Peter Feiner 68b5a65248 mm: softdirty: respect VM_SOFTDIRTY in PTE holes ...

After a VMA is created with the VM_SOFTDIRTY flag set, /proc/pid/pagemap
should report that the VMA's virtual pages are soft-dirty until
VM_SOFTDIRTY is cleared (i.e., by the next write of "4" to
/proc/pid/clear_refs).  However, pagemap ignores the VM_SOFTDIRTY flag
for virtual addresses that fall in PTE holes (i.e., virtual addresses
that don't have a PMD, PUD, or PGD allocated yet).

To observe this bug, use mmap to create a VMA large enough such that
there's a good chance that the VMA will occupy an unused PMD, then test
the soft-dirty bit on its pages.  In practice, I found that a VMA that
covered a PMD's worth of address space was big enough.

This patch adds the necessary VMA lookup to the PTE hole callback in
/proc/pid/pagemap's page walk and sets soft-dirty according to the VMAs'
VM_SOFTDIRTY flag.

Signed-off-by: Peter Feiner <pfeiner@google.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2014-08-06 18:01:22 -07:00

..

array.c

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2014-08-06 08:06:39 -07:00

base.c

Merge git://git.infradead.org/users/eparis/audit

2014-04-12 12:38:53 -07:00

cmdline.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

consoles.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

cpuinfo.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

devices.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

fd.c

proc: show mnt_id in /proc/pid/fdinfo

2014-04-07 16:36:04 -07:00

fd.h

proc: Move proc_fd() to fs/proc/fd.h

2013-05-01 17:29:39 -04:00

generic.c

proc: set attributes of pde using accessor functions

2014-01-23 16:37:01 -08:00

inode.c

fs/proc/inode.c: use RCU_INIT_POINTER(x, NULL)

2014-04-07 16:36:04 -07:00

internal.h

of: remove /proc/device-tree

2014-03-11 20:48:32 +00:00

interrupts.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Kconfig

kcore: add Kconfig help text

2013-11-13 12:09:33 +09:00

kcore.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

kmsg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

loadavg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Makefile

of: remove /proc/device-tree

2014-03-11 20:48:32 +00:00

meminfo.c

mm: export NR_SHMEM via sysinfo(2) / si_meminfo() interfaces

2014-08-06 18:01:19 -07:00

namespaces.c

new helper: readlink_copy()

2014-04-01 23:19:15 -04:00

nommu.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

page.c

mm: close PageTail race

2014-03-04 07:55:47 -08:00

proc_net.c

[readdir] convert procfs

2013-06-29 12:56:32 +04:00

proc_sysctl.c

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

proc_tty.c

proc: use seq_puts()/seq_putc() where possible

2011-01-13 08:03:16 -08:00

root.c

Major changes for 3.14 include support for the newly added ZERO_RANGE

2014-04-04 15:39:39 -07:00

self.c

new helper: readlink_copy()

2014-04-01 23:19:15 -04:00

softirqs.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

stat.c

/proc/stat: convert to single_open_size()

2014-07-03 09:21:54 -07:00

task_mmu.c

mm: softdirty: respect VM_SOFTDIRTY in PTE holes

2014-08-06 18:01:22 -07:00

task_nommu.c

seq_file: remove "%n" usage from seq_file users

2013-11-15 09:32:20 +09:00

uptime.c

cputime: Default implementation of nsecs -> cputime conversion

2014-03-13 15:56:43 +01:00

version.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

vmcore.c

fs/proc/vmcore.c: remove NULL assignment to static

2014-06-06 16:08:12 -07:00