diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2024-11-09 15:14:30 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-11-11 08:18:55 -0800 |
| commit | ae6e3a273f590a2b64f14a9fab3546c3a8f44ed4 (patch) | |
| tree | bb926d00e5d37fec39645fab3b71a950848c45c7 /include | |
| parent | f6b9a69a9e56b2083aca8a925fc1a28eb698e3ed (diff) | |
bpf: Drop special callback reference handling
Logic to prevent callbacks from acquiring new references for the program
(i.e. leaving acquired references), and releasing caller references
(i.e. those acquired in parent frames) was introduced in commit
9d9d00ac29d0 ("bpf: Fix reference state management for synchronous callbacks").
This was necessary because back then, the verifier simulated each
callback once (that could potentially be executed N times, where N can
be zero). This meant that callbacks that left lingering resources or
cleared caller resources could do it more than once, operating on
undefined state or leaking memory.
With the fixes to callback verification in commit
ab5cfac139ab ("bpf: verify callbacks as if they are called unknown number of times"),
all of this extra logic is no longer necessary. Hence, drop it as part
of this commit.
Cc: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241109231430.2475236-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf_verifier.h | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index d84beed92ae4..3a74033d49c4 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -265,23 +265,10 @@ struct bpf_reference_state { * is used purely to inform the user of a reference leak. */ int insn_idx; - union { - /* There can be a case like: - * main (frame 0) - * cb (frame 1) - * func (frame 3) - * cb (frame 4) - * Hence for frame 4, if callback_ref just stored boolean, it would be - * impossible to distinguish nested callback refs. Hence store the - * frameno and compare that to callback_ref in check_reference_leak when - * exiting a callback function. - */ - int callback_ref; - /* Use to keep track of the source object of a lock, to ensure - * it matches on unlock. - */ - void *ptr; - }; + /* Use to keep track of the source object of a lock, to ensure + * it matches on unlock. + */ + void *ptr; }; struct bpf_retval_range { |