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.
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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
This commit is contained in:
Linus Torvalds 2022-11-18 12:30:23 -08:00
commit ab290eaddc
2 changed files with 11 additions and 1 deletions

View File

@ -199,7 +199,16 @@ unsigned long __get_wchan(struct task_struct *p);
/* Has task runtime instrumentation enabled ? */ /* Has task runtime instrumentation enabled ? */
#define is_ri_task(tsk) (!!(tsk)->thread.ri_cb) #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) static __always_inline unsigned short stap(void)
{ {

View File

@ -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->minors = DCSSBLK_MINORS_PER_DISK;
dev_info->gd->fops = &dcssblk_devops; dev_info->gd->fops = &dcssblk_devops;
dev_info->gd->private_data = dev_info; 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_logical_block_size(dev_info->gd->queue, 4096);
blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->gd->queue); blk_queue_flag_set(QUEUE_FLAG_DAX, dev_info->gd->queue);