Commit 09ef5283 authored by Jaewon Kim's avatar Jaewon Kim Committed by Linus Torvalds
Browse files

mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area

On passing requirement to vm_unmapped_area, arch_get_unmapped_area and
arch_get_unmapped_area_topdown did not set align_offset.  Internally on
both unmapped_area and unmapped_area_topdown, if info->align_mask is 0,
then info->align_offset was meaningless.

But commit df529cab

 ("mm: mmap: add trace point of
vm_unmapped_area") always prints info->align_offset even though it is

Fix this uninitialized value issue by setting it to 0 explicitly.

  vm_unmapped_area: addr=0x755b155000 err=0 total_vm=0x15aaf0 flags=0x1 len=0x109000 lo=0x8000 hi=0x75eed48000 mask=0x0 ofs=0x4022

  vm_unmapped_area: addr=0x74a4ca1000 err=0 total_vm=0x168ab1 flags=0x1 len=0x9000 lo=0x8000 hi=0x753d94b000 mask=0x0 ofs=0x0
Signed-off-by: default avatarJaewon Kim <>
Signed-off-by: default avatarAndrew Morton <>
Reviewed-by: default avatarAndrew Morton <>
Cc: Matthew Wilcox (Oracle) <>
Cc: Michel Lespinasse <>
Cc: Borislav Petkov <>

Signed-off-by: default avatarLinus Torvalds <>
parent cf11e85f
......@@ -2123,6 +2123,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
info.low_limit = mm->mmap_base;
info.high_limit = mmap_end;
info.align_mask = 0;
info.align_offset = 0;
return vm_unmapped_area(&info);
......@@ -2164,6 +2165,7 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
info.low_limit = max(PAGE_SIZE, mmap_min_addr);
info.high_limit = arch_get_mmap_base(addr, mm->mmap_base);
info.align_mask = 0;
info.align_offset = 0;
addr = vm_unmapped_area(&info);
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