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2020-08-24Revert "vc_screen: extract vcs_read_buf_header"Jiri Slaby1-18/+13
This reverts commit b1c32fcfadf5593ab7a63261cc8a5747c36e627e, because Syzkaller reports a use-after-free, a write in vcs_read: BUG: KASAN: use-after-free in vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] BUG: KASAN: use-after-free in vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 Write of size 2 at addr ffff8880a8014000 by task syz-executor.5/16936 CPU: 1 PID: 16936 Comm: syz-executor.5 Not tainted 5.9.0-rc1-next-20200820-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: ... kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 There are two issues with the patch: 1) vcs_read rounds the 'count' *up* to an even number. So if we read odd bytes from the header (3 bytes in the reproducer), the second byte of a (2-byte/ushort) write to temporary con_buf won't fit. It is because with the patch applied, we only subtract the real number read (3 bytes) and not the whole header (4 bytes). 2) in this scenario, we perform unaligned accesses now: there are 2-byte/ushort writes to odd addresses. Due to the same reason as above. Revert this for now, re-think and retry later. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+ad1f53726c3bd11180cb@syzkaller.appspotmail.com Fixes: b1c32fcfadf5 ("vc_screen: extract vcs_read_buf_header") Cc: akpm@linux-foundation.org Cc: nico@fluxnic.net Link: https://lore.kernel.org/r/20200824095425.4376-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: prune macrosJiri Slaby1-4/+0
Do not undefine random words. I guess this was here as there were macros with such generic names somewhere. I very doubt they still exist. So drop these. And remove a spare blank line. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-16-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_headerJiri Slaby1-13/+18
The attribute header handling is terrible in vcs_read_buf. Separate it to a new function and simply do memmove (of up to 4 bytes) to the start of the con_buf -- if user seeked. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_bufJiri Slaby1-68/+78
And finally, move the attributes buffer handling to a separate function. Leaving vcs_read quite compact. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_noattrJiri Slaby1-11/+22
Now, move the code for no-attributes handling to a separate function. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_uniJiri Slaby1-19/+30
The same as making write more readable, extract unicode handling from vcs_read. The other two cases (w/ and w/o attributes) will follow. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vs_screen: kill tmp_count from vcs_readJiri Slaby1-8/+2
Both tmp_count computations and the single use can be eliminated using min(). Do so. Side note: we need HEADER_SIZE to be unsigned for min() not to complain. Fix that too as all its other uses do not mind. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: sanitize types in vcs_readJiri Slaby1-8/+7
* pos is derived from the passed ppos, so make it long enough, i.e. loff_t * attr and uni_mode are booleans, so... * size is limited by vcs_size() which returns an int * read, p, orig_count and this_round are always ">= 0" and "< size", so uint is enough * row, col, and max_col are derived from vc->vc_cols (uint) and p, so make them uint too * tmp_count is derived from this_round, so make it an uint too. * use u16 * for org (instead of unsigned short *). No need to initialize org too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: eliminate ifdefs from vcs_write_bufJiri Slaby1-12/+17
Introduce a new inline function called vc_compile_le16 and do the shifts and ORs there. Depending on LE x BE. I tried cpu_to_le16, but it ends up with worse assembly on BE for whatever reason -- the compiler seems to be unable to optimize the swap. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_write_bufJiri Slaby1-76/+92
This is the counterpart of the previous patch: here, we extract buffer writing with attributes from vcs_write. Now, there is no need for org to be initialized to NULL. The org0 check before update_region() confuses compilers, so check org instead. It provides the same semantics. And it also eliminates the need for initialization of org0. We switch the branches of the attr 'if' too, as the inversion brings only confusion now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_write_buf_noattrJiri Slaby1-21/+34
vcs_write is too long to be readable. Extract buffer handling w/o attributes from there to a separate function. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: sanitize types in vcs_writeJiri Slaby1-10/+7
* ret can carry error codes, so make it signed, i.e. ssize_t * pos is derived from the passed ppos, so make it long enough, i.e. loff_t * attr is a boolean, so... * size is limited by vcs_size() which returns an int * written, p, orig_count and this_round are always ">= 0" and "< size", so uint is enough * col and max_col are derived from vc->vc_cols (uint) and p, so make them uint too * place con_buf0 and con_buf declaration to a single line Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: rewrite vcs_size to accept vc, not inodeJiri Slaby1-17/+29
It is weird to fetch the information from the inode over and over. Read and write already have the needed information, so rewrite vcs_size to accept a vc, attr and unicode and adapt vcs_lseek to that. Also make sure all sites check the return value of vcs_size for errors. And document it using kernel-doc. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: document and cleanup vcs_vcJiri Slaby1-8/+12
