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path: root/drivers/tty/n_hdlc.c
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2020-03-16tty: n_hdlc, remove FILE and LINE from pr_debugJiri Slaby
As Joe suggests, dynamic debug can print module name and line number along with message. So remove __FILE__ and __LINE__ from all those pr_debug calls. Out of curiosity, I measured the savings, 200 bytes of code are gone. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Suggested-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/20200316064910.4941-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: wrap a comment properlyJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-24-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: fix whitespace around binary operatorsJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-23-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: add missing spaces after commasJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-22-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove spaces between function name and (Jiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-21-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove useless whitespace at line wrapsJiri Slaby
Do s@[ \t]\+$@@ s@ \+\t@\t@ on the file as there are many spaces at the begininning of lines and many spaces/tabs at EOLs. And vim screamed. git show -w is supposed to show no difference here. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-20-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: use __func__ and pr_ print helpersJiri Slaby
* we mark the message in n_hdlc_tty_receive as error * we use __func__ instead of explicit function name * we switch the remaining prints to pr_* helpers Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-19-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unneeded ifdefJiri Slaby
TTY_NO_WRITE_SPLIT is (always) defined in linux/tty.h, so no need to check for it. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-18-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: switch tbusy and woke_up to boolsJiri Slaby
They are in fact bools, so save some bytes (8B on x86_64). Also describe @woke_up as we know what it is. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-17-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: move tty_ldisc_ops to the bottomJiri Slaby
This makes forward declarations unnecessary. So drop them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-16-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: add helper for buffers allocationJiri Slaby
Given both rx and tx allocations do the same, add a new helper (n_hdlc_alloc_buf) and use it for both of them. This cleans up n_hdlc_alloc slightly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove checking of n_hdlcJiri Slaby
We got rid of backup_tty recently. Also, the tty layer ensures not to call other ldisc hooks after ldisc close. That means, all those tests are superfluous now so remove them. Note that we remove the magic check in write after schedule too. The tty cannot change during schedule. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove cached ttyJiri Slaby
It's not needed, as now it's clear, that it's always the same as the one passed from the tty layer. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: inline n_hdlc_releaseJiri Slaby
Put the body of n_hdlc_release into the only caller. It can be seen, that the "if" is superfluous now -- the same happens few lines above in n_hdlc_tty_close already. So drop it. Drop also n_hdlc2tty macro as this was the only user. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: expand tty2n_hdlc macroJiri Slaby
It's simple tty->disc_data, but it obfuscates code. So expand it to all locations and drop it. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused backup_ttyJiri Slaby
It's only set to NULL and never properly used. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused flagsJiri Slaby
They are only set to 0 and never read. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_pollJiri Slaby
This makes the functions return immediatelly on invalid state. And we can push the indent of the later code one level left. Pass "-w" to "git show" to see we are changing only the conditions (and whitespace). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: simplify freeing of buffer listJiri Slaby
n_hdlc_release contains four loops to free each buffer list. Create a helper (n_hdlc_free_buf_list) and call it for every list instead. It makes n_hdlc_release more readable. We are switching from "for (;;)" to "do {} while (buf)" which avoids the "if (buf)" completely -- kfree is a nop for NULL pointers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: use clamp() for maxframeJiri Slaby
It is easier to read. And use MAX_HDLC_FRAME_SIZE instead of magic constant. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: cleanup messages during registrationJiri Slaby
1) n_hdlc prints two lines during registration. Squeeze it into one. 2) prefix the error message with "N_HDLC: ", so that it's clear which ldisc failed to register. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: put init/exit strings directly to printsJiri Slaby
These strings were put aside from prints to save some bytes after module load or when built-in -- they were freed after module load (__init ones) or when the driver is selected as built-in (__exit ones). The savings are negligible, but the code readability is worse by the order of magnitude. So put the strings where they belong. Note that it also used to make little sense putting const data in .data (the __exit case). While at it, switch to pr_info, pr_err, not using the KERN_INFO and _ERR directly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: convert debuglevel use to pr_debugJiri Slaby
With pr_debug we have a fine-grained control about debugging prints. So convert the use of global debuglevel variable and tests to a commonly used pr_debug. And drop debuglevel completely. This also implicitly adds a loglevel to the messages (KERN_DEBUG) as it was missing on most of them. And also use __func__ instead of function names explicitly typed. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused macrosJiri Slaby
