kernel BUG at mm/slub.c:3474!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU 7
Modules linked in: ipt_ULOG tun fuse binfmt_misc nfnetlink caif_socket caif phonet bluetooth rfkill can llc2 pppoe pppox ppp_generic slhc irda crc_ccitt rds af_key decnet rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode usb_debug serio_raw pcspkr i2c_i801 e1000e nfsd nfs_acl auth_rpcgss lockd sunrpc i915 video i2c_algo_bit drm_kms_helper drm i2c_core [last unloaded: scsi_wait_scan]
Pid: 21252, comm: trinity-child7 Not tainted 3.5.0-rc1+ #74
RIP: 0010:[<ffffffff811945ce>] [<ffffffff811945ce>] kfree+0x26e/0x270
RSP: 0018:ffff880104065c48 EFLAGS: 00010246
RAX: 0020000000000000 RBX: ffff880104065d18 RCX: 0000000000000000
RDX: ffffffff7fffffff RSI: ffff880104065cf0 RDI: ffff880104065d18
RBP: ffff880104065c78 R08: 00000000fffffff2 R09: 0000000000000000
R10: ffffffff821e2d00 R11: 0000000000000001 R12: 0000000000000ffc
R13: ffffea0004101940 R14: 0000000000000000 R15: ffff880104065d98
FS: 00007f5baafd3740(0000) GS:ffff880148a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000ffc CR3: 0000000107181000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process trinity-child7 (pid: 21252, threadinfo ffff880104064000, task ffff8801080acd60)
Stack:
0000000000000010 ffff880104065cf0 0000000000000ffc fffffffffffffff2
0000000000000000 ffff880104065d98 ffff880104065c98 ffffffff811dc9ef
0000000000000018 0000000000000161 ffff880104065ec8 ffffffff811dcc4c
Call Trace:
[<ffffffff811dc9ef>] splice_shrink_spd+0x1f/0x30
[<ffffffff811dcc4c>] vmsplice_to_pipe+0x24c/0x290
[<ffffffff811db920>] ? page_cache_pipe_buf_release+0x30/0x30
[<ffffffff810b1e7e>] ? put_lock_stats.isra.23+0xe/0x40
[<ffffffff8164dee8>] ? _raw_spin_unlock_irqrestore+0x38/0x80
[<ffffffff8108cd97>] ? local_clock+0x47/0x60
[<ffffffff81078daa>] ? __hrtimer_start_range_ns+0x14a/0x530
[<ffffffff810b1ac8>] ? trace_hardirqs_off_caller+0x28/0xc0
[<ffffffff81078daa>] ? __hrtimer_start_range_ns+0x14a/0x530
[<ffffffff810b1e7e>] ? put_lock_stats.isra.23+0xe/0x40
[<ffffffff8164dee8>] ? _raw_spin_unlock_irqrestore+0x38/0x80
[<ffffffff8108cd97>] ? local_clock+0x47/0x60
[<ffffffff81050e0c>] ? do_setitimer+0x1cc/0x310
[<ffffffff810b1ac8>] ? trace_hardirqs_off_caller+0x28/0xc0
[<ffffffff81086f91>] ? get_parent_ip+0x11/0x50
[<ffffffff81651919>] ? sub_preempt_count+0x79/0xd0
[<ffffffff811ad4da>] ? fget_light+0x3ca/0x500
[<ffffffff811dd90d>] sys_vmsplice+0x9d/0x210
[<ffffffff81655937>] ? sysret_check+0x1b/0x56
[<ffffffff81326f3e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81655912>] system_call_fastpath+0x16/0x1b
Code: e8 58 ac fb ff e9 a8 fe ff ff 0f 0b 4d 8b 6d 30 e9 fe fd ff ff 4c 89 f1 48 89 da 4c 89 ee 4c 89 e7 e8 91 fd 4a 00 e9 87 fe ff ff <0f> 0b 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 48 89 fb 48 8b
RIP [<ffffffff811945ce>] kfree+0x26e/0x270
RSP <ffff880104065c48>
---[ end trace 77573bf4cc1dedea ]---
That's...
3473 if (unlikely(!PageSlab(page))) {
3474 BUG_ON(!PageCompound(page));
On Wed, 2012-06-06 at 22:51 -0400, Dave Jones wrote:
> kernel BUG at mm/slub.c:3474!
