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author | HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> | 2013-07-04 02:02:23 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-04 03:07:30 +0400 |
commit | 83086978c63afd7c73e1c173c84aeab184c1e916 (patch) | |
tree | 423cb50415bfd2d3840272718591400e6a1f3b26 /Documentation/cgroups/memory.txt | |
parent | 591ff71664e764a3806e341370f3c758cb2e7e3c (diff) | |
download | linux-83086978c63afd7c73e1c173c84aeab184c1e916.tar.xz |
vmcore: support mmap() on /proc/vmcore
This patch introduces mmap_vmcore().
Don't permit writable nor executable mapping even with mprotect()
because this mmap() is aimed at reading crash dump memory. Non-writable
mapping is also requirement of remap_pfn_range() when mapping linear
pages on non-consecutive physical pages; see is_cow_mapping().
Set VM_MIXEDMAP flag to remap memory by remap_pfn_range and by
remap_vmalloc_range_pertial at the same time for a single vma.
do_munmap() can correctly clean partially remapped vma with two
functions in abnormal case. See zap_pte_range(), vm_normal_page() and
their comments for details.
On x86-32 PAE kernels, mmap() supports at most 16TB memory only. This
limitation comes from the fact that the third argument of
remap_pfn_range(), pfn, is of 32-bit length on x86-32: unsigned long.
[akpm@linux-foundation.org: use min(), switch to conventional error-unwinding approach]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
Tested-by: Maxim Uvarov <muvarov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/cgroups/memory.txt')
0 files changed, 0 insertions, 0 deletions