* [PATCH v3 1/5] libtraceevent: Update gitignore
2021-04-08 21:41 [PATCH v3 0/5] libtraceevent: Copy parsing functions from trace-cmd Steven Rostedt
@ 2021-04-08 21:41 ` Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 2/5] libtraceevent: Fix dependencies in Documentation Makefile Steven Rostedt
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-04-08 21:41 UTC (permalink / raw)
To: linux-trace-devel; +Cc: Steven Rostedt (VMware)
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Update the gitignore files to not pick up files that are created in the
build as well as those auxiliary files used for creating the man pages.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
.gitignore | 5 +++++
Documentation/.gitignore | 3 +++
2 files changed, 8 insertions(+)
create mode 100644 Documentation/.gitignore
diff --git a/.gitignore b/.gitignore
index 7123c70..fde7fe6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,8 @@
TRACEEVENT-CFLAGS
libtraceevent-dynamic-list
libtraceevent.so.*
+*.o
+build_prefix
+build_uninstall
+*~
+\#*\#
diff --git a/Documentation/.gitignore b/Documentation/.gitignore
new file mode 100644
index 0000000..bdc8252
--- /dev/null
+++ b/Documentation/.gitignore
@@ -0,0 +1,3 @@
+*.m
+*.3
+*.html
--
2.29.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/5] libtraceevent: Fix dependencies in Documentation Makefile
2021-04-08 21:41 [PATCH v3 0/5] libtraceevent: Copy parsing functions from trace-cmd Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 1/5] libtraceevent: Update gitignore Steven Rostedt
@ 2021-04-08 21:41 ` Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 3/5] libtraceevent: Add the API tep_parse_kallsyms() Steven Rostedt
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-04-08 21:41 UTC (permalink / raw)
To: linux-trace-devel; +Cc: Steven Rostedt (VMware)
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Modify the Documentation Makefile to only rebuild the man pages when their
source has been modified.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/Makefile | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 21bcd5e..73dbe2a 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -11,7 +11,7 @@ MAN3_TXT= \
MAN_TXT = $(MAN3_TXT)
_MAN_XML=$(patsubst %.txt,%.xml,$(MAN_TXT))
_MAN_HTML=$(patsubst %.txt,%.html,$(MAN_TXT))
-_DOC_MAN3=$(patsubst %.txt,%.3,$(MAN3_TXT))
+_DOC_MAN3=$(patsubst %.txt,%.m,$(MAN3_TXT))
MAN_XML=$(addprefix $(OUTPUT),$(_MAN_XML))
MAN_HTML=$(addprefix $(OUTPUT),$(_MAN_HTML))
@@ -154,17 +154,22 @@ ifdef missing_tools
$(error "You need to install $(missing_tools) for man pages")
endif
-do-install-man: man
- $(call QUIET_INSTALL, Documentation-man) \
+install-%.3: $(OUTPUT)%.3
+ $(call QUIET_INSTALL, $<) \
$(INSTALL) -d -m 755 $(DESTDIR)$(man3dir); \
- $(INSTALL) -m 644 $(OUTPUT)*.3 $(DESTDIR)$(man3dir);
+ $(INSTALL) -m 644 $< $(DESTDIR)$(man3dir);
-install-man: check-man-tools man do-install-man
+do-install-man: man $(addprefix install-,$(wildcard $(OUTPUT)*.3))
-do-install-html: html
- $(call QUIET_INSTALL, Documentation-html) \
+install-man: check-man-tools man
+ $(Q)$(MAKE) -C . do-install-man
+
+install-%.txt: $(OUTPUT)%.html
+ $(call QUIET_INSTALL, $<) \
$(INSTALL) -d -m 755 $(DESTDIR)$(htmldir); \
- $(INSTALL) -m 644 $(OUTPUT)*.html $(DESTDIR)$(htmldir);
+ $(INSTALL) -m 644 $< $(DESTDIR)$(htmldir);
+
+do-install-html: html $(addprefix install-,$(wildcard *.txt))
install-html: check-man-tools html do-install-html
@@ -187,7 +192,7 @@ endif
CLEAN_FILES = \
$(MAN_XML) $(addsuffix +,$(MAN_XML)) \
$(MAN_HTML) $(addsuffix +,$(MAN_HTML)) \