> invalid opcode: 0000 [#1] PREEMPT SMP
> CPU 7
> Modules linked in: ipt_ULOG tun fuse binfmt_misc nfnetlink caif_socket caif phonet bluetooth rfkill can llc2 pppoe pppox ppp_generic slhc irda crc_ccitt rds af_key decnet rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode usb_debug serio_raw pcspkr i2c_i801 e1000e nfsd nfs_acl auth_rpcgss lockd sunrpc i915 video i2c_algo_bit drm_kms_helper drm i2c_core [last unloaded: scsi_wait_scan]
> Pid: 21252, comm: trinity-child7 Not tainted 3.5.0-rc1+ #74
> RIP: 0010:[<ffffffff811945ce>] [<ffffffff811945ce>] kfree+0x26e/0x270
> RSP: 0018:ffff880104065c48 EFLAGS: 00010246
> RAX: 0020000000000000 RBX: ffff880104065d18 RCX: 0000000000000000
> RDX: ffffffff7fffffff RSI: ffff880104065cf0 RDI: ffff880104065d18
> RBP: ffff880104065c78 R08: 00000000fffffff2 R09: 0000000000000000
> R10: ffffffff821e2d00 R11: 0000000000000001 R12: 0000000000000ffc
> R13: ffffea0004101940 R14: 0000000000000000 R15: ffff880104065d98
> FS: 00007f5baafd3740(0000) GS:ffff880148a00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000ffc CR3: 0000000107181000 CR4: 00000000001407e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process trinity-child7 (pid: 21252, threadinfo ffff880104064000, task ffff8801080acd60)
> Stack:
> 0000000000000010 ffff880104065cf0 0000000000000ffc fffffffffffffff2
> 0000000000000000 ffff880104065d98 ffff880104065c98 ffffffff811dc9ef
> 0000000000000018 0000000000000161 ffff880104065ec8 ffffffff811dcc4c
> Call Trace:
> [<ffffffff811dc9ef>] splice_shrink_spd+0x1f/0x30
> [<ffffffff811dcc4c>] vmsplice_to_pipe+0x24c/0x290
> [<ffffffff811db920>] ? page_cache_pipe_buf_release+0x30/0x30
> [<ffffffff810b1e7e>] ? put_lock_stats.isra.23+0xe/0x40
> [<ffffffff8164dee8>] ? _raw_spin_unlock_irqrestore+0x38/0x80
> [<ffffffff8108cd97>] ? local_clock+0x47/0x60
> [<ffffffff81078daa>] ? __hrtimer_start_range_ns+0x14a/0x530
> [<ffffffff810b1ac8>] ? trace_hardirqs_off_caller+0x28/0xc0
> [<ffffffff81078daa>] ? __hrtimer_start_range_ns+0x14a/0x530
> [<ffffffff810b1e7e>] ? put_lock_stats.isra.23+0xe/0x40
> [<ffffffff8164dee8>] ? _raw_spin_unlock_irqrestore+0x38/0x80
> [<ffffffff8108cd97>] ? local_clock+0x47/0x60
> [<ffffffff81050e0c>] ? do_setitimer+0x1cc/0x310
> [<ffffffff810b1ac8>] ? trace_hardirqs_off_caller+0x28/0xc0
> [<ffffffff81086f91>] ? get_parent_ip+0x11/0x50
> [<ffffffff81651919>] ? sub_preempt_count+0x79/0xd0
> [<ffffffff811ad4da>] ? fget_light+0x3ca/0x500
> [<ffffffff811dd90d>] sys_vmsplice+0x9d/0x210
> [<ffffffff81655937>] ? sysret_check+0x1b/0x56
> [<ffffffff81326f3e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
> [<ffffffff81655912>] system_call_fastpath+0x16/0x1b
> Code: e8 58 ac fb ff e9 a8 fe ff ff 0f 0b 4d 8b 6d 30 e9 fe fd ff ff 4c 89 f1 48 89 da 4c 89 ee 4c 89 e7 e8 91 fd 4a 00 e9 87 fe ff ff <0f> 0b 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 48 89 fb 48 8b
> RIP [<ffffffff811945ce>] kfree+0x26e/0x270
> RSP <ffff880104065c48>
> ---[ end trace 77573bf4cc1dedea ]---
>
>
> That's...
>
>
> 3473 if (unlikely(!PageSlab(page))) {
> 3474 BUG_ON(!PageCompound(page));
>
Thanks Dave, I'll take a look today on this report.
On Thu, 2012-06-07 at 06:27 +0200, Eric Dumazet wrote:
> Thanks Dave, I'll take a look today on this report.
>
OK, trivial bug, I am testing a fix, thanks again.
On Thu, 2012-06-07 at 06:40 +0200, Eric Dumazet wrote:
> On Thu, 2012-06-07 at 06:27 +0200, Eric Dumazet wrote:
>
> > Thanks Dave, I'll take a look today on this report.