Document parameters of vcs_vc and make viewed a bool. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-27vcs: prevent write access to vcsu devicesNicolas Pitre1-0/+3
Commit d21b0be246bf ("vt: introduce unicode mode for /dev/vcs") guarded against using devices containing attributes as this is not yet implemented. It however failed to guard against writes to any devices as this is also unimplemented. Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Signed-off-by: Nicolas Pitre <npitre@baylibre.com> Cc: <stable@vger.kernel.org> # v4.19+ Cc: Jiri Slaby <jslaby@suse.com> Fixes: d21b0be246bf ("vt: introduce unicode mode for /dev/vcs") Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.1911051030580.30289@knanqh.ubzr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-28vt: use /dev/vcs (not /dev/vcs0) in commentJakub Wilk1-1/+1
Both /dev/vcs and /dev/vcs0 were in use in the past, but these days /dev/vcs0 is mostly historical curiosity. * "/dev/vcs" is the name that has always been in the Linux allocated devices list. * "vcs" is the device name in sysfs since Linux v2.6.12. * MAKEDEV(1) in Debian used to create /dev/vcs0 only, but /dev/vcs was added in 1999: https://bugs.debian.org/45698 * MAKEDEV(1) in RedHat switched from /dev/vcs0 to /dev/vcs in 2000: * Fri Oct 20 2000 Nalin Dahyabhai <nalin@redhat.com> - change vcs0 to vcs (ditto for vcsa0) Signed-off-by: Jakub Wilk <jwilk@jwilk.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18vcs: restore and document initial POLLPRI eventNicolas Pitre1-0/+9
Restore and document the forced initial POLLPRI event reporting when poll() is used for the first time. This used to be the implemented behavior before recent changes. Because of the way poll() is implemented, this prevents losing an event happening between the last read() and the first poll() invocation. Since poll() for /dev/vcs* was not always supported, user space probes for its availability as follows: int fd = open("/dev/vcsa", O_RDONLY); struct pollfd p = { .fd = fd, .events = POLLPRI }; available = (poll(&p, 1, 0) == 1); Semantically, it makes sense to signal the first event as such even if it might be spurious. The screen could be modified, and modified back to its initial state before we get to read it, so users must be prepared for that anyway. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18vcs: fasync(): make it consistent with poll()Nicolas Pitre1-3/+12
We use POLLPRI not POLLIN to wait for data with poll() as there is never any incoming data stream per se. Let's use the same semantic with fasync() for consistency, including the fact that a vt may go away. No known user space ever relied on the SIGIO reason so far, let alone FASYNC, so the risk of breakage is pretty much nonexistent. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18vcs: poll(): cope with a deallocated vtNicolas Pitre1-6/+15
When VT_DISALLOCATE is used on a vt, user space waiting with poll() on the corresponding /dev/vcs device is not awakened. This is now fixed by returning POLLHUP|POLLERR to user space. Also, in the normal screen update case, we don't set POLLERR anymore as POLLPRI alone is a much more logical response in a non-error situation, saving some confusion on the user space side. The only known user app making use of poll() on /dev/vcs* is BRLTTY which is known to cope with that change already, so the risk of breakage is pretty much nonexistent. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18vcsa: clamp header values when they don't fitNicolas Pitre1-2/+3
The /dev/vcsa* devices have a fixed char-sized header that stores the screen geometry and cursor location. Let's make sure it doesn't contain random garbage when those values exceed 255. If ever it becomes necessary to convey larger screen info to user space then a larger header in the not-yet-implemented /dev/vcsua* devices should be considered. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28vt: unicode fallback for scrollbackNicolas Pitre1-1/+2
There is currently no provision for scrollback content in the core code, leaving that to backend video drivers where this can be highly optimized. There is currently no common method for those drivers to tell the core what part of the scrollback is actually displayed and what size the scrollback buffer is either. Because of that, the unicode screen buffer has no provision for any scrollback. At least we can provide backtranslated glyph values when the scrollback is active which should be plenty good enough for now. Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Dave Mielke <Dave@mielke.cc> Acked-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-28vt: introduce unicode mode for /dev/vcsNicolas Pitre1-14/+75
Now that the core vt code knows how to preserve unicode values for each displayed character, it is then possible to let user space access it via /dev/vcs*. Unicode characters are presented as 32 bit values in native endianity via the /dev/vcsu* devices, mimicking the simple /dev/vcs* devices. Unicode with attributes (similarly to /dev/vcsa*) is not supported at the moment. Data is available only as long as the console is in UTF-8 mode. ENODATA is returned otherwise. This was tested with the latest development version (to become version 5.7) of BRLTTY. Amongst other things, this allows ⠋⠕⠗ ⠞⠓⠊⠎ ⠃⠗⠁⠊⠇⠇⠑⠀⠞⠑⠭⠞⠀to appear directly on braille displays regardless of the console font being used. Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Dave Mielke <Dave@mielke.cc> Acked-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-1/+1
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-29vc: switch to fixed_size_llseek()Al Viro1-16/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-26vt: synchronize_rcu() under spinlock is not nice...Al Viro1-2/+4
