parallel changes of ANNOUNCE-4.6.7-rt13

4 files changed, 171 insertions, 15 deletions

diff --git a/patches/fs-dcache-resched-chill-only-if-we-make-no-progress.patch b/patches/fs-dcache-resched-chill-only-if-we-make-no-progress.patch
index a59001e85da832..185bf2e8cd886c 100644
--- a/patches/fs-dcache-resched-chill-only-if-we-make-no-progress.patch
+++ b/patches/fs-dcache-resched-chill-only-if-we-make-no-progress.patch
@@ -23,21 +23,12 @@ progress.
 Cc: stable-rt@vger.kernel.org
 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 ---
- fs/dcache.c |   19 +++++++++++++------
- 1 file changed, 13 insertions(+), 6 deletions(-)
+ fs/dcache.c |   18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
 
 --- a/fs/dcache.c
 +++ b/fs/dcache.c
-@@ -40,6 +40,8 @@
- #include <linux/ratelimit.h>
- #include <linux/list_lru.h>
- #include <linux/kasan.h>
-+#include <linux/sched/rt.h>
-+#include <linux/sched/deadline.h>
- 
- #include "internal.h"
- #include "mount.h"
-@@ -748,6 +750,8 @@ static inline bool fast_dput(struct dent
+@@ -748,6 +748,8 @@ static inline bool fast_dput(struct dent
   */
  void dput(struct dentry *dentry)
  {
@@ -46,7 +37,7 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  	if (unlikely(!dentry))
  		return;
  
-@@ -784,14 +788,17 @@ void dput(struct dentry *dentry)
+@@ -784,14 +786,18 @@ void dput(struct dentry *dentry)
  	return;
  
  kill_it:
@@ -63,10 +54,11 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 +		if (parent == dentry) {
 +			/* the task with the highest priority won't schedule */
 +			r = cond_resched();
-+			if (!r && (rt_task(current) || dl_task(current)))
++			if (!r)
 +				cpu_chill();
-+		} else
++		} else {
 +			dentry = parent;
++		}
  		goto repeat;
  	}
  }
diff --git a/patches/lockdep-Quiet-gcc-about-dangerous-__builtin_return_a.patch b/patches/lockdep-Quiet-gcc-about-dangerous-__builtin_return_a.patch
new file mode 100644
index 00000000000000..bce6d3d9d0b223
--- /dev/null
+++ b/patches/lockdep-Quiet-gcc-about-dangerous-__builtin_return_a.patch
@@ -0,0 +1,110 @@
+From: Steven Rostedt <rostedt@goodmis.org>
+Date: Thu, 8 Sep 2016 12:34:33 -0400
+Subject: [PATCH] lockdep: Quiet gcc about dangerous __builtin_return_address()
+ operations
+
+[
+  Boris, does this quiet gcc for you?
+  I haven't fully tested this yet, as I still don't have a compiler
+  that does the warning.
+]
+
+Gcc's new warnings about __builtin_return_address(n) operations with
+n > 0 is popping up around the kernel. The operation is dangerous, and
+the warning is "good to know". But there's instances that we use
+__builtin_return_address(n) with n > 0 and are aware of the issues,
+and work around them. And its used mostly for tracing and debugging. In
+these cases, the warning becomes a distraction and is not helpful.
+
+To get better lock issue traces, a function like get_lock_parent_ip()
+uses __builtin_return_address() to find the caller of the lock, and
+skip over the internal callers of the lock itself. Currently it is only
+used in the kernel/ directory and only if certain configs are enabled.
+
+Create a new config called CONFIG_USING_GET_LOCK_PARENT_IP that gets
+selected when another config relies on get_lock_parent_ip(), and this
+will now enable the function get_lock_parent_ip(), otherwise it wont be
+defined. It will also disable the frame-address warnings from gcc in
+the kernel directory.
+
+Reported-by: Borislav Petkov <bp@alien8.de>
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+---
+ include/linux/ftrace.h |    2 ++
+ kernel/Makefile        |    7 +++++++
+ kernel/trace/Kconfig   |    1 +
+ lib/Kconfig.debug      |   10 ++++++++++
+ 4 files changed, 20 insertions(+)
+
+--- a/include/linux/ftrace.h
++++ b/include/linux/ftrace.h
+@@ -713,6 +713,7 @@ static inline void __ftrace_enabled_rest
+ #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
+ #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
+ 
++#ifdef CONFIG_USING_GET_LOCK_PARENT_IP
+ static inline unsigned long get_lock_parent_ip(void)
+ {
+ 	unsigned long addr = CALLER_ADDR0;
+@@ -724,6 +725,7 @@ static inline unsigned long get_lock_par
+ 		return addr;
+ 	return CALLER_ADDR2;
+ }
++#endif
+ 
+ #ifdef CONFIG_IRQSOFF_TRACER
+   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
+--- a/kernel/Makefile
++++ b/kernel/Makefile
+@@ -11,6 +11,13 @@ obj-y     = fork.o exec_domain.o panic.o
+ 	    notifier.o ksysfs.o cred.o reboot.o \
+ 	    async.o range.o smpboot.o
+ 
++# Tracing may do some dangerous __builtin_return_address() operations
++# We know they are dangerous, we don't need gcc telling us that.
++ifdef CONFIG_USING_GET_LOCK_PARENT_IP
++FRAME_CFLAGS := $(call cc-disable-warning,frame-address)
++KBUILD_CFLAGS += $(FRAME_CFLAGS)
++endif
++
+ obj-$(CONFIG_MULTIUSER) += groups.o
+ 
+ ifdef CONFIG_FUNCTION_TRACER
+--- a/kernel/trace/Kconfig
++++ b/kernel/trace/Kconfig
+@@ -197,6 +197,7 @@ config PREEMPT_TRACER
+ 	select RING_BUFFER_ALLOW_SWAP
+ 	select TRACER_SNAPSHOT
+ 	select TRACER_SNAPSHOT_PER_CPU_SWAP
++	select USING_GET_LOCK_PARENT_IP
+ 	help
+ 	  This option measures the time spent in preemption-off critical
+ 	  sections, with microsecond accuracy.
+--- a/lib/Kconfig.debug
++++ b/lib/Kconfig.debug
+@@ -962,6 +962,7 @@ config TIMER_STATS
+ config DEBUG_PREEMPT
+ 	bool "Debug preemptible kernel"
+ 	depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
++	select USING_GET_LOCK_PARENT_IP
+ 	default y
+ 	help
+ 	  If you say Y here then the kernel will use a debug variant of the
+@@ -1144,8 +1145,17 @@ config LOCK_TORTURE_TEST
+ 
+ endmenu # lock debugging
+ 
++config USING_GET_LOCK_PARENT_IP
++        bool
++	help
++	  Enables the use of the function get_lock_parent_ip() that
++	  will use __builtin_return_address(n) with n > 0 causing
++	  some gcc warnings. When this is selected, those warnings
++	  will be suppressed.
++
+ config TRACE_IRQFLAGS
+ 	bool
++	select USING_GET_LOCK_PARENT_IP
+ 	help
+ 	  Enables hooks to interrupt enabling and disabling for
+ 	  either tracing or lock debugging.
diff --git a/patches/series b/patches/series
index 8073ce6718b692..ce850eca05c9e0 100644
--- a/patches/series
+++ b/patches/series
@@ -17,6 +17,7 @@ rbtree_augmented-fix-implicit-rcu-assign-pointer-dep.patch
 # Stuff broken upstream, patches submitted
 ############################################################
 sc16is7xx_Drop_bogus_use_of_IRQF_ONESHOT.patch
+lockdep-Quiet-gcc-about-dangerous-__builtin_return_a.patch
 
