kmemleak: Simplify the kmemleak_scan_area() function prototype

This function was taking non-necessary arguments which can be determined
by kmemleak. The patch also modifies the calling sites.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>

4 files changed, 27 insertions, 39 deletions

diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h
index 3c7497d46ee9..99d9a6766f7e 100644
--- a/include/linux/kmemleak.h
+++ b/include/linux/kmemleak.h
@@ -32,8 +32,7 @@ extern void kmemleak_padding(const void *ptr, unsigned long offset,
                              size_t size) __ref;
 extern void kmemleak_not_leak(const void *ptr) __ref;
 extern void kmemleak_ignore(const void *ptr) __ref;
-extern void kmemleak_scan_area(const void *ptr, unsigned long offset,
-                               size_t length, gfp_t gfp) __ref;
+extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref;
 extern void kmemleak_no_scan(const void *ptr) __ref;
 
 static inline void kmemleak_alloc_recursive(const void *ptr, size_t size,
@@ -84,8 +83,7 @@ static inline void kmemleak_not_leak(const void *ptr)
 static inline void kmemleak_ignore(const void *ptr)
 {
 }
-static inline void kmemleak_scan_area(const void *ptr, unsigned long offset,
-                                      size_t length, gfp_t gfp)
+static inline void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
 {
 }
 static inline void kmemleak_erase(void **ptr)
diff --git a/kernel/module.c b/kernel/module.c
index 8b7d8805819d..1eb952097077 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2043,9 +2043,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
         unsigned int i;
 
         /* only scan the sections containing data */
-        kmemleak_scan_area(mod->module_core, (unsigned long)mod -
-                           (unsigned long)mod->module_core,
-                           sizeof(struct module), GFP_KERNEL);
+        kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
 
         for (i = 1; i < hdr->e_shnum; i++) {
                 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -2054,8 +2052,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
                     && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
                         continue;
 
-                kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
-                                   (unsigned long)mod->module_core,
+                kmemleak_scan_area((void *)sechdrs[i].sh_addr,
                                    sechdrs[i].sh_size, GFP_KERNEL);
         }
 }
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 8bf765c4f58d..96106358e042 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -119,8 +119,8 @@
 /* scanning area inside a memory block */
 struct kmemleak_scan_area {
         struct hlist_node node;
-        unsigned long offset;
-        size_t length;
+        unsigned long start;
+        size_t size;
 };
 
 #define KMEMLEAK_GREY   0
@@ -241,8 +241,6 @@ struct early_log {
         const void *ptr;                /* allocated/freed memory block */
         size_t size;                    /* memory block size */
         int min_count;                  /* minimum reference count */
-        unsigned long offset;           /* scan area offset */
-        size_t length;                  /* scan area length */
         unsigned long trace[MAX_TRACE]; /* stack trace */
         unsigned int trace_len;         /* stack trace length */
 };
@@ -720,14 +718,13 @@ static void make_black_object(unsigned long ptr)
  * Add a scanning area to the object. If at least one such area is added,
  * kmemleak will only scan these ranges rather than the whole memory block.
  */
-static void add_scan_area(unsigned long ptr, unsigned long offset,
-                          size_t length, gfp_t gfp)
+static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp)
 {
         unsigned long flags;
         struct kmemleak_object *object;
         struct kmemleak_scan_area *area;
 
-        object = find_and_get_object(ptr, 0);
+        object = find_and_get_object(ptr, 1);
         if (!object) {
                 kmemleak_warn("Adding scan area to unknown object at 0x%08lx\n",
                               ptr);
@@ -741,7 +738,7 @@ static void add_scan_area(unsigned long ptr, unsigned long offset,
         }
 
         spin_lock_irqsave(&object->lock, flags);
-        if (offset + length > object->size) {
+        if (ptr + size > object->pointer + object->size) {
                 kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr);
                 dump_object_info(object);
                 kmem_cache_free(scan_area_cache, area);
@@ -749,8 +746,8 @@ static void add_scan_area(unsigned long ptr, unsigned long offset,
         }
 
