diff options
author | Long Li <lonuxli.64@gmail.com> | 2020-08-07 08:18:28 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 20:33:22 +0200 |
commit | 444050990db4abdf0c85ca6050542b888ba316a1 (patch) | |
tree | 94acbfbb4ec5aef67b237176977b953c7c8ad929 | |
parent | mm/slab: add naive detection of double free (diff) | |
download | linux-444050990db4abdf0c85ca6050542b888ba316a1.tar.xz linux-444050990db4abdf0c85ca6050542b888ba316a1.zip |
mm, slab: check GFP_SLAB_BUG_MASK before alloc_pages in kmalloc_order
kmalloc cannot allocate memory from HIGHMEM. Allocating large amounts of
memory currently bypasses the check and will simply leak the memory when
page_address() returns NULL. To fix this, factor the GFP_SLAB_BUG_MASK
check out of slab & slub, and call it from kmalloc_order() as well. In
order to make the code clear, the warning message is put in one place.
Signed-off-by: Long Li <lonuxli.64@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200704035027.GA62481@lilong
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/slab.c | 10 | ||||
-rw-r--r-- | mm/slab.h | 1 | ||||
-rw-r--r-- | mm/slab_common.c | 17 | ||||
-rw-r--r-- | mm/slub.c | 9 |
4 files changed, 23 insertions, 14 deletions
diff --git a/mm/slab.c b/mm/slab.c index 77e90f9de9c0..0781a2384441 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2589,13 +2589,9 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep, * Be lazy and only check for valid flags here, keeping it out of the * critical path in kmem_cache_alloc(). */ - if (unlikely(flags & GFP_SLAB_BUG_MASK)) { - gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; - flags &= ~GFP_SLAB_BUG_MASK; - pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", - invalid_mask, &invalid_mask, flags, &flags); - dump_stack(); - } + if (unlikely(flags & GFP_SLAB_BUG_MASK)) + flags = kmalloc_fix_flags(flags); + WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO)); local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); diff --git a/mm/slab.h b/mm/slab.h index 74f7e09a7cfd..58ed025a0b23 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -152,6 +152,7 @@ void create_kmalloc_caches(slab_flags_t); struct kmem_cache *kmalloc_slab(size_t, gfp_t); #endif +gfp_t kmalloc_fix_flags(gfp_t flags); /* Functions provided by the slab allocators */ int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); diff --git a/mm/slab_common.c b/mm/slab_common.c index e493203b5002..616ec8a0d91a 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -26,6 +26,8 @@ #define CREATE_TRACE_POINTS #include <trace/events/kmem.h> +#include "internal.h" + #include "slab.h" enum slab_state slab_state; @@ -1332,6 +1334,18 @@ void __init create_kmalloc_caches(slab_flags_t flags) } #endif /* !CONFIG_SLOB */ +gfp_t kmalloc_fix_flags(gfp_t flags) +{ + gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; + + flags &= ~GFP_SLAB_BUG_MASK; + pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", + invalid_mask, &invalid_mask, flags, &flags); + dump_stack(); + + return flags; +} + /* * To avoid unnecessary overhead, we pass through large allocation requests * directly to the page allocator. We use __GFP_COMP, because we will need to @@ -1342,6 +1356,9 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) void *ret = NULL; struct page *page; + if (unlikely(flags & GFP_SLAB_BUG_MASK)) + flags = kmalloc_fix_flags(flags); + flags |= __GFP_COMP; page = alloc_pages(flags, order); if (likely(page)) { diff --git a/mm/slub.c b/mm/slub.c index f226d66408ee..7f0764b6a3df 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1745,13 +1745,8 @@ out: static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) { - if (unlikely(flags & GFP_SLAB_BUG_MASK)) { - gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; - flags &= ~GFP_SLAB_BUG_MASK; - pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", - invalid_mask, &invalid_mask, flags, &flags); - dump_stack(); - } + if (unlikely(flags & GFP_SLAB_BUG_MASK)) + flags = kmalloc_fix_flags(flags); return allocate_slab(s, flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); |