Since this changes the function's meaning, rename it to
bpf_patch_insns(). It is still expected to only grow the function or
to preserve its size, not to shrink it.
Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
---
include/linux/filter.h | 4 ++--
kernel/bpf/core.c | 18 +++++++++---------
kernel/bpf/verifier.c | 2 +-
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 995625950cc1..d926ab1cfada 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -892,8 +892,8 @@ static inline bool bpf_dump_raw_ok(const struct cred *cred)
return kallsyms_show_value(cred);
}
-struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
- const struct bpf_insn *patch, u32 len);
+struct bpf_prog *bpf_patch_insns(struct bpf_prog *prog, u32 off, u32 len_old,
+ const struct bpf_insn *patch, u32 len);
int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt);
void bpf_clear_redirect_map(struct bpf_map *map);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ed0b3578867c..dde5f61f5a99 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -429,10 +429,10 @@ static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
linfo[i].insn_off += delta;
}
-struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
- const struct bpf_insn *patch, u32 len)
+struct bpf_prog *bpf_patch_insns(struct bpf_prog *prog, u32 off, u32 len_old,
+ const struct bpf_insn *patch, u32 len)
{
- u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
+ u32 insn_adj_cnt, insn_rest, insn_delta = len - len_old;
const u32 cnt_max = S16_MAX;
struct bpf_prog *prog_adj;
int err;
@@ -451,7 +451,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
* we afterwards may not fail anymore.
*/
if (insn_adj_cnt > cnt_max &&
- (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
+ (err = bpf_adj_branches(prog, off, off + len_old, off + len, true)))
return ERR_PTR(err);
/* Several new instructions need to be inserted. Make room
@@ -468,14 +468,13 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
/* Patching happens in 3 steps:
*
* 1) Move over tail of insnsi from next instruction onwards,
- * so we can patch the single target insn with one or more
- * new ones (patching is always from 1 to n insns, n > 0).
+ * so we can patch the target insns.
* 2) Inject new instructions at the target location.
* 3) Adjust branch offsets if necessary.
*/
insn_rest = insn_adj_cnt - off - len;
- memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
+ memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + len_old,
sizeof(*patch) * insn_rest);
memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
@@ -483,7 +482,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
* the ship has sailed to reverse to the original state. An
* overflow cannot happen at this point.
*/
- BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
+ BUG_ON(bpf_adj_branches(prog_adj, off, off + len_old, off + len,
+ false));
bpf_adj_linfo(prog_adj, off, insn_delta);
@@ -1155,7 +1155,7 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
if (!rewritten)
continue;
- tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
+ tmp = bpf_patch_insns(clone, i, 1, insn_buff, rewritten);
if (IS_ERR(tmp)) {
/* Patching may have repointed aux->prog during
* realloc from the original one, so we need to
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 814bc6c1ad16..dd0b138ee382 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9628,7 +9628,7 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
{
struct bpf_prog *new_prog;
- new_prog = bpf_patch_insn_single(env->prog, off, patch, len);
+ new_prog = bpf_patch_insns(env->prog, off, 1, patch, len);
if (IS_ERR(new_prog)) {
if (PTR_ERR(new_prog) == -ERANGE)
verbose(env,
--
2.25.4
