Messages in this thread Patch in this message | | | From | Yang Shi <> | Subject | [PATCH 2/2 -mm] mm: mremap: fix unsigned compare against 0 issue | Date | Fri, 5 Oct 2018 05:14:32 +0800 |
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Static analysis reported unsigned compare against 0 issue according to Colin Ian King.
Defined an int temp variable to check the return value of __do_munmap().
Reported-by: Colin Ian King <colin.king@canonical.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> --- Andrew, this should be able to be folded into the original patch.
mm/mremap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/mremap.c b/mm/mremap.c index 3524d16..f9d5d1f 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -566,12 +566,14 @@ static int vma_expandable(struct vm_area_struct *vma, unsigned long delta) * downgrade mmap_sem to read. */ if (old_len >= new_len) { - ret = __do_munmap(mm, addr+new_len, old_len - new_len, + int retval; + retval = __do_munmap(mm, addr+new_len, old_len - new_len, &uf_unmap, true); - if (ret < 0 && old_len != new_len) + if (retval < 0 && old_len != new_len) { + ret = retval; goto out; /* Returning 1 indicates mmap_sem is downgraded to read. */ - else if (ret == 1) + } else if (retval == 1) downgraded = true; ret = addr; goto out; -- 1.8.3.1
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