Commit-ID: ca58d7e64bdfc54f7dfe46713c1e2acc68d7522d
Gitweb: https://git.kernel.org/tip/ca58d7e64bdfc54f7dfe46713c1e2acc68d7522d
Author: Ben Gainey <[email protected]>
AuthorDate: Wed, 22 Nov 2017 18:25:41 -0600
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 18 Dec 2017 11:54:08 -0300
perf jvmti: Generate correct debug information for inlined code
tools/perf/jvmti is broken in so far as it generates incorrect debug
information. Specifically it attributes all debug lines to the original
method being output even in the case that some code is being inlined
from elsewhere. This patch fixes the issue.
To test (from within linux/tools/perf):
export JDIR=/usr/lib/jvm/java-8-openjdk-amd64/
make
cat << __EOF > Test.java
public class Test
{
private StringBuilder b = new StringBuilder();
private void loop(int i, String... args)
{
for (String a : args)
b.append(a);
long hc = b.hashCode() * System.nanoTime();
b = new StringBuilder();
b.append(hc);
System.out.printf("Iteration %d = %d\n", i, hc);
}
public void run(String... args)
{
for (int i = 0; i < 10000; ++i)
{
loop(i, args);
}
}
public static void main(String... args)
{
Test t = new Test();
t.run(args);
}
}
__EOF
$JDIR/bin/javac Test.java
./perf record -F 10000 -g -k mono $JDIR/bin/java
-agentpath:`pwd`/libperf-jvmti.so Test
./perf inject --jit -i perf.data -o perf.data.jitted
./perf annotate -i perf.data.jitted --stdio | grep Test\.java: | sort -u
Before this patch, Test.java line numbers get reported that are greater
than the number of lines in the Test.java file. They come from the
source file of the inlined function, e.g. java/lang/String.java:1085.
For further validation one can examine those lines in the JDK source
distribution and confirm that they map to inlined functions called by
Test.java.
After this patch, the filename of the inlined function is output
rather than the incorrect original source filename.
Signed-off-by: Ben Gainey <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Tested-by: Stephane Eranian <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ben Gainey <[email protected]>
Cc: Colin King <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: 598b7c6919c7 ("perf jit: add source line info support")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Kim Phillips <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/jvmti/jvmti_agent.c | 16 +++--
tools/perf/jvmti/jvmti_agent.h | 7 +-
tools/perf/jvmti/libjvmti.c | 147 ++++++++++++++++++++++++++++++++++-------
3 files changed, 134 insertions(+), 36 deletions(-)
diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c
index cf36de7..0c6d100 100644
--- a/tools/perf/jvmti/jvmti_agent.c
+++ b/tools/perf/jvmti/jvmti_agent.c
@@ -384,13 +384,13 @@ jvmti_write_code(void *agent, char const *sym,
}
int
-jvmti_write_debug_info(void *agent, uint64_t code, const char *file,
- jvmti_line_info_t *li, int nr_lines)
+jvmti_write_debug_info(void *agent, uint64_t code,
+ int nr_lines, jvmti_line_info_t *li,
+ const char * const * file_names)
{
struct jr_code_debug_info rec;
- size_t sret, len, size, flen;
+ size_t sret, len, size, flen = 0;
uint64_t addr;
- const char *fn = file;
FILE *fp = agent;
int i;
@@ -405,7 +405,9 @@ jvmti_write_debug_info(void *agent, uint64_t code, const
char *file,
return -1;
}
- flen = strlen(file) + 1;
+ for (i = 0; i < nr_lines; ++i) {
+ flen += strlen(file_names[i]) + 1;
+ }
rec.p.id = JIT_CODE_DEBUG_INFO;
size = sizeof(rec);
@@ -421,7 +423,7 @@ jvmti_write_debug_info(void *agent, uint64_t code, const
