From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/include/hashtable.h | 98 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 scripts/include/hashtable.h (limited to 'scripts/include/hashtable.h') diff --git a/scripts/include/hashtable.h b/scripts/include/hashtable.h new file mode 100644 index 000000000..45abcb12b --- /dev/null +++ b/scripts/include/hashtable.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef HASHTABLE_H +#define HASHTABLE_H + +#include "array_size.h" +#include "list.h" + +#define HASH_SIZE(name) (ARRAY_SIZE(name)) + +#define HASHTABLE_DECLARE(name, size) struct hlist_head name[size] + +#define HASHTABLE_DEFINE(name, size) \ + HASHTABLE_DECLARE(name, size) = \ + { [0 ... ((size) - 1)] = HLIST_HEAD_INIT } + +#define hash_head(table, key) (&(table)[(key) % HASH_SIZE(table)]) + +static inline void __hash_init(struct hlist_head *ht, unsigned int sz) +{ + unsigned int i; + + for (i = 0; i < sz; i++) + INIT_HLIST_HEAD(&ht[i]); +} + +/** + * hash_init - initialize a hash table + * @table: hashtable to be initialized + * + * This has to be a macro since HASH_SIZE() will not work on pointers since + * it calculates the size during preprocessing. + */ +#define hash_init(table) __hash_init(table, HASH_SIZE(table)) + +/** + * hash_add - add an object to a hashtable + * @table: hashtable to add to + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add(table, node, key) \ + hlist_add_head(node, hash_head(table, key)) + +/** + * hash_del - remove an object from a hashtable + * @node: &struct hlist_node of the object to remove + */ +static inline void hash_del(struct hlist_node *node) +{ + hlist_del_init(node); +} + +/** + * hash_for_each - iterate over a hashtable + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each(table, obj, member) \ + for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ + hlist_for_each_entry(obj, &table[_bkt], member) + +/** + * hash_for_each_safe - iterate over a hashtable safe against removal of + * hash entry + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node used for temporary storage + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_safe(table, obj, tmp, member) \ + for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ + hlist_for_each_entry_safe(obj, tmp, &table[_bkt], member) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible(table, obj, member, key) \ + hlist_for_each_entry(obj, hash_head(table, key), member) + +/** + * hash_for_each_possible_safe - iterate over all possible objects hashing to the + * same bucket safe against removals + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node used for temporary storage + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_safe(table, obj, tmp, member, key) \ + hlist_for_each_entry_safe(obj, tmp, hash_head(table, key), member) + +#endif /* HASHTABLE_H */ -- cgit v1.3.1