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| author | Yaliang Wang <Yaliang.Wang@windriver.com> | 2022-03-10 14:31:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:23:39 +0300 |
| commit | d29cda15cab086d82d692de016f7249545d4b6b4 (patch) | |
| tree | faa3a9ba2a84c580b0c5786940b4b240cf312de4 /arch/mips | |
| parent | d5e41310bd72e70c90ab9cb2d5b57da88c75a0e3 (diff) | |
| download | linux-d29cda15cab086d82d692de016f7249545d4b6b4.tar.xz | |
MIPS: pgalloc: fix memory leak caused by pgd_free()
[ Upstream commit 2bc5bab9a763d520937e4f3fe8df51c6a1eceb97 ]
pgd page is freed by generic implementation pgd_free() since commit
f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"),
however, there are scenarios that the system uses more than one page as
the pgd table, in such cases the generic implementation pgd_free() won't
be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and
MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER"
will be set as "1", which will cause allocating two pages as the pgd
table. Well, at the same time, the generic implementation pgd_free()
just free one pgd page, which will result in the memory leak.
The memory leak can be easily detected by executing shell command:
"while true; do ls > /dev/null; grep MemFree /proc/meminfo; done"
Fixes: f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()")
Signed-off-by: Yaliang Wang <Yaliang.Wang@windriver.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/include/asm/pgalloc.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h index c7925d0e9874..867e9c3db76e 100644 --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -15,6 +15,7 @@ #define __HAVE_ARCH_PMD_ALLOC_ONE #define __HAVE_ARCH_PUD_ALLOC_ONE +#define __HAVE_ARCH_PGD_FREE #include <asm-generic/pgalloc.h> static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, @@ -48,6 +49,11 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) extern void pgd_init(unsigned long page); extern pgd_t *pgd_alloc(struct mm_struct *mm); +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_pages((unsigned long)pgd, PGD_ORDER); +} + #define __pte_free_tlb(tlb,pte,address) \ do { \ pgtable_pte_page_dtor(pte); \ |