 # Those two should vanish soon (not use PIT during bootup)
 at91_dont_enable_disable_clock.patch
@@ -402,6 +403,7 @@ block-use-cpu-chill.patch
 
 # FS LIVELOCK PREVENTION
 fs-dcache-use-cpu-chill-in-trylock-loops.patch
+fs-dcache-resched-chill-only-if-we-make-no-progress.patch
 net-use-cpu-chill.patch
 
 # WORKQUEUE more fixes
@@ -428,6 +430,8 @@ net-core-cpuhotplug-drain-input_pkt_queue-lockless.patch
 net-move-xmit_recursion-to-per-task-variable-on-RT.patch
 net-provide-a-way-to-delegate-processing-a-softirq-t.patch
 net-dev-always-take-qdisc-s-busylock-in-__dev_xmit_s.patch
+net-add-back-the-missing-serialization-in-ip_send_un.patch
+net-add-a-lock-around-icmp_sk.patch
 
 # NETWORK DEBUGGING AID
 ping-sysrq.patch
@@ -551,6 +555,7 @@ preempt-lazy-support.patch
 preempt-lazy-check-preempt_schedule.patch
 sched-lazy_preempt-avoid-a-warning-in-the-RT-case.patch
 x86-preempt-lazy.patch
+x86-preempt-lazy-fixup-should_resched.patch
 arm-preempt-lazy-support.patch
 arm-lazy-preempt-correct-resched-condition.patch
 powerpc-preempt-lazy-support.patch
diff --git a/patches/x86-preempt-lazy-fixup-should_resched.patch b/patches/x86-preempt-lazy-fixup-should_resched.patch
new file mode 100644
index 00000000000000..5e771a368d9e78
--- /dev/null
+++ b/patches/x86-preempt-lazy-fixup-should_resched.patch
@@ -0,0 +1,49 @@
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Wed, 14 Sep 2016 19:18:47 +0200
+Subject: [PATCH] x86/preempt-lazy: fixup should_resched()
+
+should_resched() returns true if NEED_RESCHED is set and the
+preempt_count is 0 _or_ if NEED_RESCHED_LAZY is set ignoring the preempt
+counter. Ignoring the preemp counter is wrong. This patch adds this into
+account.
+While at it, __preempt_count_dec_and_test() ignores preempt_lazy_count
+while checking TIF_NEED_RESCHED_LAZY so we this check, too.
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ arch/x86/include/asm/preempt.h |   17 +++++++++++++++--
+ 1 file changed, 15 insertions(+), 2 deletions(-)
+
+--- a/arch/x86/include/asm/preempt.h
++++ b/arch/x86/include/asm/preempt.h
+@@ -89,6 +89,8 @@ static __always_inline bool __preempt_co
+ 	if (____preempt_count_dec_and_test())
+ 		return true;
+ #ifdef CONFIG_PREEMPT_LAZY
++	if (current_thread_info()->preempt_lazy_count)
++		return false;
+ 	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+ #else
+ 	return false;
+@@ -101,8 +103,19 @@ static __always_inline bool __preempt_co
+ static __always_inline bool should_resched(int preempt_offset)
+ {
+ #ifdef CONFIG_PREEMPT_LAZY
+-	return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset ||
+-			test_thread_flag(TIF_NEED_RESCHED_LAZY));
++	u32 tmp;
++
++	tmp = raw_cpu_read_4(__preempt_count);
++	if (tmp == preempt_offset)
++		return true;
++
++	/* preempt count == 0 ? */
++	tmp &= ~PREEMPT_NEED_RESCHED;
++	if (tmp)
++		return false;
++	if (current_thread_info()->preempt_lazy_count)
++		return false;
++	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+ #else
+ 	return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset);
+ #endif