Commit c36264df authored by Mike Galbraith's avatar Mike Galbraith Committed by Linus Torvalds
Browse files

[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: default avatarMike Galbraith <efault@gmx.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 44ddc4f5

fs/proc/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -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

fs/proc/proc_misc.c

+2 −0
Original line number Diff line number Diff line
@@ -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

kernel/printk.c

+1 −6
Original line number Diff line number Diff line
@@ -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)