Enforce the rules about compound op ordering.
Motivated by implementing RECLAIM_COMPLETE, for which the client is
implicit in the current session, so it is important to ensure a
succesful SEQUENCE proceeds the RECLAIM_COMPLETE.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The rfc allows a client to change the callback parameters, but we didn't
previously implement it.
Teach the callbacks to rerun themselves (by placing themselves on a
workqueue) when they recognize that their rpc task has been killed and
that the callback connection has changed.
Then we can change the callback connection by setting up a new rpc
client, modifying the nfs4 client to point at it, waiting for any work
in progress to complete, and then shutting down the old client.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Now that the shutdown sequence guarantees callbacks are shut down before
the client is destroyed, we no longer have a use for cl_count.
We'll probably reinstate a reference count on the client some day, but
it will be held by users other than callbacks.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The NFSv4 server's fl_break callback can sleep (dropping the BKL), in
order to allocate a new rpc task to send a recall to the client.
As far as I can tell this doesn't cause any races in the current code,
but the analysis is difficult. Also, the sleep here may complicate the
move away from the BKL.
So, just schedule some work to do the job for us instead. The work will
later also prove useful for restarting a call after the callback
information is changed.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Any null probe rpc will be synchronously destroyed by the
rpc_shutdown_client() in expire_client(), so the rpc task cannot outlast
the nfs4 client. Therefore there's no need for that task to hold a
reference on the client.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Once we've expired the client, there's no further purpose to the
callbacks; go ahead and shut down the callback client rather than
waiting for the last reference to go.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Instead of allocating this small structure, just include it in the
delegation.
The nfsd4_callback structure isn't really necessary yet, but we plan to
add to it all the information necessary to perform a callback.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This is the second attempt to fix the problem whereby a COMMIT call
causes a lease break and triggers a possible deadlock.
The problem is that nfsd attempts to break a lease on a COMMIT call.
This triggers a delegation recall if the lease is held for a delegation.
If the client is the one holding the delegation and it's the same one on
which it's issuing the COMMIT, then it can't return that delegation
until the COMMIT is complete. But, nfsd won't complete the COMMIT until
the delegation is returned. The client and server are essentially
deadlocked until the state is marked bad (due to the client not
responding on the callback channel).
The first patch attempted to deal with this by eliminating the open of
the file altogether and simply had nfsd_commit pass a NULL file pointer
to the vfs_fsync_range. That would conflict with some work in progress
by Christoph Hellwig to clean up the fsync interface, so this patch
takes a different approach.
This declares a new NFSD_MAY_NOT_BREAK_LEASE access flag that indicates
to nfsd_open that it should not break any leases when opening the file,
and has nfsd_commit set that flag on the nfsd_open call.
For now, this patch leaves nfsd_commit opening the file with write
access since I'm not clear on what sort of access would be more
appropriate.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Both the _lookup and the _update functions for these two caches
independently calculate the hash of the key.
So factor out that code for improved reuse.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (62 commits)
msi-laptop: depends on RFKILL
msi-laptop: Detect 3G device exists by standard ec command
msi-laptop: Add resume method for set the SCM load again
msi-laptop: Support some MSI 3G netbook that is need load SCM
msi-laptop: Add threeg sysfs file for support query 3G state by standard 66/62 ec command
msi-laptop: Support standard ec 66/62 command on MSI notebook and nebook
Driver core: create lock/unlock functions for struct device
sysfs: fix for thinko with sysfs_bin_attr_init()
sysfs: Kill unused sysfs_sb variable.
sysfs: Pass super_block to sysfs_get_inode
driver core: Use sysfs_rename_link in device_rename
sysfs: Implement sysfs_rename_link
sysfs: Pack sysfs_dirent more tightly.
sysfs: Serialize updates to the vfs inode
sysfs: windfarm: init sysfs attributes
sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on module dynamic attributes
sysfs: Document sysfs_attr_init and sysfs_bin_attr_init
sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes
sysfs: Use one lockdep class per sysfs attribute.
sysfs: Only take active references on attributes.
