(split) LDP_man-pages: update original to v3.34.

[linuxjm/LDP_man-pages.git] / original / man2 / syslog.2

diff --git a/original/man2/syslog.2 b/original/man2/syslog.2
index fb018a6..cb101bd 100644 (file)
--- a/original/man2/syslog.2
+++ b/original/man2/syslog.2
@@ -26,7 +26,7 @@
 .\" 2008-02-15, Michael Kerrisk <mtk.manpages@gmail.com>
 .\"     Update LOG_BUF_LEN details; update RETURN VALUE section.
 .\"
-.TH SYSLOG 2  2008-06-20 "Linux" "Linux Programmer's Manual"
+.TH SYSLOG 2  2011-09-07 "Linux" "Linux Programmer's Manual"
 .SH NAME
 syslog, klogctl \- read and/or clear kernel message ring buffer;
 set console_loglevel
@@ -50,33 +50,43 @@ then look at
 .BR syslog (3).
 The system call of this name is about controlling the kernel
 .IR printk ()
-buffer, and the glibc version is called
+buffer, and the glibc wrapper function is called
 .BR klogctl ().
 
-The \fItype\fP argument determines the action taken by this function.
+The \fItype\fP argument determines the action taken by this function,
+as follows:
 
-Quoting from
-.IR kernel/printk.c :
 .nf
-/*
- * Commands to sys_syslog:
- *
- *      0 \-\- Close the log.  Currently a NOP.
- *      1 \-\- Open the log. Currently a NOP.
- *      2 \-\- Read from the log.
- *      3 \-\- Read all messages remaining in the ring buffer.
- *      4 \-\- Read and clear all messages remaining in the ring buffer
- *      5 \-\- Clear ring buffer.
- *      6 \-\- Disable printk to console
- *      7 \-\- Enable printk to console
- *      8 \-\- Set level of messages printed to console
- *      9 \-\- Return number of unread characters in the log buffer
- *     10 \-\- Return size of the log buffer
- */
+      0 \-\- Close the log.  Currently a NOP.
+      1 \-\- Open the log. Currently a NOP.
+      2 \-\- Read from the log.
+      3 \-\- Read all messages remaining in the ring buffer.
+      4 \-\- Read and clear all messages remaining in the ring buffer
+      5 \-\- Clear ring buffer.
+      6 \-\- Disable printk to console
+      7 \-\- Enable printk to console
+      8 \-\- Set level of messages printed to console
+      9 \-\- Return number of unread characters in the log buffer
+     10 \-\- Return size of the log buffer
 .fi
 
-Only command types 3 and 10 are allowed to unprivileged processes.
-Type 9 was added in 2.4.10; type 10 in 2.6.6.
+Type 9 was added in Linux 2.4.10; type 10 in Linux 2.6.6.
+
+In Linux kernels before 2.6.37,
+only command types 3 and 10 are allowed to unprivileged processes.
+Since Linux 2.6.37,
+command types 3 and 10 are only allowed to unprivileged processes if
+.IR /proc/sys/kernel/dmesg_restrict
+has the value 0.
+Before Linux 2.6.37, "privileged" means that the caller has the
+.BR CAP_SYS_ADMIN
+capability.
+Since Linux 2.6.37,
+"privileged" means that the caller has either the
+.BR CAP_SYS_ADMIN
+capability (now deprecated for this purpose) or the (new)
+.BR CAP_SYSLOG
+capability.
 .SS The kernel log buffer
 The kernel has a cyclic buffer of length
 .B LOG_BUF_LEN
@@ -237,6 +247,8 @@ An attempt was made to change console_loglevel or clear the kernel
 message ring buffer by a process without sufficient privilege
 (more precisely: without the
 .B CAP_SYS_ADMIN
+or
+.BR CAP_SYSLOG
 capability).
 .TP
 .B ERESTARTSYS
@@ -254,4 +266,5 @@ In libc4 and libc5 the number of this call was defined by
 In glibc 2.0 the syscall is baptized
 .BR klogctl ().
 .SH "SEE ALSO"
-.BR syslog (3)
+.BR syslog (3),
+.BR capabilities (7)