@@ -184,29 +184,11 @@ static int show_stat(struct seq_file *p, void *v)
static int stat_open(struct inode *inode, struct file *file)
{
- size_t size = 1024 + 128 * num_possible_cpus();
- char *buf;
- struct seq_file *m;
- int res;
+ size_t size = 1024 + 128 * num_online_cpus();
/* minimum size to display an interrupt count : 2 bytes */
size += 2 * nr_irqs;
-
- /* don't ask for more than the kmalloc() max size */
- if (size > KMALLOC_MAX_SIZE)
- size = KMALLOC_MAX_SIZE;
- buf = kmalloc(size, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- res = single_open(file, show_stat, NULL);
- if (!res) {
- m = file->private_data;
- m->buf = buf;
- m->size = ksize(buf);
- } else
- kfree(buf);
- return res;
+ return single_open_size(file, show_stat, NULL, size);
}
static const struct file_operations proc_stat_operations = {
This is a note to let you know that I have just added a patch titled /proc/stat: convert to single_open_size() to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 5b00229efdd2897008cec6889ef45249986c55f5 Mon Sep 17 00:00:00 2001 From: Heiko Carstens <heiko.carstens@de.ibm.com> Date: Wed, 2 Jul 2014 15:22:37 -0700 Subject: /proc/stat: convert to single_open_size() commit f74373a5cc7a0155d232c4e999648c7a95435bb2 upstream. These two patches are supposed to "fix" failed order-4 memory allocations which have been observed when reading /proc/stat. The problem has been observed on s390 as well as on x86. To address the problem change the seq_file memory allocations to fallback to use vmalloc, so that allocations also work if memory is fragmented. This approach seems to be simpler and less intrusive than changing /proc/stat to use an interator. Also it "fixes" other users as well, which use seq_file's single_open() interface. This patch (of 2): Use seq_file's single_open_size() to preallocate a buffer that is large enough to hold the whole output, instead of open coding it. Also calculate the requested size using the number of online cpus instead of possible cpus, since the size of the output only depends on the number of online cpus. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Ian Kent <raven@themaw.net> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com> Cc: Andrea Righi <andrea@betterlinux.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/proc/stat.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) -- 1.9.1