linux-stable.git/drivers/rtc/rtc-proc.c, branch linux-4.9.y

rtc: fix snprintf() checking in is_rtc_hctosys()

2021-07-20T14:21:15+00:00

[ Upstream commit 54b909436ede47e0ee07f1765da27ec2efa41e84 ]

The scnprintf() function silently truncates the printf() and returns
the number bytes that it was able to copy (not counting the NUL
terminator).  Thus, the highest value it can return here is
"NAME_SIZE - 1" and the overflow check is dead code.  Fix this by
using the snprintf() function which returns the number of bytes that
would have been copied if there was enough space and changing the
condition from "> NAME_SIZE" to ">= NAME_SIZE".

Fixes: 92589c986b33 ("rtc-proc: permit the /proc/driver/rtc device to use other devices")
Signed-off-by: Dan Carpenter 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/YJov/pcGmhLi2pEl@mwanda
Signed-off-by: Sasha Levin

rtc: fix module reference count in rtc-proc

2016-01-11T19:19:55+00:00

rtc-proc.c is not built as a module. Thus, rather than dealing with
THIS_MODULE's reference count, we should deal with rtc->owner's
reference count.

Signed-off-by: Geliang Tang 
Signed-off-by: Alexandre Belloni

procfs: new helper - PDE_DATA(inode)

2013-04-09T18:13:32+00:00

The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.

Signed-off-by: Al Viro

rtc-proc: permit the /proc/driver/rtc device to use other devices

2012-10-05T18:05:01+00:00

To get time information via /proc/driver/rtc, only the first device (rtc0)
is used.  If the rtcN (eg.  rtc1 or rtc2) is used for the system clock,
there is no way to get information of rtcN via /proc/driver/rtc.  With
this patch, the time data can be retrieved from the system clock RTC.

If the RTC_HCTOSYS_DEVICE is not defined, then rtc0 is used by default.

Signed-off-by: Milo(Woogyom) Kim 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

RTC: Include information about UIE and PIE in RTC driver proc.

2011-03-09T19:25:04+00:00

Generic RTC code is always able to provide the necessary information
about update and periodic interrupts. This patch add such information to
the proc interface.

CC: Thomas Gleixner 
CC: Alessandro Zummo 
CC: Marcelo Roberto Jimenez 
CC: rtc-linux@googlegroups.com
Signed-off-by: Marcelo Roberto Jimenez 
Signed-off-by: John Stultz

drivers/rtc/rtc-proc.c: add module_put on error path in rtc_proc_open()

2011-02-12T00:12:20+00:00

In file drivers/rtc/rtc-proc.c seq_open() can return -ENOMEM.

 86        if (!try_module_get(THIS_MODULE))
 87                return -ENODEV;
 88
 89        return single_open(file, rtc_proc_show, rtc);

In this case before exiting (line 89) from rtc_proc_open the
module_put(THIS_MODULE) must be called.

Found by Linux Device Drivers Verification Project

Signed-off-by: Alexander Strakh 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc 2/2: remove struct proc_dir_entry::owner

2009-03-30T21:14:44+00:00

Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan

drivers: use non-racy method for proc entries creation (2)

2008-04-29T15:06:22+00:00

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Signed-off-by: Denis V. Lunev 
Cc: Greg Kroah-Hartman 
Cc: Alexey Dobriyan 
Cc: "Eric W. Biederman" 
Cc: Peter Osterlund 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Dmitry Torokhov 
Cc: Neil Brown 
Cc: Mauro Carvalho Chehab 
Cc: Bjorn Helgaas 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: remove rest of class_device

2007-05-08T18:15:18+00:00

Finish converting the RTC framework so it no longer uses class_device.

Signed-off-by: David Brownell 
Acked-by: Greg Kroah-Hartman 
Acked-By: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: simplified /proc/driver/rtc handling

2007-05-08T18:15:18+00:00

This simplifies the RTC procfs support by removing the class_interface that
hooks it into the rtc core.  If it's configured, then sysfs support is now
part of the RTC core, and is never a separate module.

It also removes the class_interface hook, now that its last remaining user is
gone.  (That API is usable only with a "struct class_device".)

It's another step towards being able to remove "struct class_device".

Signed-off-by: David Brownell 
Acked-by: Greg Kroah-Hartman 
Acked-By: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds