe_ptr__ign || !nr_words) + return -EINVAL; + + /* Optimization for u64 mask */ + if (nr_bits == 64) { + err = bpf_probe_read_kernel_common(&kit->bits_copy, nr_bytes, unsafe_ptr__ign); + if (err) + return -EFAULT; + + kit->nr_bits = nr_bits; + return 0; + } + + /* Fallback to memalloc */ + kit->bits = bpf_mem_alloc(&bpf_global_ma, nr_bytes); + if (!kit->bits) + return -ENOMEM; + + err = bpf_probe_read_kernel_common(kit->bits, nr_bytes, unsafe_ptr__ign); + if (err) { + bpf_mem_free(&bpf_global_ma, kit->bits); + return err; + } + + kit->nr_bits = nr_bits; + return 0; +} + +/** + * bpf_iter_bits_next() - Get the next bit in a bpf_iter_bits + * @it: The bpf_iter_bits to be checked + * + * This function returns a pointer to a number representing the value of the + * next bit in the bits. + * + * If there are no further bits available, it returns NULL. + */ +__bpf_kfunc int *bpf_iter_bits_next(struct bpf_iter_bits *it) +{ + struct bpf_iter_bits_kern *kit = (void *)it; + u32 nr_bits = kit->nr_bits; + const unsigned long *bits; + int bit; + + if (nr_bits == 0) + return NULL; + + bits = nr_bits == 64 ? &kit->bits_copy : kit->bits; + bit = find_next_bit(bits, nr_bits, kit->bit + 1); + if (bit >= nr_bits) { + kit->nr_bits = 0; + return NULL; + } + + kit->bit = bit; + return &kit->bit; +} + +/** + * bpf_iter_bits_destroy() - Destroy a bpf_iter_bits + * @it: The bpf_iter_bits to be destroyed + * + * Destroy the resource associated with the bpf_iter_bits. + */ +__bpf_kfunc void bpf_iter_bits_destroy(struct bpf_iter_bits *it) +{ + struct bpf_iter_bits_kern *kit = (void *)it; + + if (kit->nr_bits <= 64) + return; + bpf_mem_free(&bpf_global_ma, kit->bits); +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(generic_btf_ids) @@ -2891,6 +3020,9 @@ BTF_ID_FLAGS(func, bpf_wq_set_callback_impl) BTF_ID_FLAGS(func, bpf_wq_start) BTF_ID_FLAGS(func, bpf_preempt_disable) BTF_ID_FLAGS(func, bpf_preempt_enable) +BTF_ID_FLAGS(func, bpf_iter_bits_new, KF_ITER_NEW) +BTF_ID_FLAGS(func, bpf_iter_bits_next, KF_ITER_NEXT | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_iter_bits_destroy, KF_ITER_DESTROY) BTF_KFUNCS_END(common_btf_ids) static const struct btf_kfunc_id_set common_kfunc_set = { @@ -2932,7 +3064,9 @@ late_initcall(kfunc_init); */ const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u32 len) { - return bpf_dynptr_slice(ptr, 0, NULL, len); + const struct bpf_dynptr *p = (struct bpf_dynptr *)ptr; + + return bpf_dynptr_slice(p, 0, NULL, len); } /* Get a pointer to dynptr data up to len bytes for read write access. If |