diff mbox series

[bpf-next,v2,02/13] bpf: Add helper btf_find_dynptr()

Message ID 20220924133620.4147153-3-houtao@huaweicloud.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series Add support for qp-trie with dynptr key | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1362 this patch: 1362
netdev/cc_maintainers warning 2 maintainers not CCed: song@kernel.org martin.lau@linux.dev
netdev/build_clang success Errors and warnings before: 159 this patch: 159
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1354 this patch: 1354
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-4 success Logs for llvm-toolchain
bpf/vmtest-bpf-next-VM_Test-5 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-1 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-9 fail Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-6 fail Logs for test_maps on s390x with gcc

Commit Message

Hou Tao Sept. 24, 2022, 1:36 p.m. UTC 
From: Hou Tao <houtao1@huawei.com>

Add helper btf_find_dynptr() to check whether or not the passed btf type
is bpf_dynptr. It can be extend to find an embedded dynptr in passed btf
type if needed later.

It will be used by bpf map (e.g. qp-trie) with bpf_dynptr key.

Signed-off-by: Hou Tao <houtao1@huawei.com>
---
 include/linux/btf.h |  1 +
 kernel/bpf/btf.c    | 13 +++++++++++++
 2 files changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/btf.h b/include/linux/btf.h
index f9aababc5d78..5bf508c2bad2 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -165,6 +165,7 @@  int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
 int btf_find_timer(const struct btf *btf, const struct btf_type *t);
 struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
 					  const struct btf_type *t);
+int btf_find_dynptr(const struct btf *btf, const struct btf_type *t);
 bool btf_type_is_void(const struct btf_type *t);
 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index a44ad4b347ff..fefbe84c6998 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3522,6 +3522,19 @@  struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
 	return ERR_PTR(ret);
 }
 
+/* Now only allow to use 'struct bpf_dynptr' as map key.
+ * Map key with embedded bpf_dynptr is not allowed.
+ */
+int btf_find_dynptr(const struct btf *btf, const struct btf_type *t)
+{
+	/* Only allow struct type */
+	if (__btf_type_is_struct(t) && t->size == sizeof(struct bpf_dynptr) &&
+	    !strcmp("bpf_dynptr", __btf_name_by_offset(btf, t->name_off)))
+		return 0;
+
+	return -EINVAL;
+}
+
 static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
 			      u32 type_id, void *data, u8 bits_offset,
 			      struct btf_show *show)