...
Remove the EXPERIMENTAL flag from FS-Cache so that Ubuntu can make use of the
facility.
Signed-off-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that there are no more users we can remove
the sysfs_sb variable.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently sysfs_get_inode magically returns an inode on
sysfs_sb. Make the super_block parameter explicit and
the code becomes clearer.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Because of rename ordering problems we occassionally give false
warnings about invalid sysfs operations. So using sysfs_rename
create a sysfs_rename_link function that doesn't need strange
workarounds.
Cc: Benjamin Thery <benjamin.thery@bull.net>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Placing the 16bit s_mode between a pointer and a long doesn't pack well
especailly on 64bit where we wast 48 bits. So move s_mode and
declare it as a unsigned short. This is the sysfs backing store
after all we don't need fields extra large just in case someday
we want userspace to be able to use a larger value.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The vfs depends upon filesystem methods to update the
vfs inode. Sysfs adds to the normal number of places
where the vfs inode is updated by also updatng the
vfs inode in sysfs_refresh_inode.
Typically the inode mutex is used to serialize updates
to the vfs inode, but grabbing the inode mutex in
sysfs_permission and sysfs_getattr causes deadlocks,
because sometimes the vfs calls those operations with
the inode mutex held. Therefore sysfs can not use the
inode mutex to serial updates to the vfs inode.
The sysfs_mutex is acquired in all of the routines
where sysfs updates the vfs inode, and with a small
change we can consistently protext sysfs vfs inode
updates with the sysfs_mutex. To protect the sysfs
vfs inode updates with the sysfs_mutex simply requires
extending the scope of sysfs_mutex in sysfs_setattr
over inode_setattr, and over inode_change_ok (so we
have an unchanging inode when we perform the check).
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Acknowledge that the logical sysfs rwsem has one instance per
sysfs attribute with different locking depencencies for different
attributes.
There is a sysfs idiom where writing to one sysfs file causes the
addition or removal of other sysfs files. Lumping all of the
sysfs attributes together in one lock class causes lockdep to
generate lots of false positives.
This introduces the requirement that non-static sysfs attributes
need to be initialized with sysfs_attr_init or sysfs_bin_attr_init.
Strictly speaking this requirement only exists when lockdep is
enabled, and when lockdep is enabled we get a bit fat warning
if this requirement is not met.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If we exclude directories and symlinks from the set of sysfs
dirents where we need active references we are left with
sysfs attributes (binary or not).
- Tweak sysfs_deactivate to only do something on attributes
- Move lockdep initialization into sysfs_file_add_mode to
limit it to just attributes.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It turns out that holding an active reference on a directory is
pointless. The purpose of the active references are to allows us to
block when removing sysfs entries that have custom methods so we don't
remove modules while running modular code and to keep those custom
methods from accessing data structures after the files have been
removed. Further sysfs_remove_dir remove all elements in the
directory before removing the directory itself, so there is no chance
we will remove a directory with active children.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Constify struct kset_uevent_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When sysfs_readdir stops short we now cache the next
sysfs_dirent to return to user space in filp->private_data.
There is no impact on the rest of sysfs by doing this and
in the common case it allows us to pick up exactly where
we left off with no seeking.
Additionally I drop and regrab the sysfs_mutex around
filldir to avoid a page fault abritrarily increasing the
hold time on the sysfs_mutex.
v2: Returned to using INT_MAX as the EOF condition.
seekdir is ambiguous unless all directory entries have
a unique f_pos value.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14949
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adding/Removing a whole array of attributes is very common. Add a standard
utility function to do this with a simple function call, instead of
requiring drivers to open code this.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix kernel-doc notation in new seq-file functions and
correct spelling.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit a069c266ae.
It turns ou that not only was it missing a case (XFS) that needed it,
but perhaps more importantly, people sometimes want to enable new
modules that they hadn't had enabled before, and if such a module uses
list_sort(), it can't easily be inserted any more.
So rather than add a "select LIST_SORT" to the XFS case, just leave it
compiled in. It's not all _that_ big, after all, and the inconvenience
isn't worth it.
