linux-toradex.git/fs/dcookies.c, branch v3.12.29

fs/compat: fix lookup_dcookie() parameter handling

2014-02-13T21:50:14+00:00

commit d8d14bd09cddbaf0168d61af638455a26bd027ff upstream.

Commit d5dc77bfeeab ("consolidate compat lookup_dcookie()") coverted all
architectures to the new compat_sys_lookup_dcookie() syscall.

The "len" paramater of the new compat syscall must have the type
compat_size_t in order to enforce zero extension for architectures where
the ABI requires that the caller of a function performed zero and/or
sign extension to 64 bit of all parameters.

Signed-off-by: Heiko Carstens 
Cc: Al Viro 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Hendrik Brueckner 
Cc: Martin Schwidefsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

consolidate compat lookup_dcookie()

2013-03-04T04:00:23+00:00

Signed-off-by: Al Viro

teach SYSCALL_DEFINE how to deal with long long/unsigned long long

2013-03-04T03:46:22+00:00

... and convert a bunch of SYSCALL_DEFINE ones to SYSCALL_DEFINE,
killing the boilerplate crap around them.

Signed-off-by: Al Viro

fs: reduce the use of module.h wherever possible

2012-02-29T00:31:58+00:00

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker

oprofile, dcookies: Fix possible circular locking dependency

2011-05-31T14:33:35+00:00

The lockdep warning below detects a possible A->B/B->A locking
dependency of mm->mmap_sem and dcookie_mutex. The order in
sync_buffer() is mm->mmap_sem/dcookie_mutex, while in
sys_lookup_dcookie() it is vice versa.

Fixing it in sys_lookup_dcookie() by unlocking dcookie_mutex before
copy_to_user().

oprofiled/4432 is trying to acquire lock:
 (&mm->mmap_sem){++++++}, at: [] might_fault+0x53/0xa3

but task is already holding lock:
 (dcookie_mutex){+.+.+.}, at: [] sys_lookup_dcookie+0x45/0x149

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (dcookie_mutex){+.+.+.}:
       [] lock_acquire+0xf8/0x11e
       [] mutex_lock_nested+0x63/0x309
       [] get_dcookie+0x30/0x144
       [] sync_buffer+0x196/0x3ec [oprofile]
       [] task_exit_notify+0x16/0x1a [oprofile]
       [] notifier_call_chain+0x37/0x63
       [] __blocking_notifier_call_chain+0x50/0x67
       [] blocking_notifier_call_chain+0x14/0x16
       [] profile_task_exit+0x1a/0x1c
       [] do_exit+0x2a/0x6fc
       [] do_group_exit+0x83/0xae
       [] sys_exit_group+0x17/0x1b
       [] system_call_fastpath+0x16/0x1b

-> #0 (&mm->mmap_sem){++++++}:
       [] __lock_acquire+0x1085/0x1711
       [] lock_acquire+0xf8/0x11e
       [] might_fault+0x80/0xa3
       [] sys_lookup_dcookie+0x104/0x149
       [] system_call_fastpath+0x16/0x1b

other info that might help us debug this:

1 lock held by oprofiled/4432:
 #0:  (dcookie_mutex){+.+.+.}, at: [] sys_lookup_dcookie+0x45/0x149

stack backtrace:
Pid: 4432, comm: oprofiled Not tainted 2.6.39-00008-ge5a450d #9
Call Trace:
 [] print_circular_bug+0xae/0xbc
 [] __lock_acquire+0x1085/0x1711
 [] ? get_parent_ip+0x11/0x42
 [] ? might_fault+0x53/0xa3
 [] lock_acquire+0xf8/0x11e
 [] ? might_fault+0x53/0xa3
 [] ? path_put+0x22/0x27
 [] might_fault+0x80/0xa3
 [] ? might_fault+0x53/0xa3
 [] sys_lookup_dcookie+0x104/0x149
 [] system_call_fastpath+0x16/0x1b

References: https://bugzilla.kernel.org/show_bug.cgi?id=13809
Cc:  # .27+
Signed-off-by: Robert Richter

[CVE-2009-0029] System call wrapper special cases

2009-01-14T13:15:18+00:00

System calls with an unsigned long long argument can't be converted with
the standard wrappers since that would include a cast to long, which in
turn means that we would lose the upper 32 bit on 32 bit architectures.
Also semctl can't use the standard wrapper since it has a 'union'
parameter.

So we handle them as special case and add some extra wrappers instead.

Signed-off-by: Heiko Carstens

shrink struct dentry

2008-12-31T23:07:38+00:00

struct dentry is one of the most critical structures in the kernel. So it's
sad to see it going neglected.

With CONFIG_PROFILING turned on (which is probably the common case at least
for distros and kernel developers), sizeof(struct dcache) == 208 here
(64-bit). This gives 19 objects per slab.

I packed d_mounted into a hole, and took another 4 bytes off the inline
name length to take the padding out from the end of the structure. This
shinks it to 200 bytes. I could have gone the other way and increased the
length to 40, but I'm aiming for a magic number, read on...

I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant:
why was this ever a good idea? The cookie system should increase its hash
size or use a tree or something if lookups are a problem. Also the "fast
dcookie lookups" in oprofile should be moved into the dcookie code -- how
can oprofile possibly care about the dcookie_mutex? It gets dropped after
get_dcookie() returns so it can't be providing any sort of protection.

At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system
with ~140 000 entries allocated. 192 is also a multiple of 64, so we get
nice cacheline alignment on 64 and 32 byte line systems -- any given dentry
will now require 3 cachelines to touch all fields wheras previously it
would require 4.

