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authorDaniel Borkmann <daniel@iogearbox.net>2017-01-12 11:51:32 +0100
committerDavid S. Miller <davem@davemloft.net>2017-01-12 10:00:31 -0500
commit6b8cc1d11ef75c5b9c530b3d0d148f3c2dd25f93 (patch)
tree36f8bae922c1f926d8b34a489fc7e34064dedd76 /kernel
parentf811b436522d3b9c05302f1785aba61829938a54 (diff)
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bpf: pass original insn directly to convert_ctx_access
Currently, when calling convert_ctx_access() callback for the various program types, we pass in insn->dst_reg, insn->src_reg, insn->off from the original instruction. This information is needed to rewrite the instruction that is based on the user ctx structure into a kernel representation for the ctx. As we'd like to allow access size beyond just BPF_W, we'd need also insn->code for that in order to decode the original access size. Given that, lets just pass insn directly to the convert_ctx_access() callback and work on that to not clutter the callback with even more arguments we need to pass when everything is already contained in insn. So lets go through that once, no functional change. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c3
-rw-r--r--kernel/trace/bpf_trace.c15
2 files changed, 9 insertions, 9 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2efdc9128e3c..df7e47244e75 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3177,8 +3177,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
if (env->insn_aux_data[i].ptr_type != PTR_TO_CTX)
continue;
- cnt = ops->convert_ctx_access(type, insn->dst_reg, insn->src_reg,
- insn->off, insn_buf, env->prog);
+ cnt = ops->convert_ctx_access(type, insn, insn_buf, env->prog);
if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) {
verbose("bpf verifier is misconfigured\n");
return -EINVAL;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index f883c43c96f3..1860e7f1e5a8 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -572,28 +572,29 @@ static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type
return true;
}
-static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, int dst_reg,
- int src_reg, int ctx_off,
+static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
struct bpf_insn *insn_buf,
struct bpf_prog *prog)
{
struct bpf_insn *insn = insn_buf;
- switch (ctx_off) {
+ switch (si->off) {
case offsetof(struct bpf_perf_event_data, sample_period):
BUILD_BUG_ON(FIELD_SIZEOF(struct perf_sample_data, period) != sizeof(u64));
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
- data), dst_reg, src_reg,
+ data), si->dst_reg, si->src_reg,
offsetof(struct bpf_perf_event_data_kern, data));
- *insn++ = BPF_LDX_MEM(BPF_DW, dst_reg, dst_reg,
+ *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
offsetof(struct perf_sample_data, period));
break;
default:
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
- regs), dst_reg, src_reg,
+ regs), si->dst_reg, si->src_reg,
offsetof(struct bpf_perf_event_data_kern, regs));
- *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), dst_reg, dst_reg, ctx_off);
+ *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
+ si->off);
break;
}