Revision 6f6acb00514c10be35529402f36ad7a288f08c2e authored by Michal Hocko on 22 May 2014, 18:54:19 UTC, committed by Linus Torvalds on 23 May 2014, 16:37:29 UTC
Commit 284f39afeaa4 ("mm: memcg: push !mm handling out to page cache
charge function") explicitly checks for page cache charges without any
mm context (from kernel thread context[1]).
This seemed to be the only possible case where memory could be charged
without mm context so commit 03583f1a631c ("memcg: remove unnecessary
!mm check from try_get_mem_cgroup_from_mm()") removed the mm check from
get_mem_cgroup_from_mm(). This however caused another NULL ptr
dereference during early boot when loopback kernel thread splices to
tmpfs as reported by Stephan Kulow:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000360
IP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
Oops: 0000 [#1] SMP
Modules linked in: btrfs dm_multipath dm_mod scsi_dh multipath raid10 raid456 async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod parport_pc parport nls_utf8 isofs usb_storage iscsi_ibft iscsi_boot_sysfs arc4 ecb fan thermal nfs lockd fscache nls_iso8859_1 nls_cp437 sg st hid_generic usbhid af_packet sunrpc sr_mod cdrom ata_generic uhci_hcd virtio_net virtio_blk ehci_hcd usbcore ata_piix floppy processor button usb_common virtio_pci virtio_ring virtio edd squashfs loop ppa]
CPU: 0 PID: 97 Comm: loop1 Not tainted 3.15.0-rc5-5-default #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
__mem_cgroup_try_charge_swapin+0x40/0xe0
mem_cgroup_charge_file+0x8b/0xd0
shmem_getpage_gfp+0x66b/0x7b0
shmem_file_splice_read+0x18f/0x430
splice_direct_to_actor+0xa2/0x1c0
do_lo_receive+0x5a/0x60 [loop]
loop_thread+0x298/0x720 [loop]
kthread+0xc6/0xe0
ret_from_fork+0x7c/0xb0
Also Branimir Maksimovic reported the following oops which is tiggered
for the swapcache charge path from the accounting code for kernel threads:
CPU: 1 PID: 160 Comm: kworker/u8:5 Tainted: P OE 3.15.0-rc5-core2-custom #159
Hardware name: System manufacturer System Product Name/MAXIMUSV GENE, BIOS 1903 08/19/2013
task: ffff880404e349b0 ti: ffff88040486a000 task.ti: ffff88040486a000
RIP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
Call Trace:
__mem_cgroup_try_charge_swapin+0x45/0xf0
mem_cgroup_charge_file+0x9c/0xe0
shmem_getpage_gfp+0x62c/0x770
shmem_write_begin+0x38/0x40
generic_perform_write+0xc5/0x1c0
__generic_file_aio_write+0x1d1/0x3f0
generic_file_aio_write+0x4f/0xc0
do_sync_write+0x5a/0x90
do_acct_process+0x4b1/0x550
acct_process+0x6d/0xa0
do_exit+0x827/0xa70
kthread+0xc3/0xf0
This patch fixes the issue by reintroducing mm check into
get_mem_cgroup_from_mm. We could do the same trick in
__mem_cgroup_try_charge_swapin as we do for the regular page cache path
but it is not worth troubles. The check is not that expensive and it is
better to have get_mem_cgroup_from_mm more robust.
[1] - http://marc.info/?l=linux-mm&m=139463617808941&w=2
Fixes: 03583f1a631c ("memcg: remove unnecessary !mm check from try_get_mem_cgroup_from_mm()")
Reported-and-tested-by: Stephan Kulow <coolo@suse.com>
Reported-by: Branimir Maksimovic <branimir.maksimovic@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 55231e5
rmd128.c
/*
* Cryptographic API.
*
* RIPEMD-128 - RACE Integrity Primitives Evaluation Message Digest.
