diff mbox series

[bpf-next,v3,1/2] bpf: use kvmalloc for map values in syscall

Message ID 20210818235216.1159202-1-sdf@google.com
State New
Headers show
Series [bpf-next,v3,1/2] bpf: use kvmalloc for map values in syscall | expand

Commit Message

Stanislav Fomichev Aug. 18, 2021, 11:52 p.m. UTC 
Use kvmalloc/kvfree for temporary value when manipulating a map via
syscall. kmalloc might not be sufficient for percpu maps where the value
is big (and further multiplied by hundreds of CPUs).

Can be reproduced with netcnt test on qemu with "-smp 255".

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
---
 kernel/bpf/syscall.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Aug. 20, 2021, 12:52 p.m. UTC | #1 
Hello:

This series was applied to bpf/bpf-next.git (refs/heads/master):

On Wed, 18 Aug 2021 16:52:15 -0700 you wrote:
> Use kvmalloc/kvfree for temporary value when manipulating a map via

> syscall. kmalloc might not be sufficient for percpu maps where the value

> is big (and further multiplied by hundreds of CPUs).

> 

> Can be reproduced with netcnt test on qemu with "-smp 255".

> 

> Signed-off-by: Stanislav Fomichev <sdf@google.com>

> Acked-by: Song Liu <songliubraving@fb.com>

> 

> [...]


Here is the summary with links:
  - [bpf-next,v3,1/2] bpf: use kvmalloc for map values in syscall
    https://git.kernel.org/bpf/bpf-next/c/f0dce1d9b7c8
  - [bpf-next,v3,2/2] bpf: use kvmalloc for map keys in syscalls
    https://git.kernel.org/bpf/bpf-next/c/44779a4b85ab

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7420e1334ab2..075f650d297a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1076,7 +1076,7 @@  static int map_lookup_elem(union bpf_attr *attr)
 	value_size = bpf_map_value_size(map);
 
 	err = -ENOMEM;
-	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
@@ -1091,7 +1091,7 @@  static int map_lookup_elem(union bpf_attr *attr)
 	err = 0;
 
 free_value:
-	kfree(value);
+	kvfree(value);
 free_key:
 	kfree(key);
 err_put:
@@ -1137,16 +1137,10 @@  static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
 		goto err_put;
 	}
 
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
-	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
-		value_size = round_up(map->value_size, 8) * num_possible_cpus();
-	else
-		value_size = map->value_size;
+	value_size = bpf_map_value_size(map);
 
 	err = -ENOMEM;
-	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
@@ -1157,7 +1151,7 @@  static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
 	err = bpf_map_update_value(map, f, key, value, attr->flags);
 
 free_value:
-	kfree(value);
+	kvfree(value);
 free_key:
 	kfree(key);
 err_put:
@@ -1367,7 +1361,7 @@  int generic_map_update_batch(struct bpf_map *map,
 	if (!key)
 		return -ENOMEM;
 
-	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value) {
 		kfree(key);
 		return -ENOMEM;
@@ -1390,7 +1384,7 @@  int generic_map_update_batch(struct bpf_map *map,
 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
 		err = -EFAULT;
 
-	kfree(value);
+	kvfree(value);
 	kfree(key);
 	return err;
 }
@@ -1429,7 +1423,7 @@  int generic_map_lookup_batch(struct bpf_map *map,
 	if (!buf_prevkey)
 		return -ENOMEM;
 
-	buf = kmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
+	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
 	if (!buf) {
 		kfree(buf_prevkey);
 		return -ENOMEM;
@@ -1492,7 +1486,7 @@  int generic_map_lookup_batch(struct bpf_map *map,
 
 free_buf:
 	kfree(buf_prevkey);
-	kfree(buf);
+	kvfree(buf);
 	return err;
 }
 
@@ -1547,7 +1541,7 @@  static int map_lookup_and_delete_elem(union bpf_attr *attr)
 	value_size = bpf_map_value_size(map);
 
 	err = -ENOMEM;
-	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
@@ -1579,7 +1573,7 @@  static int map_lookup_and_delete_elem(union bpf_attr *attr)
 	err = 0;
 
 free_value:
-	kfree(value);
+	kvfree(value);
 free_key:
 	kfree(key);
 err_put: