5 files changed, 37 insertions, 20 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ecb9e75614bf..8bfd1aca7a3d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1400,6 +1400,21 @@ config RCU_EQS_DEBUG
 
 endmenu # "RCU Debugging"
 
+config DEBUG_WQ_FORCE_RR_CPU
+        bool "Force round-robin CPU selection for unbound work items"
+        depends on DEBUG_KERNEL
+        default n
+        help
+          Workqueue used to implicitly guarantee that work items queued
+          without explicit CPU specified are put on the local CPU.  This
+          guarantee is no longer true and while local CPU is still
+          preferred work items may be put on foreign CPUs.  Kernel
+          parameter "workqueue.debug_force_rr_cpu" is added to force
+          round-robin CPU selection to flush out usages which depend on the
+          now broken guarantee.  This config option enables the debug
+          feature by default.  When enabled, memory and cache locality will
+          be impacted.
+
 config DEBUG_BLOCK_EXT_DEVT
         bool "Force extended block device numbers and spread them"
         depends on DEBUG_KERNEL
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 49518fb48cab..e07c1ba9ba13 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -18,6 +18,8 @@ config UBSAN_SANITIZE_ALL
           This option activates instrumentation for the entire kernel.
           If you don't enable this option, you have to explicitly specify
           UBSAN_SANITIZE := y for the files/directories you want to check for UB.
+          Enabling this option will get kernel image size increased
+          significantly.
 
 config UBSAN_ALIGNMENT
         bool "Enable checking of pointers alignment"
@@ -25,5 +27,5 @@ config UBSAN_ALIGNMENT
         default y if !HAVE_EFFICIENT_UNALIGNED_ACCESS
         help
           This option enables detection of unaligned memory accesses.
-          Enabling this option on architectures that support unalligned
+          Enabling this option on architectures that support unaligned
           accesses may produce a lot of false positives.
diff --git a/lib/klist.c b/lib/klist.c
index d74cf7a29afd..0507fa5d84c5 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -282,9 +282,9 @@ void klist_iter_init_node(struct klist *k, struct klist_iter *i,
                           struct klist_node *n)
 {
         i->i_klist = k;
-        i->i_cur = n;
-        if (n)
-                kref_get(&n->n_ref);
+        i->i_cur = NULL;
+        if (n && kref_get_unless_zero(&n->n_ref))
+                i->i_cur = n;
 }
 EXPORT_SYMBOL_GPL(klist_iter_init_node);
 
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index bafa9933fa76..004fc70fc56a 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -598,9 +598,9 @@ EXPORT_SYMBOL(sg_miter_next);
  *
  * Description:
  *   Stops mapping iterator @miter.  @miter should have been started
- *   started using sg_miter_start().  A stopped iteration can be
- *   resumed by calling sg_miter_next() on it.  This is useful when
- *   resources (kmap) need to be released during iteration.
+ *   using sg_miter_start().  A stopped iteration can be resumed by
+ *   calling sg_miter_next() on it.  This is useful when resources (kmap)
+ *   need to be released during iteration.
  *
  * Context:
  *   Preemption disabled if the SG_MITER_ATOMIC is set.  Don't care
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 48ff9c36644d..f44e178e6ede 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1590,22 +1590,23 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
                         return buf;
                 }
         case 'K':
-                /*
-                 * %pK cannot be used in IRQ context because its test
-                 * for CAP_SYSLOG would be meaningless.
-                 */
-                if (kptr_restrict && (in_irq() || in_serving_softirq() ||
-                                      in_nmi())) {
-                        if (spec.field_width == -1)
-                                spec.field_width = default_width;
-                        return string(buf, end, "pK-error", spec);
-                }
-
                 switch (kptr_restrict) {
                 case 0:
                         /* Always print %pK values */
                         break;
                 case 1: {
+                        const struct cred *cred;
+
+                        /*
+                         * kptr_restrict==1 cannot be used in IRQ context
+                         * because its test for CAP_SYSLOG would be meaningless.
+                         */
+                        if (in_irq() || in_serving_softirq() || in_nmi()) {
+                                if (spec.field_width == -1)
+                                        spec.field_width = default_width;
+                                return string(buf, end, "pK-error", spec);
+                        }
+
                         /*
                          * Only print the real pointer value if the current
                          * process has CAP_SYSLOG and is running with the
@@ -1615,8 +1616,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
                          * leak pointer values if a binary opens a file using
                          * %pK and then elevates privileges before reading it.
                          */
-                        const struct cred *cred = current_cred();
-
+                        cred = current_cred();
                         if (!has_capability_noaudit(current, CAP_SYSLOG) ||
                             !uid_eq(cred->euid, cred->uid) ||
                             !gid_eq(cred->egid, cred->gid))