[PATCH 3/3] linux-user: Add strace support for printing arguments of some clock and time functions

[Filip Bozuta]

This patch implements strace argument printing functionality for following 
syscalls:

    * clock_getres, clock_gettime, clock_settime - clock and time functions

        int clock_getres(clockid_t clockid, struct timespec *res)
        int clock_gettime(clockid_t clockid, struct timespec *tp)
        int clock_settime(clockid_t clockid, const struct timespec *tp)
        man page: https://man7.org/linux/man-pages/man2/clock_getres.2.html

    * gettimeofday - get time

        int gettimeofday(struct timeval *tv, struct timezone *tz)
        man page: https://man7.org/linux/man-pages/man2/gettimeofday.2.html

    * getitimer, setitimer - get or set value of an interval timer

        int getitimer(int which, struct itimerval *curr_value)
        int setitimer(int which, const struct itimerval *new_value,
                      struct itimerval *old_value)
        man page: https://man7.org/linux/man-pages/man2/getitimer.2.html

Implementation notes:

    All of the syscalls have some structue types as argument types and thus
    a separate printing function was stated in file "strace.list" for each
    of them. All of these functions use existing functions for their
    appropriate structure types ("print_timeval()" and "print_timezone()").
    Functions "print_timespec()" and "print_itimerval()" were added in this
    patch so that they can be used to print types "struct timespec" and
    "struct itimerval" used by some of the syscalls. Function 
"print_itimerval()"
    uses the existing function "print_timeval()" to print fields of the
    structure "struct itimerval" that are of type "struct timeval".
    Also, the existing function "print_timeval()" was changed a little so
    that it prints the field names beside the values. Syscalls "clock_getres()"
    and "clocK_gettime()" have the same number and types of arguments and
    thus their print functions "print_clock_getres" and "print_clock_gettime"
    shate a common definition in file "strace.c".

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
---
 linux-user/strace.c    | 186 ++++++++++++++++++++++++++++++++++++++++-
 linux-user/strace.list |  16 ++--
 2 files changed, 194 insertions(+), 8 deletions(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 1fc4404310..414748d0fa 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -64,7 +64,9 @@ UNUSED static void print_string(abi_long, int);
 UNUSED static void print_buf(abi_long addr, abi_long len, int last);
 UNUSED static void print_raw_param(const char *, abi_long, int);
 UNUSED static void print_timeval(abi_ulong, int);
+UNUSED static void print_timespec(abi_ulong, int);
 UNUSED static void print_timezone(abi_ulong, int);
+UNUSED static void print_itimerval(abi_ulong, int);
 UNUSED static void print_number(abi_long, int);
 UNUSED static void print_signal(abi_ulong, int);
 UNUSED static void print_sockaddr(abi_ulong, abi_long, int);
@@ -833,6 +835,65 @@ print_syscall_ret_adjtimex(const struct syscallname *name, 
abi_long ret,
 }
 #endif
 
