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* Merge branch 'work.misc' of ↵Linus Torvalds2016-10-10103-448/+557
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
| * Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro2016-10-0871-220/+290
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| | * fs: Avoid premature clearing of capabilitiesJan Kara2016-09-221-6/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, notify_change() clears capabilities or IMA attributes by calling security_inode_killpriv() before calling into ->setattr. Thus it happens before any other permission checks in inode_change_ok() and user is thus allowed to trigger clearing of capabilities or IMA attributes for any file he can look up e.g. by calling chown for that file. This is unexpected and can lead to user DoSing a system. Fix the problem by calling security_inode_killpriv() at the end of inode_change_ok() instead of from notify_change(). At that moment we are sure user has permissions to do the requested change. References: CVE-2015-1350 Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
| | * fs: Give dentry to inode_change_ok() instead of inodeJan Kara2016-09-2247-63/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
| | * fuse: Propagate dentry down to inode_change_ok()Jan Kara2016-09-223-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid clearing of capabilities or security related extended attributes too early, inode_change_ok() will need to take dentry instead of inode. Propagate it down to fuse_do_setattr(). Acked-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
| | * ceph: Propagate dentry down to inode_change_ok()Jan Kara2016-09-222-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid clearing of capabilities or security related extended attributes too early, inode_change_ok() will need to take dentry instead of inode. ceph_setattr() has the dentry easily available but __ceph_setattr() is also called from ceph_set_acl() where dentry is not easily available. Luckily that call path does not need inode_change_ok() to be called anyway. So reorganize functions a bit so that inode_change_ok() is called only from paths where dentry is available. Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
| | * xfs: Propagate dentry down to inode_change_ok()Jan Kara2016-09-225-35/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid clearing of capabilities or security related extended attributes too early, inode_change_ok() will need to take dentry instead of inode. Propagate dentry down to functions calling inode_change_ok(). This is rather straightforward except for xfs_set_mode() function which does not have dentry easily available. Luckily that function does not call inode_change_ok() anyway so we just have to do a little dance with function prototypes. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
| | * posix_acl: Clear SGID bit when setting file permissionsJan Kara2016-09-2215-102/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
| * | Merge remote-tracking branch 'ovl/misc' into work.miscAl Viro2016-10-0819-88/+139
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| | * | vfat: don't use ->d_timeMiklos Szeredi2016-09-161-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use d_fsdata instead, which is the same size. Introduce helpers to hide the typecasts. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
| | * | cifs: don't use ->d_timeMiklos Szeredi2016-09-163-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use d_fsdata instead, which is the same size. Introduce helpers to hide the typecasts. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Steve French <sfrench@samba.org>
| | * | posix_acl: don't ignore return value of posix_acl_create_masq()Miklos Szeredi2016-09-161-5/+6
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com>
| | * | f2fs: use filemap_check_errors()Miklos Szeredi2016-09-161-5/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org>
| | * | btrfs: use filemap_check_errors()Miklos Szeredi2016-09-164-19/+3
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Cc: Chris Mason <clm@fb.com>
| | * | vfs: do get_write_access() on upper layer of overlayfsMiklos Szeredi2016-09-162-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem with writecount is: we want consistent handling of it for underlying filesystems as well as overlayfs. Making sure i_writecount is correct on all layers is difficult. Instead this patch makes sure that when write access is acquired, it's always done on the underlying writable layer (called the upper layer). We must also make sure to look at the writecount on this layer when checking for conflicting leases. Open for write already updates the upper layer's writecount. Leaving only truncate. For truncate copy up must happen before get_write_access() so that the writecount is updated on the upper layer. Problem with this is if something fails after that, then copy-up was done needlessly. E.g. if break_lease() was interrupted. Probably not a big deal in practice. Another interesting case is if there's a denywrite on a lower file that is then opened for write or truncated. With this patch these will succeed, which is somewhat counterintuitive. But I think it's still acceptable, considering that the copy-up does actually create a different file, so the old, denywrite mapping won't be touched. On non-overlayfs d_real() is an identity function and d_real_inode() is equivalent to d_inode() so this patch doesn't change behavior in that case. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org>
