diff options
| author | Kui-Feng Lee | 2024-02-24 14:34:17 -0800 |
|---|---|---|
| committer | Martin KaFai Lau | 2024-03-04 14:09:20 -0800 |
| commit | 187e2af05abe6bf80581490239c449456627d17a (patch) | |
| tree | 573c922b888bd957230d958b50a0756ce457262b /include | |
| parent | 73e4f9e615d7b99f39663d4722dc73e8fa5db5f9 (diff) | |
bpf: struct_ops supports more than one page for trampolines.
The BPF struct_ops previously only allowed one page of trampolines.
Each function pointer of a struct_ops is implemented by a struct_ops
bpf program. Each struct_ops bpf program requires a trampoline.
The following selftest patch shows each page can hold a little more
than 20 trampolines.
While one page is more than enough for the tcp-cc usecase,
the sched_ext use case shows that one page is not always enough and hits
the one page limit. This patch overcomes the one page limit by allocating
another page when needed and it is limited to a total of
MAX_IMAGE_PAGES (8) pages which is more than enough for
reasonable usages.
The variable st_map->image has been changed to st_map->image_pages, and
its type has been changed to an array of pointers to pages.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240224223418.526631-3-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 814dc913a968..785660810e6a 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1763,7 +1763,9 @@ int bpf_struct_ops_prepare_trampoline(struct bpf_tramp_links *tlinks, struct bpf_tramp_link *link, const struct btf_func_model *model, void *stub_func, - void *image, void *image_end); + void **image, u32 *image_off, + bool allow_alloc); +void bpf_struct_ops_image_free(void *image); static inline bool bpf_try_module_get(const void *data, struct module *owner) { if (owner == BPF_MODULE_OWNER) |