04 Jul, 2013
1 commit
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Fix various weird constructions of strncpy(dst, src, strlen(src)).
Length limits should be about the space available in the destination,
not repurposed as a method to either always include or always exclude a
trailing NULL byte. Either the NULL should always be copied (using
strlcpy), or it should not be copied (using something like memcpy).
Readable code should not depend on the weird behavior of strncpy when it
hits the length limit. Better to avoid the anti-pattern entirely.[akpm@linux-foundation.org: revert getdelays.c part due to missing bsd/string.h]
Signed-off-by: Kees Cook
Acked-by: Greg Kroah-Hartman [staging]
Acked-by: Rafael J. Wysocki [acpi]
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Ursula Braun
Cc: Frank Blaschka
Cc: Richard Weinberger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Jun, 2013
1 commit
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Signed-off-by: Al Viro
30 Apr, 2013
2 commits
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it has grown by accident - directories there do *not* use page cache, so
there's nothing to write.Signed-off-by: Al Viro
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we need to close the underlying procfs file and free ->private_data
Signed-off-by: Al Viro
04 Mar, 2013
1 commit
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Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.Acked-by: Serge Hallyn
Acked-by: Kees Cook
Reported-by: Kees Cook
Signed-off-by: "Eric W. Biederman"
23 Feb, 2013
1 commit
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Signed-off-by: Al Viro
19 Nov, 2012
1 commit
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The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
aka ns_of_pid(task_pid(tsk)) should have the same number of
cache line misses with the practical difference that
ns_of_pid(task_pid(tsk)) is released later in a processes life.Furthermore by using task_active_pid_ns it becomes trivial
to write an unshare implementation for the the pid namespace.So I have used task_active_pid_ns everywhere I can.
In fork since the pid has not yet been attached to the
process I use ns_of_pid, to achieve the same effect.Signed-off-by: Eric W. Biederman
10 Oct, 2012
2 commits
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In case of error, the function get_inode() returns ERR_PTR().
But the users hppfs_lookup() and hppfs_fill_super() use NULL
test for check the return value, not IS_ERR(), so we'd better
change the return value of get_inode() to NULL instead of
ERR_PTR().dpatch engine is used to generated this patch.
(https://github.com/weiyj/dpatch)Signed-off-by: Wei Yongjun
Signed-off-by: Richard Weinberger -
Signed-off-by: Al Viro
Signed-off-by: Richard Weinberger
23 Jul, 2012
1 commit
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Signed-off-by: Al Viro
14 Jul, 2012
1 commit
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Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument. And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...Signed-off-by: Al Viro
06 May, 2012
1 commit
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After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.Signed-off-by: Jan Kara
Signed-off-by: Fengguang Wu
21 Mar, 2012
1 commit
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Signed-off-by: Al Viro
04 Jan, 2012
2 commits
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Signed-off-by: Al Viro
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Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...Signed-off-by: Al Viro
02 Nov, 2011
1 commit
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Replace remaining direct i_nlink updates with a new set_nlink()
updater function.Signed-off-by: Miklos Szeredi
Tested-by: Toshiyuki Okajima
Signed-off-by: Christoph Hellwig
28 Jul, 2011
1 commit
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Signed-off-by: Al Viro
21 Jul, 2011
1 commit
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Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2. For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,Acked-by: Jan Kara
Signed-off-by: Josef Bacik
Signed-off-by: Al Viro
18 Jul, 2011
2 commits
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... and it's getting it wrong, too - missing ->d_revalidate() calls when
it's dealing with filesystem (procfs) that has non-trivial ->d_revalidate()...Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
07 Jan, 2011
1 commit
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RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.Signed-off-by: Nick Piggin
29 Oct, 2010
1 commit
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Signed-off-by: Al Viro
15 Oct, 2010
1 commit
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All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====Signed-off-by: Arnd Bergmann
Cc: Julia Lawall
Cc: Christoph Hellwig
10 Aug, 2010
2 commits
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Signed-off-by: Al Viro
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Signed-off-by: Al Viro
28 May, 2010
1 commit
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Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
04 Mar, 2010
1 commit
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Signed-off-by: Al Viro
14 Jan, 2010
1 commit
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current code works only because nothing in procfs has non-trivial
->put_link().Signed-off-by: Al Viro
03 Apr, 2009
1 commit
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hppfs_read_file() may return (ssize_t) -ENOMEM, or -EFAULT. When stored
in size_t 'count', these errors will not be noticed, a large value will be
added to *ppos.Signed-off-by: Roel Kluin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Nov, 2008
2 commits
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Attach creds to file structs and discard f_uid/f_gid.