| | * | locks: fix file locking on overlayfsMiklos Szeredi2016-09-164-25/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows flock, posix locks, ofd locks and leases to work correctly on overlayfs. Instead of using the underlying inode for storing lock context use the overlay inode. This allows locks to be persistent across copy-up. This is done by introducing locks_inode() helper and using it instead of file_inode() to get the inode in locking code. For non-overlayfs the two are equivalent, except for an extra pointer dereference in locks_inode(). Since lock operations are in "struct file_operations" we must also make sure not to call underlying filesystem's lock operations. Introcude a super block flag MS_NOREMOTELOCK to this effect. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org>
| | * | vfs: update ovl inode before relatime checkMiklos Szeredi2016-09-163-7/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On overlayfs relatime_need_update() needs inode times to be correct on overlay inode. But i_mtime and i_ctime are updated by filesystem code on underlying inode only, so they will be out-of-date on the overlay inode. This patch copies the times from the underlying inode if needed. This can't be done if called from RCU lookup (link following) but link m/ctime are not updated by fs, so this is all right. This patch doesn't change functionality for anything but overlayfs. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| | * | vfs: move permission checking into notify_change() for utimes(NULL)Miklos Szeredi2016-09-162-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a bug where the permission was not properly checked in overlayfs. The testcase is ltp/utimensat01. It is also cleaner and safer to do the permission checking in the vfs helper instead of the caller. This patch introduces an additional ia_valid flag ATTR_TOUCH (since touch(1) is the most obvious user of utimes(NULL)) that is passed into notify_change whenever the conditions for this special permission checking mode are met. Reported-by: Aihua Zhang <zhangaihua1@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Aihua Zhang <zhangaihua1@huawei.com> Cc: <stable@vger.kernel.org> # v3.18+
| * | | Merge branch 'work.const-qstr' into work.miscAl Viro2016-10-085-34/+34
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| | * | | orangefs: use %pd/%pDAl Viro2016-08-075-34/+34
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | Merge branch 'work.iget' into work.miscAl Viro2016-10-081-7/+34
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| | * | | | iget_locked et.al.: make sure we don't return bad inodesAl Viro2016-07-031-7/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If one thread does iget_locked(), proceeds to try and set the new inode up and fails, inode will be unhashed and dropped. However, another thread doing ilookup/iget_locked in the middle of that would end up finding a half-set-up inode, grabbing a reference, waiting for it to come unlocked and getting the resulting bad inode. It's a race (if that ilookup had been called just after the failure of setup attempt it wouldn't have found the sucker at all), particularly unpleasant in cases when failure is transient/caller-dependent/etc. While it can be dealt with in the callers, there's no reason not to handle it in fs/inode.c primitives, especially since the cost is trivial. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | proc: switch auxv to use of __mem_open()Al Viro2016-10-051-19/+26
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | hpfs: support FIEMAPMikulas Patocka2016-10-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support the FIEMAP ioctl that reports extents allocated by a file. Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | cifs: get rid of unused arguments of CIFSSMBWrite()Al Viro2016-09-273-13/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | they used to be used, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | posix_acl: xattr representation cleanupsAndreas Gruenbacher2016-09-273-16/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the unnecessary typedefs and the zero-length a_entries array in struct posix_acl_xattr_header. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | fs/aio.c: eliminate redundant loads in put_aio_ring_fileRasmus Villemoes2016-09-271-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using a local variable we can prevent gcc from reloading aio_ring_file->f_inode->i_mapping twice, eliminating 2x2 dependent loads. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | fs/internal.h: add const to ns_dentry_operations declarationRasmus Villemoes2016-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The actual definition in fs/nsfs.c is already const. