diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2023-03-02 15:50:09 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-03-04 11:14:32 -0800 |
| commit | a461f5adf17756e99ee0903d1a40961b0342ebb3 (patch) | |
| tree | 8db8906de48711da763d25dc7770cdf91b539bc8 /kernel/bpf | |
| parent | d5271c5b1950b887def1663b75e2d710cc16535f (diff) | |
bpf: generalize dynptr_get_spi to be usable for iters
Generalize the logic of fetching special stack slot object state using
spi (stack slot index). This will be used by STACK_ITER logic next.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-12-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/verifier.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d95975cbcc19..c4151c9efe24 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -710,32 +710,38 @@ static bool is_spi_bounds_valid(struct bpf_func_state *state, int spi, int nr_sl return spi - nr_slots + 1 >= 0 && spi < allocated_slots; } -static int dynptr_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +static int stack_slot_obj_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + const char *obj_kind, int nr_slots) { int off, spi; if (!tnum_is_const(reg->var_off)) { - verbose(env, "dynptr has to be at a constant offset\n"); + verbose(env, "%s has to be at a constant offset\n", obj_kind); return -EINVAL; } off = reg->off + reg->var_off.value; if (off % BPF_REG_SIZE) { - verbose(env, "cannot pass in dynptr at an offset=%d\n", off); + verbose(env, "cannot pass in %s at an offset=%d\n", obj_kind, off); return -EINVAL; } spi = __get_spi(off); - if (spi < 1) { - verbose(env, "cannot pass in dynptr at an offset=%d\n", off); + if (spi + 1 < nr_slots) { + verbose(env, "cannot pass in %s at an offset=%d\n", obj_kind, off); return -EINVAL; } - if (!is_spi_bounds_valid(func(env, reg), spi, BPF_DYNPTR_NR_SLOTS)) + if (!is_spi_bounds_valid(func(env, reg), spi, nr_slots)) return -ERANGE; return spi; } +static int dynptr_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + return stack_slot_obj_get_spi(env, reg, "dynptr", BPF_DYNPTR_NR_SLOTS); +} + static const char *kernel_type_name(const struct btf* btf, u32 id) { return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off); |