WSL2-Linux-Kernel/fs/proc
Naoya Horiguchi ea251c1d5c pagemap: set pagemap walk limit to PMD boundary
Currently one pagemap_read() call walks in PAGEMAP_WALK_SIZE bytes (== 512
pages.) But there is a corner case where walk_pmd_range() accidentally
runs over a VMA associated with a hugetlbfs file.

For example, when a process has mappings to VMAs as shown below:

  # cat /proc/<pid>/maps
  ...
  3a58f6d000-3a58f72000 rw-p 00000000 00:00 0
  7fbd51853000-7fbd51855000 rw-p 00000000 00:00 0
  7fbd5186c000-7fbd5186e000 rw-p 00000000 00:00 0
  7fbd51a00000-7fbd51c00000 rw-s 00000000 00:12 8614   /hugepages/test

then pagemap_read() goes into walk_pmd_range() path and walks in the range
0x7fbd51853000-0x7fbd51a53000, but the hugetlbfs VMA should be handled by
walk_hugetlb_range().  Otherwise PMD for the hugepage is considered bad
and cleared, which causes undesirable results.

This patch fixes it by separating pagemap walk range into one PMD.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-25 06:50:46 +09:00
..
Kconfig vmcore: it is not experimental any more 2010-10-26 16:52:05 -07:00
Makefile procfs: simplify conditional processing of fs/proc.o. 2010-08-11 08:59:20 -07:00
array.c CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials 2010-07-29 15:16:17 -07:00
base.c signals: move cred_guard_mutex from task_struct to signal_struct 2010-10-27 18:03:12 -07:00
cmdline.c proc: switch /proc/cmdline to seq_file 2008-10-23 14:29:04 +04:00
cpuinfo.c proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c 2008-10-23 15:05:11 +04:00
devices.c proc: move /proc/devices code to fs/proc/devices.c 2008-10-23 15:02:18 +04:00
generic.c remove inode_setattr 2010-08-09 16:47:37 -04:00
inode.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
internal.h proc: rename de_get() to pde_get() and inline it 2009-12-16 07:19:57 -08:00
interrupts.c proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c 2008-10-23 15:15:46 +04:00
kcore.c kcore: add _text to KCORE_TEXT 2010-05-27 09:12:47 -07:00
kmsg.c procfs: Use generic_file_llseek in /proc/kmsg 2010-04-09 16:35:41 +02:00
loadavg.c sched, timers: cleanup avenrun users 2009-05-15 15:32:45 +02:00
meminfo.c hwpoison: fix/proc/meminfo alignment 2009-10-29 07:39:25 -07:00
mmu.c fs/proc/mmu.c: headers butchery 2007-10-17 08:42:48 -07:00
nommu.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
page.c proc: export uncached bit properly in /proc/kpageflags 2010-09-09 18:57:23 -07:00
proc_devtree.c of: Drop properties with "/" in their name 2010-06-13 18:12:24 -06:00
proc_net.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
proc_sysctl.c fs: do not assign default i_ino in new_inode 2010-10-25 21:26:11 -04:00
proc_tty.c Revert "tty: Add a new file /proc/tty/consoles" 2010-10-23 08:14:12 -07:00
root.c switch procfs to ->mount() 2010-10-29 04:17:01 -04:00
softirqs.c procfs: fix /proc/softirqs formatting 2010-10-27 18:03:13 -07:00
stat.c /proc/stat: fix scalability of irq sum of all cpu 2010-10-27 18:03:13 -07:00
task_mmu.c pagemap: set pagemap walk limit to PMD boundary 2010-11-25 06:50:46 +09:00
task_nommu.c nommu: add '[stack]' label to /proc/pid/maps output 2010-06-29 15:29:30 -07:00
uptime.c [PATCH] Fix idle time field in /proc/uptime 2009-09-24 10:16:24 +02:00
version.c proc: switch /proc/version to seq_file 2008-10-23 14:19:58 +04:00
vmcore.c /proc/vmcore: fix seeking 2010-09-22 17:22:38 -07:00