From: Mike Galbraith <efault@gmx.de>
Date: Thu, 7 Dec 2006 04:37:42 +0000 (-0800)
Subject: [PATCH] remove the syslog interface when printk is disabled
X-Git-Tag: v2.6.20-rc1~145^2^2~150
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=c36264dfb2d6fa6383082de0a1bba8e12b477da1;p=linux-2.6-omap-h63xx.git

[PATCH] remove the syslog interface when printk is disabled

Attempts to read() from the non-existent dmesg buffer will return zero and
userspace tends to get stuck in a busyloop.

So just remove /dev/kmsg altogether if CONFIG_PRINTK=n.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index 7431d7ba2d0..f6c77627257 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -8,8 +8,9 @@ proc-y			:= nommu.o task_nommu.o
 proc-$(CONFIG_MMU)	:= mmu.o task_mmu.o
 
 proc-y       += inode.o root.o base.o generic.o array.o \
-		kmsg.o proc_tty.o proc_misc.o
+		proc_tty.o proc_misc.o
 
 proc-$(CONFIG_PROC_KCORE)	+= kcore.o
 proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
 proc-$(CONFIG_PROC_DEVICETREE)	+= proc_devtree.o
+proc-$(CONFIG_PRINTK)	+= kmsg.o
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 93c43b676e5..51815cece6f 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -696,9 +696,11 @@ void __init proc_misc_init(void)
 	proc_symlink("mounts", NULL, "self/mounts");
 
 	/* And now for trickier ones */
+#ifdef CONFIG_PRINTK
 	entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
 	if (entry)
 		entry->proc_fops = &proc_kmsg_operations;
+#endif
 	create_seq_entry("devices", 0, &proc_devinfo_operations);
 	create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
 #ifdef CONFIG_BLOCK
diff --git a/kernel/printk.c b/kernel/printk.c
index 66426552fbf..ba59c2a30ed 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -631,12 +631,7 @@ EXPORT_SYMBOL(vprintk);
 
 asmlinkage long sys_syslog(int type, char __user *buf, int len)
 {
-	return 0;
-}
-
-int do_syslog(int type, char __user *buf, int len)
-{
-	return 0;
+	return -ENOSYS;
 }
 
 static void call_console_drivers(unsigned long start, unsigned long end)