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| author | Alexei Starovoitov <ast@fb.com> | 2017-11-30 21:31:40 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2017-12-01 11:25:10 +0100 |
| commit | 914cb781ee1a35f4c7a5173a668d6ba2c4734b91 (patch) | |
| tree | 5245c021159fa3da5150360f21879e0e59f6c985 /kernel/bpf | |
| parent | 3bf15921c58df982f9b15d64754c483785bf66f3 (diff) | |
| download | linux-914cb781ee1a35f4c7a5173a668d6ba2c4734b91.tar.bz2 | |
bpf: cleanup register_is_null()
don't pass large struct bpf_reg_state by value.
Instead pass it by pointer.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/verifier.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index afe9a1a0a5fe..7afa92e9b409 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1265,9 +1265,9 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins } /* Does this register contain a constant zero? */ -static bool register_is_null(struct bpf_reg_state reg) +static bool register_is_null(struct bpf_reg_state *reg) { - return reg.type == SCALAR_VALUE && tnum_equals_const(reg.var_off, 0); + return reg->type == SCALAR_VALUE && tnum_equals_const(reg->var_off, 0); } /* when register 'regno' is passed into function that will read 'access_size' @@ -1280,31 +1280,31 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno, int access_size, bool zero_size_allowed, struct bpf_call_arg_meta *meta) { + struct bpf_reg_state *reg = cur_regs(env) + regno; struct bpf_verifier_state *state = env->cur_state; - struct bpf_reg_state *regs = state->regs; int off, i, slot, spi; - if (regs[regno].type != PTR_TO_STACK) { + if (reg->type != PTR_TO_STACK) { /* Allow zero-byte read from NULL, regardless of pointer type */ if (zero_size_allowed && access_size == 0 && - register_is_null(regs[regno])) + register_is_null(reg)) return 0; verbose(env, "R%d type=%s expected=%s\n", regno, - reg_type_str[regs[regno].type], + reg_type_str[reg->type], reg_type_str[PTR_TO_STACK]); return -EACCES; } /* Only allow fixed-offset stack reads */ - if (!tnum_is_const(regs[regno].var_off)) { + if (!tnum_is_const(reg->var_off)) { char tn_buf[48]; - tnum_strn(tn_buf, sizeof(tn_buf), regs[regno].var_off); + tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); verbose(env, "invalid variable stack read R%d var_off=%s\n", regno, tn_buf); } - off = regs[regno].off + regs[regno].var_off.value; + off = reg->off + reg->var_off.value; if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 || access_size < 0 || (access_size == 0 && !zero_size_allowed)) { verbose(env, "invalid stack type R%d off=%d access_size=%d\n", @@ -1412,7 +1412,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, * passed in as argument, it's a SCALAR_VALUE type. Final test * happens during stack boundary checking. */ - if (register_is_null(*reg) && + if (register_is_null(reg) && arg_type == ARG_PTR_TO_MEM_OR_NULL) /* final test in check_stack_boundary() */; else if (!type_is_pkt_pointer(type) && |