• HATAYAMA Daisuke's avatar
    vmalloc: introduce remap_vmalloc_range_partial · e69e9d4a
    HATAYAMA Daisuke authored
    We want to allocate ELF note segment buffer on the 2nd kernel in vmalloc
    space and remap it to user-space in order to reduce the risk that memory
    allocation fails on system with huge number of CPUs and so with huge ELF
    note segment that exceeds 11-order block size.
    Although there's already remap_vmalloc_range for the purpose of
    remapping vmalloc memory to user-space, we need to specify user-space
    range via vma.
     Mmap on /proc/vmcore needs to remap range across multiple objects, so
    the interface that requires vma to cover full range is problematic.
    This patch introduces remap_vmalloc_range_partial that receives user-space
    range as a pair of base address and size and can be used for mmap on
    /proc/vmcore case.
    remap_vmalloc_range is rewritten using remap_vmalloc_range_partial.
    [akpm@linux-foundation.org: use PAGE_ALIGNED()]
    Signed-off-by: default avatarHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
    Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Cc: Vivek Goyal <vgoyal@redhat.com>
    Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
    Cc: Lisa Mitchell <lisa.mitchell@hp.com>
    Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
vmalloc.c 69 KB