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | compat: remove compat_printk()Arnd Bergmann2016-09-271-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After 7e8e385aaf6e ("x86/compat: Remove sys32_vm86_warning"), this function has become unused, so we can remove it as well. Link: http://lkml.kernel.org/r/20160617142903.3070388-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | | | | fs/buffer.c: make __getblk_slow() staticEric Biggers2016-09-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __getblk_slow() was exported to modules in commit 3b5e6454aaf6 ("fs/buffer.c: support buffer cache allocations with gfp modifiers"). This seems to have been a mistake, as no users were introduced nor was the function declared in a header. Change it back to 'static'. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | proc: unsigned file descriptorsAlexey Dobriyan2016-09-273-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make struct proc_inode::fd unsigned. This allows better code generation on x86_64 (less sign extensions). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | fs/file: more unsigned file descriptorsAlexey Dobriyan2016-09-271-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Propagate unsignedness for grand total of 149 bytes: $ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux add/remove: 0/0 grow/shrink: 0/10 up/down: 0/-149 (-149) function old new delta set_close_on_exec 99 98 -1 put_files_struct 201 200 -1 get_close_on_exec 59 58 -1 do_prlimit 498 497 -1 do_execveat_common.isra 1662 1661 -1 __close_fd 178 173 -5 do_dup2 219 204 -15 seq_show 685 660 -25 __alloc_fd 384 357 -27 dup_fd 718 646 -72 It mostly comes from converting "unsigned int" to "long" for bit operations. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | fs: compat: remove redundant check of nr_segsShawn Lin2016-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nr_segs should never be less than zero as its type is unsigned long, so let's remove this check. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]David Howells2016-09-273-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An NULL-pointer dereference happens in cachefiles_mark_object_inactive() when it tries to read i_blocks so that it can tell the cachefilesd daemon how much space it's making available. The problem is that cachefiles_drop_object() calls cachefiles_mark_object_inactive() after calling cachefiles_delete_object() because the object being marked active staves off attempts to (re-)use the file at that filename until after it has been deleted. This means that d_inode is NULL by the time we come to try to access it. To fix the problem, have the caller of cachefiles_mark_object_inactive() supply the number of blocks freed up. Without this, the following oops may occur: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles] ... CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1 Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011 Workqueue: fscache_object fscache_object_work_func [fscache] task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000 RIP: 0010:[<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles] RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034 RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8 RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000 R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600 R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498 FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0 ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658 ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600 Call Trace: [<ffffffffa06c48cb>] cachefiles_drop_object+0x6b/0xf0 [cachefiles] [<ffffffffa085d846>] fscache_drop_object+0xd6/0x1e0 [fscache] [<ffffffffa085d615>] fscache_object_work_func+0xa5/0x200 [fscache] [<ffffffff810a605b>] process_one_work+0x17b/0x470 [<ffffffff810a6e96>] worker_thread+0x126/0x410 [<ffffffff810a6d70>] ? rescuer_thread+0x460/0x460 [<ffffffff810ae64f>] kthread+0xcf/0xe0 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140 [<ffffffff81695418>] ret_from_fork+0x58/0x90 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140 The oopsing code shows: callq 0xffffffff810af6a0 <wake_up_bit> mov 0xf8(%r12),%rax mov 0x30(%rax),%rax mov 0x98(%rax),%rax <---- oops here lock add %rax,0x130(%rbx) where this is: d_backing_inode(object->dentry)->i_blocks Fixes: a5b3a80b899bda0f456f1246c4c5a1191ea01519 (CacheFiles: Provide read-and-reset release counters for cachefilesd) Reported-by: Jianhong Yin <jiyin@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | cifs: don't use memcpy() to copy struct iov_iterAl Viro2016-09-271-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | it's not 70s anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | get rid of separate multipage fault-in primitivesAl Viro2016-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * the only remaining callers of "short" fault-ins are just as happy with generic variants (both in lib/iov_iter.c); switch them to multipage variants, kill the "short" ones * rename the multipage variants to now available plain ones. * get rid of compat macro defining iov_iter_fault_in_multipage_readable by expanding it in its only user. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2016-10-0727-339/+377
