[PATCH v2 -next] tools build: Check return value of fwrite_unlocked in jvmti_agent.c

[Wang ShaoBo]

Function jvmti_write_code called by compiled_method_load_cb may return
error in using fwrite_unlocked, this failure should be captured and
warned.

Signed-off-by: Wang ShaoBo <bobo.shaobowang@xxxxxxxxxx>
---
 tools/perf/jvmti/jvmti_agent.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c
index 88108598d6e9..dfb6cb8564cb 100644
--- a/tools/perf/jvmti/jvmti_agent.c
+++ b/tools/perf/jvmti/jvmti_agent.c
@@ -363,7 +363,7 @@ jvmti_write_code(void *agent, char const *sym,
 	struct jr_code_load rec;
 	size_t sym_len;
 	FILE *fp = agent;
-	int ret = -1;
+	int sret;
 
 	/* don't care about 0 length function, no samples */
 	if (size == 0)
@@ -400,17 +400,24 @@ jvmti_write_code(void *agent, char const *sym,
 	 */
 	rec.code_index = code_generation++;
 
-	ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
-	fwrite_unlocked(sym, sym_len, 1, fp);
+	sret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
+	if (sret != 1)
+		goto error;
+	sret = fwrite_unlocked(sym, sym_len, 1, fp);
+	if (sret != 1)
+		goto error;
 
-	if (code)
-		fwrite_unlocked(code, size, 1, fp);
+	if (code) {
+		sret = fwrite_unlocked(code, size, 1, fp);
+		if (sret != 1)
+			goto error;
+	}
 
 	funlockfile(fp);
-
-	ret = 0;
-
-	return ret;
+	return 0;
+error:
+	funlockfile(fp);
+	return -1;
 }
 
 int
-- 
2.25.1