diff options
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 11 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 34 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 2 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 11 |
5 files changed, 59 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8c92c974bd12..394305a5e02f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2243,6 +2243,7 @@ extern const struct bpf_func_proto bpf_kallsyms_lookup_name_proto; extern const struct bpf_func_proto bpf_find_vma_proto; extern const struct bpf_func_proto bpf_loop_proto; extern const struct bpf_func_proto bpf_strncmp_proto; +extern const struct bpf_func_proto bpf_copy_from_user_task_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 16a7574292a5..4a2f7041ebae 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5076,6 +5076,16 @@ union bpf_attr { * associated to *xdp_md*, at *offset*. * Return * 0 on success, or a negative error in case of failure. + * + * long bpf_copy_from_user_task(void *dst, u32 size, const void *user_ptr, struct task_struct *tsk, u64 flags) + * Description + * Read *size* bytes from user space address *user_ptr* in *tsk*'s + * address space, and stores the data in *dst*. *flags* is not + * used yet and is provided for future extensibility. This helper + * can only be used by sleepable programs. + * Return + * 0 on success, or a negative error in case of failure. On error + * *dst* buffer is zeroed out. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5269,6 +5279,7 @@ union bpf_attr { FN(xdp_get_buff_len), \ FN(xdp_load_bytes), \ FN(xdp_store_bytes), \ + FN(copy_from_user_task), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 01cfdf40c838..ed2780b76cc1 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -16,6 +16,7 @@ #include <linux/pid_namespace.h> #include <linux/proc_ns.h> #include <linux/security.h> +#include <linux/btf_ids.h> #include "../../lib/kstrtox.h" @@ -671,6 +672,39 @@ const struct bpf_func_proto bpf_copy_from_user_proto = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size, + const void __user *, user_ptr, struct task_struct *, tsk, u64, flags) +{ + int ret; + + /* flags is not used yet */ + if (unlikely(flags)) + return -EINVAL; + + if (unlikely(!size)) + return 0; + + ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0); + if (ret == size) + return 0; + + memset(dst, 0, size); + /* Return -EFAULT for partial read */ + return ret < 0 ? ret : -EFAULT; +} + +const struct bpf_func_proto bpf_copy_from_user_task_proto = { + .func = bpf_copy_from_user_task, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_BTF_ID, + .arg4_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], + .arg5_type = ARG_ANYTHING +}; + BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu) { if (cpu >= nr_cpu_ids) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 06a9e220069e..a2024ba32a20 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1235,6 +1235,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_task_stack_proto; case BPF_FUNC_copy_from_user: return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; + case BPF_FUNC_copy_from_user_task: + return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL; case BPF_FUNC_snprintf_btf: return &bpf_snprintf_btf_proto; case BPF_FUNC_per_cpu_ptr: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 16a7574292a5..4a2f7041ebae 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5076,6 +5076,16 @@ union bpf_attr { * associated to *xdp_md*, at *offset*. * Return * 0 on success, or a negative error in case of failure. + * + * long bpf_copy_from_user_task(void *dst, u32 size, const void *user_ptr, struct task_struct *tsk, u64 flags) + * Description + * Read *size* bytes from user space address *user_ptr* in *tsk*'s + * address space, and stores the data in *dst*. *flags* is not + * used yet and is provided for future extensibility. This helper + * can only be used by sleepable programs. + * Return + * 0 on success, or a negative error in case of failure. On error + * *dst* buffer is zeroed out. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5269,6 +5279,7 @@ union bpf_attr { FN(xdp_get_buff_len), \ FN(xdp_load_bytes), \ FN(xdp_store_bytes), \ + FN(copy_from_user_task), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper |