kernel ipc debug: various fixes

. add receive hooks in the kernel to print asynchronously
	  delivered messages
	. do not rely on MF_REPLY_PEND to decide between calls and errors,
	  as that isn't reliable for asynchronous messages; try both instead
	. add _sendcall() that extract-mfield.sh can then reliably recognize
	  the fields for messages that are sent with just send()
	. add DEBUG_DUMPIPC_NAMES to restrict printed messages to
	  from/to given process names

Change-Id: Ia65eb02a69a2b58e73bf9f009987be06dda774a3

drivers/tty/tty.c

@@ -1660,25 +1660,12 @@ int proc_nr;			/* to whom should the reply go? */
 int status;			/* reply code */
 {
 /* Send a reply to a process that wanted to read or write data. */
-  message tty_mess;
+  assert(code == TASK_REPLY);
-
-  tty_mess.m_type = code;
-  tty_mess.REP_ENDPT = proc_nr;
-  tty_mess.REP_STATUS = status;
 
   /* Don't reply to KERNEL (kernel messages) */
   if (replyee == KERNEL) return;
 
-  /* TTY is not supposed to send a TTY_REVIVE message. The
+  status = send_taskreply(replyee, proc_nr, status);
-   * REVIVE message is gone, TTY_REVIVE is only used as an internal
-   * placeholder for something that is not supposed to be a message.
-   */
-  if(code == TTY_REVIVE) {
-	printf("%s:%d: ", file, line);
-	panic("tty_reply sending TTY_REVIVE");
-  }
-
-  status = send(replyee, &tty_mess);
   if (status != OK)
 	printf("tty`tty_reply: send to %d failed: %d\n", replyee, status);
 }

include/minix/syslib.h

@@ -25,6 +25,7 @@ struct rs_pci;
  *==========================================================================*/ 
 int _taskcall(endpoint_t who, int syscallnr, message *msgptr);
 int _kernel_call(int syscallnr, message *msgptr);
+int _sendcall(endpoint_t who, int type, message *msgptr);
 
 int sys_abort(int how);
 int sys_enable_iop(endpoint_t proc_ep);
@@ -157,6 +158,8 @@ int sys_umap_data_fb(endpoint_t proc_ep, vir_bytes vir_addr, vir_bytes
 int sys_umap_remote(endpoint_t proc_ep, endpoint_t grantee, int seg,
 	vir_bytes vir_addr, vir_bytes bytes, phys_bytes *phys_addr);
 
+int send_taskreply(endpoint_t who, endpoint_t endpoint, int status);
+
 /* Shorthands for sys_getinfo() system call. */
 #define sys_getkinfo(dst)	sys_getinfo(GET_KINFO, dst, 0,0,0)
 #define sys_getloadinfo(dst)	sys_getinfo(GET_LOADINFO, dst, 0,0,0)

kernel/Makefile

@@ -72,7 +72,7 @@ CPPFLAGS+= -DUSE_TRACE
 
 CLEANFILES+=extracted-errno.h extracted-mfield.h extracted-mtype.h procoffsets.h
 
-debug.d: extracted-errno.h extracted-mfield.h extracted-mtype.h
+debug.o: extracted-errno.h extracted-mfield.h extracted-mtype.h
 
 extracted-errno.h: extract-errno.sh ../include/errno.h
 	${_MKTARGET_CREATE}

kernel/debug.c

@@ -313,25 +313,45 @@ void print_proc_recursive(struct proc *pp)
 }
 
 #if DEBUG_DUMPIPC
-static const char *mtypename(int mtype, int iscall)
+static const char *mtypename(int mtype, int *possible_callname)
 {
-	/* use generated file to recognize message types */
+	char *callname = NULL, *errname = NULL;
-	if (iscall) {
+	/* use generated file to recognize message types
-		switch(mtype) {
+	 *
-#define IDENT(x) case x: return #x;
+	 * we try to match both error numbers and call numbers, as the
+	 * reader can probably decide from context what's going on.
+	 *
+	 * whenever it might be a call number we tell the caller so the
+	 * call message fields can be decoded if known.
+	 */
+	switch(mtype) {
+#define IDENT(x) case x: callname = #x; *possible_callname = 1; break;
 #include "extracted-mtype.h"
 #undef IDENT
-		}
+	}
-	} else {
+	switch(mtype) {
-		switch(mtype) {
+#define IDENT(x) case x: errname = #x; break;
-#define IDENT(x) case x: return #x;
 #include "extracted-errno.h"
 #undef IDENT
-		}
 	}
 
