Commit 237d6e68 authored Oct 25, 2016 by Michael Holzheu Committed by Martin Schwidefsky Oct 28, 2016

s390/hypfs: Use get_free_page() instead of kmalloc to ensure page alignment



Since commit d86bd1be ("mm/slub: support left redzone") it is no longer
guaranteed that kmalloc(PAGE_SIZE) returns page aligned memory.

After the above commit we get an error for diag224 because aligned
memory is required. This leads to the following user visible error:

 # mount none -t s390_hypfs /sys/hypervisor/
 mount: unknown filesystem type 's390_hypfs'

 # dmesg | grep hypfs
 hypfs.cccfb8: The hardware system does not provide all functions
               required by hypfs
 hypfs.7a79f0: Initialization of hypfs failed with rc=-61

Fix this problem and use get_free_page() instead of kmalloc() to get
correctly aligned memory.

Cc: stable@vger.kernel.org # v3.6+
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 14970f20

arch/s390/hypfs/hypfs_diag.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -363,11 +363,11 @@ static void *diag204_store(void)
		static int diag224_get_name_table(void)
		{
		/* memory must be below 2GB */
		diag224_cpu_names = kmalloc(PAGE_SIZE, GFP_KERNEL \| GFP_DMA);
		diag224_cpu_names = (char *) __get_free_page(GFP_KERNEL \| GFP_DMA);
		if (!diag224_cpu_names)
		return -ENOMEM;
		if (diag224(diag224_cpu_names)) {
		kfree(diag224_cpu_names);
		free_page((unsigned long) diag224_cpu_names);
		return -EOPNOTSUPP;
		}
		EBCASC(diag224_cpu_names + 16, (diag224_cpu_names + 1) 16);
		@@ -376,7 +376,7 @@ static int diag224_get_name_table(void)

		static void diag224_delete_name_table(void)
		{
		kfree(diag224_cpu_names);
		free_page((unsigned long) diag224_cpu_names);
		}

		static int diag224_idx2name(int index, char *name)