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    Subject[PATCH v1 01/10] vfs: allocate page instead of names_cache buffer in mount_block_root
    First, it's incorrect to call putname() after __getname_gfp() since the
    bare __getname_gfp() call skips the auditing code, while putname()

    mount_block_root allocates a PATH_MAX buffer via __getname_gfp, and then
    calls get_fs_names to fill the buffer. That function can call
    get_filesystem_list which assumes that that buffer is a full page in
    size. On arches where PAGE_SIZE != 4k, then this could potentially

    In practice, it's hard to imagine the list of filesystem names even
    approaching 4k, but it's best to be safe. Just allocate a page for this
    purpose instead.

    With this, we can also remove the __getname_gfp() definition since there
    are no more callers.

    Signed-off-by: Jeff Layton <>
    include/linux/fs.h | 3 +--
    init/do_mounts.c | 7 ++++---
    2 files changed, 5 insertions(+), 5 deletions(-)

    diff --git a/include/linux/fs.h b/include/linux/fs.h
    index aa11047..69513a7 100644
    --- a/include/linux/fs.h
    +++ b/include/linux/fs.h
    @@ -2221,8 +2221,7 @@ extern void __init vfs_caches_init(unsigned long);

    extern struct kmem_cache *names_cachep;

    -#define __getname_gfp(gfp) kmem_cache_alloc(names_cachep, (gfp))
    -#define __getname() __getname_gfp(GFP_KERNEL)
    +#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL)
    #define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
    #define putname(name) __putname(name)
    diff --git a/init/do_mounts.c b/init/do_mounts.c
    index d3f0aee..f8a6642 100644
    --- a/init/do_mounts.c
    +++ b/init/do_mounts.c
    @@ -353,8 +353,9 @@ static int __init do_mount_root(char *name, char *fs, int flags, void *data)

    void __init mount_block_root(char *name, int flags)
    - char *fs_names = __getname_gfp(GFP_KERNEL
    + struct page *page = alloc_page(GFP_KERNEL |
    + char *fs_names = page_address(page);
    char *p;
    #ifdef CONFIG_BLOCK
    char b[BDEVNAME_SIZE];
    @@ -406,7 +407,7 @@ retry:
    panic("VFS: Unable to mount root fs on %s", b);
    - putname(fs_names);
    + put_page(page);

    #ifdef CONFIG_ROOT_NFS

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