. new kernel call sysctl for generic unprivileged system operations;

now used for printing diagnostic messages through the kernel message
   buffer. this lets processes print diagnostics without sending messages
   to tty and log directly, simplifying the message protocol a lot and
   reducing difficulties with deadlocks and other situations in which
   diagnostics are blackholed (e.g. grants don't work). this makes
   DIAGNOSTICS(_S), ASYN_DIAGNOSTICS and DIAG_REPL obsolete, although tty
   and log still accept the codes for 'old' binaries. This also simplifies
   diagnostics in several servers and drivers - only tty needs its own
   kputc() now.
 . simplifications in vfs, and some effort to get the vnode references
   right (consistent) even during shutdown. m_mounted_on is now NULL
   for root filesystems (!) (the original and new root), a less awkward
   special case than 'm_mounted_on == m_root_node'. root now has exactly
   one reference, to root, if no files are open, just like all other
   filesystems. m_driver_e is unused.

kernel/const.h

@@ -52,4 +52,7 @@
 #define INTS_ORIG	0	/* restore interrupts */
 #define INTS_MINIX	1	/* initialize interrupts for minix */
 
+/* for kputc() */
+#define END_OF_KMESS	0
+
 #endif /* CONST_H */

kernel/proto.h

@@ -93,6 +93,9 @@ _PROTOTYPE( void check_runqueues_f, (char *file, int line) );
 _PROTOTYPE( int verify_grant, (endpoint_t, endpoint_t, cp_grant_id_t, vir_bytes,
 	int, vir_bytes, vir_bytes *, endpoint_t *));
 
+/* system/do_sysctl.c */
+_PROTOTYPE( int do_sysctl, (message *m));
+
 #if SPROFILE
 /* profile.c */
 _PROTOTYPE( void init_profile_clock, (u32_t)				);

kernel/system.c

@@ -241,6 +241,7 @@ PRIVATE void initialize(void)
   /* System control. */
   map(SYS_ABORT, do_abort);		/* abort MINIX */
   map(SYS_GETINFO, do_getinfo); 	/* request system information */ 
+  map(SYS_SYSCTL, do_sysctl); 		/* misc system manipulation */ 
 
   /* Profiling. */
   map(SYS_SPROF, do_sprofile);         /* start/stop statistical profiling */

kernel/system/Makefile

@@ -43,6 +43,7 @@ OBJECTS	= \
 	$(SYSTEM)(do_privctl.o) \
 	$(SYSTEM)(do_segctl.o) \
 	$(SYSTEM)(do_safecopy.o) \
+	$(SYSTEM)(do_sysctl.o) \
 	$(SYSTEM)(do_getksig.o) \
 	$(SYSTEM)(do_endksig.o) \
 	$(SYSTEM)(do_kill.o) \
@@ -151,6 +152,9 @@ $(SYSTEM)(do_privctl.o):	do_privctl.c
 $(SYSTEM)(do_safecopy.o):	do_safecopy.c
 	$(CC) do_safecopy.c
 
+$(SYSTEM)(do_sysctl.o):	do_sysctl.c
+	$(CC) do_sysctl.c
+
 $(SYSTEM)(do_segctl.o):	do_segctl.c
 	$(CC) do_segctl.c
 

kernel/system/do_sysctl.c

@@ -0,0 +1,58 @@
+/* The kernel call implemented in this file:
+ *   m_type:	SYS_SYSCTL
+ *
+ * The parameters for this kernel call are:
+ *  	SYSCTL_CODE	request
+ * and then request-specific arguments in SYSCTL_ARG1 and SYSCTL_ARG2.
+ */
+
+#include "../system.h"
+#include "../vm.h"
+
+
+/*===========================================================================*
+ *			        do_sysctl				     *
+ *===========================================================================*/
+PUBLIC int do_sysctl(m_ptr)
+register message *m_ptr;	/* pointer to request message */
+{
+  phys_bytes ph;
+  vir_bytes len, buf;
+  static char mybuf[DIAG_BUFSIZE];
+  struct proc *caller;
+  int s, i;
+
+  caller = proc_addr(who_p);
+
+  switch (m_ptr->SYSCTL_CODE) {
+    case SYSCTL_CODE_DIAG:
+        buf = (vir_bytes) m_ptr->SYSCTL_ARG1;
+        len = (vir_bytes) m_ptr->SYSCTL_ARG2;
+	if(len < 1 || len > DIAG_BUFSIZE) {
+		kprintf("do_sysctl: diag for %d: len %d out of range\n",
+			caller->p_endpoint, len);
+		return EINVAL;
+	}
+	if((ph=umap_local(caller, D, buf, len)) == 0)
+		return EFAULT;
+	CHECKRANGE_OR_SUSPEND(caller, ph, len, 1);
+	if((s=data_copy(who_e, buf, SYSTEM, (vir_bytes) mybuf, len)) != OK) {
+		kprintf("do_sysctl: diag for %d: len %d: copy failed: %d\n",
+			caller->p_endpoint, len, s);
+		return s;
+	}
+	for(i = 0; i < len; i++)
+		kputc(mybuf[i]);
+	kputc(END_OF_KMESS);
+	return OK;
+        break;
+    default:
+	kprintf("do_sysctl: invalid request %d\n", m_ptr->SYSCTL_CODE);
+        return(EINVAL);
+  }
+
+  minix_panic("do_sysctl: can't happen", NO_NUM);
+
+  return(OK);
+}
+

kernel/table.c

@@ -83,9 +83,9 @@ PUBLIC char *t_stack[TOT_STACK_SPACE / sizeof(char *)];
  */
 #define FS_C SYS_KILL, SYS_VIRCOPY, SYS_SAFECOPYFROM, SYS_SAFECOPYTO, \
     SYS_VIRVCOPY, SYS_UMAP, SYS_GETINFO, SYS_EXIT, SYS_TIMES, SYS_SETALARM, \
-    SYS_PRIVCTL, SYS_TRACE , SYS_SETGRANT, SYS_PROFBUF
+    SYS_PRIVCTL, SYS_TRACE , SYS_SETGRANT, SYS_PROFBUF, SYS_SYSCTL
 #define DRV_C	FS_C, SYS_SEGCTL, SYS_IRQCTL, SYS_INT86, SYS_DEVIO, \
-	SYS_SDEVIO, SYS_VDEVIO, SYS_SETGRANT, SYS_PROFBUF
+	SYS_SDEVIO, SYS_VDEVIO, SYS_SETGRANT, SYS_PROFBUF, SYS_SYSCTL
 
 PRIVATE int
   fs_c[] = { FS_C },

kernel/utility.c

@@ -59,8 +59,6 @@ int nr;
 #define printf kprintf
 #include "../lib/sysutil/kprintf.c"
 
-#define END_OF_KMESS 	0
-
 /*===========================================================================*
  *				kputc				     	     *
  *===========================================================================*/