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2020-08-31Merge 5.9-rc3 into tty-nextGreg Kroah-Hartman1-1/+1
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <[email protected]>
2020-08-18tty: ldiscs, fix kernel-docJiri Slaby1-36/+36
As in the previous patch, fix kernel-doc in line disciplines. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-05-29n_hdlc_tty_read(): remove pointless access_ok()Al Viro1-7/+0
only copy_to_user() is done to the address in question Reviewed-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Al Viro <[email protected]>
2020-03-16tty: n_hdlc, remove FILE and LINE from pr_debugJiri Slaby1-21/+12
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 <[email protected]> Suggested-by: Joe Perches <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: wrap a comment properlyJiri Slaby1-2/+4
Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: fix whitespace around binary operatorsJiri Slaby1-3/+3
Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: add missing spaces after commasJiri Slaby1-9/+9
Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove spaces between function name and (Jiri Slaby1-4/+4
Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove useless whitespace at line wrapsJiri Slaby1-37/+37
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: use __func__ and pr_ print helpersJiri Slaby1-7/+7
* 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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove unneeded ifdefJiri Slaby1-2/+0
TTY_NO_WRITE_SPLIT is (always) defined in linux/tty.h, so no need to check for it. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: switch tbusy and woke_up to boolsJiri Slaby1-8/+8
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: move tty_ldisc_ops to the bottomJiri Slaby1-31/+15
This makes forward declarations unnecessary. So drop them. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: add helper for buffers allocationJiri Slaby1-22/+20
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove checking of n_hdlcJiri Slaby1-29/+3
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove cached ttyJiri Slaby1-16/+5
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: inline n_hdlc_releaseJiri Slaby1-25/+10
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: expand tty2n_hdlc macroJiri Slaby1-12/+11
It's simple tty->disc_data, but it obfuscates code. So expand it to all locations and drop it. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove unused backup_ttyJiri Slaby1-9/+1
It's only set to NULL and never properly used. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove unused flagsJiri Slaby1-4/+1
They are only set to 0 and never read. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_pollJiri Slaby1-34/+38
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: simplify freeing of buffer listJiri Slaby1-31/+14
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: use clamp() for maxframeJiri Slaby1-4/+1
It is easier to read. And use MAX_HDLC_FRAME_SIZE instead of magic constant. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: cleanup messages during registrationJiri Slaby1-4/+4
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: put init/exit strings directly to printsJiri Slaby1-22/+6
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: convert debuglevel use to pr_debugJiri Slaby1-48/+31
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove unused macrosJiri Slaby1-5/+0
VERSION and bset are unused. Remove them. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-02-21n_hdlc: remove tracing debug printsJiri Slaby1-30/+2
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-01-23tty: n_hdlc: Use flexible-array member and struct_size() helperGustavo A. R. Silva1-6/+5
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/[email protected]/ [5] commit 553d66cb1e86 ("iommu/vt-d: Use struct_size() helper") Signed-off-by: Gustavo A. R. Silva <[email protected]> Reviewed-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/20200121172138.GA3162@embeddedor Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-10-04tty: n_hdlc: fix build on SPARCRandy Dunlap1-0/+5
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 <[email protected]> Fixes: 063246641d4a ("format-security: move static strings to const") Signed-off-by: Randy Dunlap <[email protected]> Cc: Kees Cook <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Andrew Morton <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-02-14tty/n_hdlc: mark expected switch fall-throughGustavo A. R. Silva1-1/+1
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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-01-18tty/n_hdlc: fix __might_sleep warningPaul Fulghum1-0/+1
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 <[email protected]> Reported-by: syzbot <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Alan Cox <[email protected]> Cc: stable <[email protected]> Acked-by: Arnd Bergmann <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-1/+1
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 <[email protected]>
2018-12-05tty: Don't block on IO when ldisc change is pendingDmitry Safonov1-2/+2
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 <[email protected]> Reported-by: Mikulas Patocka <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-4/+4
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 <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-3/+3
Signed-off-by: Al Viro <[email protected]>
2017-11-08tty: Remove redundant license textGreg Kroah-Hartman1-2/+0
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 <[email protected]> Cc: James Hogan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman1-0/+1
