Commit Graph

58 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
5ffa6e344a tty: clean include/linux/tty.h up
There are a lot of tty-core-only functions that are listed in
include/linux/tty.h.  Move them to drivers/tty/tty.h so that no one else
can accidentally call them or think that they are public functions.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:32:17 +02:00
Jiri Slaby
981b22b877 tty: remove TTY_LDISC_MAGIC
First, it is never checked. Second, use of it as a debugging aid is
at least questionable. With the current tools, I don't think anyone used
this kind of thing for debugging purposes for years.

On the top of that, e.g. serdev does not set this field of tty_ldisc_ops
at all.

So get rid of this legacy.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:06 +01:00
Linus Torvalds
3b830a9c34 tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
The tty line discipline .read() function was passed the final user
pointer destination as an argument, which doesn't match the 'write()'
function, and makes it very inconvenient to do a splice method for
ttys.

This is a conversion to use a kernel buffer instead.

NOTE! It does this by passing the tty line discipline ->read() function
an additional "cookie" to fill in, and an offset into the cookie data.

The line discipline can fill in the cookie data with its own private
information, and then the reader will repeat the read until either the
cookie is cleared or it runs out of data.

The only real user of this is N_HDLC, which can use this to handle big
packets, even if the kernel buffer is smaller than the whole packet.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20 16:48:47 -08:00
Greg Kroah-Hartman
8f49a2fe8e Linux 5.9-rc3
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 d81lv2c=
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Merge 5.9-rc3 into tty-next

We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-31 07:19:25 +02:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
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 <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Jiri Slaby
724ac070ff tty: ldiscs, fix kernel-doc
As in the previous patch, fix kernel-doc in line disciplines.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085655.12071-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18 13:51:18 +02:00
Al Viro
1a4b8febb6 n_hdlc_tty_read(): remove pointless access_ok()
only copy_to_user() is done to the address in question

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-29 11:03:03 -04:00
Jiri Slaby
b18d1c2efa tty: n_hdlc, remove FILE and LINE from pr_debug
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>
2020-03-16 08:39:47 +01:00
Jiri Slaby
80967ff2d1 n_hdlc: wrap a comment properly
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
1283c72135 n_hdlc: fix whitespace around binary operators
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
8d79bb5c4b n_hdlc: add missing spaces after commas
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
2bfb2b753b n_hdlc: remove spaces between function name and (
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
43741e9bc0 n_hdlc: remove useless whitespace at line wraps
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
d86b05cb0e n_hdlc: use __func__ and pr_ print helpers
* 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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
b9c010dfe8 n_hdlc: remove unneeded ifdef
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>
2020-02-21 10:24:34 +01:00
Jiri Slaby
0f23829814 n_hdlc: switch tbusy and woke_up to bools
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
edee649f9d n_hdlc: move tty_ldisc_ops to the bottom
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
740708abbb n_hdlc: add helper for buffers allocation
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
844cc5f9e5 n_hdlc: remove checking of n_hdlc
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
df6de639d4 n_hdlc: remove cached tty
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
43e784eca8 n_hdlc: inline n_hdlc_release
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
75011682e7 n_hdlc: expand tty2n_hdlc macro
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
4040c82860 n_hdlc: remove unused backup_tty
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
a1274b26ac n_hdlc: remove unused flags
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
5f2895143d n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_poll
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
30fafd92c2 n_hdlc: simplify freeing of buffer list
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>
2020-02-21 10:24:33 +01:00
Jiri Slaby
c549725ff8 n_hdlc: use clamp() for maxframe
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>
2020-02-21 10:24:32 +01:00
Jiri Slaby
cda3756ca5 n_hdlc: cleanup messages during registration
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>
2020-02-21 10:24:32 +01:00
Jiri Slaby
aebe5fc3b5 n_hdlc: put init/exit strings directly to prints
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>
2020-02-21 10:24:32 +01:00
Jiri Slaby
f3c2e27750 n_hdlc: convert debuglevel use to pr_debug
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>
2020-02-21 10:24:32 +01:00
Jiri Slaby
683efabc66 n_hdlc: remove unused macros
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>
2020-02-21 10:24:32 +01:00
Jiri Slaby
66c3bdf11d n_hdlc: remove tracing debug prints
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>
2020-02-21 10:24:32 +01:00
Gustavo A. R. Silva
85f4c95172 tty: n_hdlc: Use flexible-array member and struct_size() helper
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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
[4] https://lore.kernel.org/lkml/60e14fb7-8596-e21c-f4be-546ce39e7bdb@embeddedor.com/
[5] commit 553d66cb1e ("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>
2020-01-23 19:22:49 +01:00
Randy Dunlap
47a7e5e97d tty: n_hdlc: fix build on SPARC
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: 063246641d ("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>
2019-10-04 15:14:20 +02:00
Gustavo A. R. Silva
361bf8a9d8 tty/n_hdlc: mark expected switch fall-through
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>
2019-02-14 10:49:19 +01:00
Paul Fulghum
fc01d8c61c tty/n_hdlc: fix __might_sleep warning
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>
2019-01-18 13:27:54 +01:00
Linus Torvalds
96d4f267e4 Remove 'type' argument from access_ok() function
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>
2019-01-03 18:57:57 -08:00
Dmitry Safonov
c96cf923a9 tty: Don't block on IO when ldisc change is pending
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>
2018-12-05 12:16:33 +01:00
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
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>
2018-02-11 14:34:03 -08:00
Al Viro
afc9a42b74 the rest of drivers/*: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-28 11:06:58 -05:00
Greg Kroah-Hartman
e5656d43dc tty: Remove redundant license text
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>
2017-11-08 13:08:12 +01:00
Greg Kroah-Hartman
e3b3d0f549 tty: add SPDX identifiers to all remaining files in drivers/tty/
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>
2017-11-08 13:08:12 +01:00
Kees Cook
063246641d format-security: move static strings to const
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>
2017-05-08 17:15:14 -07:00
Alexander Popov
82f2341c94 tty: n_hdlc: get rid of racy n_hdlc.tbuf
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 be10eb7589
("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>
2017-03-07 18:54:30 +01:00
Alexey Dobriyan
5b5e0928f7 lib/vsprintf.c: remove %Z support
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>
2017-02-27 18:43:47 -08:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
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>
2016-12-24 11:46:01 -08:00
Brian Bloniarz
0f40fbbcc3 Fix OpenSSH pty regression on close
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) f8747d4a46
   tty: Fix pty master read() after slave closes

2) 52bce7f8d4
   pty, n_tty: Simplify input processing on final close

3) 1a48632ffe
   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>
2016-05-01 13:22:54 -07:00
Jiri Slaby
e9b736d88a TTY: n_hdlc, fix lockdep false positive
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>
2016-02-06 23:27:46 -08:00
Peter Hurley
1a48632ffe pty: Fix input race when closing
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: 52bce7f8d4 ("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>
2015-05-10 19:26:37 +02:00
Fabian Frederick
8e25f8ce0e drivers/tty/n_hdlc.c: replace kmalloc/memset by kzalloc
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:33:18 -07:00