top: fix CPU% for thread display. Closes 4081

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 19 insertions, 15 deletions

diff --git a/libbb/procps.c b/libbb/procps.c
index 1dea61518..e15ddd1e5 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -284,27 +284,25 @@ int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
 void BUG_comm_size(void);
 procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
 {
-        struct dirent *entry;
-        char buf[PROCPS_BUFSIZE];
-        char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
-        char *filename_tail;
-        long tasknice;
-        unsigned pid;
-        int n;
-        struct stat sb;
-
         if (!sp)
                 sp = alloc_procps_scan();
 
         for (;;) {
+                struct dirent *entry;
+                char buf[PROCPS_BUFSIZE];
+                long tasknice;
+                unsigned pid;
+                int n;
+                char filename[sizeof("/proc/%u/task/%u/cmdline") + sizeof(int)*3 * 2];
+                char *filename_tail;
+
 #if ENABLE_FEATURE_SHOW_THREADS
-                if ((flags & PSSCAN_TASKS) && sp->task_dir) {
+                if (sp->task_dir) {
                         entry = readdir(sp->task_dir);
                         if (entry)
                                 goto got_entry;
                         closedir(sp->task_dir);
                         sp->task_dir = NULL;
-                        sp->main_thread_pid = 0;
                 }
 #endif
                 entry = readdir(sp->dir);
@@ -321,9 +319,9 @@ procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
                         /* We found another /proc/PID. Do not use it,
                          * there will be /proc/PID/task/PID (same PID!),
                          * so just go ahead and dive into /proc/PID/task. */
-                        char task_dir[sizeof("/proc/%u/task") + sizeof(int)*3];
-                        sprintf(task_dir, "/proc/%u/task", pid);
-                        sp->task_dir = xopendir(task_dir);
+                        sprintf(filename, "/proc/%u/task", pid);
+                        /* Note: if opendir fails, we just go to next /proc/XXX */
+                        sp->task_dir = opendir(filename);
                         sp->main_thread_pid = pid;
                         continue;
                 }
@@ -347,9 +345,15 @@ procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
                 }
 #endif
 
-                filename_tail = filename + sprintf(filename, "/proc/%u/", pid);
+#if ENABLE_FEATURE_SHOW_THREADS
+                if (sp->task_dir)
+                        filename_tail = filename + sprintf(filename, "/proc/%u/task/%u/", sp->main_thread_pid, pid);
+                else
+#endif
+                        filename_tail = filename + sprintf(filename, "/proc/%u/", pid);
 
                 if (flags & PSSCAN_UIDGID) {
+                        struct stat sb;
                         if (stat(filename, &sb))
                                 continue; /* process probably exited */
                         /* Effective UID/GID, not real */