projects/linux·commit ab290ead

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

ab290ead · Linus Torvalds <[email protected]> · 2022-11-18 12:30:23 -08:00

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
Commit
ab290eaddc4c41b237b9a366fa6a5527be890b84
Parents
5556a78c · e3c11025

Merge commit. Changes below are compared with the first parent: 5556a78c.

Changes

2 files changed · +11 −1

FileStatusAddDelContent
arch/s390/include/asm/processor.hmodified+10−1View file
drivers/s390/block/dcssblk.cmodified+1−0View file

arch/s390/include/asm/processor.h

View file
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 87be3e8..c907f74 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)
{

drivers/s390/block/dcssblk.c

View file
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 93b80da..b392b9f 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);