+#if defined(TARGET_NR_clock_gettime) || defined(TARGET_NR_clock_getres)
+static void
+print_syscall_ret_clock_gettime(const struct syscallname *name, abi_long ret,
+                                abi_long arg0, abi_long arg1, abi_long arg2,
+                                abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_err(ret);
+
+    if (ret >= 0) {
+        qemu_log(TARGET_ABI_FMT_ld, ret);
+        qemu_log(" (");
+        print_timespec(arg1, 1);
+        qemu_log(")");
+    }
+
+    qemu_log("\n");
+}
+#define print_syscall_ret_clock_getres     print_syscall_ret_clock_gettime
+#endif
+
+#ifdef TARGET_NR_gettimeofday
+static void
+print_syscall_ret_gettimeofday(const struct syscallname *name, abi_long ret,
+                               abi_long arg0, abi_long arg1, abi_long arg2,
+                               abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_err(ret);
+
+    if (ret >= 0) {
+        qemu_log(TARGET_ABI_FMT_ld, ret);
+        qemu_log(" (");
+        print_timeval(arg0, 0);
+        print_timezone(arg1, 1);
+        qemu_log(")");
+    }
+
+    qemu_log("\n");
+}
+#endif
+
+#ifdef TARGET_NR_getitimer
+static void
+print_syscall_ret_getitimer(const struct syscallname *name, abi_long ret,
+                            abi_long arg0, abi_long arg1, abi_long arg2,
+                            abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_err(ret);
+
+    if (ret >= 0) {
+        qemu_log(TARGET_ABI_FMT_ld, ret);
+        qemu_log(" (");
+        print_itimerval(arg1, 1);
+        qemu_log(")");
+    }
+
+    qemu_log("\n");
+}
+#endif
+
 #if defined(TARGET_NR_listxattr) || defined(TARGET_NR_llistxattr) \
  || defined(TARGGET_NR_flistxattr)
 static void
@@ -1371,13 +1432,34 @@ print_timeval(abi_ulong tv_addr, int last)
             print_pointer(tv_addr, last);
             return;
         }
-        qemu_log("{" TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld "}%s",
-            tswapal(tv->tv_sec), tswapal(tv->tv_usec), get_comma(last));
+        qemu_log("{tv_sec = " TARGET_ABI_FMT_ld
+                 ",tv_usec = " TARGET_ABI_FMT_ld "}%s",
+                 tswapal(tv->tv_sec), tswapal(tv->tv_usec), get_comma(last));
         unlock_user(tv, tv_addr, 0);
     } else
         qemu_log("NULL%s", get_comma(last));
 }
 
+static void
+print_timespec(abi_ulong ts_addr, int last)
+{
+    if (ts_addr) {
+        struct target_timespec *ts;
+
+        ts = lock_user(VERIFY_READ, ts_addr, sizeof(*ts), 1);
+        if (!ts) {
+            print_pointer(ts_addr, last);
+            return;
+        }
+        qemu_log("{tv_sec = " TARGET_ABI_FMT_ld
+                 ",tv_nsec = " TARGET_ABI_FMT_ld "}%s",
+                 tswapal(ts->tv_sec), tswapal(ts->tv_nsec), get_comma(last));
+        unlock_user(ts, ts_addr, 0);
+    } else {
+        qemu_log("NULL%s", get_comma(last));
+    }
+}
+
 static void
 print_timezone(abi_ulong tz_addr, int last)
 {
@@ -1397,6 +1479,21 @@ print_timezone(abi_ulong tz_addr, int last)
     }
 }
 
+static void
+print_itimerval(abi_ulong it_addr, int last)
+{
+    if (it_addr) {
+        qemu_log("{it_interval=");
+        print_timeval(it_addr, 0);
+        qemu_log("it_value=");
+        print_timeval(it_addr +
+                      offsetof(struct target_itimerval, it_value), 1);
+        qemu_log("}%s", get_comma(last));
+    } else {
+        qemu_log("NULL%s", get_comma(last));
+    }
+}
+
 #undef UNUSED
 
 #ifdef TARGET_NR_accept
@@ -1839,6 +1936,19 @@ print_futimesat(const struct syscallname *name,
 }
 #endif
 
+#ifdef TARGET_NR_gettimeofday
+static void
+print_gettimeofday(const struct syscallname *name,
+    abi_long arg0, abi_long arg1, abi_long arg2,
+    abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_pointer(arg0, 0);
+    print_pointer(arg1, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #ifdef TARGET_NR_settimeofday
 static void
 print_settimeofday(const struct syscallname *name,
@@ -1852,6 +1962,78 @@ print_settimeofday(const struct syscallname *name,
 }
 #endif
 
