From: Michal Hocko <mhocko@xxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/vmalloc.h | 19 +++++++++++++++++++ mm/vmalloc.c | 12 +----------- 2 files changed, 20 insertions(+), 11 deletions(-) diff -puN include/linux/vmalloc.h~mm-vmalloc-properly-track-vmalloc-users include/linux/vmalloc.h --- a/include/linux/vmalloc.h~mm-vmalloc-properly-track-vmalloc-users +++ a/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(unsign 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); diff -puN mm/vmalloc.c~mm-vmalloc-properly-track-vmalloc-users mm/vmalloc.c --- a/mm/vmalloc.c~mm-vmalloc-properly-track-vmalloc-users +++ a/mm/vmalloc.c @@ -1649,9 +1649,6 @@ void *vmap(struct page **pages, unsigned } 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) { @@ -1794,7 +1791,7 @@ fail: * with mm people. * */ -static void *__vmalloc_node(unsigned long size, unsigned long align, +void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, pgprot_t prot, int node, const void *caller) { @@ -1809,13 +1806,6 @@ void *__vmalloc(unsigned long size, gfp_ } EXPORT_SYMBOL(__vmalloc); -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)); -} - /** * vmalloc - allocate virtually contiguous memory * @size: allocation size _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
