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| author |   Yaliang Wang <Yaliang.Wang@windriver.com> | 2022-03-10 19:31:16 +0800 |
|---|---|---|
| committer |   Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2022-03-14 15:05:18 +0100 |
| commit | 2bc5bab9a763d520937e4f3fe8df51c6a1eceb97 (patch) | |
| tree | ecc5d717f9363a82689ba44a0f09e0dc9c486694 /arch/mips/include/asm/pgalloc.h | |
| parent | MIPS: RB532: fix return value of __setup handler (diff) | |
| download | linux-dev-2bc5bab9a763d520937e4f3fe8df51c6a1eceb97.tar.xz linux-dev-2bc5bab9a763d520937e4f3fe8df51c6a1eceb97.zip | |
MIPS: pgalloc: fix memory leak caused by pgd_free()
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>
Diffstat (limited to 'arch/mips/include/asm/pgalloc.h')
| -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); \ |