summary refs log tree commit diff
path: root/mm/mmap.c
diff options
context:
space:
mode:
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 /mm/mmap.c
parent59e1a2f4bf83744e748636415fde7d1e9f557e05 (diff)
downloadlinux-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>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c16
1 files changed, 0 insertions, 16 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 7bb64381e77c..f901065c4c64 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,