Requested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
[LogFS] Change magic number
[LogFS] Remove h_version field
[LogFS] Check feature flags
[LogFS] Only write journal if dirty
[LogFS] Fix bdev erases
[LogFS] Silence gcc
[LogFS] Prevent 64bit divisions in hash_index
[LogFS] Plug memory leak on error paths
[LogFS] Add MAINTAINERS entry
[LogFS] add new flash file system
Fixed up trivial conflict in lib/Kconfig, and a semantic conflict in
fs/logfs/inode.c introduced by write_inode() being changed to use
writeback_control' by commit a9185b41a4
("pass writeback_control to ->write_inode")
The current documentation here is out of date, and not quite right.
(Future work: some user documentation would be useful.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The original code here assumed we'd allow the user to change the lease
any time, but only allow the change to take effect on restart. Since
then we modified the code to allow setting the lease on when the server
is down. Update the rest of the code to reflect that fact, clarify
variable names, and add document.
Also, the code insisted that the grace period always be the longer of
the old and new lease periods, but that's overly conservative--as long
as it lasts at least the old lease period, old clients should still know
to recover in time.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Instead of accessing the lease time directly, some users call
nfs4_lease_time(), and some a macro, NFSD_LEASE_TIME, defined as
nfs4_lease_time(). Neither layer of indirection serves any purpose.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (21 commits)
xfs: return inode fork offset in bulkstat for fsr
xfs: Increase the default size of the reserved blocks pool
xfs: truncate delalloc extents when IO fails in writeback
xfs: check for more work before sleeping in xfssyncd
xfs: Fix a build warning in xfs_aops.c
xfs: fix locking for inode cache radix tree tag updates
xfs: remove xfs_ipin/xfs_iunpin
xfs: cleanup xfs_iunpin_wait/xfs_iunpin_nowait
xfs: kill xfs_lrw.h
xfs: factor common xfs_trans_bjoin code
xfs: stop passing opaque handles to xfs_log.c routines
xfs: split xfs_bmap_btalloc
xfs: fix xfs_fsblock_t tracing
xfs: fix inode pincount check in fsync
xfs: Non-blocking inode locking in IO completion
xfs: implement optimized fdatasync
xfs: remove wrapper for the fsync file operation
xfs: remove wrappers for read/write file operations
xfs: merge xfs_lrw.c into xfs_file.c
xfs: fix dquota trace format
...
* 'for-2.6.34' of git://linux-nfs.org/~bfields/linux: (22 commits)
nfsd4: fix minor memory leak
svcrpc: treat uid's as unsigned
nfsd: ensure sockets are closed on error
Revert "sunrpc: move the close processing after do recvfrom method"
Revert "sunrpc: fix peername failed on closed listener"
sunrpc: remove unnecessary svc_xprt_put
NFSD: NFSv4 callback client should use RPC_TASK_SOFTCONN
xfs_export_operations.commit_metadata
commit_metadata export operation replacing nfsd_sync_dir
lockd: don't clear sm_monitored on nsm_reboot_lookup
lockd: release reference to nsm_handle in nlm_host_rebooted
nfsd: Use vfs_fsync_range() in nfsd_commit
NFSD: Create PF_INET6 listener in write_ports
SUNRPC: NFS kernel APIs shouldn't return ENOENT for "transport not found"
SUNRPC: Bury "#ifdef IPV6" in svc_create_xprt()
NFSD: Support AF_INET6 in svc_addsock() function
SUNRPC: Use rpc_pton() in ip_map_parse()
nfsd: 4.1 has an rfc number
nfsd41: Create the recovery entry for the NFSv4.1 client
nfsd: use vfs_fsync for non-directories
...
Modify uid check in do_coredump so as to not apply it in the case of
pipes.
This just got noticed in testing. The end of do_coredump validates the
uid of the inode for the created file against the uid of the crashing
process to ensure that no one can pre-create a core file with different
ownership and grab the information contained in the core when they
shouldn' tbe able to. This causes failures when using pipes for a core
dumps if the crashing process is not root, which is the uid of the pipe
when it is created.