 	/* no match */
-	return NULL;
+	if(!errname && !callname)
+		return NULL;
+
+	/* 2 matches */
+	if(errname && callname) {
+		static char typename[100];
+		strcpy(typename, errname);
+		strcat(typename, " / ");
+		strcat(typename, callname);
+		return typename;
+	}
+
+	if(errname) return errname;
+
+	assert(callname);
+	return callname;
 }
 
 static void printproc(struct proc *rp)
@@ -353,24 +373,51 @@ static void printparam(const char *name, const void *data, size_t size)
 	}
 }
 
+#ifdef DEBUG_DUMPIPC_NAMES
+static int namematch(char **names, int nnames, char *name)
+{
+	int i;
+	for(i = 0; i < nnames; i++)
+		if(!strcmp(names[i], name))
+			return 1;
+	return 0;
+}
+#endif
+
 static void printmsg(message *msg, struct proc *src, struct proc *dst, 
-	char operation, int iscall, int printparams)
+	char operation, int printparams)
 {
 	const char *name;
-	int mtype = msg->m_type;
+	int mtype = msg->m_type, mightbecall = 0;
+
+#ifdef DEBUG_DUMPIPC_NAMES
+  {
+	char *names[] = DEBUG_DUMPIPC_NAMES;
+	int nnames = sizeof(names)/sizeof(names[0]);
+
+	/* skip printing messages for messages neither to
+	 * or from DEBUG_DUMPIPC_EP if it is defined; either
+	 * can be NULL to indicate kernel
+	 */
+	if(!(src && namematch(names, nnames, src->p_name)) &&
+	   !(dst && namematch(names, nnames, dst->p_name))) {
+		return;
+	}
+  }
+#endif
 
 	/* source, destination and message type */
 	printf("%c", operation);
 	printproc(src);
 	printproc(dst);
-	name = mtypename(mtype, iscall);
+	name = mtypename(mtype, &mightbecall);
 	if (name) {
-		printf(" %s(%d)", name, mtype);
+		printf(" %s(%d/0x%x)", name, mtype, mtype);
 	} else {
-		printf(" %d", mtype);
+		printf(" %d/0x%x", mtype, mtype);
 	}
 
-	if (iscall && printparams) {
+	if (mightbecall && printparams) {
 #define IDENT(x, y) if (mtype == x) printparam(#y, &msg->y, sizeof(msg->y));
 #include "extracted-mfield.h"
 #undef IDENT
@@ -473,14 +520,14 @@ static void statmsg(message *msg, struct proc *srcp, struct proc *dstp)
 void hook_ipc_msgkcall(message *msg, struct proc *proc)
 {
 #if DEBUG_DUMPIPC
-	printmsg(msg, proc, NULL, 'k', 1, 1);
+	printmsg(msg, proc, NULL, 'k', 1);
 #endif
 }
 
 void hook_ipc_msgkresult(message *msg, struct proc *proc)
 {
 #if DEBUG_DUMPIPC
-	printmsg(msg, NULL, proc, 'k', 0, 0);
+	printmsg(msg, NULL, proc, 'k', 0);
 #endif
 #if DEBUG_IPCSTATS
 	statmsg(msg, proc, NULL);
@@ -490,7 +537,7 @@ void hook_ipc_msgkresult(message *msg, struct proc *proc)
 void hook_ipc_msgrecv(message *msg, struct proc *src, struct proc *dst)
 {
 #if DEBUG_DUMPIPC
-	printmsg(msg, src, dst, 'r', src->p_misc_flags & MF_REPLY_PEND, 0);
+	printmsg(msg, src, dst, 'r', 0);
 #endif
 #if DEBUG_IPCSTATS
 	statmsg(msg, src, dst);
@@ -500,7 +547,7 @@ void hook_ipc_msgrecv(message *msg, struct proc *src, struct proc *dst)
 void hook_ipc_msgsend(message *msg, struct proc *src, struct proc *dst)
 {
 #if DEBUG_DUMPIPC
-	printmsg(msg, src, dst, 's', src->p_misc_flags & MF_REPLY_PEND, 1);
+	printmsg(msg, src, dst, 's', 1);
 #endif
 }
 

