path: root/Documentation/cgroups/freezer-subsystem.txt
diff options
authorHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>2013-07-03 15:02:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 16:07:30 -0700
commit83086978c63afd7c73e1c173c84aeab184c1e916 (patch)
tree423cb50415bfd2d3840272718591400e6a1f3b26 /Documentation/cgroups/freezer-subsystem.txt
parent591ff71664e764a3806e341370f3c758cb2e7e3c (diff)
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/freezer-subsystem.txt')
0 files changed, 0 insertions, 0 deletions

Privacy Policy