The fix is simple. Since the check for matching uid's isn't relevant for
pipes (a process can't create a pipe that the uermodehelper code will open
anyway), we can just just skip it in the event ispipe is non-zero
Reverts a pipe-affecting change which was accidentally made in
: commit c46f739dd3
: Author: Ingo Molnar <mingo@elte.hu>
: AuthorDate: Wed Nov 28 13:59:18 2007 +0100
: Commit: Linus Torvalds <torvalds@woody.linux-foundation.org>
: CommitDate: Wed Nov 28 10:58:01 2007 -0800
:
: vfs: coredumping fix
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
User visible change.
do_coredump() kills all threads which share the same ->mm but only the
coredumping process gets the proper exit_code. Other tasks which share
the same ->mm die "silently" and return status == 0 to parent.
This is historical behaviour, not actually a bug. But I think Frank
Heckenbach rightly dislikes the current behaviour. Simple test-case:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
int main(void)
{
int stat;
if (!fork()) {
if (!vfork())
kill(getpid(), SIGQUIT);
}
wait(&stat);
printf("stat=%x\n", stat);
return 0;
}
Before this patch it prints "stat=0" despite the fact the child was killed
by SIGQUIT. After this patch the output is "stat=3" which obviously makes
more sense.
Even with this patch, only the task which originates the coredumping gets
"|= 0x80" if the core was actually dumped, but at least the coredumping
signal is visible to do_wait/etc.
Reported-by: Frank Heckenbach <f.heckenbach@fh-soft.de>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass mm->flags as a coredump parameter for consistency.
---
1787 if (mm->core_state || !get_dumpable(mm)) { <- (1)
1788 up_write(&mm->mmap_sem);
1789 put_cred(cred);
1790 goto fail;
1791 }
1792
[...]
1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2)
1799 flag = O_EXCL; /* Stop rewrite attacks */
1800 cred->fsuid = 0; /* Dump root private */
1801 }
---
Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).
To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.
This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.
[akpm@linux-foundation.org: fix merge]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535. This number is determined by the number of
vmas which the process have. In particular, some extreme programs may use
more than 65535 vmas. (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.
This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.
This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By the next patch, elf_core_dump() and elf_fdpic_core_dump() will support
extended numbering and so will produce the corefiles with section header
table in a special case.
The problem is the process of writing a file header offset of the section
header table into e_shoff field of the ELF header. ELF header is
positioned at the beginning of the corefile, while section header at the
end. So, we need to take which of the following ways:
1. Seek backward to retry writing operation for ELF header
after writing process for a whole part
2. Make offset calculation process and writing process
totally sequential
The clause 1. is not always possible: one cannot assume that file system
supports seek function. Consider the no_llseek case.
Therefore, this patch adopts the clause 2.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions. This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions. For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.
This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files. Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same. So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current ELF dumper can produce broken corefiles if program headers
exceed 65535. In particular, the program in 64-bit environment often
demands more than 65535 mmaps. If you google max_map_count, then you can
find many users facing this problem.
Solaris has already dealt with this issue, and other OSes have also
adopted the same method as in Solaris. Currently, Sun's document and AMD
64 ABI include the description for the extension, where they call the
extension Extended Numbering. See Reference for further information.
I believe that linux kernel should adopt the same way as they did, so I've
written this patch.
I am also preparing for patches of GDB and binutils.
How to fix
==========
In new dumping process, there are two cases according to weather or
not the number of program headers is equal to or more than 65535.
- if less than 65535, the produced corefile format is exactly the same
as the ordinary one.
- if equal to or more than 65535, then e_phnum field is set to newly
introduced constant PN_XNUM(0xffff) and the actual number of program
headers is set to sh_info field of the section header at index 0.
Compatibility Concern
=====================
* As already mentioned in Summary, Sun and AMD64 has already adopted
this. See Reference.
* There are four combinations according to whether kernel and userland
tools are respectively modified or not. The next table summarizes
shortly for each combination.
