[PATCH] mm, vmalloc: fix vmalloc users tracking properly

From: Michal Hocko
Date: Tue May 09 2017 - 10:41:31 EST


From: Michal Hocko <mhocko@xxxxxxxx>

1f5307b1e094 ("mm, vmalloc: properly track vmalloc users") has pulled
asm/pgtable.h include dependency to linux/vmalloc.h and that turned out
to be a bad idea for some architectures. E.g. m68k fails with
In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
from arch/m68k/include/asm/pgtable.h:4,
from include/linux/vmalloc.h:9,
from arch/m68k/kernel/module.c:9:
arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
>> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

as spotted by kernel build bot. nios2 fails for other reason
In file included from ./include/asm-generic/io.h:767:0,
from ./arch/nios2/include/asm/io.h:61,
from ./include/linux/io.h:25,
from ./arch/nios2/include/asm/pgtable.h:18,
from ./include/linux/mm.h:70,
from ./include/linux/pid_namespace.h:6,
from ./include/linux/ptrace.h:9,
from ./arch/nios2/include/uapi/asm/elf.h:23,
from ./arch/nios2/include/asm/elf.h:22,
from ./include/linux/elf.h:4,
from ./include/linux/module.h:15,
from init/main.c:16:
./include/linux/vmalloc.h: In function '__vmalloc_node_flags':
./include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?

which is due to the newly added #include <asm/pgtable.h>, which on nios2
includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
again includes <linux/vmalloc.h>.

Tweaking that around just turns out a bigger headache than
necessary. This patch reverts 1f5307b1e094 and reimplements the original
fix in a different way. __vmalloc_node_flags can stay static inline
which will cover vmalloc* functions. We only have one external user
(kvmalloc_node) and we can export __vmalloc_node_flags_caller and
provide the caller directly. This is much simpler and it doesn't really
need any games with header files.

Fixes: 1f5307b1e094 ("mm, vmalloc: properly track vmalloc users")
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---

Hi Linus and Andrew,
it seems that this one slipped through cracks as well. Kbuild robot has
quickly noticed that my original fix doesn't compile on m68k [1] and
I've provided fix [2] at the time but it seems Andrew has missed it and
sent the wrong one which got merged. Other users have noticed as well [3].

This is a full revert along with the fix. I can split it to a revert
and the new fix if you prefer. Just let me know.

[1] http://lkml.kernel.org/r/201705030806.pzzQRBiN%fengguang.wu@xxxxxxxxx
[2] http://lkml.kernel.org/r/20170503063750.GC1236@xxxxxxxxxxxxxx
[3] http://lkml.kernel.org/r/20170509085045.7342-1-tklauser@xxxxxxxxxx

include/linux/vmalloc.h | 19 +++++++------------
mm/util.c | 3 ++-
mm/vmalloc.c | 18 +++++++++++++++++-
3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 0328ce003992..4a0fabeb1e92 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -6,7 +6,6 @@
#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 */
@@ -82,23 +81,19 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
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);
+extern void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags);
+static inline void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, void* caller)
+{
+ return __vmalloc_node_flags(size, node, 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));
-}
+extern void *__vmalloc_node_flags_caller(unsigned long size,
+ int node, gfp_t flags, void* caller);
#endif

extern void vfree(const void *addr);
diff --git a/mm/util.c b/mm/util.c
index 718154debc87..464df3489903 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -382,7 +382,8 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
if (ret || size <= PAGE_SIZE)
return ret;

- return __vmalloc_node_flags(size, node, flags);
+ return __vmalloc_node_flags_caller(size, node, flags,
+ __builtin_return_address(0));
}
EXPORT_SYMBOL(kvmalloc_node);

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1dda6d8a200a..4a1de70e68e1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1649,6 +1649,9 @@ void *vmap(struct page **pages, unsigned int count,
}
EXPORT_SYMBOL(vmap);

+static void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, const void *caller);
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
pgprot_t prot, int node)
{
@@ -1791,7 +1794,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
* with mm people.
*
*/
-void *__vmalloc_node(unsigned long size, unsigned long align,
+static void *__vmalloc_node(unsigned long size, unsigned long align,
gfp_t gfp_mask, pgprot_t prot,
int node, const void *caller)
{
@@ -1806,6 +1809,19 @@ void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
}
EXPORT_SYMBOL(__vmalloc);

+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));
+}
+
+
+void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, void *caller)
+{
+ return __vmalloc_node(size, 1, flags, PAGE_KERNEL, node, caller);
+}
+
/**
* vmalloc - allocate virtually contiguous memory
* @size: allocation size
--
2.11.0