From: Borislav Petkov <bp@suse.de>
Subject: sched/pasid: Add a kABI workaround
Patch-mainline: Never, kABI workaround
References: jsc#SLE-24350

Add a kABI workaround for

  patches.suse/sched-define-and-initialize-a-flag-to-identify-valid-pasid-in-the-task.patch

which adds a new bitfield to task_struct. The offsets remain the same - solely
only one bit gets added, as verified with pahole:

|  --- /root/tmp/task_struct.before        2022-05-18 10:53:49.134980574 +0200
|  +++ /root/tmp/task_struct.after 2022-05-18 11:09:34.876055028 +0200
|  @@ -131,8 +131,9 @@ struct task_struct {
|          unsigned int               in_memstall:1;        /*  2416: 8  4 */
|          unsigned int               in_page_owner:1;      /*  2416: 9  4 */
|          unsigned int               in_eventfd_signal:1;  /*  2416:10  4 */
|  +       unsigned int               pasid_activated:1;    /*  2416:11  4 */
|
|  -       /* XXX 21 bits hole, try to pack */
|  +       /* XXX 20 bits hole, try to pack */
|          /* XXX 4 bytes hole, try to pack */
|
|          long unsigned int          atomic_flags;         /*  2424     8 */
|  @@ -392,9 +393,9 @@ struct task_struct {
|          /* --- cacheline 144 boundary (9216 bytes) --- */
|          struct thread_struct       thread __attribute__((__aligned__(64))); /*  9216  4416 */
|
|  -       /* size: 13632, cachelines: 213, members: 253 */
|  +       /* size: 13632, cachelines: 213, members: 254 */
|          /* sum members: 13451, holes: 22, sum holes: 165 */
|  -       /* sum bitfield members: 79 bits, bit holes: 2, sum bit holes: 49 bits */
|  +       /* sum bitfield members: 80 bits, bit holes: 2, sum bit holes: 48 bits */
|          /* paddings: 6, sum paddings: 57 */
|          /* forced alignments: 10, forced holes: 3, sum forced holes: 92 */
|   } __attribute__((__aligned__(64)));

Signed-off-by: Borislav Petkov <bp@suse.de>

---

--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -940,8 +940,10 @@ struct task_struct {
 	unsigned			in_eventfd_signal:1;
 #endif
 #ifdef CONFIG_IOMMU_SVA
+#ifndef __GENKSYMS__
 	unsigned			pasid_activated:1;
 #endif
+#endif
 
 	unsigned long			atomic_flags; /* Flags requiring atomic access. */