---------------------------------------------
Original Kernel | Modified Kernel
---------------------------------------------
< 65535 | >= 65535 | < 65535 | >= 65535
-------------------------------------------------------------
Original Tools | OK | broken | OK | broken (#)
-------------------------------------------------------------
Modified Tools | OK | broken | OK | OK
-------------------------------------------------------------
Note that there is no case that `OK' changes to `broken'.
(#) Although this case remains broken, O-M behaves better than
O-O. That is, while in O-O case e_phnum field would be extremely
small due to integer overflow, in O-M case it is guaranteed to be at
least 65535 by being set to PN_XNUM(0xFFFF), much closer to the
actual correct value than the O-O case.
Test Program
============
Here is a test program mkmmaps.c that is useful to produce the
corefile with many mmaps. To use this, please take the following
steps:
$ ulimit -c unlimited
$ sysctl vm.max_map_count=70000 # default 65530 is too small
$ sysctl fs.file-max=70000
$ mkmmaps 65535
Then, the program will abort and a corefile will be generated.
If failed, there are two cases according to the error message
displayed.
* ``out of memory'' means vm.max_map_count is still smaller
* ``too many open files'' means fs.file-max is still smaller
So, please change it to a larger value, and then retry it.
mkmmaps.c
==
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
int main(int argc, char **argv)
{
int maps_num;
if (argc < 2) {
fprintf(stderr, "mkmmaps [number of maps to be created]\n");
exit(1);
}
if (sscanf(argv[1], "%d", &maps_num) == EOF) {
perror("sscanf");
exit(2);
}
if (maps_num < 0) {
fprintf(stderr, "%d is invalid\n", maps_num);
exit(3);
}
for (; maps_num > 0; --maps_num) {
if (MAP_FAILED == mmap((void *)NULL, (size_t) 1, PROT_READ,
MAP_SHARED | MAP_ANONYMOUS, (int) -1,
(off_t) NULL)) {
perror("mmap");
exit(4);
}
}
abort();
{
char buffer[128];
sprintf(buffer, "wc -l /proc/%u/maps", getpid());
system(buffer);
}
return 0;
}
Tested on i386, ia64 and um/sys-i386.
Built on sh4 (which covers fs/binfmt_elf_fdpic.c)
References
==========
- Sun microsystems: Linker and Libraries.
Part No: 817-1984-17, September 2008.
URL: http://docs.sun.com/app/docs/doc/817-1984
- System V ABI AMD64 Architecture Processor Supplement
Draft Version 0.99., May 11, 2009.
URL: http://www.x86-64.org/
This patch:
There are three different definitions for dump_seek() functions in
binfmt_aout.c, binfmt_elf.c and binfmt_elf_fdpic.c, respectively. The
only for binfmt_elf.c.
My next patch will move dump_seek() into a header file in order to share
the same implementations for dump_write() and dump_seek(). As the first
step, this patch unify these three definitions for dump_seek() by applying
the past commits that have been applied only for binfmt_elf.c.
Specifically, the modification made here is part of the following commits:
* d025c9db7f
* 7f14daa19e
This patch does not change a shape of corefiles.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* warn if creation goes on to non-existent directory
* warn if removal goes on from non-existing directory
* warn if non-existing proc entry is removed
Signed-off-by: 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>
remove_proc_entry() does
lock
lookup parent
unlock
lock
unlink proc entry from lists
unlock
which can be made bit more correct by doing parent translation + unlink
without dropping lock.
Signed-off-by: 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>
fs/compat_ioctl.c: In function 'do_ioctl_trans':
fs/compat_ioctl.c:534: warning: 'karg' may be used uninitialized in this function
fs/compat_ioctl.c:533: warning: 'kcmd' may be used uninitialized in this function
fs/compat_ioctl.c:656: warning: 'ret' may be used uninitialized in this function
Reduces text size by 44 bytes.
If someone calls one of these functions with an unexpected argument, the
code's buggy as-is.
Amerigo Wang <amwang@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
