[PATCH v3 21/32] tools/nolibc: implement waitpid() in terms of waitid()

[Thomas Weißschuh]

The old wait4() syscall used by waitpid() before is not available everywhere.
Switch to the waitid() syscall which is the new replacement.

Signed-off-by: Thomas Weißschuh <thomas.weisssc...@linutronix.de>
Acked-by: Willy Tarreau <w...@1wt.eu>
---
 tools/include/nolibc/sys.h | 71 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 59 insertions(+), 12 deletions(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 
5c71a2f65c7bd93f6f516a54f7e63244466fad47..e39eefb2b82cc97eccfc030005fe0321632f12c4
 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -1267,6 +1267,7 @@ int unlink(const char *path)
  * pid_t wait(int *status);
  * pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage);
  * pid_t waitpid(pid_t pid, int *status, int options);
+ * int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options);
  */
 
 static __attribute__((unused))
@@ -1291,18 +1292,6 @@ pid_t wait4(pid_t pid, int *status, int options, struct 
rusage *rusage)
        return __sysret(sys_wait4(pid, status, options, rusage));
 }
 
-
-static __attribute__((unused))
-pid_t waitpid(pid_t pid, int *status, int options)
-{
-       return __sysret(sys_wait4(pid, status, options, NULL));
-}
-
-
-/*
- * int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options);
- */
-
 static __attribute__((unused))
 int sys_waitid(int which, pid_t pid, siginfo_t *infop, int options, struct 
rusage *rusage)
 {
@@ -1316,6 +1305,64 @@ int waitid(int which, pid_t pid, siginfo_t *infop, int 
options)
 }
 
 
+static __attribute__((unused))
+pid_t waitpid(pid_t pid, int *status, int options)
+{
+       int idtype, ret;
+       siginfo_t info;
+       pid_t id;
+
+       if (pid == INT_MIN) {
+               SET_ERRNO(ESRCH);
+               return -1;
+       } else if (pid < -1) {
+               idtype = P_PGID;
+               id = -pid;
+       } else if (pid == -1) {
+               idtype = P_ALL;
+               id = 0;
+       } else if (pid == 0) {
+               idtype = P_PGID;
+               id = 0;
+       } else {
+               idtype = P_PID;
+               id = pid;
+       }
+
+       options |= WEXITED;
+
+       ret = waitid(idtype, id, &info, options);
+       if (ret)
+               return ret;
+
+       switch (info.si_code) {
+       case 0:
+               *status = 0;
+               break;
+       case CLD_EXITED:
+               *status = (info.si_status & 0xff) << 8;
+               break;
+       case CLD_KILLED:
+               *status = info.si_status & 0x7f;
+               break;
+       case CLD_DUMPED:
+               *status = (info.si_status & 0x7f) | 0x80;
+               break;
+       case CLD_STOPPED:
+       case CLD_TRAPPED:
+               *status = (info.si_status << 8) + 0x7f;
+               break;
+       case CLD_CONTINUED:
+               *status = 0xffff;
+               break;
+       default:
+               return -1;
+       }
+
+       return info.si_pid;
+}
+
+
 /*
  * ssize_t write(int fd, const void *buf, size_t count);
  */

-- 
2.49.0