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authorPeter Zijlstra <peterz@infradead.org>2020-04-29 17:03:22 +0200
committerIngo Molnar <mingo@kernel.org>2021-02-17 14:07:31 +0100
commit2d24dd5798d0474d9bf705bfca8725e7d20f9d54 (patch)
tree895ec9efd5a44987e173310f228135fbeb28b17b /tools/objtool
parent9fe1f127b913318c631d0041ecf71486e38c2c2d (diff)
rbtree: Add generic add and find helpers
I've always been bothered by the endless (fragile) boilerplate for rbtree, and I recently wrote some rbtree helpers for objtool and figured I should lift them into the kernel and use them more widely. Provide: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two Inlining and constant propagation should see the compiler inline the whole thing, including the various compare functions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Michel Lespinasse <walken@google.com> Acked-by: Davidlohr Bueso <dbueso@suse.de>
Diffstat (limited to 'tools/objtool')
-rw-r--r--tools/objtool/elf.c73
1 files changed, 11 insertions, 62 deletions
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index d8421e1d06be..e85988ce04f1 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -43,75 +43,24 @@ static void elf_hash_init(struct hlist_head *table)
#define elf_hash_for_each_possible(name, obj, member, key) \
hlist_for_each_entry(obj, &name[hash_min(key, elf_hash_bits())], member)
-static void rb_add(struct rb_root *tree, struct rb_node *node,
- int (*cmp)(struct rb_node *, const struct rb_node *))
-{
- struct rb_node **link = &tree->rb_node;
- struct rb_node *parent = NULL;
-
- while (*link) {
- parent = *link;
- if (cmp(node, parent) < 0)
- link = &parent->rb_left;
- else
- link = &parent->rb_right;
- }
-
- rb_link_node(node, parent, link);
- rb_insert_color(node, tree);
-}
-
-static struct rb_node *rb_find_first(const struct rb_root *tree, const void *key,
- int (*cmp)(const void *key, const struct rb_node *))
-{
- struct rb_node *node = tree->rb_node;
- struct rb_node *match = NULL;
-
- while (node) {
- int c = cmp(key, node);
- if (c <= 0) {
- if (!c)
- match = node;
- node = node->rb_left;
- } else if (c > 0) {
- node = node->rb_right;
- }
- }
-
- return match;
-}
-
-static struct rb_node *rb_next_match(struct rb_node *node, const void *key,
- int (*cmp)(const void *key, const struct rb_node *))
-{
- node = rb_next(node);
- if (node && cmp(key, node))
- node = NULL;
- return node;
-}
-
-#define rb_for_each(tree, node, key, cmp) \
- for ((node) = rb_find_first((tree), (key), (cmp)); \
- (node); (node) = rb_next_match((node), (key), (cmp)))
-
-static int symbol_to_offset(struct rb_node *a, const struct rb_node *b)
+static bool symbol_to_offset(struct rb_node *a, const struct rb_node *b)
{
struct symbol *sa = rb_entry(a, struct symbol, node);
struct symbol *sb = rb_entry(b, struct symbol, node);
if (sa->offset < sb->offset)
- return -1;
+ return true;
if (sa->offset > sb->offset)
- return 1;
+ return false;
if (sa->len < sb->len)
- return -1;
+ return true;
if (sa->len > sb->len)
- return 1;
+ return false;
sa->alias = sb;
- return 0;
+ return false;
}
static int symbol_by_offset(const void *key, const struct rb_node *node)
@@ -165,7 +114,7 @@ struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset)
{
struct rb_node *node;
- rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) {
struct symbol *s = rb_entry(node, struct symbol, node);
if (s->offset == offset && s->type != STT_SECTION)
@@ -179,7 +128,7 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset)
{
struct rb_node *node;
- rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) {
struct symbol *s = rb_entry(node, struct symbol, node);
if (s->offset == offset && s->type == STT_FUNC)
@@ -193,7 +142,7 @@ struct symbol *find_symbol_containing(const struct section *sec, unsigned long o
{
struct rb_node *node;
- rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) {
struct symbol *s = rb_entry(node, struct symbol, node);
if (s->type != STT_SECTION)
@@ -207,7 +156,7 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset)
{
struct rb_node *node;
- rb_for_each(&sec->symbol_tree, node, &offset, symbol_by_offset) {
+ rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) {
struct symbol *s = rb_entry(node, struct symbol, node);
if (s->type == STT_FUNC)
@@ -442,7 +391,7 @@ static int read_symbols(struct elf *elf)
sym->offset = sym->sym.st_value;
sym->len = sym->sym.st_size;
- rb_add(&sym->sec->symbol_tree, &sym->node, symbol_to_offset);
+ rb_add(&sym->node, &sym->sec->symbol_tree, symbol_to_offset);
pnode = rb_prev(&sym->node);
if (pnode)
entry = &rb_entry(pnode, struct symbol, node)->list;