vcs_poll_data_free() calls unregister_vt_notifier(), which calls atomic_notifier_chain_unregister(), which calls synchronize_rcu(). Do it *after* we'd dropped ->f_lock. Cc: stable@vger.kernel.org (all kernels since 2.6.37) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22new helper: file_inode(file)Al Viro1-4/+4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-08vt: push down the tty lock so we can see what is left to tackleAlan Cox1-2/+2
At this point we have the tty_lock guarding a couple of oddities, plus the translation and unimap still. We also extend the console_lock in a couple of spots where coverage is wrong and switch vcs_open to use the right lock ! [Fixed the locking issue Jiri reported] Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-10-31tty: Add export.h for EXPORT_SYMBOL/THIS_MODULE to exportersPaul Gortmaker1-0/+1
With module.h being implicitly everywhere via device.h, the absence of explicitly including something for EXPORT_SYMBOL went unnoticed. Since we are heading to fix things up and clean module.h from the device.h file, we need to explicitly include these files now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-04-19tty: remove invalid location line in file headerJovi Zhang1-2/+0
remove invalid location line in each file header after location moved from driver/char to driver/tty Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-16Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds1-1/+0
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: BKL: That's all, folks fs/locks.c: Remove stale FIXME left over from BKL conversion ipx: remove the BKL appletalk: remove the BKL x25: remove the BKL ufs: remove the BKL hpfs: remove the BKL drivers: remove extraneous includes of smp_lock.h tracing: don't trace the BKL adfs: remove the big kernel lock
2011-03-02drivers: remove extraneous includes of smp_lock.hArnd Bergmann1-1/+0
These were missed the last time I cleaned this up globally, because of code moving around or new code getting merged. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2011-02-17tty,vcs removing con_buf/conf_buf_mtxJiri Olsa1-46/+52
seems there's no longer need for using con_buf/conf_buf_mtx as vcs_read/vcs_write buffer for user's data. The do_con_write function, that was the other user of this, is currently using its own kmalloc-ed buffer. Not sure when this got changed, as I was able to find this code in 2.6.9, but it's already gone as far as current git history goes - 2.6.12-rc2. AFAICS there's a behaviour change with the current change. The lseek is not completely mutually exclusive with the vcs_read/vcs_write - the file->f_pos might get updated via lseek callback during the vcs_read/vcs_write processing. I tried to find out if the prefered behaviour is to keep this in sync within read/write/lseek functions, but I did not find any pattern on different places. I guess if user end up calling write/lseek from different threads she should know what she's doing. If needed we could use dedicated fd mutex/buffer. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17tty,vcs: lseek/VC-release race fixJiri Olsa1-0/+18
there's a race between vcs's lseek handler and VC release. The lseek handler does not hold console_lock and touches VC's size info. If during this the VC got released, there's an access violation. Following program triggers the issue for me: [SNIP] #define _BSD_SOURCE #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/vt.h> #include <unistd.h> #include <errno.h> static int run_seek(void) { while(1) { int fd; fd = open("./vcs30", O_RDWR); while(lseek(fd, 0, 0) != -1); close(fd); } } static int open_ioctl_tty(void) { return open("/dev/tty1", O_RDWR); } static int do_ioctl(int fd, int req, int i) { return ioctl(fd, req, i); } #define INIT(i) do_ioctl(ioctl_fd, VT_ACTIVATE, i) #define SHUT(i) do_ioctl(ioctl_fd, VT_DISALLOCATE, i) int main(int argc, char **argv) { int ioctl_fd = open_ioctl_tty(); if (ioctl < 0) { perror("open tty1 failed\n"); return -1; } if ((-1 == mknod("vcs30", S_IFCHR|0666, makedev(7, 30))) && (errno != EEXIST)) { printf("errno %d\n", errno); perror("failed to create vcs30"); return -1; } do_ioctl(ioctl_fd, VT_LOCKSWITCH, 0); if (!fork()) run_seek(); while(1) { INIT(30); SHUT(30); } return 0; } [SNIP] Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-26console: rename acquire/release_console_sem() to console_lock/unlock()Torben Hohn1-8/+8
The -rt patches change the console_semaphore to console_mutex. As a result, a quite large chunk of the patches changes all acquire/release_console_sem() to acquire/release_console_mutex() This commit makes things use more neutral function names which dont make implications about the underlying lock. The only real change is the return value of console_trylock which is inverted from try_acquire_console_sem() This patch also paves the way to switching console_sem from a semaphore to a mutex. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert] Signed-off-by: Torben Hohn <torbenh@gmx.de> Cc: Thomas Gleixner <tglx@tglx.de> Cc: Greg KH <gregkh@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-11vcs: make proper usage of the poll flagsNicolas Pitre1-3/+3
Kay Sievers pointed out that usage of POLLIN is well defined by POSIX, and the current usage here doesn't follow that definition. So let's duplicate the same semantics as implemented by sysfs_poll() instead. Signed-off-by: Nicolas Pitre <nicolas.pitre@canonical.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05TTY: create drivers/tty/vt and move the vt code thereGreg Kroah-Hartman1-0/+644
The vt and other related code is moved into the drivers/tty/vt directory. Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>