Fix global subprog PTR_TO_CTX arg handling #6432
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
![kernel-patches-daemon-bpf[bot]](https://avatars.githubusercontent.com/u/70728002?s=60&v=4){kind=small}
|
Upstream branch: 68bc61c |
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
c8d202e
to
58cae51
Compare
|
Upstream branch: 68bc61c |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
ace2b7f
to
0966ebf
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
58cae51
to
1659413
Compare
|
Upstream branch: 68bc61c |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
0966ebf
to
7f6dfd1
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
1659413
to
e6cf751
Compare
|
Upstream branch: fc1c9e4 |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
7f6dfd1
to
4ef7f5f
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
e6cf751
to
7722716
Compare
|
Upstream branch: 52dbd67 |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
4ef7f5f
to
a7b813c
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
7722716
to
9835ec6
Compare
|
Upstream branch: 12bbcf8 |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
a7b813c
to
fa8b520
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
9835ec6
to
6ee1f8b
Compare
|
Upstream branch: dc8543b |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
fa8b520
to
718f61c
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
6ee1f8b
to
78363d5
Compare
|
Upstream branch: 2c21a0f |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
718f61c
to
b42ed78
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
78363d5
to
957b42c
Compare
Return result of btf_get_prog_ctx_type() is never used and callers only check NULL vs non-NULL case to determine if given type matches expected PTR_TO_CTX type. So rename function to `btf_is_prog_ctx_type()` and return a simple true/false. We'll use this simpler interface to handle kprobe program type's special typedef case in the next patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
…al arg Expected canonical argument type for global function arguments representing PTR_TO_CTX is `bpf_user_pt_regs_t *ctx`. This currently works on s390x by accident because kernel resolves such typedef to underlying struct (which is anonymous on s390x), and erroneously accepting it as expected context type. We are fixing this problem next, which would break s390x arch, so we need to handle `bpf_user_pt_regs_t` case explicitly for KPROBE programs. Fixes: 91cc1a9 ("bpf: Annotate context types") Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
For program types that don't have named context type name (e.g., BPF
iterator programs or tracepoint programs), ctx_tname will be a non-NULL
empty string. For such programs it shouldn't be possible to have
PTR_TO_CTX argument for global subprogs based on type name alone.
arg:ctx tag is the only way to have PTR_TO_CTX passed into global
subprog for such program types.
Fix this loophole, which currently would assume PTR_TO_CTX whenever
user uses a pointer to anonymous struct as an argument to their global
subprogs. This happens in practice with the following (quite common, in
practice) approach:
typedef struct { /* anonymous */
int x;
} my_type_t;
int my_subprog(my_type_t *arg) { ... }
User's intent is to have PTR_TO_MEM argument for `arg`, but verifier
will complain about expecting PTR_TO_CTX.
This fix also closes unintended s390x-specific KPROBE handling of
PTR_TO_CTX case. Selftest change is necessary to accommodate this.
Fixes: 91cc1a9 ("bpf: Annotate context types")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Add tests validating that kernel handles pointer to anonymous struct argument as PTR_TO_MEM case, not as PTR_TO_CTX case. Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
|
Upstream branch: 32e18e7 |
kernel-patches-daemon-bpf
bot
force-pushed
the
series/825393=>bpf-next
branch
from
b42ed78
to
6fdc251
Compare
kernel-patches-daemon-bpf
bot
force-pushed
the
bpf-next_base
branch
from
957b42c
to
0f0cac4
Compare
|
At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=825393 irrelevant now. Closing PR. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Pull request for series with
subject: Fix global subprog PTR_TO_CTX arg handling
version: 2
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=825393