I know the inline name size was chosen quite carefully, however with the
reduction in cacheline footprint, it should actually be just about as fast
to do a name lookup for a 36 character name as it was before the patch (and
faster for other sizes). The memory footprint savings for names which are
<= 32 or > 36 bytes long should more than make up for the memory cost for
33-36 byte names.

Performance is a feature...

Signed-off-by: Al Viro

d_path: Make d_path() use a struct path

2008-02-15T05:17:09+00:00

d_path() is used on a  pair.  Lets use a struct path to
reflect this.

[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck 
Acked-by: Bryan Wu 
Acked-by: Christoph Hellwig 
Cc: Al Viro 
Cc: "J. Bruce Fields" 
Cc: Neil Brown 
Cc: Michael Halcrow 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

d_path: Make get_dcookie() use a struct path argument

2008-02-15T05:17:08+00:00

get_dcookie() is always called with a dentry and a vfsmount from a struct
path.  Make get_dcookie() take it directly as an argument.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jan Blunck 
Acked-by: Christoph Hellwig 
Cc: Al Viro 
Cc: "J. Bruce Fields" 
Cc: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove fs.h from mm.h

2007-07-30T00:09:29+00:00

Remove fs.h from mm.h. For this,
 1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
 2) Add back fs.h or less bloated headers (err.h) to files that need it.

As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
rebuilt down to 3444 (-12.3%).

Cross-compile tested without regressions on my two usual configs and (sigh):

alpha              arm-mx1ads        mips-bigsur          powerpc-ebony
alpha-allnoconfig  arm-neponset      mips-capcella        powerpc-g5
alpha-defconfig    arm-netwinder     mips-cobalt          powerpc-holly
alpha-up           arm-netx          mips-db1000          powerpc-iseries
arm                arm-ns9xxx        mips-db1100          powerpc-linkstation
arm-assabet        arm-omap_h2_1610  mips-db1200          powerpc-lite5200
arm-at91rm9200dk   arm-onearm        mips-db1500          powerpc-maple
arm-at91rm9200ek   arm-picotux200    mips-db1550          powerpc-mpc7448_hpc2
arm-at91sam9260ek  arm-pleb          mips-ddb5477         powerpc-mpc8272_ads
arm-at91sam9261ek  arm-pnx4008       mips-decstation      powerpc-mpc8313_rdb
arm-at91sam9263ek  arm-pxa255-idp    mips-e55             powerpc-mpc832x_mds
arm-at91sam9rlek   arm-realview      mips-emma2rh         powerpc-mpc832x_rdb
arm-ateb9200       arm-realview-smp  mips-excite          powerpc-mpc834x_itx
arm-badge4         arm-rpc           mips-fulong          powerpc-mpc834x_itxgp
arm-carmeva        arm-s3c2410       mips-ip22            powerpc-mpc834x_mds
arm-cerfcube       arm-shannon       mips-ip27            powerpc-mpc836x_mds
arm-clps7500       arm-shark         mips-ip32            powerpc-mpc8540_ads
arm-collie         arm-simpad        mips-jazz            powerpc-mpc8544_ds
arm-corgi          arm-spitz         mips-jmr3927         powerpc-mpc8560_ads
arm-csb337         arm-trizeps4      mips-malta           powerpc-mpc8568mds
arm-csb637         arm-versatile     mips-mipssim         powerpc-mpc85xx_cds
arm-ebsa110        i386              mips-mpc30x          powerpc-mpc8641_hpcn
arm-edb7211        i386-allnoconfig  mips-msp71xx         powerpc-mpc866_ads
arm-em_x270        i386-defconfig    mips-ocelot          powerpc-mpc885_ads
arm-ep93xx         i386-up           mips-pb1100          powerpc-pasemi
arm-footbridge     ia64              mips-pb1500          powerpc-pmac32
arm-fortunet       ia64-allnoconfig  mips-pb1550          powerpc-ppc64
arm-h3600          ia64-bigsur       mips-pnx8550-jbs     powerpc-prpmc2800
arm-h7201          ia64-defconfig    mips-pnx8550-stb810  powerpc-ps3
arm-h7202          ia64-gensparse    mips-qemu            powerpc-pseries
arm-hackkit        ia64-sim          mips-rbhma4200       powerpc-up
arm-integrator     ia64-sn2          mips-rbhma4500       s390
arm-iop13xx        ia64-tiger        mips-rm200           s390-allnoconfig
arm-iop32x         ia64-up           mips-sb1250-swarm    s390-defconfig
arm-iop33x         ia64-zx1          mips-sead            s390-up
arm-ixp2000        m68k              mips-tb0219          sparc
arm-ixp23xx        m68k-amiga        mips-tb0226          sparc-allnoconfig
arm-ixp4xx         m68k-apollo       mips-tb0287          sparc-defconfig
arm-jornada720     m68k-atari        mips-workpad         sparc-up
arm-kafa           m68k-bvme6000     mips-wrppmc          sparc64
arm-kb9202         m68k-hp300        mips-yosemite        sparc64-allnoconfig
arm-ks8695         m68k-mac          parisc               sparc64-defconfig
arm-lart           m68k-mvme147      parisc-allnoconfig   sparc64-up
arm-lpd270         m68k-mvme16x      parisc-defconfig     um-x86_64
arm-lpd7a400       m68k-q40          parisc-up            x86_64
arm-lpd7a404       m68k-sun3         powerpc              x86_64-allnoconfig
arm-lubbock        m68k-sun3x        powerpc-cell         x86_64-defconfig
arm-lusl7200       mips              powerpc-celleb       x86_64-up
arm-mainstone      mips-atlas        powerpc-chrp32

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds