libbpf: move arena variables out of the zero #6454
Closed
+147
−12
Conversation
This file contains hidden or 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
Author
|
Upstream branch: ff34657 |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
52f5a27 to
037d2fc
Compare
Author
|
Upstream branch: ff34657 |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
77f21ca to
db40fd1
Compare
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
037d2fc to
8f722b4
Compare
Author
|
Upstream branch: 8f7aa3d |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
db40fd1 to
ed9530c
Compare
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
8f722b4 to
03e2ed2
Compare
Author
|
Upstream branch: 835a507 |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
ed9530c to
02ec9ea
Compare
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
03e2ed2 to
3ea267d
Compare
Author
|
Upstream branch: 835a507 |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
02ec9ea to
c2d56d2
Compare
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
3ea267d to
6d4eb64
Compare
Author
|
Upstream branch: 835a507 |
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
c2d56d2 to
4531a53
Compare
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
bpf-next_base
branch
from
6d4eb64 to
af4bac7
Compare
Author
|
Upstream branch: 81f88f6 |
The big_alloc1 test in verifier_arena_large assumes that the arena base and the first page allocated by bpf_arena_alloc_pages are identical. This is not the case, because the first page in the arena is populated by global arena data. The test still passes because the code makes the tacit assumption that the first page is on offset PAGE_SIZE instead of 0. Make this distinction explicit in the code, and adjust the page offsets requested during the test to count from the beginning of the arena instead of using the address of the first allocated page. Reviewed-by: Eduard Zingerman <[email protected]> Signed-off-by: Emil Tsalapatis <[email protected]>
The verifier currently limits direct offsets into a map to 512MiB to avoid overflow during pointer arithmetic. However, this prevents arena maps from using direct addressing instructions to access data at the end of > 512MiB arena maps. This is necessary when moving arena globals to the end of the arena instead of the front. Relax the limitation for direct offsets into arena maps to 4GiB, the maximum arena size. Signed-off-by: Emil Tsalapatis <[email protected]>
Arena globals are currently placed at the beginning of the arena by libbpf. This is convenient, but prevents users from reserving guard pages in the beginning of the arena to identify NULL pointer dereferences. Adjust the load logic to place the globals at the end of the arena instead. Also modify bpftool to set the arena pointer in the program's BPF skeleton to point to the globals. Users now call bpf_map__initial_value() to find the beginning of the arena mapping and use the arena pointer in the skeleton to determine which part of the mapping holds the arena globals and which part is free. Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Emil Tsalapatis <[email protected]>
Add tests for the new libbpf globals arena offset logic. The tests cover all three cases: The globals being small enough to be placed at the maximum possible offset, being as large as the arena itself and being placed at the very beginning, and requiring an intermediate offset into the arena. Signed-off-by: Emil Tsalapatis <[email protected]>
kernel-patches-daemon-bpf-rc
bot
force-pushed
the
series/1030172=>bpf-next
branch
from
4531a53 to
4444a3d
Compare
Author
|
At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=1030172 expired. 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: libbpf: move arena variables out of the zero
version: 2
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=1030172