3.14-stable patches

added patches:
	x86-preempt-fix-preemption-for-i386.patch

diff --git a/queue-3.14/series b/queue-3.14/series
index 7d01f7089912853605c4ccf369549edc191086cb..3317296caa21a496357f82fefbf2b601419bfe43 100644 (file)
--- a/queue-3.14/series
+++ b/queue-3.14/series
@@ -10,3 +10,4 @@ netfilter-nf_conntrack-reserve-two-bytes-for-nf_ct_ext-len.patch
 blktrace-fix-accounting-of-partially-completed-requests.patch
 netfilter-can-t-fail-and-free-after-table-replacement.patch
 netfilter-nf_tables-set-names-cannot-be-larger-than-15-bytes.patch
+x86-preempt-fix-preemption-for-i386.patch

diff --git a/queue-3.14/x86-preempt-fix-preemption-for-i386.patch b/queue-3.14/x86-preempt-fix-preemption-for-i386.patch
new file mode 100644 (file)
index 0000000..aff4206
--- /dev/null
+++ b/queue-3.14/x86-preempt-fix-preemption-for-i386.patch
@@ -0,0 +1,101 @@
+From peterz@infradead.org  Tue May 13 16:56:21 2014
+From: Peter Zijlstra <peterz@infradead.org>
+Date: Wed, 9 Apr 2014 16:24:47 +0200
+Subject: x86,preempt: Fix preemption for i386
+To: Stefan Bader <stefan.bader@canonical.com>
+Cc: Toralf Förster <toralf.foerster@gmx.de>, Michele Ballabio <barra_cuda@katamail.com>, linux-kernel@vger.kernel.org, fweisbec@gmail.com, mingo@kernel.org, Steven Rostedt <rostedt@goodmis.org>, David Cohen <david.a.cohen@linux.intel.com>, Paolo Bonzini <pbonzini@redhat.com>, Borislav Petkov <bp@alien8.de>, Linus Torvalds <torvalds@linux-foundation.org>, Greg KH <greg@kroah.com>
+Message-ID: <20140409142447.GD13658@twins.programming.kicks-ass.net>
+Content-Disposition: inline
+
+
+From: Peter Zijlstra <peterz@infradead.org>
+
+Many people reported preemption/reschedule problems with i386 kernels
+for .13 and .14. After Michele bisected this to a combination of
+
+  3e8e42c69bb ("sched: Revert need_resched() to look at TIF_NEED_RESCHED")
+  ded79754754 ("irq: Force hardirq exit's softirq processing on its own stack")
+
+it finally dawned on me that i386's current_thread_info() was to
+blame.
+
+When we are on interrupt/exception stacks, we fail to observe the
+right TIF_NEED_RESCHED bit and therefore the PREEMPT_NEED_RESCHED
+folding malfunctions.
+
+Current upstream fixes this by making i386 behave the same as x86_64
+already did:
+
+  2432e1364bbe ("x86: Nuke the supervisor_stack field in i386 thread_info")
+  b807902a88c4 ("x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386")
+  0788aa6a23cb ("x86: Prepare removal of previous_esp from i386 thread_info structure")
+  198d208df437 ("x86: Keep thread_info on thread stack in x86_32")
+
+However, that is far too much to stuff into -stable. Therefore I
+propose we merge the below patch which uses task_thread_info(current)
+for tif_need_resched() instead of the ESP based current_thread_info().
+
+This makes sure we always observe the one true TIF_NEED_RESCHED bit
+and things will work as expected again.
+
+Cc: fweisbec@gmail.com
+Cc: mingo@kernel.org
+Cc: Steven Rostedt <rostedt@goodmis.org>
+Cc: David Cohen <david.a.cohen@linux.intel.com>
+Cc: Paolo Bonzini <pbonzini@redhat.com>
+Cc: Borislav Petkov <bp@alien8.de>
+Tested-by: Stefan Bader <stefan.bader@canonical.com>
+Tested-by: Toralf Förster <toralf.foerster@gmx.de>
+Tested-by: Michele Ballabio <barra_cuda@katamail.com>
+Signed-off-by: Peter Zijlstra <peterz@infradead.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/preempt.h |   11 +++++++++++
+ include/linux/preempt.h        |    4 ++++
+ include/linux/thread_info.h    |    2 --
+ 3 files changed, 15 insertions(+), 2 deletions(-)
+
+--- a/arch/x86/include/asm/preempt.h
++++ b/arch/x86/include/asm/preempt.h
+@@ -5,6 +5,17 @@
+ #include <asm/percpu.h>
+ #include <linux/thread_info.h>
+ 
++#ifdef CONFIG_X86_32
++/*
++ * i386's current_thread_info() depends on ESP and for interrupt/exception
++ * stacks this doesn't yield the actual task thread_info.
++ *
++ * We hard rely on the fact that all the TIF_NEED_RESCHED bits are
++ * the same, therefore use the slightly more expensive version below.
++ */
++#define tif_need_resched() test_tsk_thread_flag(current, TIF_NEED_RESCHED)
++#endif
++
+ DECLARE_PER_CPU(int, __preempt_count);
+ 
+ /*
+--- a/include/linux/preempt.h
++++ b/include/linux/preempt.h
+@@ -17,6 +17,10 @@
+ 
+ #include <asm/preempt.h>
+ 
++#ifndef tif_need_resched
++#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
++#endif
++
+ #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+ extern void preempt_count_add(int val);
+ extern void preempt_count_sub(int val);
+--- a/include/linux/thread_info.h
++++ b/include/linux/thread_info.h
+@@ -118,8 +118,6 @@ static inline __deprecated void set_need
+        */
+ }
+ 
+-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+-
+ #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
+ /*
+  * An arch can define its own version of set_restore_sigmask() to get the