linux/fs
KOSAKI Motohiro e575f111dc coredump_filter: add hugepage dumping
Presently hugepage's vma has a VM_RESERVED flag in order not to be
swapped.  But a VM_RESERVED vma isn't core dumped because this flag is
often used for some kernel vmas (e.g.  vmalloc, sound related).

Thus hugepages are never dumped and it can't be debugged easily.  Many
developers want hugepages to be included into core-dump.

However, We can't read generic VM_RESERVED area because this area is often
IO mapping area.  then these area reading may change device state.  it is
definitly undesiable side-effect.

So adding a hugepage specific bit to the coredump filter is better.  It
will be able to hugepage core dumping and doesn't cause any side-effect to
any i/o devices.

In additional, libhugetlb use hugetlb private mapping pages as anonymous
page.  Then, hugepage private mapping pages should be core dumped by
default.

Then, /proc/[pid]/core_dump_filter has two new bits.

 - bit 5 mean hugetlb private mapping pages are dumped or not. (default: yes)
 - bit 6 mean hugetlb shared mapping pages are dumped or not.  (default: no)

I tested by following method.

% ulimit -c unlimited
% ./crash_hugepage  50
% ./crash_hugepage  50  -p
% ls -lh
% gdb ./crash_hugepage core
%
% echo 0x43 > /proc/self/coredump_filter
% ./crash_hugepage  50
% ./crash_hugepage  50  -p
% ls -lh
% gdb ./crash_hugepage core

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>

#include "hugetlbfs.h"

int main(int argc, char** argv){
	char* p;
	int ch;
	int mmap_flags = MAP_SHARED;
	int fd;
	int nr_pages;

	while((ch = getopt(argc, argv, "p")) != -1) {
		switch (ch) {
		case 'p':
			mmap_flags &= ~MAP_SHARED;
			mmap_flags |= MAP_PRIVATE;
			break;
		default:
			/* nothing*/
			break;
		}
	}
	argc -= optind;
	argv += optind;

	if (argc == 0){
		printf("need # of pages\n");
		exit(1);
	}

	nr_pages = atoi(argv[0]);
	if (nr_pages < 2) {
		printf("nr_pages must >2\n");
		exit(1);
	}

	fd = hugetlbfs_unlinked_fd();
	p = mmap(NULL, nr_pages * gethugepagesize(),
		 PROT_READ|PROT_WRITE, mmap_flags, fd, 0);

	sleep(2);

	*(p + gethugepagesize()) = 1; /* COW */
	sleep(2);

	/* crash! */
	*(int*)0 = 1;

