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path: root/drivers/tty/vt/selection.c
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2025-04-11tty: Require CAP_SYS_ADMIN for all usages of TIOCL_SELMOUSEREPORTGünther Noack
This requirement was overeagerly loosened in commit 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"), but as it turns out, (1) the logic I implemented there was inconsistent (apologies!), (2) TIOCL_SELMOUSEREPORT might actually be a small security risk after all, and (3) TIOCL_SELMOUSEREPORT is only meant to be used by the mouse daemon (GPM or Consolation), which runs as CAP_SYS_ADMIN already. In more detail: 1. The previous patch has inconsistent logic: In commit 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"), we checked for sel_mode == TIOCL_SELMOUSEREPORT, but overlooked that the lower four bits of this "mode" parameter were actually used as an additional way to pass an argument. So the patch did actually still require CAP_SYS_ADMIN, if any of the mouse button bits are set, but did not require it if none of the mouse buttons bits are set. This logic is inconsistent and was not intentional. We should have the same policies for using TIOCL_SELMOUSEREPORT independent of the value of the "hidden" mouse button argument. I sent a separate documentation patch to the man page list with more details on TIOCL_SELMOUSEREPORT: https://lore.kernel.org/all/20250223091342.35523-2-gnoack3000@gmail.com/ 2. TIOCL_SELMOUSEREPORT is indeed a potential security risk which can let an attacker simulate "keyboard" input to command line applications on the same terminal, like TIOCSTI and some other TIOCLINUX "selection mode" IOCTLs. By enabling mouse reporting on a terminal and then injecting mouse reports through TIOCL_SELMOUSEREPORT, an attacker can simulate mouse movements on the same terminal, similar to the TIOCSTI keystroke injection attacks that were previously possible with TIOCSTI and other TIOCL_SETSEL selection modes. Many programs (including libreadline/bash) are then prone to misinterpret these mouse reports as normal keyboard input because they do not expect input in the X11 mouse protocol form. The attacker does not have complete control over the escape sequence, but they can at least control the values of two consecutive bytes in the binary mouse reporting escape sequence. I went into more detail on that in the discussion at https://lore.kernel.org/all/20250221.0a947528d8f3@gnoack.org/ It is not equally trivial to simulate arbitrary keystrokes as it was with TIOCSTI (commit 83efeeeb3d04 ("tty: Allow TIOCSTI to be disabled")), but the general mechanism is there, and together with the small number of existing legit use cases (see below), it would be better to revert back to requiring CAP_SYS_ADMIN for TIOCL_SELMOUSEREPORT, as it was already the case before commit 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"). 3. TIOCL_SELMOUSEREPORT is only used by the mouse daemons (GPM or Consolation), and they are the only legit use case: To quote console_codes(4): The mouse tracking facility is intended to return xterm(1)-compatible mouse status reports. Because the console driver has no way to know the device or type of the mouse, these reports are returned in the console input stream only when the virtual terminal driver receives a mouse update ioctl. These ioctls must be generated by a mouse-aware user-mode application such as the gpm(8) daemon. Jared Finder has also confirmed in https://lore.kernel.org/all/491f3df9de6593df8e70dbe77614b026@finder.org/ that Emacs does not call TIOCL_SELMOUSEREPORT directly, and it would be difficult to find good reasons for doing that, given that it would interfere with the reports that GPM is sending. More information on the interaction between GPM, terminals and the kernel with additional pointers is also available in this patch: https://lore.kernel.org/all/a773e48920aa104a65073671effbdee665c105fc.1603963593.git.tammo.block@gmail.com/ For background on who else uses TIOCL_SELMOUSEREPORT: Debian Code search finds one page of results, the only two known callers are the two mouse daemons GPM and Consolation. (GPM does not show up in the search results because it uses literal numbers to refer to TIOCLINUX-related enums. I looked through GPM by hand instead. TIOCL_SELMOUSEREPORT is also not used from libgpm.) https://codesearch.debian.net/search?q=TIOCL_SELMOUSEREPORT Cc: Jared Finder <jared@finder.org> Cc: Jann Horn <jannh@google.com> Cc: Hanno Böck <hanno@hboeck.de> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: stable <stable@kernel.org> Fixes: 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN") Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20250411070144.3959-2-gnoack3000@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMINGünther Noack
