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authorLecopzer Chen <lecopzer.chen@mediatek.com>2019-09-23 15:36:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-24 15:54:09 -0700
commitae83189405ea5c693683327fa69ac95a23ec59be (patch)
treea7a9ad60f73ea85044bfbca34444ae3a317b241a /mm/sparse.c
parent29a90db9299575a4bba82158f9d4e81405c54646 (diff)
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mm/sparse.c: fix memory leak of sparsemap_buf in aligned memory
sparse_buffer_alloc(xsize) gets the size of memory from sparsemap_buf after being aligned with the size. However, the size is at least PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION) and usually larger than PAGE_SIZE. Also, sparse_buffer_fini() only frees memory between sparsemap_buf and sparsemap_buf_end, since sparsemap_buf may be changed by PTR_ALIGN() first, the aligned space before sparsemap_buf is wasted and no one will touch it. In our ARM32 platform (without SPARSEMEM_VMEMMAP) Sparse_buffer_init Reserve d359c000 - d3e9c000 (9M) Sparse_buffer_alloc Alloc d3a00000 - d3E80000 (4.5M) Sparse_buffer_fini Free d3e80000 - d3e9c000 (~=100k) The reserved memory between d359c000 - d3a00000 (~=4.4M) is unfreed. In ARM64 platform (with SPARSEMEM_VMEMMAP) sparse_buffer_init Reserve ffffffc07d623000 - ffffffc07f623000 (32M) Sparse_buffer_alloc Alloc ffffffc07d800000 - ffffffc07f600000 (30M) Sparse_buffer_fini Free ffffffc07f600000 - ffffffc07f623000 (140K) The reserved memory between ffffffc07d623000 - ffffffc07d800000 (~=1.9M) is unfreed. Let's explicit free redundant aligned memory. [arnd@arndb.de: mark sparse_buffer_free as __meminit] Link: http://lkml.kernel.org/r/20190709185528.3251709-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20190705114730.28534-1-lecopzer.chen@mediatek.com Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Mark-PK Tsai <Mark-PK.Tsai@mediatek.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: YJ Chiang <yj.chiang@mediatek.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/sparse.c')
-rw-r--r--mm/sparse.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index 72f010d9bff5..2bfd078301f8 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -470,6 +470,12 @@ struct page __init *__populate_section_memmap(unsigned long pfn,
static void *sparsemap_buf __meminitdata;
static void *sparsemap_buf_end __meminitdata;
+static inline void __meminit sparse_buffer_free(unsigned long size)
+{
+ WARN_ON(!sparsemap_buf || size == 0);
+ memblock_free_early(__pa(sparsemap_buf), size);
+}
+
static void __init sparse_buffer_init(unsigned long size, int nid)
{
phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
@@ -486,7 +492,7 @@ static void __init sparse_buffer_fini(void)
unsigned long size = sparsemap_buf_end - sparsemap_buf;
if (sparsemap_buf && size > 0)
- memblock_free_early(__pa(sparsemap_buf), size);
+ sparse_buffer_free(size);
sparsemap_buf = NULL;
}
@@ -498,8 +504,12 @@ void * __meminit sparse_buffer_alloc(unsigned long size)
ptr = PTR_ALIGN(sparsemap_buf, size);
if (ptr + size > sparsemap_buf_end)
ptr = NULL;
- else
+ else {
+ /* Free redundant aligned space */
+ if ((unsigned long)(ptr - sparsemap_buf) > 0)
+ sparse_buffer_free((unsigned long)(ptr - sparsemap_buf));
sparsemap_buf = ptr + size;
+ }
}
return ptr;
}