- $(DOC_MAN3) *.3
+ $(DOC_MAN3) *.3 *.m
clean:
$(call QUIET_CLEAN, Documentation) $(RM) $(CLEAN_FILES)
@@ -200,9 +205,10 @@ $(OUTPUT)%.3 : $(OUTPUT)%.txt
mv $@+ $@
endif
-$(OUTPUT)%.3 : $(OUTPUT)%.xml
+$(OUTPUT)%.m : $(OUTPUT)%.xml
$(QUIET_XMLTO)$(RM) $@ && \
- $(XMLTO) -o $(OUTPUT). -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $<
+ $(XMLTO) -o $(OUTPUT). -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $<; \
+ touch $@
$(OUTPUT)%.xml : %.txt
$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
--
2.29.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 3/5] libtraceevent: Add the API tep_parse_kallsyms()
2021-04-08 21:41 [PATCH v3 0/5] libtraceevent: Copy parsing functions from trace-cmd Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 1/5] libtraceevent: Update gitignore Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 2/5] libtraceevent: Fix dependencies in Documentation Makefile Steven Rostedt
@ 2021-04-08 21:41 ` Steven Rostedt
2021-04-08 21:41 ` [PATCH v3 4/5] libtraceevent: Add the API tep_parse_saved_cmdlines() Steven Rostedt
2021-04-08 21:42 ` [PATCH v3 5/5] libtraceevent: Add the API tep_parse_printk_formats() Steven Rostedt
4 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-04-08 21:41 UTC (permalink / raw)
To: linux-trace-devel; +Cc: Steven Rostedt (VMware)
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Currently, trace-cmd has a tracecmd_parse_proc_kallsyms() function that
reads a string that holds the content of /proc/kallsyms and then passes
the function mapping it reads into the tep handler.
There's no reason for this to be specific to trace-cmd as other
applications can easily save /proc/kallsyms, or just read it directly and
then pass it to the tep handler.
Add the same functionality to libtraceevent as tep_parse_kallsyms().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/libtraceevent-parse-files.txt | 97 +++++++++++++++++++++
src/event-parse.c | 68 +++++++++++++++
src/event-parse.h | 1 +
3 files changed, 166 insertions(+)
create mode 100644 Documentation/libtraceevent-parse-files.txt
diff --git a/Documentation/libtraceevent-parse-files.txt b/Documentation/libtraceevent-parse-files.txt
new file mode 100644
index 0000000..10144d1
--- /dev/null
+++ b/Documentation/libtraceevent-parse-files.txt
@@ -0,0 +1,97 @@
+libtraceevent(3)
+================
+
+NAME
+----
+tep_parse_kallsyms - Parses mappings of address to function names from kallsyms format file
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <event-parse.h>*
+
+int *tep_parse_kallsyms*(struct tep_handle pass:[*]_tep_, const char pass:[*]_buf_);
+--
+
+DESCRIPTION
+-----------
+*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_kallsyms*() function returns 0 in case of success, or -1
+in case of an error.
+
+EXAMPLE
+-------
+[source,c]
+--
+...
+#include <event-parse.h>
+#include <stdlib.h>
+
+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_function(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/
diff --git a/src/event-parse.c b/src/event-parse.c
index 7c1f4cb..6bf293d 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -640,6 +640,74 @@ out_free:
return -1;
}
+/**
+ * tep_parse_kallsyms - load functions from a read of /proc/kallsyms
+ * @tep: a handle to the trace event parser
+ * @kallsyms: A string buffer that holds the content of /proc/kallsyms and ends with '\0'
+ *
+ * This is a helper function to parse the Linux kernel /proc/kallsyms
+ * format (stored in a string buffer) 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.
+ *
+ * Returns 0 on success, and -1 on error.
