6 files changed, 82 insertions, 27 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/debugobjects.c b/lib/debugobjects.c
index 547f7f923dbc..519b5a10fd70 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -21,7 +21,7 @@
 #define ODEBUG_HASH_BITS        14
 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
 
-#define ODEBUG_POOL_SIZE        512
+#define ODEBUG_POOL_SIZE        1024
 #define ODEBUG_POOL_MIN_LEVEL   256
 
 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 6745c6230db3..c30d07e99dba 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -25,6 +25,7 @@ static atomic_t dump_lock = ATOMIC_INIT(-1);
 
 asmlinkage __visible void dump_stack(void)
 {
+        unsigned long flags;
         int was_locked;
         int old;
         int cpu;
@@ -33,9 +34,8 @@ asmlinkage __visible void dump_stack(void)
          * Permit this cpu to perform nested stack dumps while serialising
          * against other CPUs
          */
-        preempt_disable();
-
 retry:
+        local_irq_save(flags);
         cpu = smp_processor_id();
         old = atomic_cmpxchg(&dump_lock, -1, cpu);
         if (old == -1) {
@@ -43,6 +43,7 @@ retry:
         } else if (old == cpu) {
                 was_locked = 1;
         } else {
+                local_irq_restore(flags);
                 cpu_relax();
                 goto retry;
         }
@@ -52,7 +53,7 @@ retry:
         if (!was_locked)
                 atomic_set(&dump_lock, -1);
 
-        preempt_enable();
+        local_irq_restore(flags);
 }
 #else
 asmlinkage __visible void dump_stack(void)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index fcf5d98574ce..6b79e9026e24 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1019,9 +1019,13 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
                 return 0;
 
         radix_tree_for_each_slot(slot, root, &iter, first_index) {
-                results[ret] = indirect_to_ptr(rcu_dereference_raw(*slot));
+                results[ret] = rcu_dereference_raw(*slot);
                 if (!results[ret])
                         continue;
+                if (radix_tree_is_indirect_ptr(results[ret])) {
+                        slot = radix_tree_iter_retry(&iter);
+                        continue;
+                }
                 if (++ret == max_items)
                         break;
         }
@@ -1098,9 +1102,13 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
                 return 0;
 
         radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
-                results[ret] = indirect_to_ptr(rcu_dereference_raw(*slot));
+                results[ret] = rcu_dereference_raw(*slot);
                 if (!results[ret])
                         continue;
+                if (radix_tree_is_indirect_ptr(results[ret])) {
+                        slot = radix_tree_iter_retry(&iter);
+                        continue;
+                }
                 if (++ret == max_items)
                         break;
         }
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/test-string_helpers.c b/lib/test-string_helpers.c
index 98866a770770..25b5cbfb7615 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -327,36 +327,67 @@ out:
 }
 
 #define string_get_size_maxbuf 16
-#define test_string_get_size_one(size, blk_size, units, exp_result)            \
+#define test_string_get_size_one(size, blk_size, exp_result10, exp_result2)    \
         do {                                                                   \
-                BUILD_BUG_ON(sizeof(exp_result) >= string_get_size_maxbuf);    \
-                __test_string_get_size((size), (blk_size), (units),            \
-                                       (exp_result));                          \
+                BUILD_BUG_ON(sizeof(exp_result10) >= string_get_size_maxbuf);  \
+                BUILD_BUG_ON(sizeof(exp_result2) >= string_get_size_maxbuf);   \
+                __test_string_get_size((size), (blk_size), (exp_result10),     \
+                                       (exp_result2));                         \
         } while (0)
 
 
-static __init void __test_string_get_size(const u64 size, const u64 blk_size,
-                                          const enum string_size_units units,
-                                          const char *exp_result)
+static __init void test_string_get_size_check(const char *units,
+                                              const char *exp,
+                                              char *res,
+                                              const u64 size,
+                                              const u64 blk_size)
 {
-        char buf[string_get_size_maxbuf];
-
-        string_get_size(size, blk_size, units, buf, sizeof(buf));
-        if (!memcmp(buf, exp_result, strlen(exp_result) + 1))
+        if (!memcmp(res, exp, strlen(exp) + 1))
                 return;
 
-        buf[sizeof(buf) - 1] = '\0';
-        pr_warn("Test 'test_string_get_size_one' failed!\n");
-        pr_warn("string_get_size(size = %llu, blk_size = %llu, units = %d\n",
+        res[string_get_size_maxbuf - 1] = '\0';
+
+        pr_warn("Test 'test_string_get_size' failed!\n");
+        pr_warn("string_get_size(size = %llu, blk_size = %llu, units = %s)\n",
                 size, blk_size, units);
-        pr_warn("expected: '%s', got '%s'\n", exp_result, buf);
+        pr_warn("expected: '%s', got '%s'\n", exp, res);
+}
+
+static __init void __test_string_get_size(const u64 size, const u64 blk_size,
+                                          const char *exp_result10,
+                                          const char *exp_result2)
+{
+        char buf10[string_get_size_maxbuf];
+        char buf2[string_get_size_maxbuf];
+
+        string_get_size(size, blk_size, STRING_UNITS_10, buf10, sizeof(buf10));
+        string_get_size(size, blk_size, STRING_UNITS_2, buf2, sizeof(buf2));
+
+        test_string_get_size_check("STRING_UNITS_10", exp_result10, buf10,
+                                   size, blk_size);
+
+        test_string_get_size_check("STRING_UNITS_2", exp_result2, buf2,
+                                   size, blk_size);
 }
 
 static __init void test_string_get_size(void)
 {
-        test_string_get_size_one(16384, 512, STRING_UNITS_2, "8.00 MiB");
-        test_string_get_size_one(8192, 4096, STRING_UNITS_10, "32.7 MB");
-        test_string_get_size_one(1, 512, STRING_UNITS_10, "512 B");
+        /* small values */
+        test_string_get_size_one(0, 512, "0 B", "0 B");
+        test_string_get_size_one(1, 512, "512 B", "512 B");
+        test_string_get_size_one(1100, 1, "1.10 kB", "1.07 KiB");
+
+        /* normal values */
+        test_string_get_size_one(16384, 512, "8.39 MB", "8.00 MiB");
+        test_string_get_size_one(500118192, 512, "256 GB", "238 GiB");
+        test_string_get_size_one(8192, 4096, "33.6 MB", "32.0 MiB");
+
+        /* weird block sizes */
+        test_string_get_size_one(3000, 1900, "5.70 MB", "5.44 MiB");
+
+        /* huge values */
+        test_string_get_size_one(U64_MAX, 4096, "75.6 ZB", "64.0 ZiB");
+        test_string_get_size_one(4096, U64_MAX, "75.6 ZB", "64.0 ZiB");
 }
 
 static int __init test_string_helpers_init(void)