	return 0;
}

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Kawai Hidehiro <hidehiro.kawai.ez@hitachi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: William Irwin <wli@holomorphy.com>
Cc: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:32 -07:00
..
9p vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
adfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
affs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
afs afs: convert to new aops 2008-10-16 11:21:48 -07:00
autofs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
autofs4 autofs4: add miscellaneous device for ioctls 2008-10-16 11:21:39 -07:00
befs befs: annotate fs32 on tests for superblock endianness 2008-10-16 11:21:46 -07:00
bfs bfs: fix Lockdep warning 2008-09-13 14:41:51 -07:00
cifs vmscan: split LRU lists into anon & file sets 2008-10-20 08:50:25 -07:00
coda device create: misc: convert device_create_drvdata to device_create 2008-10-16 09:24:43 -07:00
configfs [PATCH] configfs: Consolidate locking around configfs_detach_prep() in configfs_rmdir() 2008-08-22 11:09:02 -07:00
cramfs cramfs: fix named-pipe handling 2008-08-20 15:40:32 -07:00
debugfs integrity: special fs magic 2008-10-13 09:47:43 +11:00
devpts vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
dlm dlm: choose better identifiers 2008-09-05 09:51:30 -05:00
ecryptfs eCryptfs: remove netlink transport 2008-10-16 11:21:39 -07:00
efs EFS: Don't set f_fsid in statfs(). 2008-09-02 23:15:22 +01:00
exportfs fs: replace remaining __FUNCTION__ occurrences 2008-04-30 08:29:54 -07:00
ext2 ext2: avoid printk floods in the face of directory corruption 2008-10-16 11:21:46 -07:00
ext3 vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
ext4 ext4: Remove automatic enabling of the HUGE_FILE feature flag 2008-10-16 22:50:48 -04:00
fat vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
freevxfs fs/freevxfs/: proper externs 2008-04-29 08:06:00 -07:00
fuse vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
gfs2 vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
hfs hfs: fix namelength memory corruption 2008-10-16 11:21:46 -07:00
hfsplus hfsplus: check read_mapping_page() return value 2008-10-16 11:21:46 -07:00
hostfs [PATCH] sanitize ->permission() prototype 2008-07-26 20:53:14 -04:00
hpfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
hppfs [patch] hppfs: remove hppfs_permission 2008-07-26 20:53:07 -04:00
hugetlbfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
isofs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
jbd Merge branch 'core/locking' into core/urgent 2008-08-12 00:11:49 +02:00
jbd2 ext4: Replace hackish ext4_mb_poll_new_transaction with commit callback 2008-10-16 20:00:24 -04:00
jffs2 removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
jfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
lockd NLM: Remove "proto" argument from lockd_up() 2008-10-04 17:12:27 -04:00
minix SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
msdos fatfs: add UTC timestamp option 2008-07-25 10:53:34 -07:00
ncpfs [PATCH] don't pass nameidata to __ncp_lookup_validate() 2008-07-26 20:53:37 -04:00
nfs vmscan: split LRU lists into anon & file sets 2008-10-20 08:50:25 -07:00
nfs_common
nfsd NLM: Remove unused argument from svc_addsock() function 2008-10-04 17:12:27 -04:00
nls remove CONFIG_KMOD from fs 2008-10-17 02:38:36 +11:00
ntfs vmscan: split LRU lists into anon & file sets 2008-10-20 08:50:25 -07:00
ocfs2 ocfs2: fix build error 2008-10-14 18:31:46 -07:00
omfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
openpromfs SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
partitions block: add partition attribute for partition number 2008-10-17 08:46:56 +02:00
proc vmstat: mlocked pages statistics 2008-10-20 08:52:31 -07:00
qnx4 SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
ramfs Ramfs and Ram Disk pages are unevictable 2008-10-20 08:50:26 -07:00
reiserfs fs/reiserfs: use an IS_ERR test rather than a NULL test 2008-10-16 11:21:46 -07:00
romfs romfs_readpage: don't report errors for pages beyond i_size 2008-07-30 14:30:34 -07:00
smbfs [PATCH] sanitize ->permission() prototype 2008-07-26 20:53:14 -04:00
sysfs kobject: Cleanup kobject_rename and !CONFIG_SYSFS 2008-10-16 09:24:52 -07:00
sysv SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
ubifs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
udf vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
ufs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
vfat fatfs: add UTC timestamp option 2008-07-25 10:53:34 -07:00
xfs xfs: fix remount rw with unrecognized options 2008-10-15 10:00:00 -07:00
aio.c [PATCH] f_count may wrap around 2008-07-26 20:53:40 -04:00
anon_inodes.c flag parameters: NONBLOCK in anon_inode_getfd 2008-07-24 10:47:28 -07:00
attr.c [patch 4/4] vfs: immutable inode checking cleanup 2008-07-26 20:53:28 -04:00
bad_inode.c [PATCH] sanitize ->permission() prototype 2008-07-26 20:53:14 -04:00
binfmt_aout.c tracehook: exec 2008-07-26 12:00:08 -07:00