With this, processes without CAP_SYS_ADMIN are able to use TIOCLINUX with subcode TIOCL_SETSEL, in the selection modes TIOCL_SETPOINTER, TIOCL_SELCLEAR and TIOCL_SELMOUSEREPORT. TIOCL_SETSEL was previously changed to require CAP_SYS_ADMIN, as this IOCTL let callers change the selection buffer and could be used to simulate keypresses. These three TIOCL_SETSEL selection modes, however, are safe to use, as they do not modify the selection buffer. This fixes a mouse support regression that affected Emacs (invisible mouse cursor). Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/ee3ec63269b43b34e1c90dd8c9743bf8@finder.org Fixes: 8d1b43f6a6df ("tty: Restrict access to TIOCLINUX' copy-and-paste subcommands") Signed-off-by: Günther Noack <gnoack@google.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250110142122.1013222-1-gnoack@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: fix up kernel-docJiri Slaby (SUSE)
selection.c and vt.c still uses tabs in the kernel-doc. This misrenders the functions in the output -- sphinx misinterprets the description. So remove these tabs, incl. those around dashes. 'enum' keyword is needed before enum names. Fix that. Superfluous \n after the comments are also removed. They are not completely faulty, but this unifies all the kernel-doc in the files. Finally fix up the cross references. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-47-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: make vc_is_sel()'s vc constJiri Slaby (SUSE)
It's only an aid to people reading the header and/or calling vc_is_sel(). vc is only tested there, so having it const makes sense. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-9-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: push console lock from tioclinux() down to 2 functionsJiri Slaby (SUSE)
Avoid costly user copies under the console lock. So push the lock down from tioclinux() to sel_loadlut() and set_vesa_blanking(). It is now obvious what is actually protected. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-7-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: pass proper pointers from tioclinux()Jiri Slaby (SUSE)
Pass proper types and proper pointers (the data with an offset) to the TIOCL_* handlers. So that they need not to cast or add anything to the passed pointer. This makes obvious what is passed/consumed. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11tty: switch count in tty_ldisc_receive_buf() to size_tJiri Slaby (SUSE)
It comes from both paste_selection() and tty_port_default_receive_buf() as unsigned (int and size_t respectively). Switch to size_t to converge to that eventually. Return the count as size_t too (the two callers above expect that). Switch paste_selection()'s type of 'count' too, so that the returned and passed type match. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230810091510.13006-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10tty/vt: consolemap: make parameters of inverse_translate() sanerJiri Slaby
- int use_unicode -> bool: it's used as bool at some places already, so make it explicit. - int glyph -> u16: every caller passes a u16 in. So make it explicit too. And remove a negative check from inverse_translate() as it never could be negative. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220607104946.18710-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20tty: vt: selection: Correct misspelled function sel_loadlut()Lee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/vt/selection.c:119: warning: expecting prototype for set loadlut(). Prototype was for sel_loadlut() instead Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20210520121906.3468725-2-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13vt: Move custom isspace() to its own namespaceAndy Shevchenko
If by some reason any of the headers will include ctype.h we will have a name collision. Avoid this by moving isspace() to the dedicate namespace. First appearance of the code is in the commit 24a1c2a769cf ("Import 1.1.92"). Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210510144947.58270-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc: propagate "viewed as bool" from screenpos upJiri Slaby
viewed is used as a flag, i.e. bool. So treat is as such in most of the places. vcs_vc is handled in the next patch. Note: the last parameter of invert_screen was misnamed in the declaration since 1.1.92. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-01tty/vt: Do not warn when huge selection requestedAlexey Kardashevskiy
The tty TIOCL_SETSEL ioctl allocates a memory buffer big enough for text selection area. The maximum allowed console size is VC_RESIZE_MAXCOL * VC_RESIZE_MAXROW == 32767*32767 == ~1GB and typical MAX_ORDER is set to allow allocations lot less than than (circa 16MB). So it is quite possible to trigger huge allocation (and syzkaller just did that) which is going to fail (which is fine) with a backtrace in mm/page_alloc.c at WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)) and this may trigger panic (if panic_on_warn is enabled) and leak kernel addresses to dmesg. This passes __GFP_NOWARN to kmalloc_array to avoid unnecessary user- triggered WARN_ON. Note that the error is not ignored and the warning is still printed. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Link: https://lore.kernel.org/r/20200617070444.116704-1-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16vt: extract selection chars storing from vc_do_selectionJiri Slaby
