[GIT PULL] s390 updates for 6.1-rc6

[Alexander Gordeev]

Hello Linus,

please pull s390 changes for 6.1-rc6.

Thank you,
Alexander

The following changes since commit 30d17fac6aaedb40d111bb159f4b35525637ea78:

  scripts/min-tool-version.sh: raise minimum clang version to 15.0.0 for s390 (2022-10-31 13:34:56 +0100)

are available in the Git repository at e3c11025bcd2142a61abe5806b2f86a0e78118df:

  git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git tags/s390-6.1-5

for you to fetch changes up to :

  s390: avoid using global register for current_stack_pointer (2022-11-04 12:06:47 +0100)

----------------------------------------------------------------
s390 updates for 6.1-rc6

- Fix deadlock in discontiguous saved segments (DCSS) block device
  driver. When adding a disk and scanning partitions the scan would
  not break out early without a missed flag.

- Avoid using global register variable for current_stack_pointer
  due to an old bug in gcc versions prior to gcc-8.4. Due to this
  bug a broken code is generated, which leads to stack corruptions.

----------------------------------------------------------------
Gerald Schaefer (1):
  s390/dcssblk: fix deadlock when adding a DCSS

Vasily Gorbik (1):
  s390: avoid using global register for current_stack_pointer

 arch/s390/include/asm/processor.h | 11 ++++++++++-
 drivers/s390/block/dcssblk.c      |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 87be3e855bf7..c907f747d2a0 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -199,7 +199,16 @@ unsigned long __get_wchan(struct task_struct *p);
 /* Has task runtime instrumentation enabled ? */
 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
 
-register unsigned long current_stack_pointer asm("r15");
+/* avoid using global register due to gcc bug in versions < 8.4 */
+#define current_stack_pointer (__current_stack_pointer())
+
+static __always_inline unsigned long __current_stack_pointer(void)
+{
+	unsigned long sp;
+
+	asm volatile("lgr %0,15" : "=d" (sp));
+	return sp;
+}
 
 static __always_inline unsigned short stap(void)
 {
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 93b80da60277..b392b9f5482e 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -636,6 +636,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 	dev_info->gd->minors = DCSSBLK_MINORS_PER_DISK;
 	dev_info->gd->fops = &dcssblk_devops;
 	dev_info->gd->private_data = dev_info;
+	dev_info->gd->flags |= GENHD_FL_NO_PART;
 	blk_queue_logical_block_size(dev_info->gd->queue, 4096);
 	blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->gd->queue);