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authorEric Dumazet <edumazet@google.com>2017-09-09 01:15:54 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-09 03:26:49 +0200
commitbc9ae2247ac92fd4d962507bafa3afffff6660ff (patch)
tree56c87a7b15fc0beb1f51e57167840e1d0fd3c917 /lib
parentlib/cmdline.c: remove meaningless comment (diff)
downloadlinux-bc9ae2247ac92fd4d962507bafa3afffff6660ff.tar.xz
linux-bc9ae2247ac92fd4d962507bafa3afffff6660ff.zip
radix-tree: must check __radix_tree_preload() return value
__radix_tree_preload() only disables preemption if no error is returned. So we really need to make sure callers always check the return value. idr_preload() contract is to always disable preemption, so we need to add a missing preempt_disable() if an error happened. Similarly, ida_pre_get() only needs to call preempt_enable() in the case no error happened. Link: http://lkml.kernel.org/r/1504637190.15310.62.camel@edumazet-glaptop3.roam.corp.google.com Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree") Fixes: 7ad3d4d85c7a ("ida: Move ida_bitmap to a percpu variable") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [4.11+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/radix-tree.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 9717e2a50374..8b1feca1230a 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -463,7 +463,7 @@ radix_tree_node_free(struct radix_tree_node *node)
* To make use of this facility, the radix tree must be initialised without
* __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
*/
-static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
+static __must_check int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
{
struct radix_tree_preload *rtp;
struct radix_tree_node *node;
@@ -2104,7 +2104,8 @@ EXPORT_SYMBOL(radix_tree_tagged);
*/
void idr_preload(gfp_t gfp_mask)
{
- __radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE);
+ if (__radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE))
+ preempt_disable();
}
EXPORT_SYMBOL(idr_preload);
@@ -2118,13 +2119,13 @@ EXPORT_SYMBOL(idr_preload);
*/
int ida_pre_get(struct ida *ida, gfp_t gfp)
{
- __radix_tree_preload(gfp, IDA_PRELOAD_SIZE);
/*
* The IDA API has no preload_end() equivalent. Instead,
* ida_get_new() can return -EAGAIN, prompting the caller
* to return to the ida_pre_get() step.
*/
- preempt_enable();
+ if (!__radix_tree_preload(gfp, IDA_PRELOAD_SIZE))
+ preempt_enable();
if (!this_cpu_read(ida_bitmap)) {
struct ida_bitmap *bitmap = kmalloc(sizeof(*bitmap), gfp);