         INIT_HLIST_NODE(&area->node);
-        area->offset = offset;
-        area->length = length;
+        area->start = ptr;
+        area->size = size;
 
         hlist_add_head(&area->node, &object->area_list);
 out_unlock:
@@ -786,7 +783,7 @@ static void object_no_scan(unsigned long ptr)
  * processed later once kmemleak is fully initialized.
  */
 static void __init log_early(int op_type, const void *ptr, size_t size,
-                             int min_count, unsigned long offset, size_t length)
+                             int min_count)
 {
         unsigned long flags;
         struct early_log *log;
@@ -808,8 +805,6 @@ static void __init log_early(int op_type, const void *ptr, size_t size,
         log->ptr = ptr;
         log->size = size;
         log->min_count = min_count;
-        log->offset = offset;
-        log->length = length;
         if (op_type == KMEMLEAK_ALLOC)
                 log->trace_len = __save_stack_trace(log->trace);
         crt_early_log++;
@@ -858,7 +853,7 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count,
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 create_object((unsigned long)ptr, size, min_count, gfp);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_ALLOC, ptr, size, min_count, 0, 0);
+                log_early(KMEMLEAK_ALLOC, ptr, size, min_count);
 }
 EXPORT_SYMBOL_GPL(kmemleak_alloc);
 
@@ -873,7 +868,7 @@ void __ref kmemleak_free(const void *ptr)
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 delete_object_full((unsigned long)ptr);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0);
+                log_early(KMEMLEAK_FREE, ptr, 0, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free);
 
@@ -888,7 +883,7 @@ void __ref kmemleak_free_part(const void *ptr, size_t size)
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 delete_object_part((unsigned long)ptr, size);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_FREE_PART, ptr, size, 0, 0, 0);
+                log_early(KMEMLEAK_FREE_PART, ptr, size, 0);
 }
 EXPORT_SYMBOL_GPL(kmemleak_free_part);
 
@@ -903,7 +898,7 @@ void __ref kmemleak_not_leak(const void *ptr)
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 make_gray_object((unsigned long)ptr);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0, 0, 0);
+                log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_not_leak);
 
@@ -919,22 +914,21 @@ void __ref kmemleak_ignore(const void *ptr)
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 make_black_object((unsigned long)ptr);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_IGNORE, ptr, 0, 0, 0, 0);
+                log_early(KMEMLEAK_IGNORE, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_ignore);
 
 /*
  * Limit the range to be scanned in an allocated memory block.
  */
-void __ref kmemleak_scan_area(const void *ptr, unsigned long offset,
-                              size_t length, gfp_t gfp)
+void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp)
 {
         pr_debug("%s(0x%p)\n", __func__, ptr);
 
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
-                add_scan_area((unsigned long)ptr, offset, length, gfp);
+                add_scan_area((unsigned long)ptr, size, gfp);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_SCAN_AREA, ptr, 0, 0, offset, length);
+                log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0);
 }
 EXPORT_SYMBOL(kmemleak_scan_area);
 
@@ -948,7 +942,7 @@ void __ref kmemleak_no_scan(const void *ptr)
         if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
                 object_no_scan((unsigned long)ptr);
         else if (atomic_read(&kmemleak_early_log))
-                log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0, 0, 0);
+                log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0);
 }
 EXPORT_SYMBOL(kmemleak_no_scan);
 
@@ -1075,9 +1069,9 @@ static void scan_object(struct kmemleak_object *object)
                 }
         } else
                 hlist_for_each_entry(area, elem, &object->area_list, node)
-                        scan_block((void *)(object->pointer + area->offset),
-                                   (void *)(object->pointer + area->offset
-                                            + area->length), object, 0);
+                        scan_block((void *)area->start,
+                                   (void *)(area->start + area->size),
+                                   object, 0);
 out:
         spin_unlock_irqrestore(&object->lock, flags);
 }
@@ -1642,8 +1636,7 @@ void __init kmemleak_init(void)
                         kmemleak_ignore(log->ptr);
                         break;
                 case KMEMLEAK_SCAN_AREA:
-                        kmemleak_scan_area(log->ptr, log->offset, log->length,
-                                           GFP_KERNEL);
+                        kmemleak_scan_area(log->ptr, log->size, GFP_KERNEL);
                         break;
                 case KMEMLEAK_NO_SCAN:
                         kmemleak_no_scan(log->ptr);
diff --git a/mm/slab.c b/mm/slab.c
index 646db3085193..d2713a944ebd 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2584,8 +2584,8 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
                  * kmemleak does not treat the ->s_mem pointer as a reference
                  * to the object. Otherwise we will not report the leak.
                  */
-                kmemleak_scan_area(slabp, offsetof(struct slab, list),
-                                   sizeof(struct list_head), local_flags);
+                kmemleak_scan_area(&slabp->list, sizeof(struct list_head),
+                                   local_flags);
                 if (!slabp)
                         return NULL;
         } else {