Add TIOCGICOUNT ioctl.

Author: bernhardu

src/kernel_abi.h

@@ -782,6 +782,22 @@ struct BaseArch : public wordsize,
   };
   RR_VERIFY_TYPE(serial_struct);
 
+  struct serial_icounter_struct {
+    int cts;
+    int dsr;
+    int rng;
+    int dcd;
+    int rx;
+    int tx;
+    int frame;
+    int overrun;
+    int parity;
+    int brk;
+    int buf_overrun;
+    int reserved[9];
+  };
+  RR_VERIFY_TYPE(serial_icounter_struct);
+
   struct winsize {
     unsigned_short ws_row;
     unsigned_short ws_col;

src/record_syscall.cc

@@ -1853,6 +1853,10 @@ static Switchable prepare_ioctl(RecordTask* t,
     case TIOCSSERIAL:
       return PREVENT_SWITCH;
 
+    case TIOCGICOUNT:
+      syscall_state.reg_parameter<typename Arch::serial_icounter_struct>(3);
+      return PREVENT_SWITCH;
+
     case SNDRV_CTL_IOCTL_PVERSION:
       syscall_state.reg_parameter<int>(3);
       return PREVENT_SWITCH;

src/test/ioctl_ttyS.c

@@ -1,10 +1,12 @@
 /* -*- Mode: C; tab-width: 8; c-basic-offset: 2; indent-tabs-mode: nil; -*- */
 
 #include "util.h"
+#include <linux/serial.h>
 
 int main(void) {
   int fd;
   int* mbits;
+  struct serial_icounter_struct* sicnt;
 
   fd = open("/dev/ttyS0", O_RDWR);
   if (fd < 0) {
@@ -20,6 +22,13 @@ int main(void) {
   test_assert(0 == ioctl(fd, TIOCMSET, mbits));
   atomic_printf("TIOCMSET mbits=0x%x afterwards\n", *mbits);
 
+  ALLOCATE_GUARD(sicnt, 'b');
+  test_assert(0 == ioctl(fd, TIOCGICOUNT, sicnt));
+  VERIFY_GUARD(sicnt);
+  atomic_printf("TIOCGICOUNT returned %d, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d\n",
+                sicnt->cts, sicnt->dsr, sicnt->rng, sicnt->dcd, sicnt->rx, sicnt->tx,
+                sicnt->frame, sicnt->overrun, sicnt->parity, sicnt->brk, sicnt->buf_overrun);
+
   atomic_puts("EXIT-SUCCESS");
   return 0;
 }