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
| * | | | | | cred: simpler, 1D supplementary groupsAlexey Dobriyan2016-10-073-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | mm, proc: fix region lost in /proc/self/smapsRobert Ho2016-10-071-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently, Redhat reported that nvml test suite failed on QEMU/KVM, more detailed info please refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1365721 Actually, this bug is not only for NVDIMM/DAX but also for any other file systems. This simple test case abstracted from nvml can easily reproduce this bug in common environment: -------------------------- testcase.c ----------------------------- int is_pmem_proc(const void *addr, size_t len) { const char *caddr = addr; FILE *fp; if ((fp = fopen("/proc/self/smaps", "r")) == NULL) { printf("!/proc/self/smaps"); return 0; } int retval = 0; /* assume false until proven otherwise */ char line[PROCMAXLEN]; /* for fgets() */ char *lo = NULL; /* beginning of current range in smaps file */ char *hi = NULL; /* end of current range in smaps file */ int needmm = 0; /* looking for mm flag for current range */ while (fgets(line, PROCMAXLEN, fp) != NULL) { static const char vmflags[] = "VmFlags:"; static const char mm[] = " wr"; /* check for range line */ if (sscanf(line, "%p-%p", &lo, &hi) == 2) { if (needmm) { /* last range matched, but no mm flag found */ printf("never found mm flag.\n"); break; } else if (caddr < lo) { /* never found the range for caddr */ printf("#######no match for addr %p.\n", caddr); break; } else if (caddr < hi) { /* start address is in this range */ size_t rangelen = (size_t)(hi - caddr); /* remember that matching has started */ needmm = 1; /* calculate remaining range to search for */ if (len > rangelen) { len -= rangelen; caddr += rangelen; printf("matched %zu bytes in range " "%p-%p, %zu left over.\n", rangelen, lo, hi, len); } else { len = 0; printf("matched all bytes in range " "%p-%p.\n", lo, hi); } } } else if (needmm && strncmp(line, vmflags, sizeof(vmflags) - 1) == 0) { if (strstr(&line[sizeof(vmflags) - 1], mm) != NULL) { printf("mm flag found.\n"); if (len == 0) { /* entire range matched */ retval = 1; break; } needmm = 0; /* saw what was needed */ } else { /* mm flag not set for some or all of range */ printf("range has no mm flag.\n"); break; } } } fclose(fp); printf("returning %d.\n", retval); return retval; } void *Addr; size_t Size; /* * worker -- the work each thread performs */ static void * worker(void *arg) { int *ret = (int *)arg; *ret = is_pmem_proc(Addr, Size); return NULL; } int main(int argc, char *argv[]) { if (argc < 2 || argc > 3) { printf("usage: %s file [env].\n", argv[0]); return -1; } int fd = open(argv[1], O_RDWR); struct stat stbuf; fstat(fd, &stbuf); Size = stbuf.st_size; Addr = mmap(0, stbuf.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); close(fd); pthread_t threads[NTHREAD]; int ret[NTHREAD]; /* kick off NTHREAD threads */ for (int i = 0; i < NTHREAD; i++) pthread_create(&threads[i], NULL, worker, &ret[i]); /* wait for all the threads to complete */ for (int i = 0; i < NTHREAD; i++) pthread_join(threads[i], NULL); /* verify that all the threads return the same value */ for (int i = 1; i < NTHREAD; i++) { if (ret[0] != ret[i]) { printf("Error i %d ret[0] = %d ret[i] = %d.\n", i, ret[0], ret[i]); } } printf("%d", ret[0]); return 0; } It failed as some threads can not find the memory region in "/proc/self/smaps" which is allocated in the main process It is caused by proc fs which uses 'file->version' to indicate the VMA that is the last one has already been handled by read() system call. When the next read() issues, it uses the 'version' to find the VMA, then the next VMA is what we want to handle, the related code is as follows: if (last_addr) { vma = find_vma(mm, last_addr); if (vma && (vma = m_next_vma(priv, vma))) return vma; } However, VMA will be lost if the last VMA is gone, e.g: The process VMA list is A->B->C->D CPU 0 CPU 1 read() system call handle VMA B version = B return to userspace unmap VMA B issue read() again to continue to get the region info find_vma(version) will get VMA C m_next_vma(C) will get VMA D handle D !!! VMA C is lost !!! In order to fix this bug, we make 'file->version' indicate the end address of the current VMA. m_start will then look up a vma which with vma_start < last_vm_end and moves on to the next vma if we found the same or an overlapping vma. This will guarantee that we will not miss an exclusive vma but we can still miss one if the previous vma was shrunk. This is acceptable because guaranteeing "never miss a vma" is simply not feasible. User has to cope with some inconsistencies if the file is not read in one go. [mhocko@suse.com: changelog fixes] Link: http://lkml.kernel.org/r/1475296958-27652-1-git-send-email-robert.hu@intel.com Acked-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Robert