[PATCH 4/7] dm: use kvmalloc

From: Mikulas Patocka
Date: Tue Jul 07 2015 - 11:11:26 EST


Use the function kvmalloc to allocate ioctl parameters.

Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>

---
drivers/md/dm-ioctl.c | 26 +++++---------------------
drivers/md/dm-table.c | 37 +++++++++++++++++++++++++++++++++++++
include/linux/device-mapper.h | 2 ++
3 files changed, 44 insertions(+), 21 deletions(-)

Index: linux-4.1/drivers/md/dm-ioctl.c
===================================================================
--- linux-4.1.orig/drivers/md/dm-ioctl.c 2015-07-02 19:21:15.000000000 +0200
+++ linux-4.1/drivers/md/dm-ioctl.c 2015-07-02 19:21:21.000000000 +0200
@@ -1676,12 +1676,8 @@ static void free_params(struct dm_ioctl
if (param_flags & DM_WIPE_BUFFER)
memset(param, 0, param_size);

- if (param_flags & DM_PARAMS_ALLOC) {
- if (is_vmalloc_addr(param))
- vfree(param);
- else
- kfree(param);
- }
+ if (param_flags & DM_PARAMS_ALLOC)
+ kvfree(param);
}

static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
@@ -1712,21 +1708,7 @@ static int copy_params(struct dm_ioctl _
* Try to avoid low memory issues when a device is suspended.
* Use kmalloc() rather than vmalloc() when we can.
*/
- dmi = NULL;
- if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
- dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
- if (dmi)
- *param_flags |= DM_PARAMS_ALLOC;
- }
-
- if (!dmi) {
- unsigned noio_flag;
- noio_flag = memalloc_noio_save();
- dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
- memalloc_noio_restore(noio_flag);
- if (dmi)
- *param_flags |= DM_PARAMS_ALLOC;
- }
+ dmi = kvmalloc(param_kernel->data_size, GFP_NOIO);

if (!dmi) {
if (secure_data && clear_user(user, param_kernel->data_size))
@@ -1734,6 +1716,8 @@ static int copy_params(struct dm_ioctl _
return -ENOMEM;
}

+ *param_flags |= DM_PARAMS_ALLOC;
+
if (copy_from_user(dmi, user, param_kernel->data_size))
goto bad;


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