VERSION and bset are unused. Remove them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove tracing debug printsJiri Slaby
We can trace functions using ftrace, so there is no need for this additional prints. Remove them. We keep only those which print some additional info, not only function name & "entry"/"exit". Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23tty: n_hdlc: Use flexible-array member and struct_size() helperGustavo A. R. Silva
Old code in the kernel uses 1-byte and 0-byte arrays to indicate the presence of a "variable length array": struct something { int length; u8 data[1]; }; struct something *instance; instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL); instance->length = size; memcpy(instance->data, source, size); There is also 0-byte arrays. Both cases pose confusion for things like sizeof(), CONFIG_FORTIFY_SOURCE, etc.[1] Instead, the preferred mechanism to declare variable-length types such as the one above is a flexible array member[2] which need to be the last member of a structure and empty-sized: struct something { int stuff; u8 data[]; }; Also, by making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. Lastly, make use of the struct_size() helper to safely calculate the allocation size for instances of struct n_hdlc_buf and avoid any potential type mistakes[4][5]. [1] https://github.com/KSPP/linux/issues/21 [2] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") [4] https://lore.kernel.org/lkml/60e14fb7-8596-e21c-f4be-546ce39e7bdb@embeddedor.com/ [5] commit 553d66cb1e86 ("iommu/vt-d: Use struct_size() helper") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200121172138.GA3162@embeddedor Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04tty: n_hdlc: fix build on SPARCRandy Dunlap
Fix tty driver build on SPARC by not using __exitdata. It appears that SPARC does not support section .exit.data. Fixes these build errors: `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o Reported-by: kbuild test robot <lkp@intel.com> Fixes: 063246641d4a ("format-security: move static strings to const") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/675e7bd9-955b-3ff3-1101-a973b58b5b75@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-14tty/n_hdlc: mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warning: drivers/tty/n_hdlc.c: In function ‘n_hdlc_tty_ioctl’: drivers/tty/n_hdlc.c:775:3: warning: this statement may fall through [-Wimplicit-fallthrough=] switch (arg) { ^~~~~~ drivers/tty/n_hdlc.c:782:2: note: here default: ^~~~~~~ Warning level 3 was used: -Wimplicit-fallthrough=3 Notice that, in this particular case, the code comment is modified in accordance with what GCC is expecting to find. This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18tty/n_hdlc: fix __might_sleep warningPaul Fulghum
Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum <paulkf@microgate.com> Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@vger.kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-05tty: Don't block on IO when ldisc change is pendingDmitry Safonov
There might be situations where tty_ldisc_lock() has blocked, but there is already IO on tty and it prevents line discipline changes. It might theoretically turn into dead-lock. Basically, provide more priority to pending tty_ldisc_lock() than to servicing reads/writes over tty. User-visible issue was reported by Mikulas where on pa-risc with Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper locking in tty_reopen(). Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
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 Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-08tty: Remove redundant license textGreg Kroah-Hartman
Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-08format-security: move static strings to constKees Cook
While examining output from trial builds with -Wformat-security enabled, many strings were found that should be defined as "const", or as a char array instead of char pointer. This makes some static analysis easier, by producing fewer false positives. As these are all trivial changes, it seemed best to put them all in a single patch rather than chopping them up per maintainer. Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Jes Sorensen <jes@trained-monkey.org> [runner.c] Cc: Tony Lindgren <tony@atomide.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: David Airlie <airlied@linux.ie> Cc: Yisen Zhuang <yisen.zhuang@huawei.com> Cc: Salil Mehta <salil.mehta@huawei.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Jiri Slaby <jslaby@suse.com> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Mugunthan V N <mugunthanvnm@ti.com> Cc: Felipe Balbi <felipe.balbi@linux.intel.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Florian Westphal <fw@strlen.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kejian Yan <yankejian@huawei.com> Cc: Daode Huang <huangdaode@hisilicon.com> Cc: Qianqian Xie <xieqianqian@huawei.com> Cc: Philippe Reynes <tremyfr@gmail.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Christian Gromm <christian.gromm@microchip.com> Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de> Cc: Jason Litzinger <jlitzingerdev@gmail.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-07tty: n_hdlc: get rid of racy n_hdlc.tbufAlexander Popov
Currently N_HDLC line discipline uses a self-made singly linked list for data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after an error. The commit be10eb7589337e5defbe214dae038a53dd21add8 ("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf. After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put one data buffer to tx_free_buf_list twice. That causes double free in n_hdlc_release(). Let's use standard kernel linked list and get rid of n_hdlc.tbuf: in case of tx error put current data buffer after the head of tx_buf_list. Signed-off-by: Alexander Popov <alex.popov@linux.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
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>
2016-05-01Fix OpenSSH pty regression on closeBrian Bloniarz
