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authorYangtao Li <tiny.windzz@gmail.com>2018-12-28 00:34:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:47 -0800
commit9cabf929e7d92139a7d1ef3e517ad57dfece4739 (patch)
tree3a5404254a15517f3907c4222698ec662ef75e62
parent59e1a2f4bf83744e748636415fde7d1e9f557e05 (diff)
downloadnolibc-9cabf929e7d92139a7d1ef3e517ad57dfece4739.tar.gz
mm/mmap.c: remove verify_mm_writelocked()
We should get rid of this function. It no longer serves its purpose. This is a historical artifact from 2005 where do_brk was called outside of the core mm. We do have a proper abstraction in vm_brk_flags and that one does the locking properly so there is no need to use this function. Link: http://lkml.kernel.org/r/20181108174856.10811-1-tiny.windzz@gmail.com Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mmap.c16
1 files changed, 0 insertions, 16 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 7bb64381e77c09..f901065c4c64cf 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2973,16 +2973,6 @@ out:
return ret;
}
-static inline void verify_mm_writelocked(struct mm_struct *mm)
-{
-#ifdef CONFIG_DEBUG_VM
- if (unlikely(down_read_trylock(&mm->mmap_sem))) {
- WARN_ON(1);
- up_read(&mm->mmap_sem);
- }
-#endif
-}
-
/*
* this is really a simplified "do_mmap". it only handles
* anonymous maps. eventually we may be able to do some
@@ -3010,12 +3000,6 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
return error;
/*
- * mm->mmap_sem is required to protect against another thread
- * changing the mappings in case we sleep.
- */
- verify_mm_writelocked(mm);
-
- /*
* Clear old maps. this also does some error checking for us
*/
while (find_vma_links(mm, addr, addr + len, &prev, &rb_link,