Merge tag 'memblock-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt...

[platform/kernel/linux-starfive.git] / lib / stackdepot.c

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index e73fda2..79e894c 100644 (file)
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -43,7 +43,8 @@
 #define STACK_ALLOC_OFFSET_BITS (STACK_ALLOC_ORDER + PAGE_SHIFT - \
                                        STACK_ALLOC_ALIGN)
 #define STACK_ALLOC_INDEX_BITS (DEPOT_STACK_BITS - \
-               STACK_ALLOC_NULL_PROTECTION_BITS - STACK_ALLOC_OFFSET_BITS)
+               STACK_ALLOC_NULL_PROTECTION_BITS - \
+               STACK_ALLOC_OFFSET_BITS - STACK_DEPOT_EXTRA_BITS)
 #define STACK_ALLOC_SLABS_CAP 8192
 #define STACK_ALLOC_MAX_SLABS \
        (((1LL << (STACK_ALLOC_INDEX_BITS)) < STACK_ALLOC_SLABS_CAP) ? \
@@ -56,6 +57,7 @@ union handle_parts {
                u32 slabindex : STACK_ALLOC_INDEX_BITS;
                u32 offset : STACK_ALLOC_OFFSET_BITS;
                u32 valid : STACK_ALLOC_NULL_PROTECTION_BITS;
+               u32 extra : STACK_DEPOT_EXTRA_BITS;
        };
 };
 
@@ -77,6 +79,14 @@ static int next_slab_inited;
 static size_t depot_offset;
 static DEFINE_RAW_SPINLOCK(depot_lock);
 
+unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle)
+{
+       union handle_parts parts = { .handle = handle };
+
+       return parts.extra;
+}
+EXPORT_SYMBOL(stack_depot_get_extra_bits);
+
 static bool init_stack_slab(void **prealloc)
 {
        if (!*prealloc)
@@ -140,6 +150,7 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
        stack->handle.slabindex = depot_index;
        stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN;
        stack->handle.valid = 1;
+       stack->handle.extra = 0;
        memcpy(stack->entries, entries, flex_array_size(stack, entries, size));
        depot_offset += required_size;
 
@@ -382,6 +393,7 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch);
  *
  * @entries:           Pointer to storage array
  * @nr_entries:                Size of the storage array
+ * @extra_bits:                Flags to store in unused bits of depot_stack_handle_t
  * @alloc_flags:       Allocation gfp flags
  * @can_alloc:         Allocate stack slabs (increased chance of failure if false)
  *
@@ -393,6 +405,10 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch);
  * If the stack trace in @entries is from an interrupt, only the portion up to
  * interrupt entry is saved.
  *
+ * Additional opaque flags can be passed in @extra_bits, stored in the unused
+ * bits of the stack handle, and retrieved using stack_depot_get_extra_bits()
+ * without calling stack_depot_fetch().
+ *
  * Context: Any context, but setting @can_alloc to %false is required if
  *          alloc_pages() cannot be used from the current context. Currently
  *          this is the case from contexts where neither %GFP_ATOMIC nor
@@ -402,10 +418,11 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch);
  */
 depot_stack_handle_t __stack_depot_save(unsigned long *entries,
                                        unsigned int nr_entries,
+                                       unsigned int extra_bits,
                                        gfp_t alloc_flags, bool can_alloc)
 {
        struct stack_record *found = NULL, **bucket;
-       depot_stack_handle_t retval = 0;
+       union handle_parts retval = { .handle = 0 };
        struct page *page = NULL;
        void *prealloc = NULL;
        unsigned long flags;
@@ -489,9 +506,11 @@ exit:
                free_pages((unsigned long)prealloc, STACK_ALLOC_ORDER);
        }
        if (found)
-               retval = found->handle.handle;
+               retval.handle = found->handle.handle;
 fast_exit:
-       return retval;
+       retval.extra = extra_bits;
+
+       return retval.handle;
 }
 EXPORT_SYMBOL_GPL(__stack_depot_save);
 
@@ -511,6 +530,6 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
                                      unsigned int nr_entries,
                                      gfp_t alloc_flags)
 {
-       return __stack_depot_save(entries, nr_entries, alloc_flags, true);
+       return __stack_depot_save(entries, nr_entries, 0, alloc_flags, true);
 }
 EXPORT_SYMBOL_GPL(stack_depot_save);