Instead of using multiple flags, make struct btf_id tagged with an
enum value indicating its kind in the context of resolve_btfids.
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
---
tools/bpf/resolve_btfids/main.c | 61 ++++++++++++++++++++++-----------
1 file changed, 41 insertions(+), 20 deletions(-)
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index b7b44e72e765..7f5a9f7dde7f 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -98,6 +98,13 @@
# error "Unknown machine endianness!"
#endif
+enum btf_id_kind {
+ BTF_ID_KIND_NONE,
+ BTF_ID_KIND_SYM,
+ BTF_ID_KIND_SET,
+ BTF_ID_KIND_SET8
+};
+
struct btf_id {
struct rb_node rb_node;
char *name;
@@ -105,9 +112,8 @@ struct btf_id {
int id;
int cnt;
};
- int addr_cnt;
- bool is_set;
- bool is_set8;
+ enum btf_id_kind kind:8;
+ int addr_cnt:8;
Elf64_Addr addr[ADDR_CNT];
};
@@ -260,26 +266,33 @@ static char *get_id(const char *prefix_end)
return id;
}
-static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)
+static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind kind)
{
/*
* __BTF_ID__set__name
* name = ^
* id = ^
*/
- char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;
+ int prefixlen = kind == BTF_ID_KIND_SET8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__");
+ char *id = name + prefixlen - 1;
int len = strlen(name);
+ struct btf_id *btf_id;
if (id >= name + len) {
pr_err("FAILED to parse set name: %s\n", name);
return NULL;
}
- return btf_id__add(&obj->sets, id, true);
+ btf_id = btf_id__add(&obj->sets, id, true);
+ if (btf_id)
+ btf_id->kind = kind;
+
+ return btf_id;
}
static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
{
+ struct btf_id *btf_id;
char *id;
id = get_id(name + size);
@@ -288,7 +301,10 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
return NULL;
}
- return btf_id__add(root, id, false);
+ btf_id = btf_id__add(root, id, false);
+ btf_id->kind = BTF_ID_KIND_SYM;
+
+ return btf_id;
}
/* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
@@ -491,28 +507,24 @@ static int symbols_collect(struct object *obj)
id = add_symbol(&obj->funcs, prefix, sizeof(BTF_FUNC) - 1);
/* set8 */
} else if (!strncmp(prefix, BTF_SET8, sizeof(BTF_SET8) - 1)) {
- id = add_set(obj, prefix, true);
+ id = add_set(obj, prefix, BTF_ID_KIND_SET8);
/*
* SET8 objects store list's count, which is encoded
* in symbol's size, together with 'cnt' field hence
* that - 1.
*/
- if (id) {
+ if (id)
id->cnt = sym.st_size / sizeof(uint64_t) - 1;
- id->is_set8 = true;
- }
/* set */
} else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) {
- id = add_set(obj, prefix, false);
+ id = add_set(obj, prefix, BTF_ID_KIND_SET);
/*
* SET objects store list's count, which is encoded
* in symbol's size, together with 'cnt' field hence
* that - 1.
*/
- if (id) {
+ if (id)
id->cnt = sym.st_size / sizeof(int) - 1;
- id->is_set = true;
- }
} else {
pr_err("FAILED unsupported prefix %s\n", prefix);
return -1;
@@ -643,7 +655,7 @@ static int id_patch(struct object *obj, struct btf_id *id)
int i;
/* For set, set8, id->id may be 0 */
- if (!id->id && !id->is_set && !id->is_set8) {
+ if (!id->id && id->kind == BTF_ID_KIND_SYM) {
pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
warnings++;
}
@@ -696,6 +708,7 @@ static int sets_patch(struct object *obj)
{
Elf_Data *data = obj->efile.idlist;
struct rb_node *next;
+ int cnt;
next = rb_first(&obj->sets);
while (next) {
@@ -715,11 +728,15 @@ static int sets_patch(struct object *obj)
return -1;
}
- if (id->is_set) {
+ switch (id->kind) {
+ case BTF_ID_KIND_SET:
set = data->d_buf + off;
+ cnt = set->cnt;
qsort(set->ids, set->cnt, sizeof(set->ids[0]), cmp_id);
- } else {
+ break;
+ case BTF_ID_KIND_SET8:
set8 = data->d_buf + off;
+ cnt = set8->cnt;
/*
* Make sure id is at the beginning of the pairs
* struct, otherwise the below qsort would not work.