*
* Based on the reference implementation by Antoon Bosselaers, ESAT-COSIC
*
* Copyright (c) 2008 Adrian-Ken Rueegsegger <ken@codelabs.ch>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <asm/byteorder.h>
#include "ripemd.h"
struct rmd128_ctx {
u64 byte_count;
u32 state[4];
__le32 buffer[16];
};
#define K1 RMD_K1
#define K2 RMD_K2
#define K3 RMD_K3
#define K4 RMD_K4
#define KK1 RMD_K6
#define KK2 RMD_K7
#define KK3 RMD_K8
#define KK4 RMD_K1
#define F1(x, y, z) (x ^ y ^ z) /* XOR */
#define F2(x, y, z) (z ^ (x & (y ^ z))) /* x ? y : z */
#define F3(x, y, z) ((x | ~y) ^ z)
#define F4(x, y, z) (y ^ (z & (x ^ y))) /* z ? x : y */
#define ROUND(a, b, c, d, f, k, x, s) { \
(a) += f((b), (c), (d)) + le32_to_cpup(&(x)) + (k); \
(a) = rol32((a), (s)); \
}
static void rmd128_transform(u32 *state, const __le32 *in)
{
u32 aa, bb, cc, dd, aaa, bbb, ccc, ddd;
/* Initialize left lane */
aa = state[0];
bb = state[1];
cc = state[2];
dd = state[3];
/* Initialize right lane */
aaa = state[0];
bbb = state[1];
ccc = state[2];
ddd = state[3];
/* round 1: left lane */
ROUND(aa, bb, cc, dd, F1, K1, in[0], 11);
ROUND(dd, aa, bb, cc, F1, K1, in[1], 14);
ROUND(cc, dd, aa, bb, F1, K1, in[2], 15);
ROUND(bb, cc, dd, aa, F1, K1, in[3], 12);
ROUND(aa, bb, cc, dd, F1, K1, in[4], 5);
ROUND(dd, aa, bb, cc, F1, K1, in[5], 8);
ROUND(cc, dd, aa, bb, F1, K1, in[6], 7);
ROUND(bb, cc, dd, aa, F1, K1, in[7], 9);
ROUND(aa, bb, cc, dd, F1, K1, in[8], 11);
ROUND(dd, aa, bb, cc, F1, K1, in[9], 13);
ROUND(cc, dd, aa, bb, F1, K1, in[10], 14);
ROUND(bb, cc, dd, aa, F1, K1, in[11], 15);
ROUND(aa, bb, cc, dd, F1, K1, in[12], 6);
ROUND(dd, aa, bb, cc, F1, K1, in[13], 7);
ROUND(cc, dd, aa, bb, F1, K1, in[14], 9);
ROUND(bb, cc, dd, aa, F1, K1, in[15], 8);
/* round 2: left lane */
ROUND(aa, bb, cc, dd, F2, K2, in[7], 7);
ROUND(dd, aa, bb, cc, F2, K2, in[4], 6);
ROUND(cc, dd, aa, bb, F2, K2, in[13], 8);
ROUND(bb, cc, dd, aa, F2, K2, in[1], 13);
ROUND(aa, bb, cc, dd, F2, K2, in[10], 11);
ROUND(dd, aa, bb, cc, F2, K2, in[6], 9);
ROUND(cc, dd, aa, bb, F2, K2, in[15], 7);
ROUND(bb, cc, dd, aa, F2, K2, in[3], 15);
ROUND(aa, bb, cc, dd, F2, K2, in[12], 7);
ROUND(dd, aa, bb, cc, F2, K2, in[0], 12);
ROUND(cc, dd, aa, bb, F2, K2, in[9], 15);
ROUND(bb, cc, dd, aa, F2, K2, in[5], 9);
ROUND(aa, bb, cc, dd, F2, K2, in[2], 11);
ROUND(dd, aa, bb, cc, F2, K2, in[14], 7);
ROUND(cc, dd, aa, bb, F2, K2, in[11], 13);
ROUND(bb, cc, dd, aa, F2, K2, in[8], 12);
/* round 3: left lane */
ROUND(aa, bb, cc, dd, F3, K3, in[3], 11);
ROUND(dd, aa, bb, cc, F3, K3, in[10], 13);
ROUND(cc, dd, aa, bb, F3, K3, in[14], 6);
ROUND(bb, cc, dd, aa, F3, K3, in[4], 7);
ROUND(aa, bb, cc, dd, F3, K3, in[9], 14);
ROUND(dd, aa, bb, cc, F3, K3, in[15], 9);
ROUND(cc, dd, aa, bb, F3, K3, in[8], 13);
ROUND(bb, cc, dd, aa, F3, K3, in[1], 15);
ROUND(aa, bb, cc, dd, F3, K3, in[2], 14);
ROUND(dd, aa, bb, cc, F3, K3, in[7], 8);
ROUND(cc, dd, aa, bb, F3, K3, in[0], 13);
ROUND(bb, cc, dd, aa, F3, K3, in[6], 6);
ROUND(aa, bb, cc, dd, F3, K3, in[13], 5);
ROUND(dd, aa, bb, cc, F3, K3, in[11], 12);
ROUND(cc, dd, aa, bb, F3, K3, in[5], 7);
ROUND(bb, cc, dd, aa, F3, K3, in[12], 5);
/* round 4: left lane */
ROUND(aa, bb, cc, dd, F4, K4, in[1], 11);
ROUND(dd, aa, bb, cc, F4, K4, in[9], 12);
ROUND(cc, dd, aa, bb, F4, K4, in[11], 14);
ROUND(bb, cc, dd, aa, F4, K4, in[10], 15);
ROUND(aa, bb, cc, dd, F4, K4, in[0], 14);
ROUND(dd, aa, bb, cc, F4, K4, in[8], 15);
ROUND(cc, dd, aa, bb, F4, K4, in[12], 9);
ROUND(bb, cc, dd, aa, F4, K4, in[4], 8);
ROUND(aa, bb, cc, dd, F4, K4, in[13], 9);
ROUND(dd, aa, bb, cc, F4, K4, in[3], 14);
ROUND(cc, dd, aa, bb, F4, K4, in[7], 5);
ROUND(bb, cc, dd, aa, F4, K4, in[15], 6);
ROUND(aa, bb, cc, dd, F4, K4, in[14], 8);
ROUND(dd, aa, bb, cc, F4, K4, in[5], 6);
ROUND(cc, dd, aa, bb, F4, K4, in[6], 5);
ROUND(bb, cc, dd, aa, F4, K4, in[2], 12);
/* round 1: right lane */
ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[5], 8);
ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[14], 9);
ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[7], 9);
ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[0], 11);
ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[9], 13);
ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[2], 15);
ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[11], 15);
ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[4], 5);
ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[13], 7);
ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[6], 7);
ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[15], 8);
ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[8], 11);
ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[1], 14);
ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[10], 14);
ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[3], 12);
ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[12], 6);
/* round 2: right lane */
ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[6], 9);
ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[11], 13);
ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[3], 15);
ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[7], 7);
ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[0], 12);
ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[13], 8);
ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[5], 9);
ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[10], 11);
ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[14], 7);
ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[15], 7);
ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[8], 12);
ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[12], 7);
ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[4], 6);
ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[9], 15);
ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[1], 13);
ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[2], 11);
/* round 3: right lane */
ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[15], 9);
ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[5], 7);
ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[1], 15);
ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[3], 11);
ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[7], 8);
ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[14], 6);
ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[6], 6);
ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[9], 14);
ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[11], 12);
ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[8], 13);
ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[12], 5);
ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[2], 14);
ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[10], 13);
ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[0], 13);
ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[4], 7);
ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[13], 5);
/* round 4: right lane */
ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[8], 15);
ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[6], 5);
ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[4], 8);
ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[1], 11);
ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[3], 14);
ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[11], 14);
ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[15], 6);
ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[0], 14);
ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[5], 6);
ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[12], 9);
ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[2], 12);
ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[13], 9);
ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[9], 12);
ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[7], 5);
ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[10], 15);
ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[14], 8);
/* combine results */
ddd += cc + state[1]; /* final result for state[0] */
state[1] = state[2] + dd + aaa;
state[2] = state[3] + aa + bbb;
state[3] = state[0] + bb + ccc;
state[0] = ddd;
return;
}
static int rmd128_init(struct shash_desc *desc)
{
struct rmd128_ctx *rctx = shash_desc_ctx(desc);
rctx->byte_count = 0;
rctx->state[0] = RMD_H0;
rctx->state[1] = RMD_H1;
rctx->state[2] = RMD_H2;
rctx->state[3] = RMD_H3;
memset(rctx->buffer, 0, sizeof(rctx->buffer));
return 0;
}
static int rmd128_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct rmd128_ctx *rctx = shash_desc_ctx(desc);
const u32 avail = sizeof(rctx->buffer) - (rctx->byte_count & 0x3f);
rctx->byte_count += len;
/* Enough space in buffer? If so copy and we're done */
if (avail > len) {
memcpy((char *)rctx->buffer + (sizeof(rctx->buffer) - avail),
data, len);
goto out;
}
memcpy((char *)rctx->buffer + (sizeof(rctx->buffer) - avail),
data, avail);
rmd128_transform(rctx->state, rctx->buffer);
data += avail;
len -= avail;
while (len >= sizeof(rctx->buffer)) {
memcpy(rctx->buffer, data, sizeof(rctx->buffer));
rmd128_transform(rctx->state, rctx->buffer);
data += sizeof(rctx->buffer);
len -= sizeof(rctx->buffer);
}
memcpy(rctx->buffer, data, len);
out:
return 0;
}
/* Add padding and return the message digest. */
static int rmd128_final(struct shash_desc *desc, u8 *out)
{
struct rmd128_ctx *rctx = shash_desc_ctx(desc);
u32 i, index, padlen;
__le64 bits;
__le32 *dst = (__le32 *)out;
static const u8 padding[64] = { 0x80, };
bits = cpu_to_le64(rctx->byte_count << 3);
/* Pad out to 56 mod 64 */
index = rctx->byte_count & 0x3f;
padlen = (index < 56) ? (56 - index) : ((64+56) - index);
rmd128_update(desc, padding, padlen);
/* Append length */
rmd128_update(desc, (const u8 *)&bits, sizeof(bits));
/* Store state in digest */
for (i = 0; i < 4; i++)
dst[i] = cpu_to_le32p(&rctx->state[i]);
/* Wipe context */
memset(rctx, 0, sizeof(*rctx));
return 0;
}
static struct shash_alg alg = {
.digestsize = RMD128_DIGEST_SIZE,
.init = rmd128_init,
.update = rmd128_update,
.final = rmd128_final,
.descsize = sizeof(struct rmd128_ctx),
.base = {
.cra_name = "rmd128",
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = RMD128_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
};
static int __init rmd128_mod_init(void)
{
return crypto_register_shash(&alg);
}
static void __exit rmd128_mod_fini(void)
{
crypto_unregister_shash(&alg);
}
module_init(rmd128_mod_init);
module_exit(rmd128_mod_fini);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Adrian-Ken Rueegsegger <ken@codelabs.ch>");
MODULE_DESCRIPTION("RIPEMD-128 Message Digest");
Computing file changes ...
