This patch makes it so that simple_fill_super and get_sb_pseudo assign their
root inodes to be number 1. It also fixes up a couple of callers of
simple_fill_super that were passing in files arrays that had an index at
number 1, and adds a warning for any caller that sends in such an array.
It would have been nice to have made it so that it wasn't possible to make
such a collision, but some callers need to be able to control what inode
number their entries get, so I think this is the best that can be done.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>
The problems are:
- on filesystems w/o permanent inode numbers, i_ino values can be larger
than 32 bits, which can cause problems for some 32 bit userspace programs on
a 64 bit kernel. We can't do anything for filesystems that have actual
>32-bit inode numbers, but on filesystems that generate i_ino values on the
fly, we should try to have them fit in 32 bits. We could trivially fix this
by making the static counters in new_inode and iunique 32 bits, but...
- many filesystems call new_inode and assume that the i_ino values they are
given are unique. They are not guaranteed to be so, since the static
counter can wrap. This problem is exacerbated by the fix for #1.
- after allocating a new inode, some filesystems call iunique to try to get
a unique i_ino value, but they don't actually add their inodes to the
hashtable, and so they're still not guaranteed to be unique if that counter
wraps.
This patch set takes the simpler approach of simply using iunique and hashing
the inodes afterward. Christoph H. previously mentioned that he thought that
this approach may slow down lookups for filesystems that currently hash their
inodes.
The questions are:
1) how much would this slow down lookups for these filesystems?
2) is it enough to justify adding more infrastructure to avoid it?
What might be best is to start with this approach and then only move to using
IDR or some other scheme if these extra inodes in the hashtable prove to be
problematic.
I've done some cursory testing with this patch and the overhead of hashing and
unhashing the inodes with pipefs is pretty low -- just a few seconds of system
time added on to the creation and destruction of 10 million pipes (very
similar to the overhead that the IDR approach would add).
The hard thing to measure is what effect this has on other filesystems. I'm
open to ways to try and gauge this.
Again, I've only converted pipefs as an example. If this approach is
acceptable then I'll start work on patches to convert other filesystems.
With a pretty-much-worst-case microbenchmark provided by Eric Dumazet
<dada1@cosmosbay.com>:
hashing patch (pipebench):
sys 1m15.329s
sys 1m16.249s
sys 1m17.169s
unpatched (pipebench):
sys 1m9.836s
sys 1m12.541s
sys 1m14.153s
Which works out to 1.05642174294555027017. So ~5-6% slowdown.
This patch:
When a 32-bit program that was not compiled with large file offsets does a
stat and gets a st_ino value back that won't fit in the 32 bit field, glibc
(correctly) generates an EOVERFLOW error. We can't do anything about fs's
with larger permanent inode numbers, but when we generate them on the fly, we
ought to try and have them fit within a 32 bit field.
This patch takes the first step toward this by making the static counters in
these two functions be 32 bits.
[jlayton@redhat.com: mention that it's only the case for 32bit, non-LFS stat]
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>
Here is a driver for the Alchemy au1550 PSC (Programmable Serial
Controller) in SPI master mode.
It supports dma transfers using the Alchemy descriptor based dma controller
for 4-8 bits per word SPI transfers. For 9-24 bits per word transfers, pio
irq based mode is used to avoid setup of dma channels from scratch on each
number of bits per word change.
Tested with au1550; this may also work on other MIPS Alchemy cpus, like
au1200/au1210/au1250. Used extensively with SD card connected via SPI;
this handles 8.1MHz SPI clock transfers using dma without any problem (the
highest SPI clock freq possible with au1550 running on 324MHz).
The driver supports sharing of SPI bus by multiple devices. All features
of Alchemy SPI mode are supported (all SPI modes, msb/lsb first, bits per
word in 4-24 range).
As the SPI clock of the controller depends on main input clock that shall
be configured externally, platform data structure for au1550 SPI controller
driver contains mainclk_hz attribute to define the input clock rate. From
this value, dividers of the controller for SPI clock are set up for
required frequency.
Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
Whitespace and section fixups. Remove partial workaround for platform
setup bug in dma_mask setup; it couldn't work with multiple controllers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various documentation updates for the SPI infrastructure, to clarify things
that may not have been clear, to cope with lack of editing, and fix
omissions.
Also, plug SPI into the kernel-api DocBook template, and fix all the
resulting glitches in document generation.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a filesystem API for <linux/spi/spi.h> stack. The initial version of
this interface is purely synchronous.
dbrownell@users.sourceforge.net:
Cleaned up, bugfixed; much simplified; added preliminary documentation.
Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.
Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
groups of one or more transfers (each of which may be full duplex if
desired).
This is marked as EXPERIMENTAL with an explicit disclaimer that the API
(notably the ioctls) is subject to change.
Signed-off-by: Andrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify the spi_butterfly driver by removing incomplete/unused support for
the second SPI bus, implemented by the USI controller. This should make
this a clearer example of how to write a parport bitbang driver.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove some obviously old interrupt disable/enable code that has been
commented out.
Signed-off-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The misc character device driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The hdaps driver uses a semaphore as mutex. Use the mutex API instead of the
(binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Robert Love <rlove@rlove.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The TPM driver uses two semaphores as mutexes. Use the mutex API instead of
the (binary) semaphores.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Kylene Hall <kjhall@us.ibm.com>
Cc: Marcel Selhorst <tpm@selhorst.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The RocketPort driver uses a semaphore as mutex. Use the mutex API instead of
the (binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Other symbols of the hrtimers API are already exported.
Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When elf loader fails to map executable (due to memory shortage or because
binary is malformed), it can return 0. Normally, this is invisible because
process is killed with SIGKILL and it never returns to user space.
But if exec() is called from kernel thread (hotplug, whatever)
consequences are more interesting and vary depending on architecture.
i386. Nothing especially interesting, execve() just returns
with "success" :-)
x86_64. Fake zero frame is used on way to caller, RSP/RIP are loaded
with zeros, ergo... double fault.
ia64. Similar to i386, but r32...r95 are corrupted. Sometimes it
oopses due to return to zero PC, sometimes it sees NaT in
rXX and oopses due to NaT consumption.
Signed-off-by: Alexey Kuznetsov <alexey@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix misnamed fields of 'struct clock_event_device' in the kernel-doc
comment. Convert the acronyms to uppercase, while at it...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Jan Kara <jack@ucw.cz>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add taskstats.h to include/linux/Kbuild, make headers_install would then
pickup taskstats.h. This needs to be done as taskstats.h is a user
interface header.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
You currently cannot remove all cpus or mems from cpus_allowed or
mems_allowed of a cpuset. We now allow both if there are no attached
tasks.
Acked-by: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Paul Menage <menage@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup using simple_read_from_buffer() in procfs.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a new list for kexec/kdump discussion.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that the moxa input checking security bug described by
CVE-2005-0504 appears to remain unfixed upstream.
The issue is described here:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-0504
Debian has been shipping the following patch from Andres Salomon.
(akpm: it's a privileged operation)
Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears that a minor thinko occurred in udf_rmdir and the
(already-cleared) link count on the directory that is being removed was
being decremented instead of the link count on its parent directory. This
gives rise to lots of kernel messages similar to:
UDF-fs warning (device loop1): udf_rmdir: empty directory has nlink != 2 (8)
when removing directory trees. No other ill effects have been observed but
I guess it could theoretically result in the link count overflowing on a
very long-lived, much modified directory.
Signed-off-by: Stephen Mollett <molletts@yahoo.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you compile and run the below test case in an msdos or vfat directory on
an x86-64 system with -m32 you'll get garbage in the kernel_dirent struct
followed by a SIGSEGV.
The patch fixes this.
Reported and initial fix by Bart Oldeman
#include <sys/types.h>
#include <sys/ioctl.h>
#include <dirent.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
struct kernel_dirent {
long d_ino;
long d_off;
unsigned short d_reclen;
char d_name[256]; /* We must not include limits.h! */
};
#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct kernel_dirent [2])
#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct kernel_dirent [2])
int main(void)
{
int fd = open(".", O_RDONLY);
struct kernel_dirent de[2];
while (1) {
int i = ioctl(fd, VFAT_IOCTL_READDIR_BOTH, (long)de);
if (i == -1) break;
if (de[0].d_reclen == 0) break;
printf("SFN: reclen=%2d off=%d ino=%d, %-12s",
de[0].d_reclen, de[0].d_off, de[0].d_ino, de[0].d_name);
if (de[1].d_reclen)
printf("\tLFN: reclen=%2d off=%d ino=%d, %s",
de[1].d_reclen, de[1].d_off, de[1].d_ino, de[1].d_name);
printf("\n");
}
return 0;
}
Signed-off-by: Bart Oldeman <bartoldeman@users.sourceforge.net>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma_declare_coherent_memory() allocates a bitmap 1 bit per page, it
calculates the bitmap size based on size of long, but allocates bytes...