kernel/debug.h

@@ -46,6 +46,9 @@
  */
 #define DEBUG_DUMPIPC			0
 
+/* If defined, restrict DEBUG_DUMPIPC to particular process names */
+/* #define DEBUG_DUMPIPC_NAMES		{ "tty", "inet" } */
+
 /* DEBUG_IPCSTATS collects information on who sends messages to whom. */
 #define DEBUG_IPCSTATS			0
 

kernel/extract-mfield.sh

@@ -5,7 +5,7 @@ set -e
 find_files_and_lines()
 (
 	find  ../lib/libc/sys-minix ../lib/libsys -name '*.c' | \
-	xargs egrep -n '((_syscall|_taskcall)\([^,][^,]*,[ 	]*|_kernel_call\()[A-Z_][A-Z0-9_]*,[ 	]*&m\)' | \
+	xargs egrep -n '((_sendcall|_syscall|_taskcall)\([^,][^,]*,[ 	]*|_kernel_call\()[A-Z_][A-Z0-9_]*,[ 	]*&m\)' | \
 	cut -d: -f1,2
 )
 

kernel/proc.c

@@ -1223,6 +1223,9 @@ int try_deliver_senda(struct proc *caller_ptr,
 		dst_ptr->p_misc_flags |= MF_DELIVERMSG;
 		IPC_STATUS_ADD_CALL(dst_ptr, SENDA);
 		RTS_UNSET(dst_ptr, RTS_RECEIVING);
+#if DEBUG_IPC_HOOK
+		hook_ipc_msgrecv(&dst_ptr->p_delivermsg, caller_ptr, dst_ptr);
+#endif
 	} else if (r == OK) {
 		/* Inform receiver that something is pending */
 		set_sys_bit(priv(dst_ptr)->s_asyn_pending, 
@@ -1398,6 +1401,9 @@ static int try_one(struct proc *src_ptr, struct proc *dst_ptr)
 	dst_ptr->p_delivermsg = tabent.msg;
 	dst_ptr->p_delivermsg.m_source = src_ptr->p_endpoint;
 	dst_ptr->p_misc_flags |= MF_DELIVERMSG;
+#if DEBUG_IPC_HOOK
+	hook_ipc_msgrecv(&dst_ptr->p_delivermsg, src_ptr, dst_ptr);
+#endif
 
 store_result:
 	/* Store results for sender */

lib/libsys/Makefile

@@ -75,6 +75,7 @@ SRCS+=  \
 	sys_vsafecopy.c \
 	sys_vtimer.c \
 	sys_vumap.c \
+	send_taskreply.c \
 	taskcall.c \
 	tickdelay.c \
 	timers.c \

lib/libsys/send_taskreply.c

@@ -0,0 +1,20 @@
+
+#include <string.h>
+
+#include "syslib.h"
+
+/*===========================================================================*
+ *				sys_taskreply				     *
+ *===========================================================================*/
+int send_taskreply(endpoint_t who, endpoint_t endpoint, int status)
+{
+  message m;
+
+  memset(&m, 0, sizeof(m));
+
+  m.REP_ENDPT = endpoint;
+  m.REP_STATUS = status;
+
+  return _sendcall(who, TASK_REPLY, &m);
+}
+

lib/libsys/taskcall.c

@@ -6,6 +6,13 @@
 #include <lib.h>
 #include <minix/syslib.h>
 
+int _sendcall(endpoint_t who, int type, message *msgptr)
+{
+  msgptr->m_type = type;
+  return send(who, msgptr);
+}
+
+
 int _taskcall(who, syscallnr, msgptr)
 endpoint_t who;
 int syscallnr;