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bpf: allocate local storage buffers using GFP_ATOMIC

PATCH Applied Roman Gushchin 3 participants 3 messages Nov 14, 2018 – Nov 17, 2018

Subsystems (3)
Networking Network drivers BPF
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Roman Gushchin

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#0 lore raw

PATCH 1/1 bpf: allocate local storage buffers using GFP_ATOMIC

Naresh reported an issue with the non-atomic memory allocation of cgroup local storage buffers:

[   73.047526] BUG: sleeping function called from invalid context at
/srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421
[   73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto
[   73.068342] INFO: lockdep is turned off.
[   73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted
4.20.0-rc2-next-20181113 #1
[   73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[   73.088018] Call Trace:
[   73.090463]  dump_stack+0x70/0xa5
[   73.093783]  ___might_sleep+0x152/0x240
[   73.097619]  __might_sleep+0x4a/0x80
[   73.101191]  __kmalloc_node+0x1cf/0x2f0
[   73.105031]  ? cgroup_storage_update_elem+0x46/0x90
[   73.109909]  cgroup_storage_update_elem+0x46/0x90

cgroup_storage_update_elem() (as well as other update map update callbacks) is called with disabled preemption, so GFP_ATOMIC allocation should be used: e.g. alloc_htab_elem() in hashtab.c.

Reported-by Naresh Kamboju <[email protected]>
Tested-by Naresh Kamboju <[email protected]>
Signed-off-by Roman Gushchin <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>
---
 kernel/bpf/local_storage.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
kernel/bpf/local_storage.c +2 -1
index c97a8f968638..bed9d48a7ae9 100644
@@ -139,7 +139,8 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *_key,
 		return -ENOENT;
 
 	new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
-			   map->value_size, __GFP_ZERO | GFP_USER,
+			   map->value_size,
+			   __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN,
 			   map->numa_node);
 	if (!new)
 		return -ENOMEM;
Signature · 1 line
2.17.2
Acked-by Yonghong Song on v1 1/1
#1 lore raw
Quoted 24 lines · Roman Gushchin

Naresh reported an issue with the non-atomic memory allocation of cgroup local storage buffers:

[   73.047526] BUG: sleeping function called from invalid context at
/srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421
[   73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto
[   73.068342] INFO: lockdep is turned off.
[   73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted
4.20.0-rc2-next-20181113 #1
[   73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[   73.088018] Call Trace:
[   73.090463]  dump_stack+0x70/0xa5
[   73.093783]  ___might_sleep+0x152/0x240
[   73.097619]  __might_sleep+0x4a/0x80
[   73.101191]  __kmalloc_node+0x1cf/0x2f0
[   73.105031]  ? cgroup_storage_update_elem+0x46/0x90
[   73.109909]  cgroup_storage_update_elem+0x46/0x90

cgroup_storage_update_elem() (as well as other update map update callbacks) is called with disabled preemption, so GFP_ATOMIC allocation should be used: e.g. alloc_htab_elem() in hashtab.c.

Quoted 5 lines
Reported-by Naresh Kamboju <[email protected]>
Tested-by Naresh Kamboju <[email protected]>
Signed-off-by Roman Gushchin <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>
Acked-by Yonghong Song <[email protected]>
Quoted 3 lines
---
 kernel/bpf/local_storage.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
Applied
#2 lore raw
In reply to Roman Gushchin
Quoted 23 lines · Roman Gushchin

Naresh reported an issue with the non-atomic memory allocation of cgroup local storage buffers:

[   73.047526] BUG: sleeping function called from invalid context at
/srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421
[   73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto
[   73.068342] INFO: lockdep is turned off.
[   73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted
4.20.0-rc2-next-20181113 #1
[   73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.0b 07/27/2017
[   73.088018] Call Trace:
[   73.090463]  dump_stack+0x70/0xa5
[   73.093783]  ___might_sleep+0x152/0x240
[   73.097619]  __might_sleep+0x4a/0x80
[   73.101191]  __kmalloc_node+0x1cf/0x2f0
[   73.105031]  ? cgroup_storage_update_elem+0x46/0x90
[   73.109909]  cgroup_storage_update_elem+0x46/0x90

cgroup_storage_update_elem() (as well as other update map update callbacks) is called with disabled preemption, so GFP_ATOMIC allocation should be used: e.g. alloc_htab_elem() in hashtab.c.

Quoted 5 lines
Reported-by Naresh Kamboju <[email protected]>
Tested-by Naresh Kamboju <[email protected]>
Signed-off-by Roman Gushchin <[email protected]>
Cc Alexei Starovoitov <[email protected]>
Cc Daniel Borkmann <[email protected]>

applied to bpf tree, thanks