binfmt_elf_fdpic.c binfmt_elf_fdpic: wire up AT_EXECFD, AT_EXECFN, AT_SECURE 2008-10-16 11:21:46 -07:00
binfmt_elf.c coredump_filter: add hugepage dumping 2008-10-20 08:52:32 -07:00
binfmt_em86.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_flat.c uclinux: fix gzip header parsing in binfmt_flat.c 2008-10-16 11:21:29 -07:00
binfmt_misc.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_script.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_som.c binfmt_som.c: add MODULE_LICENSE 2008-10-16 11:21:38 -07:00
bio-integrity.c block: Introduce integrity data ownership flag 2008-10-09 08:56:21 +02:00
bio.c block: mark bio_split_pool static 2008-10-09 08:57:05 +02:00
block_dev.c block: fix current kernel-doc warnings 2008-10-17 08:46:57 +02:00
buffer.c fs: buffer lock use lock bitops 2008-10-20 08:52:32 -07:00
char_dev.c remove CONFIG_KMOD from fs 2008-10-17 02:38:36 +11:00
compat_binfmt_elf.c
compat_ioctl.c remove unused #include <linux/dirent.h>'s 2008-07-25 10:53:34 -07:00
compat.c compat: move cp_compat_stat to common code 2008-10-16 11:21:33 -07:00
dcache.c Fix NULL pointer dereference in proc_sys_compare 2008-09-29 07:42:57 -07:00
dcookies.c d_path: Make d_path() use a struct path 2008-02-14 21:17:09 -08:00
direct-io.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
dnotify.c [PATCH] split linux/file.h 2008-05-01 13:08:16 -04:00
dquot.c quota: remove CVS keywords 2008-10-16 11:21:46 -07:00
drop_caches.c vfs: skip inodes without pages to free in drop_pagecache_sb() 2008-04-29 08:06:05 -07:00
eventfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
eventpoll.c epoll: drop unnecessary test 2008-10-16 11:21:32 -07:00
exec.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 2008-10-16 12:38:34 -07:00
fcntl.c [PATCH] clean dup2() up a bit 2008-08-01 11:25:24 -04:00
fifo.c [PATCH] reuse xxx_fifo_fops for xxx_pipe_fops 2008-07-26 20:53:06 -04:00
file_table.c [PATCH] f_count may wrap around 2008-07-26 20:53:40 -04:00
file.c [PATCH] merge locate_fd() and get_unused_fd() 2008-08-01 11:25:23 -04:00
filesystems.c
fs-writeback.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
generic_acl.c
inode.c fs/inode.c: properly init address_space->writeback_index 2008-08-15 08:35:44 -07:00
inotify_user.c inotify: fix lock ordering wrt do_page_fault's mmap_sem 2008-10-02 15:53:13 -07:00
inotify.c
internal.h [PATCH] move a bunch of declarations to fs/internal.h 2008-04-21 23:11:01 -04:00
ioctl.c provide generic_block_fiemap() only with BLOCK=y 2008-10-12 11:44:37 -07:00
ioprio.c fix setpriority(PRIO_PGRP) thread iterator breakage 2008-08-20 15:40:32 -07:00
Kconfig Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2 2008-10-14 16:34:11 -07:00
Kconfig.binfmt COMPAT_BINFMT_ELF definition tweak 2008-10-16 11:21:47 -07:00
libfs.c VFS: increase pseudo-filesystem block size to PAGE_SIZE 2008-07-30 09:41:44 -07:00
locks.c SL*B: drop kmem cache argument from constructor 2008-07-26 12:00:07 -07:00
Makefile Configure out AIO support 2008-10-16 11:21:51 -07:00
mbcache.c vfs: fix possible deadlock in ext2, ext3, ext4 when using xattrs 2008-04-15 19:35:41 -07:00
mpage.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
namei.c [patch 3/4] vfs: remove unused nameidata argument of may_create() 2008-08-01 11:25:30 -04:00
namespace.c [PATCH] pass struct path * to do_add_mount() 2008-08-01 11:25:32 -04:00
nfsctl.c Introduce path_put() 2008-02-14 21:13:33 -08:00
no-block.c
open.c tty: the vhangup syscall is racy 2008-10-13 09:51:41 -07:00
pipe.c [PATCH] reuse xxx_fifo_fops for xxx_pipe_fops 2008-07-26 20:53:06 -04:00
pnode.c [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
pnode.h [patch 7/7] vfs: mountinfo: show dominating group id 2008-04-23 00:05:09 -04:00
posix_acl.c
quota_v1.c quota: move function-macros from quota.h to quotaops.h 2008-07-25 10:53:35 -07:00
quota_v2.c quota: move function-macros from quota.h to quotaops.h 2008-07-25 10:53:35 -07:00
quota.c quota: cleanup loop in sync_dquots() 2008-07-25 10:53:35 -07:00
read_write.c Remove BKL from remote_llseek v2 2008-07-02 15:06:27 -06:00
read_write.h
readdir.c [PATCH] fix regular readdir() and friends 2008-08-25 01:18:08 -04:00
select.c Fix performance regression on lmbench select benchmark 2008-06-22 12:23:15 -07:00
seq_file.c [PATCH] deal with the first call of ->show() generating no output 2008-08-25 01:18:10 -04:00
signalfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
splice.c Don't allow splice() to files opened with O_APPEND 2008-10-09 14:26:38 -07:00
stack.c
stat.c [PATCH] sanitize __user_walk_fd() et.al. 2008-07-26 20:53:34 -04:00
super.c fix soft lock up at NFS mount via per-SB LRU-list of unused dentries 2008-07-24 10:47:15 -07:00
sync.c SYNC_FILE_RANGE_WRITE may and will block. Document that. 2008-07-24 10:47:17 -07:00
timerfd.c flag parameters: check magic constants 2008-07-24 10:47:29 -07:00
utimes.c [PATCH] sanitize __user_walk_fd() et.al. 2008-07-26 20:53:34 -04:00
xattr_acl.c
xattr.c [PATCH] sanitize __user_walk_fd() et.al. 2008-07-26 20:53:34 -04:00