diff mbox series

[bpf-next,v2,09/15] bpf: Always raise reference in btf_get_module_btf

Message ID 20220317115957.3193097-10-memxor@gmail.com (mailing list archive)
State Superseded
Commit 9492450fd28736262dea9143ebb3afc2c131ace1
Delegated to: BPF
Headers show
Series Introduce typed pointer support in BPF maps | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next
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: 11 this patch: 11
netdev/cc_maintainers warning 6 maintainers not CCed: netdev@vger.kernel.org songliubraving@fb.com yhs@fb.com john.fastabend@gmail.com kafai@fb.com kpsingh@kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 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 success VM_Test
bpf/vmtest-bpf-next-PR success PR summary

Commit Message

Kumar Kartikeya Dwivedi March 17, 2022, 11:59 a.m. UTC 
Align it with helpers like bpf_find_btf_id, so all functions returning
BTF in out parameter follow the same rule of raising reference
consistently, regardless of module or vmlinux BTF.

Adjust existing callers to handle the change accordinly.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 kernel/bpf/btf.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

Comments

Alexei Starovoitov March 19, 2022, 6:43 p.m. UTC | #1 
On Thu, Mar 17, 2022 at 05:29:51PM +0530, Kumar Kartikeya Dwivedi wrote:
> Align it with helpers like bpf_find_btf_id, so all functions returning
> BTF in out parameter follow the same rule of raising reference
> consistently, regardless of module or vmlinux BTF.
> 
> Adjust existing callers to handle the change accordinly.
> 
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

Applied this and 1st patches.
diff mbox series

Patch

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 12a89e55e77b..2e51b391b684 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6767,20 +6767,23 @@  struct module *btf_try_get_module(const struct btf *btf)
 	return res;
 }
 
-/* Returns struct btf corresponding to the struct module
- *
- * This function can return NULL or ERR_PTR. Note that caller must
- * release reference for struct btf iff btf_is_module is true.
+/* Returns struct btf corresponding to the struct module.
+ * This function can return NULL or ERR_PTR.
  */
 static struct btf *btf_get_module_btf(const struct module *module)
 {
-	struct btf *btf = NULL;
 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
 	struct btf_module *btf_mod, *tmp;
 #endif
+	struct btf *btf = NULL;
+
+	if (!module) {
+		btf = bpf_get_btf_vmlinux();
+		if (!IS_ERR(btf))
+			btf_get(btf);
+		return btf;
+	}
 
-	if (!module)
-		return bpf_get_btf_vmlinux();
 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
 	mutex_lock(&btf_module_mutex);
 	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
@@ -7018,9 +7021,7 @@  int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
 
 	hook = bpf_prog_type_to_kfunc_hook(prog_type);
 	ret = btf_populate_kfunc_set(btf, hook, kset);
-	/* reference is only taken for module BTF */
-	if (btf_is_module(btf))
-		btf_put(btf);
+	btf_put(btf);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set);