[PATCH] x86_64: Add compat_printk and sysctl to turn off compat layer warnings

Sometimes e.g. with crashme the compat layer warnings can be noisy.
Add a way to turn them off by gating all output through compat_printk
that checks a global sysctl. The default is not changed.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 7e7e5bc4f3cf..e31e9cf96647 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -55,6 +55,20 @@
 
 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
 
+int compat_log = 1;
+
+int compat_printk(const char *fmt, ...)
+{
+        va_list ap;
+        int ret;
+        if (!compat_log)
+                return 0;
+        va_start(ap, fmt);
+        ret = vprintk(fmt, ap);
+        va_end(ap);
+        return ret;
+}
+
 /*
  * Not all architectures have sys_utime, so implement this in terms
  * of sys_utimes.
@@ -359,7 +373,7 @@ static void compat_ioctl_error(struct file *filp, unsigned int fd,
         sprintf(buf,"'%c'", (cmd>>24) & 0x3f);
         if (!isprint(buf[1]))
                 sprintf(buf, "%02x", buf[1]);
-        printk("ioctl32(%s:%d): Unknown cmd fd(%d) "
+        compat_printk("ioctl32(%s:%d): Unknown cmd fd(%d) "
                         "cmd(%08x){%s} arg(%08x) on %s\n",
                         current->comm, current->pid,
                         (int)fd, (unsigned int)cmd, buf,