char *file,
* file[] : source file name
*/
size += nr_lines * sizeof(struct debug_entry);
- size += flen * nr_lines;
+ size += flen;
rec.p.total_size = size;
/*
@@ -452,7 +454,7 @@ jvmti_write_debug_info(void *agent, uint64_t code, const
char *file,
if (sret != 1)
goto error;
- sret = fwrite_unlocked(fn, flen, 1, fp);
+ sret = fwrite_unlocked(file_names[i], strlen(file_names[i]) +
1, 1, fp);
if (sret != 1)
goto error;
}
diff --git a/tools/perf/jvmti/jvmti_agent.h b/tools/perf/jvmti/jvmti_agent.h
index fe32d83..6ed82f6 100644
--- a/tools/perf/jvmti/jvmti_agent.h
+++ b/tools/perf/jvmti/jvmti_agent.h
@@ -14,6 +14,7 @@ typedef struct {
unsigned long pc;
int line_number;
int discrim; /* discriminator -- 0 for now */
+ jmethodID methodID;
} jvmti_line_info_t;
void *jvmti_open(void);
@@ -22,11 +23,9 @@ int jvmti_write_code(void *agent, char const *symbol_name,
uint64_t vma, void const *code,
const unsigned int code_size);
-int jvmti_write_debug_info(void *agent,
- uint64_t code,
- const char *file,
+int jvmti_write_debug_info(void *agent, uint64_t code, int nr_lines,
jvmti_line_info_t *li,
- int nr_lines);
+ const char * const * file_names);
#if defined(__cplusplus)
}
diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c
index c62c9fc..6add3e9 100644
--- a/tools/perf/jvmti/libjvmti.c
+++ b/tools/perf/jvmti/libjvmti.c
@@ -47,6 +47,7 @@ do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m,
jint bci,
tab[lines].pc = (unsigned long)pc;
tab[lines].line_number = loc_tab[i].line_number;
tab[lines].discrim = 0; /* not yet used */
+ tab[lines].methodID = m;
lines++;
} else {
break;
@@ -125,6 +126,99 @@ get_line_numbers(jvmtiEnv *jvmti, const void
*compile_info, jvmti_line_info_t **
return JVMTI_ERROR_NONE;
}
+static void
+copy_class_filename(const char * class_sign, const char * file_name, char *
result, size_t max_length)
+{
+ /*
+ * Assume path name is class hierarchy, this is a common practice with
Java programs
+ */
+ if (*class_sign == 'L') {
+ int j, i = 0;
+ char *p = strrchr(class_sign, '/');
+ if (p) {
+ /* drop the 'L' prefix and copy up to the final '/' */
+ for (i = 0; i < (p - class_sign); i++)
+ result[i] = class_sign[i+1];
+ }
+ /*
+ * append file name, we use loops and not string ops to avoid
modifying
+ * class_sign which is used later for the symbol name
+ */
+ for (j = 0; i < (max_length - 1) && file_name && j <
strlen(file_name); j++, i++)
+ result[i] = file_name[j];
+
+ result[i] = '\0';
+ } else {
+ /* fallback case */
+ size_t file_name_len = strlen(file_name);
+ strncpy(result, file_name, file_name_len < max_length ?
file_name_len : max_length);
+ }
+}
+
+static jvmtiError
+get_source_filename(jvmtiEnv *jvmti, jmethodID methodID, char ** buffer)
+{
+ jvmtiError ret;
+ jclass decl_class;
+ char *file_name = NULL;
+ char *class_sign = NULL;
+ char fn[PATH_MAX];
+ size_t len;
+
+ ret = (*jvmti)->GetMethodDeclaringClass(jvmti, methodID, &decl_class);
+ if (ret != JVMTI_ERROR_NONE) {
+ print_error(jvmti, "GetMethodDeclaringClass", ret);
+ return ret;
+ }
+
+ ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
+ if (ret != JVMTI_ERROR_NONE) {
+ print_error(jvmti, "GetSourceFileName", ret);
+ return ret;
+ }
+
+ ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL);
+ if (ret != JVMTI_ERROR_NONE) {
+ print_error(jvmti, "GetClassSignature", ret);
+ goto free_file_name_error;
+ }
+
+ copy_class_filename(class_sign, file_name, fn, PATH_MAX);
+ len = strlen(fn);
+ *buffer = malloc((len + 1) * sizeof(char));
+ if (!*buffer) {
