Merge branch 'master' into next

[karo-tx-linux.git] / kernel / printk.c

diff --git a/kernel/printk.c b/kernel/printk.c
index b2ebaee8c377d2aa92c073e772748242b5ce5c90..f64b8997fc768f401831ac7d8d5ebac7945f5a6d 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -42,12 +42,6 @@
 
 #include <asm/uaccess.h>
 
-/*
- * for_each_console() allows you to iterate on each console
- */
-#define for_each_console(con) \
-       for (con = console_drivers; con != NULL; con = con->next)
-
 /*
  * Architectures can override it:
  */
@@ -261,6 +255,12 @@ static inline void boot_delay_msec(void)
 }
 #endif
 
+#ifdef CONFIG_SECURITY_DMESG_RESTRICT
+int dmesg_restrict = 1;
+#else
+int dmesg_restrict;
+#endif
+
 int do_syslog(int type, char __user *buf, int len, bool from_file)
 {
        unsigned i, j, limit, count;
@@ -268,7 +268,20 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
        char c;
        int error = 0;
 
-       error = security_syslog(type, from_file);
+       /*
+        * If this is from /proc/kmsg we only do the capabilities checks
+        * at open time.
+        */
+       if (type == SYSLOG_ACTION_OPEN || !from_file) {
+               if (dmesg_restrict && !capable(CAP_SYSLOG))
+                       goto warn; /* switch to return -EPERM after 2.6.39 */
+               if ((type != SYSLOG_ACTION_READ_ALL &&
+                    type != SYSLOG_ACTION_SIZE_BUFFER) &&
+                   !capable(CAP_SYSLOG))
+                       goto warn; /* switch to return -EPERM after 2.6.39 */
+       }
+
+       error = security_syslog(type);
        if (error)
                return error;
 
@@ -409,6 +422,12 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
        }
 out:
        return error;
+warn:
+       /* remove after 2.6.39 */
+       if (capable(CAP_SYS_ADMIN))
+               WARN_ONCE(1, "Attempt to access syslog with CAP_SYS_ADMIN "
+                 "but no CAP_SYSLOG (deprecated and denied).\n");
+       return -EPERM;
 }
 
 SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
@@ -1055,21 +1074,23 @@ static DEFINE_PER_CPU(int, printk_pending);
 
 void printk_tick(void)
 {
-       if (__get_cpu_var(printk_pending)) {
-               __get_cpu_var(printk_pending) = 0;
+       if (__this_cpu_read(printk_pending)) {
+               __this_cpu_write(printk_pending, 0);
                wake_up_interruptible(&log_wait);
        }
 }
 
 int printk_needs_cpu(int cpu)
 {
-       return per_cpu(printk_pending, cpu);
+       if (cpu_is_offline(cpu))
+               printk_tick();
+       return __this_cpu_read(printk_pending);
 }
 
 void wake_up_klogd(void)
 {
        if (waitqueue_active(&log_wait))
-               __raw_get_cpu_var(printk_pending) = 1;
+               this_cpu_write(printk_pending, 1);
 }
 
 /**
@@ -1338,6 +1359,7 @@ void register_console(struct console *newcon)
                spin_unlock_irqrestore(&logbuf_lock, flags);
        }
        release_console_sem();
+       console_sysfs_notify();
 
        /*
         * By unregistering the bootconsoles after we enable the real console
@@ -1396,6 +1418,7 @@ int unregister_console(struct console *console)
                console_drivers->flags |= CON_CONSDEV;
 
        release_console_sem();
+       console_sysfs_notify();
        return res;
 }
 EXPORT_SYMBOL(unregister_console);