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authorJaewon Kim <jaewon31.kim@samsung.com>2020-04-10 14:32:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-10 15:36:21 -0700
commit09ef5283fd96ac424ef0e569626f359bf9ab86c9 (patch)
tree5f266bca26ab77e3e1bcce02ba67a0ab3bbec263
parentcf11e85fc08cc6a4fe3ac2ba2e610c962bf20bc3 (diff)
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 df529cabb7a2 ("mm: mmap: add trace point of vm_unmapped_area") always prints info->align_offset even though it is uninitialized. Fix this uninitialized value issue by setting it to 0 explicitly. Before: vm_unmapped_area: addr=0x755b155000 err=0 total_vm=0x15aaf0 flags=0x1 len=0x109000 lo=0x8000 hi=0x75eed48000 mask=0x0 ofs=0x4022 After: 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: Jaewon Kim <jaewon31.kim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michel Lespinasse <walken@google.com> Cc: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20200409094035.19457-1-jaewon31.kim@samsung.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mmap.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 8d77dbbb80fe..de07bbc0e21f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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);
}
#endif
@@ -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);
/*