rasdaemon: fix return value type issue of read/write function from unistd.h

The return value type of read/write function from unistd.h is ssize_t.
It's signed normally, and return -1 on error. Fix incorrect use in the
function read_ras_event_all_cpus().

BTW, make setting buffer_percent as a separate function.

Fixes: 94750bcf9309 ("rasdaemon: Fix poll() on per_cpu trace_pipe_raw blocks indefinitely")
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/ras-events.c b/ras-events.c
index fced7aba289a78ef39af50055168e24908bed301..9eb45b3f8c1f2ec5931ede2b8a3798ceb25eca6d 100644 (file)
--- a/ras-events.c
+++ b/ras-events.c
@@ -368,10 +368,37 @@ static int get_num_cpus(struct ras_events *ras)
 #endif
 }
 
+static int set_buffer_percent(struct ras_events *ras, int percent)
+{
+       char buf[16];
+       ssize_t size;
+       int res = 0;
+       int fd;
+
+       fd = open_trace(ras, "buffer_percent", O_WRONLY);
+       if (fd >= 0) {
+               /* For the backward compatibility to the old kernels, do not return
+                * if fail to set the buffer_percent.
+                */
+               snprintf(buf, sizeof(buf), "%d", percent);
+               size = write(fd, buf, strlen(buf));
+               if (size <= 0) {
+                       log(TERM, LOG_WARNING, "can't write to buffer_percent\n");
+                       res = -1;
+               }
+               close(fd);
+       } else {
+               log(TERM, LOG_WARNING, "Can't open buffer_percent\n");
+               res = -1;
+       }
+
+       return res;
+}
+
 static int read_ras_event_all_cpus(struct pthread_data *pdata,
                                   unsigned n_cpus)
 {
-       unsigned size;
+       ssize_t size;
        unsigned long long time_stamp;
        void *data;
        int ready, i, count_nready;
@@ -383,8 +410,6 @@ static int read_ras_event_all_cpus(struct pthread_data *pdata,
        int warnonce[n_cpus];
        char pipe_raw[PATH_MAX];
        int legacy_kernel = 0;
-       int fd;
-       char buf[16];
 #if 0
        int need_sleep = 0;
 #endif
@@ -411,18 +436,8 @@ static int read_ras_event_all_cpus(struct pthread_data *pdata,
         * Set buffer_percent to 0 so that poll() will return immediately
         * when the trace data is available in the ras per_cpu trace pipe_raw
         */
-       fd = open_trace(pdata[0].ras, "buffer_percent", O_WRONLY);
-       if (fd >= 0) {
-               /* For the backward compatibility to the old kernels, do not return
-                * if fail to set the buffer_percent.
-                */
-               snprintf(buf, sizeof(buf), "0");
-               size = write(fd, buf, strlen(buf));
-               if (size <= 0)
-                       log(TERM, LOG_WARNING, "can't write to buffer_percent\n");
-               close(fd);
-       } else
-               log(TERM, LOG_WARNING, "Can't open buffer_percent\n");
+       if (set_buffer_percent(pdata[0].ras, 0))
+               log(TERM, LOG_WARNING, "Set buffer_percent failed\n");
 
        for (i = 0; i < (n_cpus + 1); i++)
                fds[i].fd = -1;