Let's put it to a separate function, named vc_selection_store_chars. Again, this makes vc_do_selection a bit shorter and more readable. Having 4 local variables instead of 12 (5.6-rc1) looks much better now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200415093608.10348-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16vt: selection, split __set_selection_kernelJiri Slaby
Handle these actions: * poking console * TIOCL_SELCLEAR * TIOCL_SELMOUSEREPORT * start/end precomputation * clear_selection if the console changed in a separate function, thus making __set_selection_kernel way shorter and more readable. The function still needs dissection, but we are approaching. This includes introduction of vc_selection and renaming __set_selection_kernel to vc_do_selection. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200415093608.10348-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-16vt: selection, use rounddown() for start/endline computationJiri Slaby
We have a helper called rounddown for these modulo computations. So use it. No functional change intended and "objdump -d" proves that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200316065911.11024-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-16vt: selection, fix double lock introduced by a mergeJiri Slaby
The merge commit cb05c6c82fb0 (Merge 5.6-rc5 into tty-next) introduced a double lock to set_selection_kernel. vc_sel.lock is locked both in set_selection_kernel and its callee __set_selection_kernel now. Remove the latter. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://lore.kernel.org/r/20200316064544.4799-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-10Merge 5.6-rc5 into tty-nextGreg Kroah-Hartman
We need the vt fixes in here and it resolves a merge issue with drivers/tty/vt/selection.c Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vt: selection, indent switch-case properlyJiri Slaby
Shift the cases one level left as this is how we are supposed to write the switch-case code according to the CodingStyle. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vt: selection, remove redeclaration of poke_blanked_consoleJiri Slaby
It is declared in vt_kern.h, so no need to declare it in selection.c which includes the header. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vt: selection, create struct from console selection globalsJiri Slaby
Move all the selection global variables to a structure vc_selection, instantiated as vc_sel. This helps to group all the variables together and see what should be protected by the embedded lock too. It might be used later also for per-console selection support. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vt: selection, localize use_unicodeJiri Slaby
use_unicode needs not be global. It is used only in set_selection_kernel and sel_pos (a callee). It is also always set there prior calling sel_pos. So make use_unicode local and rename it to plain shorter "unicode". Finally, propagate it to sel_pos via parameter. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vt: selection, remove 2 local variables from set_selection_kernelJiri Slaby
multiplier and mode are not actually needed: * multiplier is used only in kmalloc_array, so use "use_unicode ? 4 : 1" directly * mode is used only to assign a bool in this manner: if (cond) x = true; else x = false; So do "x = cond" directly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28vt: selection, push sel_lock upJiri Slaby
sel_lock cannot nest in the console lock. Thanks to syzkaller, the kernel states firmly: > WARNING: possible circular locking dependency detected > 5.6.0-rc3-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor.4/20336 is trying to acquire lock: > ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > > but task is already holding lock: > ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #2 (sel_lock){+.+.}: > mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 > set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217 > set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181 > tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_SETSEL). Locks held on the path: console_lock -> sel_lock > -> #1 (console_lock){+.+.}: > console_lock+0x46/0x70 kernel/printk/printk.c:2289 > con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223 > n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350 > do_tty_write drivers/tty/tty_io.c:962 [inline] > tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046 This is write(). Locks held on the path: termios_rwsem -> console_lock > -> #0 (&tty->termios_rwsem){++++}: > down_write+0x57/0x140 kernel/locking/rwsem.c:1534 > tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902 > tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465 > paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389 > tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_PASTESEL). Locks held on the path: sel_lock -> termios_rwsem > other info that might help us debug this: > > Chain exists of: > &tty->termios_rwsem --> console_lock --> sel_lock Clearly. From the above, we have: console_lock -> sel_lock sel_lock -> termios_rwsem termios_rwsem -> console_lock Fix this by reversing the console_lock -> sel_lock dependency in ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28vt: selection, push console lock downJiri Slaby
