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-kernel@xxxxxxxxxxxxxxxxxxx>
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-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Andrei Vagin <avagin@xxxxxxxxxx>
Cc: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Abdul Haleem <abdhalee@xxxxxxxxxxxxxxxxxx>
Cc: Joel Stanley <joel@xxxxxxxxx>
Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
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
