This is a note to let you know that I've just added the patch titled
tools/resolve_btfids: Refactor set sorting with types from btf_ids.h
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tools-resolve_btfids-refactor-set-sorting-with-types.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 72b86c24dc9a1df824ac377e05362a76c1ed6682
Author: Viktor Malik <vmalik@xxxxxxxxxx>
Date: Tue Feb 6 13:46:09 2024 +0100
tools/resolve_btfids: Refactor set sorting with types from btf_ids.h
[ Upstream commit 9707ac4fe2f5bac6406d2403f8b8a64d7b3d8e43 ]
Instead of using magic offsets to access BTF ID set data, leverage types
from btf_ids.h (btf_id_set and btf_id_set8) which define the actual
layout of the data. Thanks to this change, set sorting should also
continue working if the layout changes.
This requires to sync the definition of 'struct btf_id_set8' from
include/linux/btf_ids.h to tools/include/linux/btf_ids.h. We don't sync
the rest of the file at the moment, b/c that would require to also sync
multiple dependent headers and we don't need any other defs from
btf_ids.h.
Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Acked-by: Daniel Xu <dxu@xxxxxxxxx>
Link: https://lore.kernel.org/bpf/ff7f062ddf6a00815fda3087957c4ce667f50532.1707223196.git.vmalik@xxxxxxxxxx
Stable-dep-of: 903fad439466 ("tools/resolve_btfids: Fix cross-compilation to non-host endianness")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 77058174082d7..cd42977c6a1f4 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -70,6 +70,7 @@
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
+#include <linux/btf_ids.h>
#include <linux/rbtree.h>
#include <linux/zalloc.h>
#include <linux/err.h>
@@ -78,7 +79,7 @@
#include <subcmd/parse-options.h>
#define BTF_IDS_SECTION ".BTF_ids"
-#define BTF_ID "__BTF_ID__"
+#define BTF_ID_PREFIX "__BTF_ID__"
#define BTF_STRUCT "struct"
#define BTF_UNION "union"
@@ -161,7 +162,7 @@ static int eprintf(int level, int var, const char *fmt, ...)
static bool is_btf_id(const char *name)
{
- return name && !strncmp(name, BTF_ID, sizeof(BTF_ID) - 1);
+ return name && !strncmp(name, BTF_ID_PREFIX, sizeof(BTF_ID_PREFIX) - 1);
}
static struct btf_id *btf_id__find(struct rb_root *root, const char *name)
@@ -441,7 +442,7 @@ static int symbols_collect(struct object *obj)
* __BTF_ID__TYPE__vfs_truncate__0
* prefix = ^
*/
- prefix = name + sizeof(BTF_ID) - 1;
+ prefix = name + sizeof(BTF_ID_PREFIX) - 1;
/* struct */
if (!strncmp(prefix, BTF_STRUCT, sizeof(BTF_STRUCT) - 1)) {
@@ -649,19 +650,18 @@ static int cmp_id(const void *pa, const void *pb)
static int sets_patch(struct object *obj)
{
Elf_Data *data = obj->efile.idlist;
- int *ptr = data->d_buf;
struct rb_node *next;
next = rb_first(&obj->sets);
while (next) {
- unsigned long addr, idx;
+ struct btf_id_set8 *set8;
+ struct btf_id_set *set;
+ unsigned long addr, off;
struct btf_id *id;
- int *base;
- int cnt;
id = rb_entry(next, struct btf_id, rb_node);
addr = id->addr[0];
- idx = addr - obj->efile.idlist_addr;
+ off = addr - obj->efile.idlist_addr;
/* sets are unique */
if (id->addr_cnt != 1) {
@@ -670,14 +670,21 @@ static int sets_patch(struct object *obj)
return -1;
}
- idx = idx / sizeof(int);
- base = &ptr[idx] + (id->is_set8 ? 2 : 1);
- cnt = ptr[idx];
+ if (id->is_set) {
+ set = data->d_buf + off;
+ qsort(set->ids, set->cnt, sizeof(set->ids[0]), cmp_id);
+ } else {
+ set8 = data->d_buf + off;
+ /*
+ * Make sure id is at the beginning of the pairs
+ * struct, otherwise the below qsort would not work.
+ */
+ BUILD_BUG_ON(set8->pairs != &set8->pairs[0].id);
+ qsort(set8->pairs, set8->cnt, sizeof(set8->pairs[0]), cmp_id);
+ }
pr_debug("sorting addr %5lu: cnt %6d [%s]\n",
- (idx + 1) * sizeof(int), cnt, id->name);
-
- qsort(base, cnt, id->is_set8 ? sizeof(uint64_t) : sizeof(int), cmp_id);
+ off, id->is_set ? set->cnt : set8->cnt, id->name);
next = rb_next(next);
}
diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h
index 2f882d5cb30f5..72535f00572f6 100644
--- a/tools/include/linux/btf_ids.h
+++ b/tools/include/linux/btf_ids.h
@@ -8,6 +8,15 @@ struct btf_id_set {
u32 ids[];
};
+struct btf_id_set8 {
+ u32 cnt;
+ u32 flags;
+ struct {
+ u32 id;
+ u32 flags;
+ } pairs[];
+};
+
#ifdef CONFIG_DEBUG_INFO_BTF
#include <linux/compiler.h> /* for __PASTE */