Thanks to James Bottomley for clarifications and corrections.
Signed-off-by: G. Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several people have observed that perhaps LOG_BUF_SHIFT should be in a more
obvious place than under DEBUG_KERNEL. Under some circumstances (such as the
PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an
undesirable trade off for something as trivial as increasing the kernel log
buffer size.
Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more
likely to be able to change it such a circumstance that the default buffer
size is insufficient.
Signed-off-by: Alistair John Strachan <s0348365@sms.ed.ac.uk>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eliminate 19439 (!!) sparse warnings like:
include/linux/mm.h:321:22: warning: constant 0xffff810000000000 is so big it is unsigned long
Eliminate 56 sparse warnings like:
arch/x86_64/kernel/setup.c:248:16: warning: constant 0xffffffff80000000 is so big it is unsigned long
Eliminate 5 sparse warnings like:
arch/x86_64/kernel/module.c:49:13: warning: constant 0xfffffffffff00000 is so big it is unsigned long
Eliminate 23 sparse warnings like:
arch/x86_64/mm/init.c:551:37: warning: constant 0xffffc20000000000 is so big it is unsigned long
Eliminate 6 sparse warnings like:
arch/x86_64/kernel/module.c:49:13: warning: constant 0xffffffff88000000 is so big it is unsigned long
Eliminate 23 sparse warnings like:
arch/x86_64/mm/init.c:552:6: warning: constant 0xffffe1ffffffffff is so big it is unsigned long
Eliminate 3 sparse warnings like:
arch/x86_64/kernel/e820.c:186:17: warning: constant 0x3fffffffffff is so big it is long
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make a global linux/const.h header file instead of having multiple,
per-arch files, and convert current users of asm/const.h to use
linux/const.h.
Built on x86_64 and sparc64.
[akpm@linux-foundation.org: fix include/asm-x86_64/Kbuild]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
flush_scheduled_work() can sleep, and we're calling it under spinlock.
AFAICS, moving flush_scheduled_work before spin_lock() should not cause any
problems.
Reason being - The only thing that can race against tpm_release is tpm_open
(tpm_release is called when last reference to the file is closed and only
thing that can happen after that is tpm_open??) and tpm_open acquires
driver_lock and more over it bails out with EBUSY if chip->num_opens is
greater than 0.
I also moved chip->num_pending-- to after deleting timer and setting data
pending as it looks more correct for the paranoid although it probably doesn't
matter as it is guarded by driver_lock. None the less this change should not
cause problems.
While I was at it I noticed a missing NULL check in tpm_register_hardware
which is fixed with this patch as well.
Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 226a6b84aa renumbered Chapter 11 in
Documentation/CodingStyle to Chapter 12, but it didn't update the reference
to that chapter further down in the file. This patch corrects the chapter
reference.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Propagate flags such as S_APPEND, S_IMMUTABLE, etc. from i_flags into
ext2-specific i_flags. Hence, when someone sets these flags via a different
interface than ioctl, they are stored correctly.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It seems that the recent Windows changed specification, and it's
undocumented. Windows doesn't update ->free_clusters correctly.
This patch doesn't use ->free_clusters by default. (instead, add "usefree"
for forcing to use it)
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Juergen Beisert <juergen127@kreuzholzen.de>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It looks like a remainder from designing...
Signed-off-by: Jarek Poplawski <jarkao@o2.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures defined three macros, MK_IOSPACE_PFN(), GET_IOSPACE()
and GET_PFN() in pgtable.h. However, the only callers of any of these
macros are in Sparc specific code, either in arch/sparc, arch/sparc64 or
drivers/sbus.
