fs, elf: don't complain MAP_FIXED_NOREPLACE unless -EEXIST error

Commit 4ed28639519c ("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.

Link: http://lkml.kernel.org/r/201804182307.FAC17665.SFMOFJVFtHOLOQ@I-love.SAKURA.ne.jp
Fixes: 4ed28639519c7bad ("fs, elf: drop MAP_FIXED usage from elf_map") is
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 41e0418..4ad6f66 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -377,10 +377,10 @@ 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) &&
+           PTR_ERR((void *)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);
 }