From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 6 Dec 2017 13:53:56 +0000 (+0100)
Subject: 4.9-stable patches
X-Git-Tag: v3.18.87~21
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0eb2fb84e13b7a4a51ef80a9e0a7bb64bb540df1;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	s390-runtime-instrumentation-simplify-task-exit-handling.patch
---

diff --git a/queue-4.9/s390-runtime-instrumentation-simplify-task-exit-handling.patch b/queue-4.9/s390-runtime-instrumentation-simplify-task-exit-handling.patch
new file mode 100644
index 00000000000..fde5003fcb5
--- /dev/null
+++ b/queue-4.9/s390-runtime-instrumentation-simplify-task-exit-handling.patch
@@ -0,0 +1,115 @@
+From 8d9047f8b967ce6181fd824ae922978e1b055cc0 Mon Sep 17 00:00:00 2001
+From: Heiko Carstens <heiko.carstens@de.ibm.com>
+Date: Mon, 11 Sep 2017 11:24:22 +0200
+Subject: s390/runtime instrumentation: simplify task exit handling
+
+From: Heiko Carstens <heiko.carstens@de.ibm.com>
+
+commit 8d9047f8b967ce6181fd824ae922978e1b055cc0 upstream.
+
+Free data structures required for runtime instrumentation from
+arch_release_task_struct(). This allows to simplify the code a bit,
+and also makes the semantics a bit easier: arch_release_task_struct()
+is never called from the task that is being removed.
+
+In addition this allows to get rid of exit_thread() in a later patch.
+
+Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
+Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ arch/s390/include/asm/runtime_instr.h |    4 +++-
+ arch/s390/kernel/process.c            |    3 +--
+ arch/s390/kernel/runtime_instr.c      |   30 +++++++++++++++---------------
+ 3 files changed, 19 insertions(+), 18 deletions(-)
+
+--- a/arch/s390/include/asm/runtime_instr.h
++++ b/arch/s390/include/asm/runtime_instr.h
+@@ -85,6 +85,8 @@ static inline void restore_ri_cb(struct
+ 		load_runtime_instr_cb(&runtime_instr_empty_cb);
+ }
+ 
+-void exit_thread_runtime_instr(void);
++struct task_struct;
++
++void runtime_instr_release(struct task_struct *tsk);
+ 
+ #endif /* _RUNTIME_INSTR_H */
+--- a/arch/s390/kernel/process.c
++++ b/arch/s390/kernel/process.c
+@@ -70,8 +70,6 @@ extern void kernel_thread_starter(void);
+  */
+ void exit_thread(struct task_struct *tsk)
+ {
+-	if (tsk == current)
+-		exit_thread_runtime_instr();
+ }
+ 
+ void flush_thread(void)
+@@ -84,6 +82,7 @@ void release_thread(struct task_struct *
+ 
+ void arch_release_task_struct(struct task_struct *tsk)
+ {
++	runtime_instr_release(tsk);
+ }
+ 
+ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+--- a/arch/s390/kernel/runtime_instr.c
++++ b/arch/s390/kernel/runtime_instr.c
+@@ -18,11 +18,24 @@
+ /* empty control block to disable RI by loading it */
+ struct runtime_instr_cb runtime_instr_empty_cb;
+ 
++void runtime_instr_release(struct task_struct *tsk)
++{
++	kfree(tsk->thread.ri_cb);
++}
++
+ static void disable_runtime_instr(void)
+ {
+-	struct pt_regs *regs = task_pt_regs(current);
++	struct task_struct *task = current;
++	struct pt_regs *regs;
+ 
++	if (!task->thread.ri_cb)
++		return;
++	regs = task_pt_regs(task);
++	preempt_disable();
+ 	load_runtime_instr_cb(&runtime_instr_empty_cb);
++	kfree(task->thread.ri_cb);
++	task->thread.ri_cb = NULL;
++	preempt_enable();
+ 
+ 	/*
+ 	 * Make sure the RI bit is deleted from the PSW. If the user did not
+@@ -43,19 +56,6 @@ static void init_runtime_instr_cb(struct
+ 	cb->valid = 1;
+ }
+ 
+-void exit_thread_runtime_instr(void)
+-{
+-	struct task_struct *task = current;
+-
+-	preempt_disable();
+-	if (!task->thread.ri_cb)
+-		return;
+-	disable_runtime_instr();
+-	kfree(task->thread.ri_cb);
+-	task->thread.ri_cb = NULL;
+-	preempt_enable();
+-}
+-
+ SYSCALL_DEFINE1(s390_runtime_instr, int, command)
+ {
+ 	struct runtime_instr_cb *cb;
+@@ -64,7 +64,7 @@ SYSCALL_DEFINE1(s390_runtime_instr, int,
+ 		return -EOPNOTSUPP;
+ 
+ 	if (command == S390_RUNTIME_INSTR_STOP) {
+-		exit_thread_runtime_instr();
++		disable_runtime_instr();
+ 		return 0;
+ 	}
+ 
diff --git a/queue-4.9/series b/queue-4.9/series
index a8cbe7036c6..8e85e09ba30 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -7,3 +7,4 @@ mm-oom_reaper-gather-each-vma-to-prevent-leaking-tlb-entry.patch
 uas-always-apply-us_fl_no_ata_1x-quirk-to-seagate-devices.patch
 usb-quirks-add-no-lpm-quirk-for-ky-688-usb-3.1-type-c-hub.patch
 serial-8250_pci-add-amazon-pci-serial-device-id.patch
+s390-runtime-instrumentation-simplify-task-exit-handling.patch