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 <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: David Sterba <[email protected]> Cc: James Hogan <[email protected]> Cc: Rob Herring <[email protected]> Cc: Eric Anholt <[email protected]> Cc: Stefan Wahren <[email protected]> Cc: Florian Fainelli <[email protected]> Cc: Ray Jui <[email protected]> Cc: Scott Branden <[email protected]> Cc: [email protected] Cc: "James E.J. Bottomley" <[email protected]> Cc: Helge Deller <[email protected]> Cc: Joachim Eastwood <[email protected]> Cc: Matthias Brugger <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Tobias Klauser <[email protected]> Cc: Russell King <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Richard Genoud <[email protected]> Cc: Alexander Shiyan <[email protected]> Cc: Baruch Siach <[email protected]> Cc: "Maciej W. Rozycki" <[email protected]> Cc: "Uwe Kleine-König" <[email protected]> Cc: Pat Gefre <[email protected]> Cc: "Guilherme G. Piccoli" <[email protected]> Cc: Jason Wessel <[email protected]> Cc: Vladimir Zapolskiy <[email protected]> Cc: Sylvain Lemieux <[email protected]> Cc: Carlo Caione <[email protected]> Cc: Kevin Hilman <[email protected]> Cc: Liviu Dudau <[email protected]> Cc: Sudeep Holla <[email protected]> Cc: Lorenzo Pieralisi <[email protected]> Cc: Andy Gross <[email protected]> Cc: David Brown <[email protected]> Cc: "Andreas Färber" <[email protected]> Cc: Kevin Cernekee <[email protected]> Cc: Laxman Dewangan <[email protected]> Cc: Thierry Reding <[email protected]> Cc: Jonathan Hunter <[email protected]> Cc: Barry Song <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: Maxime Coquelin <[email protected]> Cc: Alexandre Torgue <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Peter Korsgaard <[email protected]> Cc: Timur Tabi <[email protected]> Cc: Tony Prisk <[email protected]> Cc: Michal Simek <[email protected]> Cc: "Sören Brinkmann" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Kate Stewart <[email protected]> Cc: Philippe Ombredanne <[email protected]> Cc: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2017-05-08format-security: move static strings to constKees Cook1-5/+5
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 <[email protected]> Acked-by: Jes Sorensen <[email protected]> [runner.c] Cc: Tony Lindgren <[email protected]> Cc: Russell King <[email protected]> Cc: "Maciej W. Rozycki" <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Viresh Kumar <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Jani Nikula <[email protected]> Cc: Sean Paul <[email protected]> Cc: David Airlie <[email protected]> Cc: Yisen Zhuang <[email protected]> Cc: Salil Mehta <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: James Hogan <[email protected]> Cc: Paul Burton <[email protected]> Cc: Matt Redfearn <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Mugunthan V N <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Jarod Wilson <[email protected]> Cc: Florian Westphal <[email protected]> Cc: Antonio Quartulli <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Kejian Yan <[email protected]> Cc: Daode Huang <[email protected]> Cc: Qianqian Xie <[email protected]> Cc: Philippe Reynes <[email protected]> Cc: Colin Ian King <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Christian Gromm <[email protected]> Cc: Andrey Shvetsov <[email protected]> Cc: Jason Litzinger <[email protected]> Cc: WANG Cong <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2017-03-07tty: n_hdlc: get rid of racy n_hdlc.tbufAlexander Popov1-63/+69
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 <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan1-1/+1
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 <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Rasmus Villemoes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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 <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2016-05-01Fix OpenSSH pty regression on closeBrian Bloniarz1-2/+2
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 <[email protected]> Reported-by: Volth <[email protected]> Reported-by: Marc Aurele La France <[email protected]> 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 <[email protected]> Reviewed-by: Peter Hurley <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2016-02-06TTY: n_hdlc, fix lockdep false positiveJiri Slaby1-15/+4
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 <[email protected]> Reported-by: Dmitry Vyukov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2015-05-10pty: Fix input race when closingPeter Hurley1-2/+2
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: <[email protected]> # 3.19+ Reported-by: Andy Whitcroft <[email protected]> Reported-by: H.J. Lu <[email protected]> Signed-off-by: Peter Hurley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2014-05-28drivers/tty/n_hdlc.c: replace kmalloc/memset by kzallocFabian Frederick1-3/+1
Cc: Greg Kroah-Hartman <[email protected]> Signed-off-by: Fabian Frederick <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2014-05-27tty: n_hdlc: Drop redundant error messageJean Delvare1-4/+0
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 <[email protected]> Cc: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells1-1/+0
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 <[email protected]>
2011-11-30tty: n_hdlc not atomic use tty->flags.Ilya Zykov1-3/+3
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 <[email protected]> Acked-by: Alan Cox <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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