Adding upstream version 1:1.7.1.upstream/1%1.7.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 149 insertions, 0 deletions

diff --git a/Documentation/libtraceevent-parse-files.txt b/Documentation/libtraceevent-parse-files.txt
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+libtraceevent(3)
+================
+
+NAME
+----
+tep_parse_saved_cmdlines, tep_parse_printk_formats, tep_parse_kallsyms
+- Parsing functions to load mappings
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <event-parse.h>*
+
+int *tep_parse_saved_cmdlines*(struct tep_handle pass:[*]_tep_, const char pass:[*]_buf_);
+int *tep_parse_printk_formats*(struct tep_handle pass:[*]_tep_, const char pass:[*]_buf_);
+int *tep_parse_kallsyms*(struct tep_handle pass:[*]_tep_, const char pass:[*]_buf_);
+--
+
+DESCRIPTION
+-----------
+*tep_parse_saved_cmdlines()* is a helper function to parse content in the tracefs
+file system of the "saved_cmdlines" file (stored in a string buffer passed in by _buf_)
+and loads the mapping of the process IDs (pid) to the comm names in the
+_tep_ handler. The events store the pid and this is used to be able to show the
+process names associated to those process ids. It parses the string _buf_ that
+holds the content of saved_cmdlines and ends with a nul character ('\0').
+
+*tep_parse_printk_formats()* is a helper function to parse content in the tracefs
+file system of the "printk_formats" file (stored in a string buffer passed in by _buf_)
+and loads the mapping of addresses of strings that may be referenced by events.
+Events only store the address of constant strings in the kernel, and the mapping
+of their address to the string is exported to user space in the printk_formats
+file. It parses the string _buf_ that holds the content of printk_formats and
+ends with a nul character ('\0').
+
+*tep_parse_kallsyms()* is a helper function to parse the Linux kernel /proc/kallsyms format
+(stored in a string buffer passed in by _buf_) and load the functions into the
+_tep_ handler such that function IP addresses can be mapped to their name when
+parsing events with %pS in the print format field. It parses the string _buf_ that
+holds the content of /proc/kallsyms and ends with a nul character ('\0').
+
+RETURN VALUE
+------------
+The *tep_parse_saved_cmdlines*() function returns 0 in case of success, or -1
+in case of an error.
+
+The *tep_parse_printk_formats*() function returns 0 in case of success, or -1
+in case of an error.
+
+The *tep_parse_kallsyms*() function returns 0 in case of success, or -1
+in case of an error.
+
+EXAMPLE
+-------
+[source,c]
+--
+...
+#include <event-parse.h>
+#include <tracefs.h>
+#include <stdlib.h>
+
+int load_cmdlines(struct tep_handle *tep)
+{
+        char *buf = NULL;
+        int r;
+
+        buf = tracefs_instance_file_read(NULL, "saved_cmdlines", NULL);
+        if (!buf)
+                return -1;
+        r = tep_parse_saved_cmdlines(tep, buf);
+        free(buf);
+        return r;
+}
+
+int load_print_strings(struct tep_handle *tep)
+{
+        char *buf = NULL;
+        int r;
+
+        buf = tracefs_instance_file_read(NULL, "printk_formats", NULL);
+        if (!buf)
+                return -1;
+        r = tep_parse_printk_formats(tep, buf);
+        free(buf);
+        return r;
+}
+
+int load_kallsyms(struct tep_handle *tep)
+{
+        char *line = NULL;
+        char *buf = NULL;
+        size_t sz = 0;
+        FILE *fp;
+        int len = 0;
+        int r;
+
+        fp = fopen("/proc/kallsyms", "r");
+        while ((r = getline(&line, &sz, fp)) >= 0) {
+                buf = realloc(buf, len + r + 1);
+                memcpy(buf + len, line, r);
+                len += r;
+        }
+        free(line);
+        fclose(fp);
+        if (!buf)
+                return -1;
+        buf[len] = 0;
+
+        r = tep_parse_kallsyms(tep, buf);
+        free(buf);
+        return r;
+}
+...
+--
+
+FILES
+-----
+[verse]
+--
+*event-parse.h*
+	Header file to include in order to have access to the library APIs.
+*-ltraceevent*
+	Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+*libtraceevent*(3), *trace-cmd*(1), *tep_register_comm*(3), *tep_register_function*(3),
+*tep_register_print_string*(3)
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*.
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, coauthor of *libtraceevent*.
+--
+REPORTING BUGS
+--------------
+Report bugs to  <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtraceevent is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/