Hu <robert.hu@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | proc: fix timerslack_ns CAP_SYS_NICE check when adjusting selfJohn Stultz2016-10-071-15/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS) to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds when p == current, but the CAP_SYS_NICE doesn't. Thus while the previous commit was intended to loosen the needed privileges to modify a processes timerslack, it needlessly restricted a task modifying its own timerslack via the proc/<tid>/timerslack_ns (which is permitted also via the PR_SET_TIMERSLACK method). This patch corrects this by checking if p == current before checking the CAP_SYS_NICE value. This patch applies on top of my two previous patches currently in -mm Link: http://lkml.kernel.org/r/1471906870-28624-1-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | proc: add LSM hook checks to /proc/<tid>/timerslack_nsJohn Stultz2016-10-071-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As requested, this patch checks the existing LSM hooks task_getscheduler/task_setscheduler when reading or modifying the task's timerslack value. Previous versions added new get/settimerslack LSM hooks, but since they checked the same PROCESS__SET/GETSCHED values as existing hooks, it was suggested we just use the existing ones. Link: http://lkml.kernel.org/r/1469132667-17377-2-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: James Morris <jmorris@namei.org> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | proc: relax /proc/<tid>/timerslack_ns capability requirementsJohn Stultz2016-10-071-14/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an interface to allow a task to change another tasks timerslack was first proposed, it was suggested that something greater then CAP_SYS_NICE would be needed, as a task could be delayed further then what normally could be done with nice adjustments. So CAP_SYS_PTRACE was adopted instead for what became the /proc/<tid>/timerslack_ns interface. However, for Android (where this feature originates), giving the system_server CAP_SYS_PTRACE would allow it to observe and modify all tasks memory. This is considered too high a privilege level for only needing to change the timerslack. After some discussion, it was realized that a CAP_SYS_NICE process can set a task as SCHED_FIFO, so they could fork some spinning processes and set them all SCHED_FIFO 99, in effect delaying all other tasks for an infinite amount of time. So as a CAP_SYS_NICE task can already cause trouble for other tasks, using it as a required capability for accessing and modifying /proc/<tid>/timerslack_ns seems sufficient. Thus, this patch loosens the capability requirements to CAP_SYS_NICE and removes CAP_SYS_PTRACE, simplifying some of the code flow as well. This is technically an ABI change, but as the feature just landed in 4.6, I suspect no one is yet using it. Link: http://lkml.kernel.org/r/1469132667-17377-1-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Nick Kralevich <nnk@google.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | meminfo: break apart a very long seq_printf with #ifdefsJoe Perches2016-10-071-116/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a specific routine to emit most lines so that the code is easier to read and maintain. akpm: text data bss dec hex filename 2976 8 0 2984 ba8 fs/proc/meminfo.o before 2669 8 0 2677 a75 fs/proc/meminfo.o after Link: http://lkml.kernel.org/r/8fce7fdef2ba081a4ef531594e97da8a9feebb58.1470810406.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not charJoe Perches2016-10-073-133/+151
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow some seq_puts removals by taking a string instead of a single char. [akpm@linux-foundation.org: update vmstat_show(), per Joe] Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | proc: faster /proc/*/statusAlexey Dobriyan2016-10-071-40/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | top(1) opens the following files for every PID: /proc/*/stat /proc/*/statm /proc/*/status This patch switches /proc/*/status away from seq_printf(). The result is 13.5% speedup. Benchmark is open("/proc/self/status")+read+close 1.000.000 million times. BEFORE $ perf stat -r 10 taskset -c 3 ./proc-self-status Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs): 10748.474301 task-clock (msec) # 0.954 CPUs utilized ( +- 0.91% ) 12 context-switches # 0.001 K/sec ( +- 1.09% ) 1 cpu-migrations # 0.000 K/sec 104 page-faults # 0.010 K/sec ( +- 0.45% ) 37,424,127,876 cycles # 3.482 GHz ( +- 0.04% ) 8,453,010,029 stalled-cycles-frontend # 22.59% frontend cycles idle ( +- 0.12% ) 3,747,609,427 stalled-cycles-backend # 10.01% backend cycles idle ( +- 0.68% ) 65,632,764,147 instructions # 1.75 insn per cycle # 0.13 stalled cycles per insn ( +- 0.00% ) 13,981,324,775 branches # 1300.773 M/sec ( +- 0.00% ) 138,967,110 branch-misses # 0.99% of all branches ( +- 0.18% ) 11.263885428 seconds time elapsed ( +- 0.04% ) ^^^^^^^^^^^^ AFTER $ perf stat -r 10 taskset -c 3 ./proc-self-status Performance counter stats for 'taskset -c 3 ./proc-self-status' (10 runs): 9010.521776 