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authorJiri Olsa <jolsa@kernel.org>2016-09-08 10:57:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-09-20 23:32:49 +0300
commitf5beeb1851ea6f8cfcf2657f26cb24c0582b4945 (patch)
treef619d5d6686ec8e43fe5f234c52f551f1febacad
parentd2ffb0103aaefa9b169da042cf39ce27bfb6cdbb (diff)
downloadlinux-f5beeb1851ea6f8cfcf2657f26cb24c0582b4945.tar.xz
fs/proc/kcore.c: Make bounce buffer global for read
Next patch adds bounce buffer for ktext area, so it's convenient to have single bounce buffer for both vmalloc/module and ktext cases. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/proc/kcore.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index a939f5ed7f89..bd3ac9dca252 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -430,6 +430,7 @@ static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
static ssize_t
read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
{
+ char *buf = file->private_data;
ssize_t acc = 0;
size_t size, tsz;
size_t elf_buflen;
@@ -500,18 +501,10 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
if (clear_user(buffer, tsz))
return -EFAULT;
} else if (is_vmalloc_or_module_addr((void *)start)) {
- char * elf_buf;
-
- elf_buf = kzalloc(tsz, GFP_KERNEL);
- if (!elf_buf)
- return -ENOMEM;
- vread(elf_buf, (char *)start, tsz);
+ vread(buf, (char *)start, tsz);
/* we have to zero-fill user buffer even if no read */
- if (copy_to_user(buffer, elf_buf, tsz)) {
- kfree(elf_buf);
+ if (copy_to_user(buffer, buf, tsz))
return -EFAULT;
- }
- kfree(elf_buf);
} else {
if (kern_addr_valid(start)) {
unsigned long n;
@@ -549,6 +542,11 @@ static int open_kcore(struct inode *inode, struct file *filp)
{
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
+
+ filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!filp->private_data)
+ return -ENOMEM;
+
if (kcore_need_update)
kcore_update_ram();
if (i_size_read(inode) != proc_root_kcore->size) {
@@ -559,10 +557,16 @@ static int open_kcore(struct inode *inode, struct file *filp)
return 0;
}
+static int release_kcore(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+ return 0;
+}
static const struct file_operations proc_kcore_operations = {
.read = read_kcore,
.open = open_kcore,
+ .release = release_kcore,
.llseek = default_llseek,
};