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| author | Kui-Feng Lee <thinker.li@gmail.com> | 2024-10-24 01:47:48 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-10-24 19:25:58 +0200 |
| commit | 1cb80d9e93f861018fabe81a69ea0ded20f5a2d0 (patch) | |
| tree | 6a9df68efe29654d957abc53e09d322345442ece /kernel/bpf/syscall.c | |
| parent | Merge branch 'fix-libbpf-s-bpf_object-and-bpf-subskel-interoperability' (diff) | |
| download | linux-1cb80d9e93f861018fabe81a69ea0ded20f5a2d0.tar.xz linux-1cb80d9e93f861018fabe81a69ea0ded20f5a2d0.zip | |
bpf: Support __uptr type tag in BTF
This patch introduces the "__uptr" type tag to BTF. It is to define
a pointer pointing to the user space memory. This patch adds BTF
logic to pass the "__uptr" type tag.
btf_find_kptr() is reused for the "__uptr" tag. The "__uptr" will only
be supported in the map_value of the task storage map. However,
btf_parse_struct_meta() also uses btf_find_kptr() but it is not
interested in "__uptr". This patch adds a "field_mask" argument
to btf_find_kptr() which will return BTF_FIELD_IGNORE if the
caller is not interested in a “__uptr” field.
btf_parse_kptr() is also reused to parse the uptr.
The btf_check_and_fixup_fields() is changed to do extra
checks on the uptr to ensure that its struct size is not larger
than PAGE_SIZE. It is not clear how a uptr pointing to a CO-RE
supported kernel struct will be used, so it is also not allowed now.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20241023234759.860539-2-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | kernel/bpf/syscall.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4d04d4d9c1f3..2d2935d9c096 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -548,6 +548,7 @@ void btf_record_free(struct btf_record *rec) case BPF_KPTR_UNREF: case BPF_KPTR_REF: case BPF_KPTR_PERCPU: + case BPF_UPTR: if (rec->fields[i].kptr.module) module_put(rec->fields[i].kptr.module); if (btf_is_kernel(rec->fields[i].kptr.btf)) @@ -597,6 +598,7 @@ struct btf_record *btf_record_dup(const struct btf_record *rec) case BPF_KPTR_UNREF: case BPF_KPTR_REF: case BPF_KPTR_PERCPU: + case BPF_UPTR: if (btf_is_kernel(fields[i].kptr.btf)) btf_get(fields[i].kptr.btf); if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { |