diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2025-07-31 01:47:30 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-07-31 11:30:05 -0700 |
| commit | 12df58ad294253ac1d8df0c9bb9cf726397a671d (patch) | |
| tree | 2c41db06de937e6136bf501931826eb6bcf38867 /kernel/bpf/syscall.c | |
| parent | d6084bb815c453de27af8071a23163a711586a6c (diff) | |
bpf: Add cookie object to bpf maps
Add a cookie to BPF maps to uniquely identify BPF maps for the timespan
when the node is up. This is different to comparing a pointer or BPF map
id which could get rolled over and reused.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e63039817af3..7a814e98d5f5 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -37,6 +37,7 @@ #include <linux/trace_events.h> #include <linux/tracepoint.h> #include <linux/overflow.h> +#include <linux/cookie.h> #include <net/netfilter/nf_bpf_link.h> #include <net/netkit.h> @@ -53,6 +54,7 @@ #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) DEFINE_PER_CPU(int, bpf_prog_active); +DEFINE_COOKIE(bpf_map_cookie); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); static DEFINE_IDR(map_idr); @@ -1487,6 +1489,10 @@ static int map_create(union bpf_attr *attr, bool kernel) if (err < 0) goto free_map; + preempt_disable(); + map->cookie = gen_cookie_next(&bpf_map_cookie); + preempt_enable(); + atomic64_set(&map->refcnt, 1); atomic64_set(&map->usercnt, 1); mutex_init(&map->freeze_mutex); |