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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-08-13 15:19:52 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-03 07:40:07 +0200 |
| commit | 803d690e68f0c5230183f1a42c7d50a41d16e380 (patch) | |
| tree | 5321b7b7bff1906c707c8cbc55233a9e36ef44d0 /arch | |
| parent | powerpc/tm: Reformat comments (diff) | |
| download | linux-803d690e68f0c5230183f1a42c7d50a41d16e380.tar.xz linux-803d690e68f0c5230183f1a42c7d50a41d16e380.zip | |
powerpc/mm: Don't report hugepage tables as memory leaks when using kmemleak
When a process allocates a hugepage, the following leak is
reported by kmemleak. This is a false positive which is
due to the pointer to the table being stored in the PGD
as physical memory address and not virtual memory pointer.
unreferenced object 0xc30f8200 (size 512):
comm "mmap", pid 374, jiffies 4872494 (age 627.630s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<e32b68da>] huge_pte_alloc+0xdc/0x1f8
[<9e0df1e1>] hugetlb_fault+0x560/0x8f8
[<7938ec6c>] follow_hugetlb_page+0x14c/0x44c
[<afbdb405>] __get_user_pages+0x1c4/0x3dc
[<b8fd7cd9>] __mm_populate+0xac/0x140
[<3215421e>] vm_mmap_pgoff+0xb4/0xb8
[<c148db69>] ksys_mmap_pgoff+0xcc/0x1fc
[<4fcd760f>] ret_from_syscall+0x0/0x38
See commit a984506c542e2 ("powerpc/mm: Don't report PUDs as
memory leaks when using kmemleak") for detailed explanation.
To fix that, this patch tells kmemleak to ignore the allocated
hugepage table.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/mm/hugetlbpage.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 9504641bd4d9..a7226ed9cae6 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -19,6 +19,7 @@ #include <linux/moduleparam.h> #include <linux/swap.h> #include <linux/swapops.h> +#include <linux/kmemleak.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/tlb.h> @@ -112,6 +113,8 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, for (i = i - 1 ; i >= 0; i--, hpdp--) *hpdp = __hugepd(0); kmem_cache_free(cachep, new); + } else { + kmemleak_ignore(new); } spin_unlock(ptl); return 0; |