[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.shaobow...@huawei.com>
---
 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