From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
I needed a way to get the size of a function, and instead of creating
another function that gets the size (having to look up the function by
address again), I decided it would be better to have a single function
that retrieved the name, starting address and the size.
This implements tep_find_function_info() that does just that.
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
Documentation/libtraceevent-func_find.txt | 51 +++++++++++++++++++++--
include/traceevent/event-parse.h | 3 ++
src/event-parse.c | 37 ++++++++++++++++
3 files changed, 87 insertions(+), 4 deletions(-)
diff --git a/Documentation/libtraceevent-func_find.txt b/Documentation/libtraceevent-func_find.txt
index 20982e91fa0b..26fac681fe8e 100644
--- a/Documentation/libtraceevent-func_find.txt
+++ b/Documentation/libtraceevent-func_find.txt
@@ -3,7 +3,7 @@ libtraceevent(3)
NAME
----
-tep_find_function,tep_find_function_address - Find function name / start address.
+tep_find_function,tep_find_function_address,tep_find_function_info - Find function name / start address.
SYNOPSIS
--------
@@ -13,6 +13,8 @@ SYNOPSIS
const char pass:[*]*tep_find_function*(struct tep_handle pass:[*]_tep_, unsigned long long _addr_);
unsigned long long *tep_find_function_address*(struct tep_handle pass:[*]_tep_, unsigned long long _addr_);
+int *tep_find_function_info*(struct tep_handle pass:[*]_tep_, unsigned long long _addr_, const char pass:[**]_name_,
+ unsigned long long pass:[*]_start_, unsigned long pass:[*]_size_);
--
DESCRIPTION
@@ -28,6 +30,11 @@ The *tep_find_function_address()* function returns the function start address,
by given address _addr_. The _addr_ does not have to be exact, it will select the
function that would contain it. The _tep_ argument is the trace event parser context.
+The *tep_find_function_info()* function retrieves the _name_, starting address (_start_),
+and the function text _size_ of the function at _address_, if it is found. Note,
+if the _tep_ handle has a function resolver (used by perf), then _size_ is set to
+zero.
+
RETURN VALUE
------------
The *tep_find_function()* function returns the function name, or NULL in case
@@ -36,6 +43,9 @@ it cannot be found.
The *tep_find_function_address()* function returns the function start address,
or 0 in case it cannot be found.
+The *tep_find_function_info()* function returns 1 if a function is found for the
+given address, or 0 if it is not.
+
EXAMPLE
-------
[source,c]
@@ -44,12 +54,45 @@ EXAMPLE
...
struct tep_handle *tep = tep_alloc();
...
-void show_function( unsigned long long addr)
+void show_function_name(unsigned long long addr)
+{
+ const char *fname = tep_find_function(tep, addr);
+
+ if (fname)
+ printf("Found function %s at 0x%0llx\n", fname, addr);
+ else
+ printf("No function found at 0x%0llx\n", addr);
+}
+
+void show_function_start_addr(unsigned long long addr)
{
const char *fname = tep_find_function(tep, addr);
- unsigned long long fstart = tep_find_function_address(tep, addr);
+ unsigned long long fstart;
+
+ if (!fname) {
+ printf("No function found at 0x%0llx\n", addr);
+ return;
+ }
+
+ fstart = tep_find_function_address(tep, addr);
+ printf("Function %s at 0x%llx starts at 0x%0llx\n",
+ fname, addr, fstart);
+}
+
+void show_function_info(unsigned long long addr)
+{
+ const char *fname;
+ unsigned long long fstart;
+ unsigned long size;
+
+ ret = tep_find_function_info(tep, addr, &fname, &fstart, &size);
+ if (!ret) {
+ printf("No function found at 0x%0lx\n", addr);
+ return;
+ }
- /* addr is in function named fname, starting at fstart address, at offset (addr - fstart) */
+ printf("Function %s at 0x%lx starts at 0x%0lx and is %ld in size\n",
+ fname, addr, fstart, size);
}
...
--
diff --git a/include/traceevent/event-parse.h b/include/traceevent/event-parse.h
index f749cc2656ba..df307666abfa 100644
--- a/include/traceevent/event-parse.h
+++ b/include/traceevent/event-parse.h
@@ -527,6 +527,9 @@ struct tep_format_field *tep_find_any_field(struct tep_event *event, const char
const char *tep_find_function(struct tep_handle *tep, unsigned long long addr);
unsigned long long
tep_find_function_address(struct tep_handle *tep, unsigned long long addr);
+int tep_find_function_info(struct tep_handle *tep, unsigned long long addr,
+ const char **name, unsigned long long *start,
+ unsigned long *size);
unsigned long long tep_read_number(struct tep_handle *tep, const void *ptr, int size);
int tep_read_number_field(struct tep_format_field *field, const void *data,
unsigned long long *value);
diff --git a/src/event-parse.c b/src/event-parse.c
index d842f9d4bbce..a6e9e936ac87 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -613,6 +613,43 @@ find_func(struct tep_handle *tep, unsigned long long addr)
return map;
}
+/**
+ * tep_find_function_info - find a function by a given address
+ * @tep: a handle to the trace event parser context
+ * @addr: the address to find the function with
+ * @name: Return the name of the function (if found)
+ * @start: Return the start of the function (if found)
+ * @size: Return the size of the function (if found)
+ *
+ * Returns 1 if found, and 0 if it is not.
+ * If found then @name will point to the name of the function.
+ * @start: will contain the starting address of the function.
+ * @size: will contain the size of the function.
+ */
+int tep_find_function_info(struct tep_handle *tep, unsigned long long addr,
+ const char **name, unsigned long long *start,
+ unsigned long *size)
+{
+ struct func_map *map;
+
+ map = find_func(tep, addr);
+ if (!map)
+ return 0;
+
+ if (name)
+ *name = map->func;
+ if (start)
+ *start = map->addr;
+ if (size) {
+ if (!tep->func_resolver)
+ *size = map[1].addr - map->addr;
+ else
+ *size = 0;
+ }
+
+ return 1;
+}
+
/**
* tep_find_function - find a function by a given address
* @tep: a handle to the trace event parser context
--
2.35.1
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