diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-02-24 17:01:52 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-02-25 03:20:10 +0300 |
| commit | 66150d0dde030c5ee68ccd93e4c54a73c47ebebd (patch) | |
| tree | 0d39c932913bd7bd18238e6cdd60393292c0a0c7 /kernel | |
| parent | 7f805d17f1523c7b2c0da319ddb427d6c5d94ff1 (diff) | |
| download | linux-66150d0dde030c5ee68ccd93e4c54a73c47ebebd.tar.xz | |
bpf, lpm: Make locking RT friendly
The LPM trie map cannot be used in contexts like perf, kprobes and tracing
as this map type dynamically allocates memory.
The memory allocation happens with a raw spinlock held which is a truly
spinning lock on a PREEMPT RT enabled kernel which disables preemption and
interrupts.
As RT does not allow memory allocation from such a section for various
reasons, convert the raw spinlock to a regular spinlock.
On a RT enabled kernel these locks are substituted by 'sleeping' spinlocks
which provide the proper protection but keep the code preemptible.
On a non-RT kernel regular spinlocks map to raw spinlocks, i.e. this does
not cause any functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145644.602129531@linutronix.de
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/lpm_trie.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 56e6c75d354d..3b3c420bc8ed 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -34,7 +34,7 @@ struct lpm_trie { size_t n_entries; size_t max_prefixlen; size_t data_size; - raw_spinlock_t lock; + spinlock_t lock; }; /* This trie implements a longest prefix match algorithm that can be used to @@ -315,7 +315,7 @@ static int trie_update_elem(struct bpf_map *map, if (key->prefixlen > trie->max_prefixlen) return -EINVAL; - raw_spin_lock_irqsave(&trie->lock, irq_flags); + spin_lock_irqsave(&trie->lock, irq_flags); /* Allocate and fill a new node */ @@ -422,7 +422,7 @@ out: kfree(im_node); } - raw_spin_unlock_irqrestore(&trie->lock, irq_flags); + spin_unlock_irqrestore(&trie->lock, irq_flags); return ret; } @@ -442,7 +442,7 @@ static int trie_delete_elem(struct bpf_map *map, void *_key) if (key->prefixlen > trie->max_prefixlen) return -EINVAL; - raw_spin_lock_irqsave(&trie->lock, irq_flags); + spin_lock_irqsave(&trie->lock, irq_flags); /* Walk the tree looking for an exact key/length match and keeping * track of the path we traverse. We will need to know the node @@ -518,7 +518,7 @@ static int trie_delete_elem(struct bpf_map *map, void *_key) kfree_rcu(node, rcu); out: - raw_spin_unlock_irqrestore(&trie->lock, irq_flags); + spin_unlock_irqrestore(&trie->lock, irq_flags); return ret; } @@ -575,7 +575,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr) if (ret) goto out_err; - raw_spin_lock_init(&trie->lock); + spin_lock_init(&trie->lock); return &trie->map; out_err: |