Commit 9cabf929 authored by Yangtao Li's avatar Yangtao Li Committed by Linus Torvalds

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.comSigned-off-by: default avatarYangtao Li <tiny.windzz@gmail.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarDavid 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 59e1a2f4
...@@ -2973,16 +2973,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, ...@@ -2973,16 +2973,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
return ret; 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 * this is really a simplified "do_mmap". it only handles
* anonymous maps. eventually we may be able to do some * anonymous maps. eventually we may be able to do some
...@@ -3009,12 +2999,6 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla ...@@ -3009,12 +2999,6 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
if (error) if (error)
return error; 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 * Clear old maps. this also does some error checking for us
*/ */
......
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