OpenSSH expects the (non-blocking) read() of pty master to return EAGAIN only if it has received all of the slave-side output after it has received SIGCHLD. This used to work on pre-3.12 kernels. This fix effectively forces non-blocking read() and poll() to block for parallel i/o to complete for all ttys. It also unwinds these changes: 1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12 tty: Fix pty master read() after slave closes 2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73 pty, n_tty: Simplify input processing on final close 3) 1a48632ffed61352a7810ce089dc5a8bcd505a60 pty: Fix input race when closing Inspired by analysis and patch from Marc Aurele La France <tsi@tuyoix.net> Reported-by: Volth <openssh@volth.com> Reported-by: Marc Aurele La France <tsi@tuyoix.net> BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52 BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492 Signed-off-by: Brian Bloniarz <brian.bloniarz@gmail.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06TTY: n_hdlc, fix lockdep false positiveJiri Slaby
The class of 4 n_hdls buf locks is the same because a single function n_hdlc_buf_list_init is used to init all the locks. But since flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep emits a warning: ============================================= [ INFO: possible recursive locking detected ] 4.3.0-25.g91e30a7-default #1 Not tainted --------------------------------------------- a.out/1248 is trying to acquire lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] but task is already holding lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->spinlock)->rlock); lock(&(&list->spinlock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by a.out/1248: #0: (&tty->ldisc_sem){++++++}, at: [<ffffffff814c9eb0>] tty_ldisc_ref_wait+0x20/0x50 #1: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] ... Call Trace: ... [<ffffffff81738fd0>] _raw_spin_lock_irqsave+0x50/0x70 [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] [<ffffffffa01fdc24>] n_hdlc_tty_ioctl+0x144/0x1d0 [n_hdlc] [<ffffffff814c25c1>] tty_ioctl+0x3f1/0xe40 ... Fix it by initializing the spin_locks separately. This removes also reduntand memset of a freshly kzallocated space. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10pty: Fix input race when closingPeter Hurley
A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28drivers/tty/n_hdlc.c: replace kmalloc/memset by kzallocFabian Frederick
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27tty: n_hdlc: Drop redundant error messageJean Delvare
On initialization failure, an error message is already printed with level KERN_ERR, no need to print another one with level KERN_INFO. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2011-11-30tty: n_hdlc not atomic use tty->flags.Ilya Zykov
N_HDLC can spoil tty->flags because use not atomic operations on tty->flags. I use n_hdlc line discipline and it happens. Signed-off-by: Ilya Zykov <ilya@ilyx.ru> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-04Revert "tty: make receive_buf() return the amout of bytes received"Linus Torvalds
This reverts commit b1c43f82c5aa265442f82dba31ce985ebb7aa71c. It was broken in so many ways, and results in random odd pty issues. It re-introduced the buggy schedule_work() in flush_to_ldisc() that can cause endless work-loops (see commit a5660b41af6a: "tty: fix endless work loop when the buffer fills up"). It also used an "unsigned int" return value fo the ->receive_buf() function, but then made multiple functions return a negative error code, and didn't actually check for the error in the caller. And it didn't actually work at all. BenH bisected down odd tty behavior to it: "It looks like the patch is causing some major malfunctions of the X server for me, possibly related to PTYs. For example, cat'ing a large file in a gnome terminal hangs the kernel for -minutes- in a loop of what looks like flush_to_ldisc/workqueue code, (some ftrace data in the quoted bits further down). ... Some more data: It -looks- like what happens is that the flush_to_ldisc work queue entry constantly re-queues itself (because the PTY is full ?) and the workqueue thread will basically loop forver calling it without ever scheduling, thus starving the consumer process that could have emptied the PTY." which is pretty much exactly the problem we fixed in a5660b41af6a. Milton Miller pointed out the 'unsigned int' issue. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: Milton Miller <miltonm@bga.com> Cc: Stefan Bigler <stefan.bigler@keymile.com> Cc: Toby Gray <toby.gray@realvnc.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-22tty: make receive_buf() return the amout of bytes receivedFelipe Balbi
it makes it simpler to keep track of the amount of bytes received and simplifies how flush_to_ldisc counts the remaining bytes. It also fixes a bug of lost bytes on n_tty when flushing too many bytes via the USB serial gadget driver. Tested-by: Stefan Bigler <stefan.bigler@keymile.com> Tested-by: Toby Gray <toby.gray@realvnc.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-02drivers: remove extraneous includes of smp_lock.hArnd Bergmann
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>
2011-01-22n_hdlc: fix read and write lockingPaul Fulghum
Fix locking in read and write code of n_hdlc line discipline. 2.6.36 replaced lock_kernel() with tty_lock(). The tty mutex is not dropped automatically when the thread sleeps like the BKL. This results in a blocked read or write holding the tty mutex and stalling operations by other devices that use the tty mutex. A review of n_hdlc read and write code shows: 1. neither BKL or tty mutex are required for correct operation 2. read can block while read data is available if data is posted between availability check and call to interruptible_sleep_on() 3. write does not set process state to TASK_INTERRUPTIBLE on each pass through the processing loop which can cause unneeded scheduling of the thread The unnecessary tty mutex references have been removed. Read changed to use same code as n_tty read for completing reads and blocking. Write corrected to set process state to TASK_INTERRUPTIBLE on each pass through processing loop. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>