mm, vmalloc: properly track vmalloc users
__vmalloc_node_flags used to be static inline but this has changed by
"mm: introduce kv[mz]alloc helpers" because kvmalloc_node needs to use
it as well and the code is outside of the vmalloc proper. I haven't
realized that changing this will lead to a subtle bug though. The
function is responsible to track the caller as well. This caller is
then printed by /proc/vmallocinfo. If __vmalloc_node_flags is not
inline then we would get only direct users of __vmalloc_node_flags as
callers (e.g. v[mz]alloc) which reduces usefulness of this debugging
feature considerably. It simply doesn't help to see that the given
range belongs to vmalloc as a caller:
0xffffc90002c79000-0xffffc90002c7d000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N0=3
0xffffc90002c81000-0xffffc90002c85000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3
0xffffc90002c8d000-0xffffc90002c91000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3
0xffffc90002c95000-0xffffc90002c99000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3
We really want to catch the _caller_ of the vmalloc function. Fix this
issue by making __vmalloc_node_flags static inline again.
Link: http://lkml.kernel.org/r/20170502134657.12381-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 46991ad..0328ce0 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -6,6 +6,7 @@
#include <linux/list.h>
#include <linux/llist.h>
#include <asm/page.h> /* pgprot_t */
+#include <asm/pgtable.h> /* PAGE_KERNEL */
#include <linux/rbtree.h>
struct vm_area_struct; /* vma defining user mapping in mm_types.h */
@@ -80,7 +81,25 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long start, unsigned long end, gfp_t gfp_mask,
pgprot_t prot, unsigned long vm_flags, int node,
const void *caller);
+#ifndef CONFIG_MMU
extern void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags);
+#else
+extern void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, const void *caller);
+
+/*
+ * We really want to have this inlined due to caller tracking. This
+ * function is used by the highlevel vmalloc apis and so we want to track
+ * their callers and inlining will achieve that.
+ */
+static inline void *__vmalloc_node_flags(unsigned long size,
+ int node, gfp_t flags)
+{
+ return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
+ node, __builtin_return_address(0));
+}
+#endif
extern void vfree(const void *addr);
extern void vfree_atomic(const void *addr);