file_operations::open() methods (such as hppfs_open()) should use file->f_cred
rather than current_cred(). At the moment file->f_cred will be current_cred()
at this point.Signed-off-by: David Howells
Reviewed-by: James Morris
Signed-off-by: James Morris -
Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.Signed-off-by: David Howells
Acked-by: James Morris
Signed-off-by: James Morris
27 Jul, 2008
1 commit
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hppfs_permission() is equivalent to the '.permission == NULL' case.
Signed-off-by: Miklos Szeredi
Signed-off-by: Al Viro
22 May, 2008
1 commit
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Fallout from commit 46d7b522ebf486edbd096965d534cc6465e9e309 ("uml: move
hppfs_kern.c to hppfs.c")Signed-off-by: Al Viro
Acked-by: Jeff Dike
Signed-off-by: Linus Torvalds
13 May, 2008
2 commits
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There's no reason for the _kern in hppfs_kern.c, so move it to hppfs.c.
Signed-off-by: Jeff Dike
Cc: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
hppfs tidying and fixes noticed during hch's get_inode work -
style fixes
a copy_to_user got its return value checked
hppfs_write no longer fiddles file->f_pos because it gets and
returns pos in its arguments
hppfs_delete_inode dputs the underlyng procfs dentry stored in
its private data and mntputs the vfsmnt stashed in s_fs_info
hppfs_put_super no longer needs to mntput the s_fs_info, so it
no longer needs to exist
hppfs_readlink and hppfs_follow_link were doing a bunch of stuff
with a struct file which they didn't use
there is now a ->permission which calls generic_permission
get_inode was always returning 0 for some reason - it now
returns an inode if nothing bad happenedSigned-off-by: Jeff Dike
Cc: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Mar, 2008
2 commits
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* hppfs_iget() and its users are racy; there's no need to pollute icache
anyway, new_inode() works fine and is safe, unlike the current kludges
(these relied on overwriting ->i_ino before another iget_locked() gets
to that one - and did it after unlocking).
* merge hppfs_iget()/init_inode()/hppfs_read_inode(), while we are
at it.
* to pass proper vfsmount to dentry_open() store the reference
in hppfs superblock.Signed-off-by: Al Viro
-- -
Here's patch for hppfs that uses vfs_kern_mount to make sure it always has a
procfs instance and passed the vfsmount on through the inode private data.
Also fixes a procfs file_system_type leak for every attempted hppfs mount.[ jdike - gave this file a style workover, plus deleted hppfs_dentry_ops ]
Acked-by: Al Viro
Signed-off-by: Christoph Hellwig
Signed-off-by: Jeff Dike
Signed-off-by: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro
08 Feb, 2008
1 commit
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Stop the HPPFS filesystem from using iget() and read_inode(). Provide an
hppfs_iget(), and call that instead of iget(). hppfs_iget() then uses
iget_locked() directly and returns a proper error code instead of an inode in
the event of an error.hppfs_fill_sb_common() returns any error incurred when getting the root inode
instead of EINVAL.Note that the contents of hppfs_kern.c need to be examined:
(*) The HPPFS inode retains a pointer to the proc dentry it is shadowing, but
whilst it does appear to retain a reference to it, it doesn't appear to
destroy the reference if the inode goes away.(*) hppfs_iget() should perhaps subsume init_inode() and hppfs_read_inode().
(*) It would appear that all hppfs inodes are the same inode because iget()
was being called with inode number 0, which forms the lookup key.Signed-off-by: David Howells
Acked-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2007
2 commits
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This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".Compile tested with gcc & sparse.
Signed-off-by: Josef 'Jeff' Sipek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
