From a786c06d9f2719203c00b3d97b21f9a96980d0b5 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 11 Apr 2014 12:01:03 -0400
Subject: [PATCH] missing bits of "splice: fix racy pipe->buffers uses"
that commit has fixed only the parts of that mess in fs/splice.c itself;
there had been more in several other ->splice_read() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
kernel/relay.c | 2 +-
kernel/trace/trace.c | 4 ++--
mm/shmem.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/relay.c b/kernel/relay.c
index 98833f664fb68..7d38607649a32 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1251,7 +1251,7 @@ static ssize_t subbuf_splice_actor(struct file *in,
subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
pidx = (read_start / PAGE_SIZE) % subbuf_pages;
poff = read_start & ~PAGE_MASK;
- nr_pages = min_t(unsigned int, subbuf_pages, pipe->buffers);
+ nr_pages = min_t(unsigned int, subbuf_pages, spd.nr_pages_max);
for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {
unsigned int this_len, this_end, private;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7511de35257fa..27924caaa1243 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4410,7 +4410,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
trace_access_lock(iter->cpu_file);
/* Fill as many pages as possible. */
- for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
+ for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) {
spd.pages[i] = alloc_page(GFP_KERNEL);
if (!spd.pages[i])
break;
@@ -5267,7 +5267,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
trace_access_lock(iter->cpu_file);
entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
- for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
+ for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
struct page *page;
int r;
diff --git a/mm/shmem.c b/mm/shmem.c
index 17d3799d04bdb..37400a148f29e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1613,7 +1613,7 @@ static ssize_t shmem_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);
spd.nr_pages = find_get_pages_contig(mapping, index,
nr_pages, spd.pages);
--
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