task-clock (msec) # 0.925 CPUs utilized ( +- 1.54% ) 11 context-switches # 0.001 K/sec ( +- 1.54% ) 1 cpu-migrations # 0.000 K/sec ( +- 11.11% ) 103 page-faults # 0.011 K/sec ( +- 0.60% ) 32,352,310,603 cycles # 3.591 GHz ( +- 0.07% ) 7,849,199,578 stalled-cycles-frontend # 24.26% frontend cycles idle ( +- 0.27% ) 3,269,738,842 stalled-cycles-backend # 10.11% backend cycles idle ( +- 0.73% ) 56,012,163,567 instructions # 1.73 insn per cycle # 0.14 stalled cycles per insn ( +- 0.00% ) 11,735,778,795 branches # 1302.453 M/sec ( +- 0.00% ) 98,084,459 branch-misses # 0.84% of all branches ( +- 0.28% ) 9.741247736 seconds time elapsed ( +- 0.07% ) ^^^^^^^^^^^ Link: http://lkml.kernel.org/r/20160806125608.GB1187@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | mm: remove unnecessary condition in remove_inode_hugepageszhong jiang2016-10-071-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the huge page is added to the page cahce (huge_add_to_page_cache), the page private flag will be cleared. since this code (remove_inode_hugepages) will only be called for pages in the page cahce, PagePrivate(page) will always be false. The patch remove the code without any functional change. Link: http://lkml.kernel.org/r/1475113323-29368-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGEYisheng Xie2016-10-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid making ifdef get pretty unwieldy if many ARCHs support gigantic page. No functional change with this patch. Link: http://lkml.kernel.org/r/1475227569-63446-2-git-send-email-xieyisheng1@huawei.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | mm: remove page_file_indexHuang Ying2016-10-074-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After using the offset of the swap entry as the key of the swap cache, the page_index() becomes exactly same as page_file_index(). So the page_file_index() is removed and the callers are changed to use page_index() instead. Link: http://lkml.kernel.org/r/1473270649-27229-2-git-send-email-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | thp: reduce usage of huge zero page's atomic counterAaron Lu2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The global zero page is used to satisfy an anonymous read fault. If THP(Transparent HugePage) is enabled then the global huge zero page is used. The global huge zero page uses an atomic counter for reference counting and is allocated/freed dynamically according to its counter value. CPU time spent on that counter will greatly increase if there are a lot of processes doing anonymous read faults. This patch proposes a way to reduce the access to the global counter so that the CPU load can be reduced accordingly. To do this, a new flag of the mm_struct is introduced: MMF_USED_HUGE_ZERO_PAGE. With this flag, the process only need to touch the global counter in two cases: 1 The first time it uses the global huge zero page; 2 The time when mm_user of its mm_struct reaches zero. Note that right now, the huge zero page is eligible to be freed as soon as its last use goes away. With this patch, the page will not be eligible to be freed until the exit of the last process from which it was ever used. And with the use of mm_user, the kthread is not eligible to use huge zero page either. Since no kthread is using huge zero page today, there is no difference after applying this patch. But if that is not desired, I can change it to when mm_count reaches zero. Case used for test on Haswell EP: usemem -n 72 --readonly -j 0x200000 100G Which spawns 72 processes and each will mmap 100G anonymous space and then do read only access to that space sequentially with a step of 2MB. CPU cycles from perf report for base commit: 54.03% usemem [kernel.kallsyms] [k] get_huge_zero_page CPU cycles from perf report for this commit: 0.11% usemem [kernel.kallsyms] [k] mm_get_huge_zero_page Performance(throughput) of the workload for base commit: 1784430792 Performance(throughput) of the workload for this commit: 4726928591 164% increase. Runtime of the workload for base commit: 707592 us Runtime of the workload for this commit: 303970 us 50% drop. Link: http://lkml.kernel.org/r/fe51a88f-446a-4622-1363-ad1282d71385@intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | fs/proc/task_mmu.c: make the task_mmu walk_page_range() limit in ↵James Morse2016-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clear_refs_write() obvious Trying to walk all of virtual memory requires architecture specific knowledge. On x86_64, addresses must be sign extended from bit 48, whereas on arm64 the top VA_BITS of address space have their own set of page tables. clear_refs_write() calls walk_page_range() on the range 0 to ~0UL, it provides a test_walk() callback that only expects to be walking over VMAs. Currently walk_pmd_range() will skip memory regions that don't have a VMA, reporting them as a hole. As this call only expects to walk user address space, make it walk 0 to 'highest_vm_end'. Link: http://lkml.kernel.org/r/1472655792-22439-1-git-send-email-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.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>