[3.19.y-ckt stable] Patch "tty: remove platform_sysrq_reset_seq" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tty: remove platform_sysrq_reset_seq

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.y-ckt4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From cedef66fe103a83ab00d50da485f93a2ef4311f5 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd at arndb.de>
Date: Tue, 26 May 2015 14:45:29 -0700
Subject: tty: remove platform_sysrq_reset_seq

commit ffb6e0c9a0572f8e5f8e9337a1b40ac2ec1493a1 upstream.

The platform_sysrq_reset_seq code was intended as a way for an embedded
platform to provide its own sysrq sequence at compile time. After over two
years, nobody has started using it in an upstream kernel, and the platforms
that were interested in it have moved on to devicetree, which can be used
to configure the sequence without requiring kernel changes. The method is
also incompatible with the way that most architectures build support for
multiple platforms into a single kernel.

Now the code is producing warnings when built with gcc-5.1:

drivers/tty/sysrq.c: In function 'sysrq_init':
drivers/tty/sysrq.c:959:33: warning: array subscript is above array bounds [-Warray-bounds]
   key = platform_sysrq_reset_seq[i];

We could fix this, but it seems unlikely that it will ever be used, so
let's just remove the code instead. We still have the option to pass the
sequence either in DT, using the kernel command line, or using the
/sys/module/sysrq/parameters/reset_seq file.

Fixes: 154b7a489a ("Input: sysrq - allow specifying alternate reset sequence")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/tty/sysrq.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 42bad18..647d3df 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -55,9 +55,6 @@
 static int __read_mostly sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
 static bool __read_mostly sysrq_always_enabled;

-unsigned short platform_sysrq_reset_seq[] __weak = { KEY_RESERVED };
-int sysrq_reset_downtime_ms __weak;
-
 static bool sysrq_on(void)
 {
 	return sysrq_enabled || sysrq_always_enabled;
@@ -567,6 +564,7 @@ void handle_sysrq(int key)
 EXPORT_SYMBOL(handle_sysrq);

 #ifdef CONFIG_INPUT
+static int sysrq_reset_downtime_ms;

 /* Simple translation table for the SysRq keys */
 static const unsigned char sysrq_xlate[KEY_CNT] =
@@ -947,23 +945,8 @@ static bool sysrq_handler_registered;

 static inline void sysrq_register_handler(void)
 {
-	unsigned short key;
 	int error;
-	int i;
-
-	/* First check if a __weak interface was instantiated. */
-	for (i = 0; i < ARRAY_SIZE(sysrq_reset_seq); i++) {
-		key = platform_sysrq_reset_seq[i];
-		if (key == KEY_RESERVED || key > KEY_MAX)
-			break;
-
-		sysrq_reset_seq[sysrq_reset_seq_len++] = key;
-	}

-	/*
-	 * DT configuration takes precedence over anything that would
-	 * have been defined via the __weak interface.
-	 */
 	sysrq_of_get_keyreset_config();

 	error = input_register_handler(&sysrq_handler);
--
1.9.1