+ */
+int tep_parse_kallsyms(struct tep_handle *tep, const char *kallsyms)
+{
+ unsigned long long addr;
+ char *copy;
+ char *func;
+ char *line;
+ char *next = NULL;
+ char *mod;
+ char ch;
+ int ret = -1;
+
+ copy = strdup(kallsyms);
+ if (!copy)
+ return -1;
+
+ line = strtok_r(copy, "\n", &next);
+ while (line) {
+ int func_start, func_end = 0;
+ int mod_start, mod_end = 0;
+ int n;
+
+ mod = NULL;
+ errno = 0;
+ n = sscanf(line, "%16llx %c %n%*s%n%*1[\t][%n%*s%n",
+ &addr, &ch, &func_start, &func_end, &mod_start, &mod_end);
+ if (errno)
+ goto out;
+
+ if (n != 2 || !func_end)
+ goto out;
+
+ func = line + func_start;
+ /*
+ * Hacks for
+ * - arm arch that adds a lot of bogus '$a' functions
+ * - x86-64 that reports per-cpu variable offsets as absolute
+ */
+ if (func[0] != '$' && ch != 'A' && ch != 'a') {
+ line[func_end] = 0;
+ if (mod_end) {
+ mod = line + mod_start;
+ /* truncate the extra ']' */
+ line[mod_end - 1] = 0;
+ }
+ tep_register_function(tep, func, addr, mod);
+ }
+
+ line = strtok_r(NULL, "\n", &next);
+ }
+ ret = 0;
+ out:
+ free(copy);
+
+ return ret;
+}
+
/**
* tep_print_funcs - print out the stored functions
* @tep: a handle to the trace event parser context
diff --git a/src/event-parse.h b/src/event-parse.h
index a67ad9a..3fbd3c4 100644
--- a/src/event-parse.h
+++ b/src/event-parse.h
@@ -439,6 +439,7 @@ int tep_set_function_resolver(struct tep_handle *tep,
void tep_reset_function_resolver(struct tep_handle *tep);
int tep_register_comm(struct tep_handle *tep, const char *comm, int pid);
int tep_override_comm(struct tep_handle *tep, const char *comm, int pid);
+int tep_parse_kallsyms(struct tep_handle *tep, const char *kallsyms);
int tep_register_function(struct tep_handle *tep, char *name,
unsigned long long addr, char *mod);
int tep_register_print_string(struct tep_handle *tep, const char *fmt,
--
2.29.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 4/5] libtraceevent: Add the API tep_parse_saved_cmdlines()
2021-04-08 21:41 [PATCH v3 0/5] libtraceevent: Copy parsing functions from trace-cmd Steven Rostedt
` (2 preceding siblings ...)
2021-04-08 21:41 ` [PATCH v3 3/5] libtraceevent: Add the API tep_parse_kallsyms() Steven Rostedt
@ 2021-04-08 21:41 ` Steven Rostedt
2021-04-08 21:42 ` [PATCH v3 5/5] libtraceevent: Add the API tep_parse_printk_formats() Steven Rostedt
4 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-04-08 21:41 UTC (permalink / raw)
To: linux-trace-devel; +Cc: Steven Rostedt (VMware)
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Currently, trace-cmd has a tracecmd_parse_cmdlines() function that
reads a string that holds the content of saved_cmdlines from the tracefs
file system, and then passes the pid to comm mapping to the tep handler.
There's no reason for this to be specific to trace-cmd as other
applications can easily read the saved_cmdlines with the tracefs API and
then pass it to the tep handler.
Add the same functionality to libtraceevent as tep_parse_saved_cmdlines().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/libtraceevent-parse-files.txt | 30 ++++++++++++++-
src/event-parse.c | 42 +++++++++++++++++++++
src/event-parse.h | 1 +
3 files changed, 71 insertions(+), 2 deletions(-)
diff --git a/Documentation/libtraceevent-parse-files.txt b/Documentation/libtraceevent-parse-files.txt
index 10144d1..594cef2 100644
--- a/Documentation/libtraceevent-parse-files.txt
+++ b/Documentation/libtraceevent-parse-files.txt
@@ -3,7 +3,8 @@ libtraceevent(3)
NAME
----
-tep_parse_kallsyms - Parses mappings of address to function names from kallsyms format file
+tep_parse_saved_cmdlines, tep_parse_kallsyms
+- Parsing functions to load mappings
SYNOPSIS
--------
@@ -11,11 +12,19 @@ SYNOPSIS
--
*#include <event-parse.h>*
+int *tep_parse_saved_cmdlines*(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_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
@@ -24,6 +33,9 @@ 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_kallsyms*() function returns 0 in case of success, or -1
in case of an error.
