Commit ab290ead authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 's390-6.1-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 

Pull s390 fixes from Alexander Gordeev:

 - 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.

* tag 's390-6.1-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: avoid using global register for current_stack_pointer
  s390/dcssblk: fix deadlock when adding a DCSS
parents 5556a78c e3c11025

arch/s390/include/asm/processor.h

+10 −1
Original line number Diff line number Diff line
@@ -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)

{

drivers/s390/block/dcssblk.c

+1 −0
Original line number Diff line number Diff line
@@ -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);