@@ -744,10 +761,14 @@ static int sets_patch(struct object *obj)
bswap_32(set8->pairs[i].flags);
}
}
+ break;
+ case BTF_ID_KIND_SYM:
+ default:
+ pr_err("Unexpected btf_id_kind %d for set '%s'\n", id->kind, id->name);
+ return -1;
}
- pr_debug("sorting addr %5lu: cnt %6d [%s]\n",
- off, id->is_set ? set->cnt : set8->cnt, id->name);
+ pr_debug("sorting addr %5lu: cnt %6d [%s]\n", off, cnt, id->name);
next = rb_next(next);
}
--
2.52.0> diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
> index b7b44e72e..7f5a9f7dd 100644
> --- a/tools/bpf/resolve_btfids/main.c
> +++ b/tools/bpf/resolve_btfids/main.c
[ ... ]
> @@ -260,26 +266,33 @@ static char *get_id(const char *prefix_end)
> return id;
> }
>
> -static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)
> +static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind kind)
> {
> /*
> * __BTF_ID__set__name
> * name = ^
> * id = ^
> */
> - char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;
> + int prefixlen = kind == BTF_ID_KIND_SET8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__");
> + char *id = name + prefixlen - 1;
> int len = strlen(name);
> + struct btf_id *btf_id;
>
> if (id >= name + len) {
> pr_err("FAILED to parse set name: %s\n", name);
> return NULL;
> }
>
> - return btf_id__add(&obj->sets, id, true);
> + btf_id = btf_id__add(&obj->sets, id, true);
> + if (btf_id)
> + btf_id->kind = kind;
> +
> + return btf_id;
> }
>
> static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
> {
> + struct btf_id *btf_id;
> char *id;
>
> id = get_id(name + size);
> @@ -288,7 +301,10 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
> return NULL;
> }
>
> - return btf_id__add(root, id, false);
> + btf_id = btf_id__add(root, id, false);
> + btf_id->kind = BTF_ID_KIND_SYM;
^^^^
Can add_symbol() dereference a NULL pointer here? The function
btf_id__add() can return NULL on allocation failure (when zalloc fails),
but the new code sets btf_id->kind before checking if btf_id is NULL.
In contrast, add_set() checks for NULL before setting the kind field.
Should add_symbol() do the same?
> +
> + return btf_id;
> }
[ ... ]
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19689674924
On 11/25/25 6:09 PM, bot+bpf-ci@kernel.org wrote:
>> diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
>> index b7b44e72e..7f5a9f7dd 100644
>> --- a/tools/bpf/resolve_btfids/main.c
>> +++ b/tools/bpf/resolve_btfids/main.c
>
> [ ... ]
>
>> @@ -260,26 +266,33 @@ static char *get_id(const char *prefix_end)
>> return id;
>> }
>>
>> -static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)
>> +static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind kind)
>> {
>> /*
>> * __BTF_ID__set__name
>> * name = ^
>> * id = ^
>> */
>> - char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;
>> + int prefixlen = kind == BTF_ID_KIND_SET8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__");
>> + char *id = name + prefixlen - 1;
>> int len = strlen(name);
>> + struct btf_id *btf_id;
>>
>> if (id >= name + len) {
>> pr_err("FAILED to parse set name: %s\n", name);
>> return NULL;
>> }
>>
>> - return btf_id__add(&obj->sets, id, true);
>> + btf_id = btf_id__add(&obj->sets, id, true);
>> + if (btf_id)
>> + btf_id->kind = kind;
>> +
>> + return btf_id;
>> }
>>
>> static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
>> {
>> + struct btf_id *btf_id;
>> char *id;
>>
>> id = get_id(name + size);
>> @@ -288,7 +301,10 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
>> return NULL;
>> }
>>
>> - return btf_id__add(root, id, false);
>> + btf_id = btf_id__add(root, id, false);
>> + btf_id->kind = BTF_ID_KIND_SYM;
> ^^^^
>
> Can add_symbol() dereference a NULL pointer here? The function
> btf_id__add() can return NULL on allocation failure (when zalloc fails),
> but the new code sets btf_id->kind before checking if btf_id is NULL.
>
> In contrast, add_set() checks for NULL before setting the kind field.
> Should add_symbol() do the same?
We pass unique=false to btf_id__add() and that means that it can only
return NULL if zalloc() fails, which is unlikely.
Checking for NULL here is little too defensive, but won't hurt.
>
>> +
>> + return btf_id;
>> }
>
> [ ... ]
>
>
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
>
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19689674924
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