We need to nest the console lock in sel_lock, so we have to push it down a bit. Fortunately, the callers of set_selection_* just lock the console lock around the function call. So moving it down is easy. In the next patch, we switch the order. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-24Merge 5.6-rc3 into tty-nextGreg Kroah-Hartman
We want the tty fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21vt: selection, introduce vc_is_selJiri Slaby
Avoid global variables (namely sel_cons) by introducing vc_is_sel. It checks whether the parameter is the current selection console. This will help putting sel_cons to a struct later. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-13vt: selection, close sel_buffer raceJiri Slaby
syzkaller reported this UAF: BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741 Read of size 1 at addr ffff8880089e40e9 by task syz-executor.1/13184 CPU: 0 PID: 13184 Comm: syz-executor.1 Not tainted 5.4.7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: ... kasan_report+0xe/0x20 mm/kasan/common.c:634 n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741 tty_ldisc_receive_buf+0xac/0x190 drivers/tty/tty_buffer.c:461 paste_selection+0x297/0x400 drivers/tty/vt/selection.c:372 tioclinux+0x20d/0x4e0 drivers/tty/vt/vt.c:3044 vt_ioctl+0x1bcf/0x28d0 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x525/0x15a0 drivers/tty/tty_io.c:2657 vfs_ioctl fs/ioctl.c:47 [inline] It is due to a race between parallel paste_selection (TIOCL_PASTESEL) and set_selection_user (TIOCL_SETSEL) invocations. One uses sel_buffer, while the other frees it and reallocates a new one for another selection. Add a mutex to close this race. The mutex takes care properly of sel_buffer and sel_buffer_lth only. The other selection global variables (like sel_start, sel_end, and sel_cons) are protected only in set_selection_user. The other functions need quite some more work to close the races of the variables there. This is going to happen later. This likely fixes (I am unsure as there is no reproducer provided) bug 206361 too. It was marked as CVE-2020-8648. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+59997e8d5cbdc486e6f6@syzkaller.appspotmail.com References: https://bugzilla.kernel.org/show_bug.cgi?id=206361 Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-13vt: selection, handle pending signals in paste_selectionJiri Slaby
When pasting a selection to a vt, the task is set as INTERRUPTIBLE while waiting for a tty to unthrottle. But signals are not handled at all. Normally, this is not a problem as tty_ldisc_receive_buf receives all the goods and a user has no reason to interrupt the task. There are two scenarios where this matters: 1) when the tty is throttled and a signal is sent to the process, it spins on a CPU until the tty is unthrottled. schedule() does not really echedule, but returns immediately, of course. 2) when the sel_buffer becomes invalid, KASAN prevents any reads from it and the loop simply does not proceed and spins forever (causing the tty to throttle, but the code never sleeps, the same as above). This sometimes happens as there is a race in the sel_buffer handling code. So add signal handling to this ioctl (TIOCL_PASTESEL) and return -EINTR in case a signal is pending. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200210081131.23572-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-19vt: selection: allow functions to be called from inside kernelOkash Khawaja
This patch breaks set_selection() into two functions so that when called from kernel, copy_from_user() can be avoided. The two functions are called set_selection_user() and set_selection_kernel() in order to be explicit about their purposes. This also means updating any references to set_selection() and fixing for name change. It also exports set_selection_kernel() and paste_selection(). These changes are used the following patch where speakup's selection functionality calls into the above functions, thereby doing away with parallel implementation. Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Tested-by: Gregory Nowak <greg@gregn.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21vt: selection: take screen contents from uniscr if availableAdam Borowski
This preserves whatever was written even if we can't currently display the given glyph. Mouse paste won't corrupt any character of wcwidth() == 1 anymore. Note that for now uniscr doesn't get allocated until something reads /dev/vcsuN for that console, making this code dormant for most users. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21vt: selection: handle storing of characters above U+FFFFAdam Borowski
Those above U+10FFFF get replaced with U+FFFD. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-21vt: don't reinvent min()Adam Borowski
