diff options
| author | Dave Marchevsky <davemarchevsky@fb.com> | 2021-04-16 13:47:02 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-04-19 18:23:33 -0700 |
| commit | fd0b88f73f5372c08ceff5cc7ddd8ceac502679c (patch) | |
| tree | 292c4dd9e447473e3308fc67627992a41978320a | |
| parent | 137733d08f4ab14a354dacaa9a8fc35217747605 (diff) | |
| download | linux-fd0b88f73f5372c08ceff5cc7ddd8ceac502679c.tar.bz2 | |
bpf: Refine retval for bpf_get_task_stack helper
Verifier can constrain the min/max bounds of bpf_get_task_stack's return
value more tightly than the default tnum_unknown. Like bpf_get_stack,
return value is num bytes written into a caller-supplied buf, or error,
so do_refine_retval_range will work.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210416204704.2816874-2-davemarchevsky@fb.com
| -rw-r--r-- | kernel/bpf/verifier.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 994ef36c5f60..58730872f7e5 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5808,6 +5808,7 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type, if (ret_type != RET_INTEGER || (func_id != BPF_FUNC_get_stack && + func_id != BPF_FUNC_get_task_stack && func_id != BPF_FUNC_probe_read_str && func_id != BPF_FUNC_probe_read_kernel_str && func_id != BPF_FUNC_probe_read_user_str)) |