@@ -33,8 +45,22 @@ EXAMPLE
--
...
#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_kallsyms(struct tep_handle *tep)
{
char *line = NULL;
@@ -75,7 +101,7 @@ FILES
SEE ALSO
--------
-_libtraceevent(3)_, _trace-cmd(1)_, _tep_register_function(3)_
+_libtraceevent(3)_, _trace-cmd(1)_, _tep_register_comm(3)_, _tep_register_function(3)_
AUTHOR
------
diff --git a/src/event-parse.c b/src/event-parse.c
index 6bf293d..0d12ec4 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -387,6 +387,48 @@ int tep_override_comm(struct tep_handle *tep, const char *comm, int pid)
return _tep_register_comm(tep, comm, pid, true);
}
+/**
+ * tep_parse_saved_cmdlines - parse the comms from the saved_cmdlines file
+ * @tep: a handle to the trace event parser
+ * @buf: A string buffer that holds the content of saved_cmdlines and ends with '\0'
+ *
+ * This is a helper function to parse the comms in the tracefs saved_cmdlines
+ * file (stored in a string buffer) and load the comms into the @tep handler
+ * such that comm name matches an process ID (pid). This is used to show
+ * the names of the processes as the events only hold the pid.
+ *
+ * Returns 0 on success, and -1 on error.
+ */
+int tep_parse_saved_cmdlines(struct tep_handle *tep, const char *buf)
+{
+ char *copy;
+ char *comm;
+ char *line;
+ char *next = NULL;
+ int pid;
+ int ret = -1;
+ int n;
+
+ copy = strdup(buf);
+ if (!copy)
+ return -1;
+
+ line = strtok_r(copy, "\n", &next);
+ while (line) {
+ errno = 0;
+ n = sscanf(line, "%d %m[^\n]s", &pid, &comm);
+ if (errno || n != 2 || !comm)
+ goto out;
+ tep_register_comm(tep, comm, pid);
+ free(comm);
+ line = strtok_r(NULL, "\n", &next);
+ }
+ ret = 0;
+ out:
+ free(copy);
+ return ret;
+}
+
struct func_map {
unsigned long long addr;
char *func;
diff --git a/src/event-parse.h b/src/event-parse.h
index 3fbd3c4..078b202 100644
--- a/src/event-parse.h
+++ b/src/event-parse.h
@@ -439,6 +439,7 @@ int tep_set_function_resolver(struct tep_handle *tep,
void tep_reset_function_resolver(struct tep_handle *tep);
int tep_register_comm(struct tep_handle *tep, const char *comm, int pid);
int tep_override_comm(struct tep_handle *tep, const char *comm, int pid);
+int tep_parse_saved_cmdlines(struct tep_handle *tep, const char *buf);
int tep_parse_kallsyms(struct tep_handle *tep, const char *kallsyms);
int tep_register_function(struct tep_handle *tep, char *name,
unsigned long long addr, char *mod);
--
2.29.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 5/5] libtraceevent: Add the API tep_parse_printk_formats()
2021-04-08 21:41 [PATCH v3 0/5] libtraceevent: Copy parsing functions from trace-cmd Steven Rostedt
` (3 preceding siblings ...)
2021-04-08 21:41 ` [PATCH v3 4/5] libtraceevent: Add the API tep_parse_saved_cmdlines() Steven Rostedt
@ 2021-04-08 21:42 ` Steven Rostedt
4 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-04-08 21:42 UTC (permalink / raw)
To: linux-trace-devel; +Cc: Steven Rostedt (VMware)
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Currently, trace-cmd has a tracecmd_parse_ftrace_printk() function that
reads a string that holds the content of printk_formats from the tracefs
file system, and then passes the address of the printk strings mappings
to the tep handler.
There's no reason for this to be specific to trace-cmd as other
applications can easily read the printk_formats with the tracefs API and
then pass it to the tep handler.
