The patch titled
Subject: mm/mmap.c: brk: fix unsigned compare against 0 issue
has been removed from the -mm tree. Its filename was
mm-brk-downgrade-mmap_sem-to-read-when-shrinking-fix-2.patch
This patch was dropped because it was folded into mm-brk-downgrade-mmap_sem-to-read-when-shrinking.patch
------------------------------------------------------
From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Subject: mm/mmap.c: brk: fix unsigned compare against 0 issue
Static analysis reported an unsigned compare against 0 issue.
Define an int temp variable to check the return value of __do_munmap().
Link: http://lkml.kernel.org/r/1538687672-17795-1-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx
Reported-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/mmap.c~mm-brk-downgrade-mmap_sem-to-read-when-shrinking-fix-2
+++ a/mm/mmap.c
@@ -242,18 +242,21 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
* __do_munmap() may downgrade mmap_sem to read.
*/
if (brk <= mm->brk) {
+ int ret;
+
/*
* mm->brk must to be protected by write mmap_sem so update it
* before downgrading mmap_sem. When __do_munmap() fails,
* mm->brk will be restored from origbrk.
*/
mm->brk = brk;
- retval = __do_munmap(mm, newbrk, oldbrk-newbrk, &uf, true);
- if (retval < 0) {
+ ret = __do_munmap(mm, newbrk, oldbrk-newbrk, &uf, true);
+ if (ret < 0) {
mm->brk = origbrk;
goto out;
- } else if (retval == 1)
+ } else if (ret == 1) {
downgraded = true;
+ }
goto success;
}
_
Patches currently in -mm which might be from yang.shi@xxxxxxxxxxxxxxxxx are
mm-mmap-zap-pages-with-read-mmap_sem-in-munmap.patch
mm-unmap-vm_hugetlb-mappings-with-optimized-path.patch
mm-unmap-vm_pfnmap-mappings-with-optimized-path.patch
mm-mremap-downgrade-mmap_sem-to-read-when-shrinking.patch
mm-brk-downgrade-mmap_sem-to-read-when-shrinking.patch
mm-dax-add-comment-for-pfn_special.patch