+#if defined(TARGET_NR_clock_gettime) || defined(TARGET_NR_clock_getres)
+static void
+print_clock_gettime(const struct syscallname *name,
+    abi_long arg0, abi_long arg1, abi_long arg2,
+    abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_clockid(arg0, 0);
+    print_pointer(arg1, 1);
+    print_syscall_epilogue(name);
+}
+#define print_clock_getres     print_clock_gettime
+#endif
+
+#ifdef TARGET_NR_clock_settime
+static void
+print_clock_settime(const struct syscallname *name,
+    abi_long arg0, abi_long arg1, abi_long arg2,
+    abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_clockid(arg0, 0);
+    print_timespec(arg1, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
+#ifdef TARGET_NR_getitimer
+static void
+print_getitimer(const struct syscallname *name,
+    abi_long arg0, abi_long arg1, abi_long arg2,
+    abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    switch (arg0) {
+    case ITIMER_REAL:
+        qemu_log("ITIMER_REAL,"); break;
+    case ITIMER_VIRTUAL:
+        qemu_log("ITIMER_VIRTUAL,"); break;
+    case ITIMER_PROF:
+        qemu_log("ITIMER_PROF,"); break;
+    default:
+        print_raw_param("%#x", arg1, 0);
+    }
+    print_pointer(arg1, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
+#ifdef TARGET_NR_setitimer
+static void
+print_setitimer(const struct syscallname *name,
+    abi_long arg0, abi_long arg1, abi_long arg2,
+    abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    switch (arg0) {
+    case ITIMER_REAL:
+        qemu_log("ITIMER_REAL,"); break;
+    case ITIMER_VIRTUAL:
+        qemu_log("ITIMER_VIRTUAL,"); break;
+    case ITIMER_PROF:
+        qemu_log("ITIMER_PROF,"); break;
+    default:
+        print_raw_param("%#x", arg1, 0);
+    }
+    print_itimerval(arg1, 0);
+    print_itimerval(arg2, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #ifdef TARGET_NR_link
 static void
 print_link(const struct syscallname *name,
diff --git a/linux-user/strace.list b/linux-user/strace.list
index 822b6be49c..6b5cef149f 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -83,16 +83,18 @@
 { TARGET_NR_clock_adjtime, "clock_adjtime" , NULL, print_clock_adjtime, NULL },
 #endif
 #ifdef TARGET_NR_clock_getres
-{ TARGET_NR_clock_getres, "clock_getres" , NULL, NULL, NULL },
+{ TARGET_NR_clock_getres, "clock_getres" , NULL, print_clock_getres,
+                          print_syscall_ret_clock_getres },
 #endif
 #ifdef TARGET_NR_clock_gettime
-{ TARGET_NR_clock_gettime, "clock_gettime" , NULL, NULL, NULL },
+{ TARGET_NR_clock_gettime, "clock_gettime" , NULL, print_clock_gettime,
+                           print_syscall_ret_clock_gettime },
 #endif
 #ifdef TARGET_NR_clock_nanosleep
 { TARGET_NR_clock_nanosleep, "clock_nanosleep" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_clock_settime
-{ TARGET_NR_clock_settime, "clock_settime" , NULL, NULL, NULL },
+{ TARGET_NR_clock_settime, "clock_settime" , NULL, print_clock_settime, NULL },
 #endif
 #ifdef TARGET_NR_clone
 { TARGET_NR_clone, "clone" , NULL, print_clone, NULL },
@@ -315,7 +317,8 @@
 { TARGET_NR_gethostname, "gethostname" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_getitimer
-{ TARGET_NR_getitimer, "getitimer" , NULL, NULL, NULL },
+{ TARGET_NR_getitimer, "getitimer" , NULL, print_getitimer,
+                       print_syscall_ret_getitimer },
 #endif
 #ifdef TARGET_NR_get_kernel_syms
 { TARGET_NR_get_kernel_syms, "get_kernel_syms" , NULL, NULL, NULL },
@@ -388,7 +391,8 @@
 { TARGET_NR_gettid, "gettid" , "%s()", NULL, NULL },
 #endif
 #ifdef TARGET_NR_gettimeofday
-{ TARGET_NR_gettimeofday, "gettimeofday" , NULL, NULL, NULL },
+{ TARGET_NR_gettimeofday, "gettimeofday" , NULL, print_gettimeofday,
+                          print_syscall_ret_gettimeofday },
 #endif
 #ifdef TARGET_NR_getuid
 { TARGET_NR_getuid, "getuid" , "%s()", NULL, NULL },
@@ -1290,7 +1294,7 @@
 { TARGET_NR_sethostname, "sethostname" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_setitimer
-{ TARGET_NR_setitimer, "setitimer" , NULL, NULL, NULL },
+{ TARGET_NR_setitimer, "setitimer" , NULL, print_setitimer, NULL },
 #endif
 #ifdef TARGET_NR_set_mempolicy
 { TARGET_NR_set_mempolicy, "set_mempolicy" , NULL, NULL, NULL },
-- 
2.17.1