This patch defines kernel_read_file_from_fd(), a wrapper for the VFS
common kernel_read_file(), and replaces the kexec copy_file_from_fd()
calls with the kernel_read_file_from_fd() wrapper.
Signed-off-by: Mimi Zohar <zohar at linux.vnet.ibm.com>
---
fs/exec.c | 15 +++++++++++
include/linux/fs.h | 1 +
kernel/kexec_file.c | 76 +++++------------------------------------------------
3 files changed, 23 insertions(+), 69 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 3c48a19..4ad2fca 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -887,6 +887,21 @@ out:
}
EXPORT_SYMBOL_GPL(kernel_read_file);
+int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
+ int policy_id)
+{
+ struct fd f = fdget(fd);
+ int ret = -ENOEXEC;
+
+ if (!f.file)
+ goto out;
+
+ ret = kernel_read_file(f.file, buf, size, max_size, policy_id);
+out:
+ fdput(f);
+ return ret;
+}
+
ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
{
ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9b1468c..9642623 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2528,6 +2528,7 @@ extern int do_pipe_flags(int *, int);
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
extern int kernel_read_file(struct file *, void **, loff_t *, loff_t, int);
+extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t, int);
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
extern struct file * open_exec(const char *);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 81d20e8..f7c3ce4 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -34,69 +34,6 @@ size_t __weak kexec_purgatory_size = 0;
static int kexec_calculate_store_digests(struct kimage *image);
-static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len,
- enum ima_policy_id policy_id)
-{
- struct fd f = fdget(fd);
- int ret;
- struct kstat stat;
- loff_t pos;
- ssize_t bytes = 0;
-
- if (!f.file)
- return -EBADF;
-
- ret = vfs_getattr(&f.file->f_path, &stat);
- if (ret)
- goto out;
-
- if (stat.size > INT_MAX) {
- ret = -EFBIG;
- goto out;
- }
-
- /* Don't hand 0 to vmalloc, it whines. */
- if (stat.size == 0) {
- ret = -EINVAL;
- goto out;
- }
-
- *buf = vmalloc(stat.size);
- if (!*buf) {
- ret = -ENOMEM;
- goto out;
- }
-
- pos = 0;
- while (pos < stat.size) {
- bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
- stat.size - pos);
- if (bytes < 0) {
- ret = bytes;
- goto out_free;
- }
-
- if (bytes == 0)
- break;
- pos += bytes;
- }
-
- if (pos != stat.size)
- ret = -EBADF;
-
- ret = ima_hash_and_process_file(f.file, *buf, stat.size, policy_id);
- if (!ret)
- *buf_len = pos;
-out_free:
- if (ret < 0) {
- vfree(*buf);
- *buf = NULL;
- }
-out:
- fdput(f);
- return ret;
-}
-
/* Architectures can provide this probe function */
int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
@@ -185,16 +122,17 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
{
int ret = 0;
void *ldata;
+ loff_t size;
- ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
- &image->kernel_buf_len, KEXEC_CHECK);
+ ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
+ &size, INT_MAX, KEXEC_CHECK);
if (ret)
return ret;
+ image->kernel_buf_len = size;
/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
image->kernel_buf_len);
-
if (ret)
goto out;
@@ -209,11 +147,11 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
#endif
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
- ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
- &image->initrd_buf_len,
- INITRAMFS_CHECK);
+ ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
+ &size, INT_MAX, INITRAMFS_CHECK);
if (ret)
goto out;
+ image->initrd_buf_len = size;
}
if (cmdline_len) {
--
2.1.0