> >
>
> OK, trivial bug, I am testing a fix, thanks again.
>
Not sure if you can reproduce this bug easily, if so could you test
following patch ?
Problem is that bipe->buffers can change anytime if we dont lock the
pipe mutex. So we must store in spd a new nr_pages_max field to shadow
pipe->buffers for the duration of the syscall.
Bug introduced in commit 35f3d14dbbc ( pipe: add support for shrinking
and growing pipes )
Thanks
fs/splice.c | 35 ++++++++++++++++++++---------------
include/linux/splice.h | 8 ++++----
kernel/relay.c | 5 +++--
kernel/trace/trace.c | 6 ++++--
mm/shmem.c | 3 ++-
net/core/skbuff.c | 1 +
6 files changed, 34 insertions(+), 24 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c
index c9f1318..7bf08fa 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -273,13 +273,16 @@ void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
* Check if we need to grow the arrays holding pages and partial page
* descriptions.
*/
-int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
+int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ unsigned int buffers = ACCESS_ONCE(pipe->buffers);
+
+ spd->nr_pages_max = buffers;
+ if (buffers <= PIPE_DEF_BUFFERS)
return 0;
- spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
- spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
+ spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL);
+ spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL);
if (spd->pages && spd->partial)
return 0;
@@ -289,10 +292,9 @@ int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
return -ENOMEM;
}
-void splice_shrink_spd(struct pipe_inode_info *pipe,
- struct splice_pipe_desc *spd)
+void splice_shrink_spd(struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
return;
kfree(spd->pages);
@@ -315,6 +317,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &page_cache_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -326,7 +329,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
index = *ppos >> PAGE_CACHE_SHIFT;
loff = *ppos & ~PAGE_CACHE_MASK;
req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- nr_pages = min(req_pages, pipe->buffers);
+ nr_pages = min(req_pages, spd.nr_pages_max);
/*
* Lookup the (hopefully) full range of pages we need.
@@ -497,7 +500,7 @@ fill_it:
if (spd.nr_pages)
error = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return error;
}
@@ -598,6 +601,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &default_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -608,8 +612,8 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
res = -ENOMEM;
vec = __vec;
- if (pipe->buffers > PIPE_DEF_BUFFERS) {
- vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
+ if (spd.nr_pages_max > PIPE_DEF_BUFFERS) {
+ vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL);
if (!vec)
goto shrink_ret;
}
@@ -617,7 +621,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
offset = *ppos & ~PAGE_CACHE_MASK;
nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
+ for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) {
struct page *page;
page = alloc_page(GFP_USER);
@@ -665,7 +669,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
shrink_ret:
if (vec != __vec)
kfree(vec);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return res;
err:
@@ -1614,6 +1618,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &user_page_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -1629,13 +1634,13 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
spd.partial, false,
- pipe->buffers);
+ spd.nr_pages_max);
if (spd.nr_pages <= 0)
ret = spd.nr_pages;
else
ret = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return ret;
}
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 26e5b61..09a545a 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -51,7 +51,8 @@ struct partial_page {
struct splice_pipe_desc {
struct page **pages; /* page map */
struct partial_page *partial; /* pages[] may not be contig */
- int nr_pages; /* number of pages in map */
+ int nr_pages; /* number of populated pages in map */
+ unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
unsigned int flags; /* splice flags */
const struct pipe_buf_operations *ops;/* ops associated with output pipe */
void (*spd_release)(struct splice_pipe_desc *, unsigned int);
@@ -85,9 +86,8 @@ extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
/*
* for dynamic pipe sizing
*/
-extern int splice_grow_spd(struct pipe_inode_info *, struct splice_pipe_desc *);
-extern void splice_shrink_spd(struct pipe_inode_info *,
- struct splice_pipe_desc *);
+extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
+extern void splice_shrink_spd(struct splice_pipe_desc *);
extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
diff --git a/kernel/relay.c b/kernel/relay.c
index ab56a17..e8cd202 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1235,6 +1235,7 @@ static ssize_t subbuf_splice_actor(struct file *in,
struct splice_pipe_desc spd = {
.pages = pages,
.nr_pages = 0,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.partial = partial,
.flags = flags,
.ops = &relay_pipe_buf_ops,
@@ -1302,8 +1303,8 @@ static ssize_t subbuf_splice_actor(struct file *in,
ret += padding;
out:
- splice_shrink_spd(pipe, &spd);
- return ret;
+ splice_shrink_spd(&spd);
+ return ret;
}
static ssize_t relay_file_splice_read(struct file *in,
