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authorJiong Wang <jiong.wang@netronome.com>2019-04-12 22:59:37 +0100
committerAlexei Starovoitov <ast@kernel.org>2019-04-12 17:06:33 -0700
commitc342dc109aa5a4f0bb36335cb441aaafc98b98ef (patch)
treee9a038688270daccc0271ba1bc93b7e745863037 /kernel/bpf
parent55e7f3b5ac94a8c9f2e35961a45e9aa526a9e41d (diff)
downloadlinux-c342dc109aa5a4f0bb36335cb441aaafc98b98ef.tar.bz2
bpf: refactor "check_reg_arg" to eliminate code redundancy
There are a few "regs[regno]" here are there across "check_reg_arg", this patch factor it out into a simple "reg" pointer. The intention is to simplify code indentation and make the later patches in this set look cleaner. Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/verifier.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3fdb301c4f8c..c7220153c5b1 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1177,30 +1177,32 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
{
struct bpf_verifier_state *vstate = env->cur_state;
struct bpf_func_state *state = vstate->frame[vstate->curframe];
- struct bpf_reg_state *regs = state->regs;
+ struct bpf_reg_state *reg, *regs = state->regs;
if (regno >= MAX_BPF_REG) {
verbose(env, "R%d is invalid\n", regno);
return -EINVAL;
}
+ reg = &regs[regno];
if (t == SRC_OP) {
/* check whether register used as source operand can be read */
- if (regs[regno].type == NOT_INIT) {
+ if (reg->type == NOT_INIT) {
verbose(env, "R%d !read_ok\n", regno);
return -EACCES;
}
/* We don't need to worry about FP liveness because it's read-only */
- if (regno != BPF_REG_FP)
- return mark_reg_read(env, &regs[regno],
- regs[regno].parent);
+ if (regno == BPF_REG_FP)
+ return 0;
+
+ return mark_reg_read(env, reg, reg->parent);
} else {
/* check whether register used as dest operand can be written to */
if (regno == BPF_REG_FP) {
verbose(env, "frame pointer is read only\n");
return -EACCES;
}
- regs[regno].live |= REG_LIVE_WRITTEN;
+ reg->live |= REG_LIVE_WRITTEN;
if (t == DST_OP)
mark_reg_unknown(env, regs, regno);
}