All the helper function saved us was a cast. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-28tty: vt: replace _manual_ swap with swap macro in set_selectionGustavo A. R. Silva
Make use of the swap macro instead of _manually_ swapping values and remove unnecessary variable tmp. This makes the code easier to read and maintain. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-17Merge branch 'misc.compat' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat and uaccess updates from Al Viro: - {get,put}_compat_sigset() series - assorted compat ioctl stuff - more set_fs() elimination - a few more timespec64 conversions - several removals of pointless access_ok() in places where it was followed only by non-__ variants of primitives * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits) coredump: call do_unlinkat directly instead of sys_unlink fs: expose do_unlinkat for built-in callers ext4: take handling of EXT4_IOC_GROUP_ADD into a helper, get rid of set_fs() ipmi: get rid of pointless access_ok() pi433: sanitize ioctl cxlflash: get rid of pointless access_ok() mtdchar: get rid of pointless access_ok() r128: switch compat ioctls to drm_ioctl_kernel() selection: get rid of field-by-field copyin VT_RESIZEX: get rid of field-by-field copyin i2c compat ioctls: move to ->compat_ioctl() sched_rr_get_interval(): move compat to native, get rid of set_fs() mips: switch to {get,put}_compat_sigset() sparc: switch to {get,put}_compat_sigset() s390: switch to {get,put}_compat_sigset() ppc: switch to {get,put}_compat_sigset() parisc: switch to {get,put}_compat_sigset() get_compat_sigset() get rid of {get,put}_compat_itimerspec() io_getevents: Use timespec64 to represent timeouts ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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>
2017-09-29selection: get rid of field-by-field copyinAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-11vt: make mouse selection of non-ASCII consistentAdam Borowski
For some reason a handful of ISO-8859-1 symbols are excluded from "word chars" while the vast majority of Unicode is hard-coded as included, even when inappropriate (we really would want to _not_ select line-drawing/etc). Those symbols are: ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿×÷ Thus, let's not special-case any non-ASCII anymore. Attempts to set these via ioctl will be silently ignored. As an extra bonus, we debloat the kernel by 128 bytes. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11vt: set mouse selection word-chars to gpm's defaultAdam Borowski
Since forever, gpm was this code's only user, and it overrides the table on start so the default was never seen -- until Bill Allombert's "consolation" came in. The in-kernel set is "A-Za-z0-9_" which fails to catch typical file names, etc. Let's change this to gpm's conservative default, ie "-A-Za-z0-9_./"; most terminals include more, for example xfce4-terminal has "-A-Za-z0-9,./?%&#:_=+@~". There's some discussion at https://bugs.debian.org/846587 Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
2016-04-30tty: Replace TTY_THROTTLED bit tests with tty_throttled()Peter Hurley
Abstract TTY_THROTTLED bit tests with tty_throttled(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-27tty: Prepare for destroying line discipline on hangupPeter Hurley
tty file_operations (read/write/ioctl) wait for the ldisc reference indefinitely (until ldisc lifetime events, such as hangup or TIOCSETD, finish). Since hangup now destroys the ldisc and does not instance another copy, file_operations must now be prepared to receive a NULL ldisc reference from tty_ldisc_ref_wait(): CPU 0 CPU 1 ----- ----- (*f_op->read)() => tty_read() __tty_hangup() ... f_op = &hung_up_tty_fops; ... tty_ldisc_hangup() tty_ldisc_lock() tty_ldisc_kill() tty->ldisc = NULL tty_ldisc_unlock() ld = tty_ldisc_ref_wait() /* ld == NULL */ Instead, the action taken now is to return the same value as if the tty had been hungup a moment earlier: CPU 0 CPU 1 ----- ----- __tty_hangup() ... f_op = &hung_up_tty_fops; (*f_op->read)() => hung_up_tty_read() return 0; ... tty_ldisc_hangup() tty_ldisc_lock() tty_ldisc_kill() tty->ldisc = NULL tty_ldisc_unlock() Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23tty: vt: Fix !TASK_RUNNING diagnostic warning from paste_selection()Peter Hurley
Pasting text with gpm on a VC produced warning [1]. Reset task state to TASK_RUNNING in the paste_selection() loop, if the loop did not sleep. [1] WARNING: CPU: 6 PID: 1960 at /home/peter/src/kernels/mainline/kernel/sched/core.c:7286 __might_sleep+0x7f/0x90() do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8151805e>] paste_selection+0x9e/0x1a0 Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c ..... CPU: 6 PID: 1960 Comm: gpm Not tainted 4.1.0-rc7+tty-xeon+debug #rc7+tty Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff81c9c0a0 ffff8802b0fd3ac8 ffffffff8185778a 0000000000000001 ffff8802b0fd3b18 ffff8802b0fd3b08 ffffffff8108039a ffffffff82ae8510 ffffffff81c9ce00 0000000000000015 0000000000000000 0000000000000000 Call Trace: [<ffffffff8185778a>] dump_stack+0x4f/0x7b [<ffffffff8108039a>] warn_slowpath_common+0x8a/0xc0 [<ffffffff81080416>] warn_slowpath_fmt+0x46/0x50 [<ffffffff810ddced>] ? __lock_acquire+0xe2d/0x13a0 [<ffffffff8151805e>] ? paste_selection+0x9e/0x1a0 [<ffffffff8151805e>] ? paste_selection+0x9e/0x1a0 [<ffffffff810ad4ff>] __might_sleep+0x7f/0x90 [<ffffffff8185f76a>] down_read+0x2a/0xa0 [<ffffffff810bb1d8>] ? sched_clock_cpu+0xb8/0xe0 [<ffffffff8150d1dc>] n_tty_receive_buf_common+0x4c/0xba0 [<ffffffff810dc875>] ? mark_held_locks+0x75/0xa0 [<ffffffff81861c95>] ? _raw_spin_unlock_irqrestore+0x65/0x80 [<ffffffff810b49a1>] ? get_parent_ip+0x11/0x50 [<ffffffff8150dd44>] n_tty_receive_buf2+0x14/0x20 [<ffffffff81518117>] paste_selection+0x157/0x1a0 [<ffffffff810b77b0>] ? wake_up_state+0x20/0x20 [<ffffffff815203f8>] tioclinux+0xb8/0x2c0 [<ffffffff81515bfe>] vt_ioctl+0xaee/0x11a0 [<ffffffff810baf75>] ? sched_clock_local+0x25/0x90 [<ffffffff810bbe11>] ? vtime_account_user+0x91/0xa0 [<ffffffff8150810c>] tty_ioctl+0x20c/0xe20 [<ffffffff810bbe11>] ? vtime_account_user+0x91/0xa0 [<ffffffff810b49a1>] ? get_parent_ip+0x11/0x50 [<ffffffff810b4a69>] ? preempt_count_sub+0x49/0x50 [<ffffffff811ab71c>] ? context_tracking_exit+0x5c/0x290 [<ffffffff811ab71c>] ? context_tracking_exit+0x5c/0x290 [<ffffffff81248b98>] do_vfs_ioctl+0x318/0x570 [<ffffffff810dca8d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff810dc9b5>] ? trace_hardirqs_on_caller+0x115/0x1e0 [<ffffffff81254acc>] ? __fget_light+0x6c/0xa0 [<ffffffff81248e71>] SyS_ioctl+0x81/0xa0 [<ffffffff81862832>] system_call_fastpath+0x16/0x7a Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Fix unsafe vt paste_selection()Peter Hurley
Convert the tty_buffer_flush() exclusion mechanism to a public interface - tty_buffer_lock/unlock_exclusive() - and use the interface to safely write the paste selection to the line discipline. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Make ldisc input flow control concurrency-friendlyPeter Hurley
Although line discipline receiving is single-producer/single-consumer, using tty->receive_room to manage flow control creates unnecessary critical regions requiring additional lock use. Instead, introduce the optional .receive_buf2() ldisc method which returns the # of bytes actually received. Serialization is guaranteed by the caller. In turn, the line discipline should schedule the buffer work item whenever space becomes available; ie., when there is room to receive data and receive_room() previously returned 0 (the buffer work item stops processing if receive_buf2() returns 0). Note the 'no room' state need not be atomic despite concurrent use by two threads because only the buffer work thread can set the state and only the read() thread can clear the state. Add n_tty_receive_buf2() as the receive_buf2() method for N_TTY. Provide a public helper function, tty_ldisc_receive_buf(), to use when directly accessing the receive_buf() methods. Line disciplines not using input flow control can continue to set tty->receive_room to a fixed value and only provide the receive_buf() method. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: vt, fix paste_selection ldisc handlingJiri Slaby
There used to be a single tty_ldisc_ref_wait. But then, when a big-tty-mutex (BTM) was introduced, it has to be tty_ldisc_ref + tty_unlock + tty_ldisc_ref_wait + tty_lock. Later, BTM was removed from that path and tty_ldisc_ref + tty_ldisc_ref_wait remained there. But it makes no sense now. So leave there only tty_ldisc_ref_wait. And when we have a reference to an ldisc, actually use it in the loop. Otherwise it may be racy. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08vt: tackle the main part of the selection logicAlan Cox
We leave the existing paste mess alone and just fix up the vt side of things. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08vt: push down tioclinux casesAlan Cox
Some of this ventures into selection which is still a complete lost cause. We are not making it any worse. It's completely busted anyway. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08vt:tackle kbd_tableAlan Cox
Keyboard struct lifetime is easy, but the locking is not and is completely ignored by the existing code. Tackle this one head on - Make the kbd_table private so we can run down all direct users - Hoick the relevant ioctl handlers into the keyboard layer - Lock them with the keyboard lock so they don't change mid keypress - Add helpers for things like console stop/start so we isolate the poking around properly - Tweak the braille console so it still builds There are a couple of FIXME locking cases left for ioctls that are so hideous they should be addressed in a later patch. After this patch the kbd_table is private and all the keyboard jiggery pokery is in one place. This update fixes speakup and also a memory leak in the original. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-08-23TTY: remove tty_lockedJiri Slaby
We used it really only serial and ami_serial. The rest of the callsites were BUG/WARN_ONs to check if BTM is held. Now that we pruned tty_locked from both of the real users, we can get rid of tty_lock along with __big_tty_mutex_owner. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>