+ print_error(jvmti, "GetClassSignature", ret);
+ ret = JVMTI_ERROR_OUT_OF_MEMORY;
+ goto free_class_sign_error;
+ }
+ strcpy(*buffer, fn);
+ ret = JVMTI_ERROR_NONE;
+
+free_class_sign_error:
+ (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
+free_file_name_error:
+ (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
+
+ return ret;
+}
+
+static jvmtiError
+fill_source_filenames(jvmtiEnv *jvmti, int nr_lines,
+ const jvmti_line_info_t * line_tab,
+ char ** file_names)
+{
+ int index;
+ jvmtiError ret;
+
+ for (index = 0; index < nr_lines; ++index) {
+ ret = get_source_filename(jvmti, line_tab[index].methodID,
&(file_names[index]));
+ if (ret != JVMTI_ERROR_NONE)
+ return ret;
+ }
+
+ return JVMTI_ERROR_NONE;
+}
+
static void JNICALL
compiled_method_load_cb(jvmtiEnv *jvmti,
jmethodID method,
@@ -135,16 +229,18 @@ compiled_method_load_cb(jvmtiEnv *jvmti,
const void *compile_info)
{
jvmti_line_info_t *line_tab = NULL;
+ char ** line_file_names = NULL;
jclass decl_class;
char *class_sign = NULL;
char *func_name = NULL;
char *func_sign = NULL;
- char *file_name= NULL;
+ char *file_name = NULL;
char fn[PATH_MAX];
uint64_t addr = (uint64_t)(uintptr_t)code_addr;
jvmtiError ret;
int nr_lines = 0; /* in line_tab[] */
size_t len;
+ int output_debug_info = 0;
ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
&decl_class);
@@ -158,6 +254,19 @@ compiled_method_load_cb(jvmtiEnv *jvmti,
if (ret != JVMTI_ERROR_NONE) {
warnx("jvmti: cannot get line table for method");
nr_lines = 0;
+ } else if (nr_lines > 0) {
+ line_file_names = malloc(sizeof(char*) * nr_lines);
+ if (!line_file_names) {
+ warnx("jvmti: cannot allocate space for line
table method names");
+ } else {
+ memset(line_file_names, 0, sizeof(char*) *
nr_lines);
+ ret = fill_source_filenames(jvmti, nr_lines,
line_tab, line_file_names);
+ if (ret != JVMTI_ERROR_NONE) {
+ warnx("jvmti: fill_source_filenames
failed");
+ } else {
+ output_debug_info = 1;
+ }
+ }
}
}
@@ -181,33 +290,14 @@ compiled_method_load_cb(jvmtiEnv *jvmti,
goto error;
}
- /*
- * Assume path name is class hierarchy, this is a common practice with
Java programs
- */
- if (*class_sign == 'L') {
- int j, i = 0;
- char *p = strrchr(class_sign, '/');
- if (p) {
- /* drop the 'L' prefix and copy up to the final '/' */
- for (i = 0; i < (p - class_sign); i++)
- fn[i] = class_sign[i+1];
- }
- /*
- * append file name, we use loops and not string ops to avoid
modifying
- * class_sign which is used later for the symbol name
- */
- for (j = 0; i < (PATH_MAX - 1) && file_name && j <
strlen(file_name); j++, i++)
- fn[i] = file_name[j];
- fn[i] = '\0';
- } else {
- /* fallback case */
- strcpy(fn, file_name);
- }
+ copy_class_filename(class_sign, file_name, fn, PATH_MAX);
+
/*
* write source line info record if we have it
*/
- if (jvmti_write_debug_info(jvmti_agent, addr, fn, line_tab, nr_lines))
- warnx("jvmti: write_debug_info() failed");
+ if (output_debug_info)
+ if (jvmti_write_debug_info(jvmti_agent, addr, nr_lines,
line_tab, (const char * const *) line_file_names))
+ warnx("jvmti: write_debug_info() failed");
len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
{
@@ -223,6 +313,13 @@ error:
(*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
(*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
free(line_tab);
+ while (line_file_names && (nr_lines > 0)) {
+ if (line_file_names[nr_lines - 1]) {
+ free(line_file_names[nr_lines - 1]);
+ }
+ nr_lines -= 1;
+ }
+ free(line_file_names);
}
static void JNICALL