This patch removes the redundant macros from all architectures except
sparc and sparc64.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch shuts warnings of the sort:
make -C /mnt/samsung_200/sam/kernel/trees/21-rc6/build \
KBUILD_SRC=/mnt/samsung_200/sam/kernel/trees/21-rc6 \
KBUILD_EXTMOD="" -f /mnt/samsung_200/sam/kernel/trees/21-rc6/Makefile mandocs
make -f /mnt/samsung_200/sam/kernel/trees/21-rc6/scripts/Makefile.build obj=scripts/basic
make -f /mnt/samsung_200/sam/kernel/trees/21-rc6/scripts/Makefile.build obj=Documentation/DocBook mandocs
SRCTREE=/mnt/samsung_200/sam/kernel/trees/21-rc6/ /mnt/samsung_200/sam/kernel/trees/21-rc6/build/scripts/basic/docproc doc /mnt/samsung_200/sam/kernel/trees/21-rc6/Documentation/DocBook/wanbook.tmpl >Documentation/DocBook/wanbook.xml
if grep -q refentry Documentation/DocBook/wanbook.xml; then xmlto man -m /mnt/samsung_200/sam/kernel/trees/21-rc6/Documentation/DocBook/stylesheet.xsl -o Documentation/DocBook/man Documentation/DocBook/wanbook.xml ; gzip -f Documentation/DocBook/man/*.9; fi
Note: meta version: No productnumber or alternative sppp_close
Note: meta version: No refmiscinfo@class=version sppp_close
Note: Writing sppp_close.9
Note: meta version: No productnumber or alternative sppp_open
Note: meta version: No refmiscinfo@class=version sppp_open
by adding a RefMiscInfo xml tag in the form of the current kernel version
to the function, struct and enum definitions in files included by
kernel-doc when building 'mandocs'. However, the version string appears
truncated on the manpage due to some constraints in the xml DTD for the man
header, I believe, for the troff output is truncated too.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As scheduled, do_setitimer() now returns -EINVAL for invalid timeval.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ingo Molnar's semaphore to mutex conversions left some noise on a few
trylock calls. Clean it up.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the thread failed to create the subsequent wait_event will hang forever.
This is likely to happen if kernel hits max_threads limit.
Will be critical for virtualization systems that limit the number of tasks
and kernel memory usage within the container.
(akpm: JBD should be converted fully to the kthread API: kthread_should_stop()
and kthread_stop()).
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a missing check for CAP_SYS_ADMIN in do_change_type().
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The UTF-8 part of the vt driver suffers from the following issues which are
addressed in my patch:
1) If there's no glyph found for a particular valid UTF-8 character, we try
to display U+FFFD. However if this one is not found either, here's what
the current kernel does:
- First, if the Unicode value is less than the number of glyphs, use the
glyph directly from that position of the glyph table. While it may be a
good idea in the 8-bit world, it has absolutely no sense with Unicode
in mind. For example, if a Latin-2 font is loaded and an application
prints U+00FB ("u with circumflex", not present in Latin-2) then as a
fallback solution the glyph from the 0xFB position of the Latin-2
fontset (which is an "u with double accent" - a different character) is
displayed.
- Second, if this fallback fails too, a simple ASCII question mark is
printed, which is visually undistinguishable from a real question mark.
I changed the code to skip the first step (except if in non-UTF-8 mode),
and changed the second step to print the question mark with inverse color
attributes, so it is visually clear that it's not a real question mark,
and resembles more to the common glyph of U+FFFD.
2) The UTF-8 decoder is buggy in many ways:
- Lone continuation bytes (section 3.1 of Markus Kuhn's UTF-8 stress
test) are not caught, they are displayed as some "random" (taken
directly form the font table, see above) glyphs instead the replacement
character.
- Incomplete sequences (sections 3.2 and 3.3 of the stress test) emit no
replacement character, but rather cause the subsequent valid character
to be displayed more times(!).
- The decoder is not safe: overlong sequences are not caught currently,
they are displayed as if these were valid representations. This may
even have security impacts.
- The decoder does not handle D800..DFFF and FFFE..FFFF specially, it
just emits these code points and lets it be looked up in the glyph
table. Since these are invalid code points, I replace them by U+FFFD
and hence give no chance for them to be looked up in the glyph table.
(Assuming no font ships glyphs for these code points, this change is
not visible to the users since the glyph shown will be the same.)
With my fixes to the decoder it now behaves exactly as Markus Kuhn's
stress test recommends.
3) It has no concept of double-width (CJK) characters. It's way beyond the
scope of my patch to try to display them, but at least I think it's
important for the cursor to jump two positions when printing such
characters, since this is what applications (such as text editors)
expect. Currently the cursor only jumps one position, and hence
applications suffer from displaying and refreshing problems, and editing
some English letters that are preceded by some CJK characters in the same
line is a nightmare. With my patch an additional space is inserted after
the CJK character has been printed (which usually means a replacement
symbol of course). (If U+FFFD isn't availble and hence an inverse
question mark is displayed in the first cell, I keep the inverted state
for the space in the 2nd column so it's quite easy to see that they are
tied together.)
4) There is a small built-in table of zero-width spaces that are not to be
printed but silently skipped. U+200A is included there, but it's not a
zero-width character, so I remove it from there.
Signed-off-by: Egmont Koblinger <egmont@uhulinux.hu>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