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 68032c6..2884880 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3609,6 +3609,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
.pages = pages_def,
.partial = partial_def,
.nr_pages = 0, /* This gets updated below. */
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &tracing_pipe_buf_ops,
.spd_release = tracing_spd_release_pipe,
@@ -3680,7 +3681,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
ret = splice_to_pipe(pipe, &spd);
out:
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return ret;
out_err:
@@ -4231,6 +4232,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages_def,
.partial = partial_def,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &buffer_pipe_buf_ops,
.spd_release = buffer_spd_release,
@@ -4318,7 +4320,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
}
ret = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
out:
return ret;
}
diff --git a/mm/shmem.c b/mm/shmem.c
index 585bd220..c244e93 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1577,6 +1577,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &page_cache_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -1665,7 +1666,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
if (spd.nr_pages)
error = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
if (error > 0) {
*ppos += error;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 016694d..bac3c57 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1755,6 +1755,7 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = MAX_SKB_FRAGS,
.flags = flags,
.ops = &sock_pipe_buf_ops,
.spd_release = sock_spd_release,
On Thu, 2012-06-07 at 07:52 +0200, Eric Dumazet wrote:
> On Thu, 2012-06-07 at 06:40 +0200, Eric Dumazet wrote:
> > On Thu, 2012-06-07 at 06:27 +0200, Eric Dumazet wrote:
> >
> > > Thanks Dave, I'll take a look today on this report.
> > >
> >
> > OK, trivial bug, I am testing a fix, thanks again.
> >
>
> Not sure if you can reproduce this bug easily, if so could you test
> following patch ?
By the way, following program triggers the bug instantly :
#define __USE_GNU 1
#define _GNU_SOURCE
#include <fcntl.h>
#include <pthread.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
int pfd[2];
void *worker(void *arg)
{
unsigned int page_size = 4096;
while (1) {
fcntl(pfd[1], F_SETPIPE_SZ, 16 * page_size);
fcntl(pfd[1], F_SETPIPE_SZ, 64 * page_size);
}
}
char buffer[1024*1024];
int main(int argc, char *argv[])
{
pthread_t tid;
int res, fdnull = open("/dev/null", O_WRONLY);
if (pipe(pfd) == -1) {
perror("pipe");
return 1;
}
res = pthread_create(&tid, NULL, worker, NULL);
if (res) {
errno = res;
perror("pthread_create");
return 1;
}
while (1) {
struct iovec iov[1];
int wr;
iov[0].iov_base = buffer;
iov[0].iov_len = 1024*1024;
wr = vmsplice(pfd[1], iov, 1, SPLICE_F_GIFT);
if (wr > 0) {
wr = splice(pfd[0], NULL,
fdnull, NULL,
wr, SPLICE_F_MOVE | SPLICE_F_MORE);
}
}
}
From: Eric Dumazet <[email protected]>
Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()
commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe->buffers.
Problem is some paths don't hold pipe mutex and assume pipe->buffers
doesn't change for their duration.
Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe->buffers where appropriate.
splice_shrink_spd() loses its struct pipe_inode_info argument.
Reported-by: Dave Jones <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Tom Herbert <[email protected]>
Cc: stable <[email protected]> # 2.6.35
---
fs/splice.c | 35 ++++++++++++++++++++---------------
include/linux/splice.h | 8 ++++----
kernel/relay.c | 5 +++--
kernel/trace/trace.c | 6 ++++--
mm/shmem.c | 3 ++-
net/core/skbuff.c | 1 +
6 files changed, 34 insertions(+), 24 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c
index c9f1318..7bf08fa 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -273,13 +273,16 @@ void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
* Check if we need to grow the arrays holding pages and partial page
* descriptions.
*/
-int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
+int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ unsigned int buffers = ACCESS_ONCE(pipe->buffers);
+
+ spd->nr_pages_max = buffers;
+ if (buffers <= PIPE_DEF_BUFFERS)
return 0;
- spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
- spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
+ spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL);
+ spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL);
if (spd->pages && spd->partial)
return 0;
@@ -289,10 +292,9 @@ int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
return -ENOMEM;
}
-void splice_shrink_spd(struct pipe_inode_info *pipe,
- struct splice_pipe_desc *spd)
+void splice_shrink_spd(struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
return;
kfree(spd->pages);
@@ -315,6 +317,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &page_cache_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -326,7 +329,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
index = *ppos >> PAGE_CACHE_SHIFT;
loff = *ppos & ~PAGE_CACHE_MASK;
req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- nr_pages = min(req_pages, pipe->buffers);
+ nr_pages = min(req_pages, spd.nr_pages_max);
/*
* Lookup the (hopefully) full range of pages we need.
@@ -497,7 +500,7 @@ fill_it:
if (spd.nr_pages)
error = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return error;
}
@@ -598,6 +601,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &default_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -608,8 +612,8 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
res = -ENOMEM;
vec = __vec;
- if (pipe->buffers > PIPE_DEF_BUFFERS) {
- vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
+ if (spd.nr_pages_max > PIPE_DEF_BUFFERS) {
+ vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL);
if (!vec)
goto shrink_ret;
}
@@ -617,7 +621,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
offset = *ppos & ~PAGE_CACHE_MASK;
nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
+ for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) {
struct page *page;
page = alloc_page(GFP_USER);
@@ -665,7 +669,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
shrink_ret:
if (vec != __vec)
kfree(vec);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return res;
err:
@@ -1614,6 +1618,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &user_page_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -1629,13 +1634,13 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
spd.partial, false,
- pipe->buffers);
+ spd.nr_pages_max);
if (spd.nr_pages <= 0)
ret = spd.nr_pages;
else
ret = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return ret;
}
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 26e5b61..09a545a 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -51,7 +51,8 @@ struct partial_page {
struct splice_pipe_desc {
struct page **pages; /* page map */
struct partial_page *partial; /* pages[] may not be contig */
- int nr_pages; /* number of pages in map */
+ int nr_pages; /* number of populated pages in map */
+ unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
unsigned int flags; /* splice flags */
const struct pipe_buf_operations *ops;/* ops associated with output pipe */
void (*spd_release)(struct splice_pipe_desc *, unsigned int);
@@ -85,9 +86,8 @@ extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
/*
* for dynamic pipe sizing
*/
-extern int splice_grow_spd(struct pipe_inode_info *, struct splice_pipe_desc *);
-extern void splice_shrink_spd(struct pipe_inode_info *,
- struct splice_pipe_desc *);
+extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
+extern void splice_shrink_spd(struct splice_pipe_desc *);
extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
diff --git a/kernel/relay.c b/kernel/relay.c
index ab56a17..e8cd202 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1235,6 +1235,7 @@ static ssize_t subbuf_splice_actor(struct file *in,
struct splice_pipe_desc spd = {
.pages = pages,
.nr_pages = 0,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.partial = partial,
.flags = flags,
.ops = &relay_pipe_buf_ops,
@@ -1302,8 +1303,8 @@ static ssize_t subbuf_splice_actor(struct file *in,
ret += padding;
out:
- splice_shrink_spd(pipe, &spd);
- return ret;
+ splice_shrink_spd(&spd);
+ return ret;
}
static ssize_t relay_file_splice_read(struct file *in,
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 68032c6..2884880 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3609,6 +3609,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
.pages = pages_def,
.partial = partial_def,
.nr_pages = 0, /* This gets updated below. */
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &tracing_pipe_buf_ops,
.spd_release = tracing_spd_release_pipe,
@@ -3680,7 +3681,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
ret = splice_to_pipe(pipe, &spd);
out:
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return ret;
out_err:
@@ -4231,6 +4232,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages_def,
.partial = partial_def,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &buffer_pipe_buf_ops,
.spd_release = buffer_spd_release,
@@ -4318,7 +4320,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
}
ret = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
out:
return ret;
}
diff --git a/mm/shmem.c b/mm/shmem.c
index 585bd220..c244e93 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1577,6 +1577,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &page_cache_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -1665,7 +1666,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
if (spd.nr_pages)
error = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
if (error > 0) {
*ppos += error;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 016694d..bac3c57 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1755,6 +1755,7 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = MAX_SKB_FRAGS,
.flags = flags,
.ops = &sock_pipe_buf_ops,
.spd_release = sock_spd_release,
On Thu, Jun 07, 2012 at 07:52:45AM +0200, Eric Dumazet wrote:
> On Thu, 2012-06-07 at 06:40 +0200, Eric Dumazet wrote:
> > On Thu, 2012-06-07 at 06:27 +0200, Eric Dumazet wrote:
> >
> > > Thanks Dave, I'll take a look today on this report.
> > >
> >
> > OK, trivial bug, I am testing a fix, thanks again.
> >
>
> Not sure if you can reproduce this bug easily, if so could you test
> following patch ?
haven't seen this reoccur since applying this patch, so it looks good to me.
Tested-by: Dave Jones <[email protected]>