Alexei Starovoitov 4fe8435909 bpf: convert htab map to hlist_nulls ...

when all map elements are pre-allocated one cpu can delete and reuse htab_elem
while another cpu is still walking the hlist. In such case the lookup may
miss the element. Convert hlist to hlist_nulls to avoid such scenario.
When bucket lock is taken there is no need to take such precautions,
so only convert map_lookup and map_get_next to nulls.
The race window is extremely small and only reproducible with explicit
udelay() inside lookup_nulls_elem_raw()

Similar to hlist add hlist_nulls_for_each_entry_safe() and
hlist_nulls_entry_safe() helpers.

Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements")
Reported-by: Jonathan Perry <jonperry@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2017-03-09 13:27:17 -08:00

..

arraymap.c

bpf: mark all registered map/prog types as __ro_after_init

2017-02-17 13:40:04 -05:00

bpf_lru_list.c

bpf: Make unnecessarily global functions static

2017-01-10 21:00:59 -05:00

bpf_lru_list.h

bpf: Add percpu LRU list

2016-11-15 11:50:20 -05:00

cgroup.c

bpf: introduce BPF_F_ALLOW_OVERRIDE flag

2017-02-12 21:52:19 -05:00

core.c

bpf: make jited programs visible in traces

2017-02-17 13:40:05 -05:00

hashtab.c

bpf: convert htab map to hlist_nulls

2017-03-09 13:27:17 -08:00

helpers.c

bpf: rename ARG_PTR_TO_STACK

2017-01-09 16:56:27 -05:00

inode.c

bpf: add initial bpf tracepoints

2017-01-25 13:17:47 -05:00

lpm_trie.c

bpf: add get_next_key callback to LPM map

2017-03-05 17:55:29 -08:00

Makefile

bpf: add a longest prefix match trie map implementation

2017-01-23 16:10:38 -05:00

percpu_freelist.c

bpf: introduce percpu_freelist

2016-03-08 15:28:31 -05:00

percpu_freelist.h

bpf: introduce percpu_freelist

2016-03-08 15:28:31 -05:00

stackmap.c

bpf: mark all registered map/prog types as __ro_after_init

2017-02-17 13:40:04 -05:00

syscall.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>

2017-03-02 08:42:29 +01:00

verifier.c

bpf: update the comment about the length of analysis

2017-03-01 14:56:50 -08:00