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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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f8d161756d
Upcoming changes require a notation to specify regular expression
matches for regular verifier log messages, disassembly of BPF
instructions, disassembly of jited instructions.
Neither basic nor extended POSIX regular expressions w/o additional
escaping are good for this role because of wide use of special
characters in disassembly, for example:
movq -0x10(%rbp), %rax ;; () are special characters
cmpq $0x21, %rax ;; $ is a special character
*(u64 *)(r10 -16) = r1 ;; * and () are special characters
This commit borrows syntax from LLVM's FileCheck utility.
It replaces __regex macro with ability to embed regular expressions
in __msg patters using "{{" "}}" pairs for escaping.
Syntax for __msg patterns:
pattern := (<verbatim text> | regex)*
regex := "{{" <posix extended regular expression> "}}"
For example, pattern "foo{{[0-9]+}}" matches strings like
"foo0", "foo007", etc.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240820102357.3372779-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
121 lines
2.7 KiB
C
121 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_core_read.h>
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#include "bpf_experimental.h"
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#include "bpf_misc.h"
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struct node_acquire {
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long key;
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long data;
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struct bpf_rb_node node;
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struct bpf_refcount refcount;
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};
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extern void bpf_rcu_read_lock(void) __ksym;
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extern void bpf_rcu_read_unlock(void) __ksym;
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#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
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private(A) struct bpf_spin_lock glock;
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private(A) struct bpf_rb_root groot __contains(node_acquire, node);
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static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)
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{
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struct node_acquire *node_a;
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struct node_acquire *node_b;
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node_a = container_of(a, struct node_acquire, node);
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node_b = container_of(b, struct node_acquire, node);
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return node_a->key < node_b->key;
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}
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SEC("?tc")
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__failure __msg("Unreleased reference id=4 alloc_insn={{[0-9]+}}")
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long rbtree_refcounted_node_ref_escapes(void *ctx)
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{
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struct node_acquire *n, *m;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return 1;
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bpf_spin_lock(&glock);
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bpf_rbtree_add(&groot, &n->node, less);
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/* m becomes an owning ref but is never drop'd or added to a tree */
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m = bpf_refcount_acquire(n);
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bpf_spin_unlock(&glock);
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if (!m)
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return 2;
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m->key = 2;
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return 0;
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}
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SEC("?tc")
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__failure __msg("Possibly NULL pointer passed to trusted arg0")
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long refcount_acquire_maybe_null(void *ctx)
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{
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struct node_acquire *n, *m;
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n = bpf_obj_new(typeof(*n));
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/* Intentionally not testing !n
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* it's MAYBE_NULL for refcount_acquire
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*/
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m = bpf_refcount_acquire(n);
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if (m)
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bpf_obj_drop(m);
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if (n)
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bpf_obj_drop(n);
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return 0;
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}
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SEC("?tc")
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__failure __msg("Unreleased reference id=3 alloc_insn={{[0-9]+}}")
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long rbtree_refcounted_node_ref_escapes_owning_input(void *ctx)
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{
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struct node_acquire *n, *m;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return 1;
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/* m becomes an owning ref but is never drop'd or added to a tree */
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m = bpf_refcount_acquire(n);
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m->key = 2;
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bpf_spin_lock(&glock);
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bpf_rbtree_add(&groot, &n->node, less);
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bpf_spin_unlock(&glock);
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return 0;
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}
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SEC("?fentry.s/bpf_testmod_test_read")
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__failure __msg("function calls are not allowed while holding a lock")
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int BPF_PROG(rbtree_fail_sleepable_lock_across_rcu,
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struct file *file, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
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{
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struct node_acquire *n;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return 0;
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/* spin_{lock,unlock} are in different RCU CS */
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bpf_rcu_read_lock();
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bpf_spin_lock(&glock);
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bpf_rbtree_add(&groot, &n->node, less);
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bpf_rcu_read_unlock();
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bpf_rcu_read_lock();
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bpf_spin_unlock(&glock);
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bpf_rcu_read_unlock();
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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