The patch titled
Subject: mm: (k)vrealloc: document concurrency restrictions
has been added to the -mm mm-unstable branch. Its filename is
mm-kvmalloc-align-kvrealloc-with-krealloc-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kvmalloc-align-kvrealloc-with-krealloc-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Danilo Krummrich <dakr@xxxxxxxxxx>
Subject: mm: (k)vrealloc: document concurrency restrictions
Date: Thu, 25 Jul 2024 14:54:37 +0200
Document that concurrent calls to vrealloc() with itself or vfree() for
the same memory allocation are not permitted, since it leads to undefined
behavior.
Consequently, the same applies for kvrealloc(), hence also document it
for kvrealloc().
Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@xxxxxxxxxx
Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Suggested-by: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/util.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/util.c~mm-kvmalloc-align-kvrealloc-with-krealloc-fix
+++ a/mm/util.c
@@ -732,6 +732,9 @@ EXPORT_SYMBOL(kvfree_sensitive);
* If @p is %NULL, kvrealloc() behaves exactly like kvmalloc(). If @size is 0
* and @p is not a %NULL pointer, the object pointed to is freed.
*
+ * This function must not be called concurrently with itself or kvfree() for the
+ * same memory allocation.
+ *
* Return: pointer to the allocated memory or %NULL in case of error
*/
void *kvrealloc_noprof(const void *p, size_t size, gfp_t flags)
_
Patches currently in -mm which might be from dakr@xxxxxxxxxx are
mm-vmalloc-implement-vrealloc.patch
mm-vmalloc-implement-vrealloc-fix.patch
mm-vmalloc-implement-vrealloc-fix-2.patch
mm-kvmalloc-align-kvrealloc-with-krealloc.patch
mm-kvmalloc-align-kvrealloc-with-krealloc-fix.patch
