4.4-stable patches

added patches:
	asm-generic-default-bug_on-x-to-if-x-bug.patch

diff --git a/queue-4.4/asm-generic-default-bug_on-x-to-if-x-bug.patch b/queue-4.4/asm-generic-default-bug_on-x-to-if-x-bug.patch
new file mode 100644 (file)
index 0000000..70151ae
--- /dev/null
+++ b/queue-4.4/asm-generic-default-bug_on-x-to-if-x-bug.patch
@@ -0,0 +1,76 @@
+From 3c047057d1206ec0f3b88c7809cacba478067a0c Mon Sep 17 00:00:00 2001
+From: Arnd Bergmann <arnd@arndb.de>
+Date: Sat, 21 Nov 2015 00:27:26 +0100
+Subject: asm-generic: default BUG_ON(x) to if(x)BUG()
+
+From: Arnd Bergmann <arnd@arndb.de>
+
+commit 3c047057d1206ec0f3b88c7809cacba478067a0c upstream.
+
+When CONFIG_BUG is disabled, BUG_ON() will only evaluate the condition,
+but will not actually stop the current thread. GCC warns about a couple
+of BUG_ON() users where this actually leads to further undefined
+behavior:
+
+include/linux/ceph/osdmap.h: In function 'ceph_can_shift_osds':
+include/linux/ceph/osdmap.h:54:1: warning: control reaches end of non-void function
+fs/ext4/inode.c: In function 'ext4_map_blocks':
+fs/ext4/inode.c:548:5: warning: 'retval' may be used uninitialized in this function
+drivers/mfd/db8500-prcmu.c: In function 'prcmu_config_clkout':
+drivers/mfd/db8500-prcmu.c:762:10: warning: 'div_mask' may be used uninitialized in this function
+drivers/mfd/db8500-prcmu.c:769:13: warning: 'mask' may be used uninitialized in this function
+drivers/mfd/db8500-prcmu.c:757:7: warning: 'bits' may be used uninitialized in this function
+drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
+drivers/tty/serial/8250/8250_core.c:252:18: warning: 'i' may be used uninitialized in this function
+drivers/tty/serial/8250/8250_core.c:235:19: note: 'i' was declared here
+
+There is an obvious conflict of interest here: on the one hand, someone
+who disables CONFIG_BUG() will want the kernel to be as small as possible
+and doesn't care about printing error messages to a console that nobody
+looks at. On the other hand, running into a BUG_ON() condition means that
+something has gone wrong, and we probably want to also stop doing things
+that might cause data corruption.
+
+This patch picks the second choice, and changes the NOP to BUG(), which
+normally stops the execution of the current thread in some form (endless
+loop or a trap). This follows the logic we applied in a4b5d580e078 ("bug:
+Make BUG() always stop the machine").
+
+For ARM multi_v7_defconfig, the size slightly increases:
+
+section                CONFIG_BUG=y    CONFIG_BUG=n    CONFIG_BUG=n+patch
+
+  .text            8320248   |     8180944   |     8207688
+  .rodata          3633720   |     3567144   |     3570648
+  __bug_table        32508   |         ---   |         ---
+  __modver             692   |        1584   |        2176
+  .init.text        558132   |      548300   |      550088
+  .exit.text         12380   |       12256   |       12380
+  .data            1016672   |     1016064   |     1016128
+  Total           14622556   |    14374510   |    14407326
+
+So instead of saving 1.70% of the total image size, we only save 1.48%
+by turning off CONFIG_BUG, but in return we can ensure that we don't run
+into cases of uninitialized variable or return code uses when something
+bad happens. Aside from that, we significantly reduce the number of
+warnings in randconfig builds, which makes it easier to fix the warnings
+about other problems.
+
+Signed-off-by: Arnd Bergmann <arnd@arndb.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/asm-generic/bug.h |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/include/asm-generic/bug.h
++++ b/include/asm-generic/bug.h
+@@ -143,7 +143,7 @@ extern void warn_slowpath_null(const cha
+ #endif
+ 
+ #ifndef HAVE_ARCH_BUG_ON
+-#define BUG_ON(condition) do { if (condition) ; } while (0)
++#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
+ #endif
+ 
+ #ifndef HAVE_ARCH_WARN_ON

diff --git a/queue-4.4/series b/queue-4.4/series
index 2fc6cffb5c8d3deb50b31e6c3d7bef9208ffc956..71c8336fb970d586aeb468bfb95c4a85bfe285ae 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -65,3 +65,4 @@ backport-minimal-compiler_attributes.h-to-support-gc.patch
 include-linux-module.h-copy-__init-__exit-attrs-to-i.patch
 arm64-compat-allow-single-byte-watchpoints-on-all-addresses.patch
 input-psmouse-fix-build-error-of-multiple-definition.patch
+asm-generic-default-bug_on-x-to-if-x-bug.patch