Michal Hocko wrote:
> > Don't complain if IS_ERR_VALUE(),
> 
> this is simply wrong. We do want to warn on the failure because this is
> when the actual clash happens. We should just warn on EEXIST.

>From 25442cdd31aa5cc8522923a0153a77dfd2ebc832 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Date: Wed, 18 Apr 2018 20:38:15 +0900
Subject: [PATCH] fs, elf: don't complain MAP_FIXED_NOREPLACE unless -EEXIST
 error.

Commit 4ed28639519c7bad ("fs, elf: drop MAP_FIXED usage from elf_map") is
printing spurious messages under memory pressure due to map_addr == -ENOMEM.

 9794 (a.out): Uhuuh, elf segment at 00007f2e34738000(fffffffffffffff4) 
requested but the memory is mapped already
 14104 (a.out): Uhuuh, elf segment at 00007f34fd76c000(fffffffffffffff4) 
requested but the memory is mapped already
 16843 (a.out): Uhuuh, elf segment at 00007f930ecc7000(fffffffffffffff4) 
requested but the memory is mapped already

Complain only if -EEXIST, and use %px for printing the address.

Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Cc: Michal Hocko <mho...@suse.com>
Cc: Andrei Vagin <ava...@openvz.org>
Cc: Khalid Aziz <khalid.a...@oracle.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Kees Cook <keesc...@chromium.org>
Cc: Abdul Haleem <abdha...@linux.vnet.ibm.com>
Cc: Joel Stanley <j...@jms.id.au>
Cc: Anshuman Khandual <khand...@linux.vnet.ibm.com>
---
 fs/binfmt_elf.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 41e0418..96615d9 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -377,10 +377,9 @@ static unsigned long elf_map(struct file *filep, unsigned 
long addr,
        } else
                map_addr = vm_mmap(filep, addr, size, prot, type, off);
 
-       if ((type & MAP_FIXED_NOREPLACE) && BAD_ADDR(map_addr))
-               pr_info("%d (%s): Uhuuh, elf segment at %p requested but the 
memory is mapped already\n",
-                               task_pid_nr(current), current->comm,
-                               (void *)addr);
+       if ((type & MAP_FIXED_NOREPLACE) && map_addr == -EEXIST)
+               pr_info("%d (%s): Uhuuh, elf segment at %px requested but the 
memory is mapped already\n",
+                       task_pid_nr(current), current->comm, (void *)addr);
 
        return(map_addr);
 }
-- 
1.8.3.1

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