Index: coregrind/m_syswrap/syswrap-generic.c
===================================================================
--- coregrind/m_syswrap/syswrap-generic.c	(revision 10399)
+++ coregrind/m_syswrap/syswrap-generic.c	(working copy)
@@ -2558,6 +2558,15 @@
 
    } else {
       path = (Char*)ARG1;
+      if (VG_(clo_xml)) {
+        VG_(message)(Vg_UserMsg, "");
+        VG_(message)(Vg_UserMsg, "<execv/>");
+        VG_(message)(Vg_UserMsg, "");
+        VG_(message)(Vg_UserMsg, "</valgrindoutput>");
+        VG_(message)(Vg_UserMsg, "");
+      } else {
+        VG_(message)(Vg_UserMsg, "execv called - the tool will now quit");
+      }
    }
 
    // Set up the child's environment.
@@ -4093,4 +4102,3 @@
 /*--------------------------------------------------------------------*/
 /*--- end                                                          ---*/
 /*--------------------------------------------------------------------*/
-
Index: coregrind/m_main.c
===================================================================
--- coregrind/m_main.c	(revision 10399)
+++ coregrind/m_main.c	(working copy)
@@ -755,15 +755,26 @@
    If logging to file or a socket, write details of parent PID and
    command line args, to help people trying to interpret the
    results of a run which encompasses multiple processes. */
-static void print_preamble(Bool logging_to_fd, const char* toolname)
+
+// TODO(timurrrr): we add a non-static declaration of this function since
+// we need it in coregrind/m_libcproc.c
+// Should we move it to some header file?
+void print_preamble(Bool logging_to_fd, const char* toolname);
+
+void print_preamble(Bool logging_to_fd, const char* toolname)
 {
    HChar* xpre  = VG_(clo_xml) ? "  <line>" : "";
    HChar* xpost = VG_(clo_xml) ? "</line>" : "";
    Int    i;
+   static const char* last_toolname = NULL;
 
    vg_assert( VG_(args_for_client) );
    vg_assert( VG_(args_for_valgrind) );
+   // This way you may pass toolname == NULL provided the first invocation
+   // with toolname != NULL takes place in valgrind_main().
+   toolname = (toolname == NULL ? last_toolname : toolname);
    vg_assert( toolname );
+   last_toolname = toolname;
 
    if (VG_(clo_xml)) {
       VG_(message)(Vg_UserMsg, "<?xml version=\"1.0\"?>");
Index: coregrind/m_libcproc.c
===================================================================
--- coregrind/m_libcproc.c	(revision 10399)
+++ coregrind/m_libcproc.c	(working copy)
@@ -33,9 +33,12 @@
 #include "pub_core_vkiscnums.h"
 #include "pub_core_libcbase.h"
 #include "pub_core_libcassert.h"
+#include "pub_core_libcfile.h"
 #include "pub_core_libcprint.h"
 #include "pub_core_libcproc.h"
 #include "pub_core_libcsignal.h"
+#include "pub_core_tooliface.h"
+#include "pub_core_options.h"
 #include "pub_core_seqmatch.h"
 #include "pub_core_mallocfree.h"
 #include "pub_core_syscall.h"
@@ -703,10 +706,59 @@
          (*atforks[i].parent)(tid);
 }
 
+// Defined in m_main.c
+void print_preamble(Bool logging_to_fd, const char* toolname);
+
+// If --log-file=ABC%pXYZ is specified, we'd like to have separate log files
+// for each forked child.
+// If %p is present in the --log-file option, this function creates
+// a new log file and redirects the child's output to it.
+static void open_new_logfile_for_forked_child(void)
+{
+   SysRes sres;
+   Int tmp_log_fd = -1;
+   Char *logfilename, *clo_log_name;
+
+   clo_log_name = VG_(clo_log_name);
+   if (clo_log_name == NULL || !VG_(strstr)(clo_log_name, "%p")) {
+      // Don't create new log streams unless --log-file=ABC%pXYZ is specified.
+      return;
+   }
+
+   logfilename = VG_(expand_file_name)("--log-file", clo_log_name);
+   sres = VG_(open) (logfilename,
+                    VKI_O_CREAT | VKI_O_WRONLY | VKI_O_TRUNC,
+                    VKI_S_IRUSR | VKI_S_IWUSR);
+   if (!sr_isError(sres)) {
+      tmp_log_fd = sr_Res(sres);
+      // Move log_fd into the safe range,
+      // so it doesn't conflict with any app fds.
+      tmp_log_fd = VG_(fcntl) (tmp_log_fd, VKI_F_DUPFD, VG_(fd_hard_limit));
+      if (tmp_log_fd >= 0) {
+         VG_(clo_log_fd) = tmp_log_fd;
+         VG_(fcntl) (VG_(clo_log_fd), VKI_F_SETFD, VKI_FD_CLOEXEC);
+      } else {
+         VG_(message) (Vg_UserMsg,
+                       "valgrind: failed to move logfile fd into safe range, "
+                       "using stderr");
+         VG_(clo_log_fd) = 2;    // stderr
+      }
+   } else {
+      VG_(message) (Vg_UserMsg,
+                    "Can't create log file '%s' (%s); giving up!",
+                    logfilename, VG_(strerror) (sr_Err(sres)));
+      VG_(core_panic)("Error creating log file for child process");
+   }
+
+   print_preamble(False, NULL);
+}
+
 void VG_(do_atfork_child)(ThreadId tid)
 {
    Int i;
 
+   open_new_logfile_for_forked_child();
+
    for (i = 0; i < n_atfork; i++)
       if (atforks[i].child != NULL)
          (*atforks[i].child)(tid);