Add the same functionality to libtraceevent as tep_parse_printk_formats().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/libtraceevent-parse-files.txt | 30 +++++++++++-
src/event-parse.c | 51 +++++++++++++++++++++
src/event-parse.h | 1 +
3 files changed, 80 insertions(+), 2 deletions(-)
diff --git a/Documentation/libtraceevent-parse-files.txt b/Documentation/libtraceevent-parse-files.txt
index 594cef2..211f4f4 100644
--- a/Documentation/libtraceevent-parse-files.txt
+++ b/Documentation/libtraceevent-parse-files.txt
@@ -3,7 +3,7 @@ libtraceevent(3)
NAME
----
-tep_parse_saved_cmdlines, tep_parse_kallsyms
+tep_parse_saved_cmdlines, tep_parse_printk_formats, tep_parse_kallsyms
- Parsing functions to load mappings
SYNOPSIS
@@ -13,6 +13,7 @@ SYNOPSIS
*#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_);
--
@@ -25,6 +26,14 @@ _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
@@ -36,6 +45,9 @@ 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.
@@ -61,6 +73,19 @@ int load_cmdlines(struct tep_handle *tep)
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;
@@ -101,7 +126,8 @@ FILES
SEE ALSO
--------
-_libtraceevent(3)_, _trace-cmd(1)_, _tep_register_comm(3)_, _tep_register_function(3)_
+_libtraceevent(3)_, _trace-cmd(1)_, _tep_register_comm(3)_, _tep_register_function(3)_,
+_tep_register_print_string_(3)
AUTHOR
------
diff --git a/src/event-parse.c b/src/event-parse.c
index 0d12ec4..cec4ad1 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -913,6 +913,57 @@ void tep_print_printk(struct tep_handle *tep)
}
}
+/**
+ * tep_parse_printk_formats - Parse the address to strings
+ * @tep: a handle to the trace event parser
+ * @buf: A string buffer that holds the content of printk_formats and ends with '\0'
+ *
+ * This is a helper function to parse the address to printk formats in
+ * the kernel. Some events use %s to a kernel address that holds a constant
+ * string. The printk_formats file has a mapping of these addresses to the
+ * strings that are in the kernel. This parses the content of that file
+ * and registers those strings and their addresses so that the parsing of
+ * events can display the string as the event only has the address of the string.
+ *
+ * Returns 0 on success, and -1 on error.
+ */
+int tep_parse_printk_formats(struct tep_handle *tep, const char *buf)
+{
+ unsigned long long addr;
+ char *copy;
+ char *printk;
+ char *line;
+ char *next = NULL;
+ char *addr_str;
+ char *fmt;
+ int ret = -1;
+
+ copy = strdup(buf);
+ if (!copy)
+ return -1;
+
+ line = strtok_r(copy, "\n", &next);
+ while (line) {
+ addr_str = strtok_r(line, ":", &fmt);
+ if (!addr_str) {
+ tep_warning("printk format with empty entry");
+ break;
+ }
+ addr = strtoull(addr_str, NULL, 16);
+ /* fmt still has a space, skip it */
+ printk = strdup(fmt+1);
+ if (!printk)
+ goto out;
+ line = strtok_r(NULL, "\n", &next);
+ tep_register_print_string(tep, printk, addr);
+ free(printk);
+ }
+ ret = 0;
+ out:
+ free(copy);
+ return ret;
+}
+
static struct tep_event *alloc_event(void)
{
return calloc(1, sizeof(struct tep_event));
diff --git a/src/event-parse.h b/src/event-parse.h
index 078b202..05b156b 100644
--- a/src/event-parse.h
+++ b/src/event-parse.h
@@ -443,6 +443,7 @@ int tep_parse_saved_cmdlines(struct tep_handle *tep, const char *buf);
int tep_parse_kallsyms(struct tep_handle *tep, const char *kallsyms);
int tep_register_function(struct tep_handle *tep, char *name,
unsigned long long addr, char *mod);
+int tep_parse_printk_formats(struct tep_handle *tep, const char *buf);
int tep_register_print_string(struct tep_handle *tep, const char *fmt,
unsigned long long addr);
bool tep_is_pid_registered(struct tep_handle *tep, int pid);
--
2.29.2
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