diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2020-08-27 15:01:12 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-08-28 21:20:33 +0200 |
| commit | 07be4c4a3e7a0db148e44b16c5190e753d1c8569 (patch) | |
| tree | 6069d0aed091b6505371ef8e405a6c5c7efd4c1c /kernel | |
| parent | 1e6c62a8821557720a9b2ea9617359b264f2f67c (diff) | |
bpf: Add bpf_copy_from_user() helper.
Sleepable BPF programs can now use copy_from_user() to access user memory.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-4-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/helpers.c | 22 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 2 |
2 files changed, 24 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index be43ab3e619f..5cc7425ee476 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -601,6 +601,28 @@ const struct bpf_func_proto bpf_event_output_data_proto = { .arg5_type = ARG_CONST_SIZE_OR_ZERO, }; +BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size, + const void __user *, user_ptr) +{ + int ret = copy_from_user(dst, user_ptr, size); + + if (unlikely(ret)) { + memset(dst, 0, size); + ret = -EFAULT; + } + + return ret; +} + +const struct bpf_func_proto bpf_copy_from_user_proto = { + .func = bpf_copy_from_user, + .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, +}; + const struct bpf_func_proto bpf_get_current_task_proto __weak; const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d973d891f2e2..b2a5380eb187 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1228,6 +1228,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_jiffies64_proto; case BPF_FUNC_get_task_stack: return &bpf_get_task_stack_proto; + case BPF_FUNC_copy_from_user: + return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; default: return NULL; } |