New kernel call, SYS_PARAMCTL, that sets parameters of the caller

and is therefore unprivileged. Used to set grant tables.

include/minix/com.h

@@ -286,11 +286,12 @@
 #  define SYS_IOPENABLE  (KERNEL_CALL + 28)	/* sys_enable_iop() */
 #  define SYS_VM_SETBUF  (KERNEL_CALL + 29)	/* sys_vm_setbuf() */
 #  define SYS_VM_MAP  	 (KERNEL_CALL + 30)	/* sys_vm_map() */
-#  define SYS_SAFECOPYFROM  (KERNEL_CALL + 31)	/* sys_safecopyfrom() */
-#  define SYS_SAFECOPYTO    (KERNEL_CALL + 32)	/* sys_safecopyto() */
+#  define SYS_SAFECOPYFROM (KERNEL_CALL + 31)	/* sys_safecopyfrom() */
+#  define SYS_SAFECOPYTO   (KERNEL_CALL + 32)	/* sys_safecopyto() */
 #  define SYS_VSAFECOPY  (KERNEL_CALL + 33)	/* sys_vsafecopy() */
+#  define SYS_PARAMCTL   (KERNEL_CALL + 34)	/* sys_paramctl() */
 
-#define NR_SYS_CALLS	34	/* number of system calls */ 
+#define NR_SYS_CALLS	35	/* number of system calls */ 
 
 /* Pseudo call for use in kernel/table.c. */
 #define SYS_ALL_CALLS (NR_SYS_CALLS)
@@ -301,7 +302,9 @@
 #define SYS_PRIV_ADD_MEM	3	/* Add memory range (struct mem_range)
 					 */
 #define SYS_PRIV_ADD_IRQ	4	/* Add IRQ */
-#define SYS_PRIV_SET_GRANTS	5	/* Set grant table */
+
+/* Subfunctions for SYS_PARAMCTL */
+#define SYS_PARAM_SET_GRANT	1	/* Set address and size of grant table */
 
 /* Field names for SYS_MEMSET, SYS_SEGCTL. */
 #define MEM_PTR		m2_p1	/* base */
@@ -444,6 +447,12 @@
 #define CTL_ADDRESS    m2_l1	/* address at traced process' space */
 #define CTL_DATA       m2_l2	/* data field for tracing */
 
+/* Field names for SYS_PARAMCTL */
+#define PCTL_REQ	m2_i1	/* request code */
+#define PCTL_INT1	m2_i2	/* int param 1 */
+#define PCTL_INT2	m2_i3	/* int param 2 */
+#define PCTL_ADDR1	m2_p1	/* address param 1 */
+
 /* Field names for SYS_KILL, SYS_SIGCTL */
 #define SIG_REQUEST    m2_l2	/* PM signal control request */
 #define S_GETSIG 	   0	/* get pending kernel signal */

include/minix/syslib.h

@@ -37,6 +37,7 @@ _PROTOTYPE( int sys_exit, (endpoint_t proc));
 _PROTOTYPE( int sys_trace, (int req, endpoint_t proc, long addr, long *data_p));
 
 _PROTOTYPE( int sys_privctl, (endpoint_t proc, int req, int i, void *p));
+_PROTOTYPE( int sys_paramctl, (int req, int int1, void *addr1, int int2));
 _PROTOTYPE( int sys_nice, (endpoint_t proc, int priority));
 
 _PROTOTYPE( int sys_int86, (struct reg86u *reg86p));

kernel/system.c

@@ -148,6 +148,7 @@ PRIVATE void initialize(void)
   map(SYS_NICE, do_nice);		/* set scheduling priority */
   map(SYS_PRIVCTL, do_privctl);		/* system privileges control */
   map(SYS_TRACE, do_trace);		/* request a trace operation */
+  map(SYS_PARAMCTL, do_paramctl);	/* get/set own parameters */
 
   /* Signal handling. */
   map(SYS_KILL, do_kill); 		/* cause a process to be signaled */

kernel/system.h

@@ -176,6 +176,7 @@ _PROTOTYPE( int do_setalarm, (message *m_ptr) );
 _PROTOTYPE( int do_safecopy, (message *m_ptr) );	
 _PROTOTYPE( int do_vsafecopy, (message *m_ptr) );	
 _PROTOTYPE( int do_iopenable, (message *m_ptr) );	
+_PROTOTYPE( int do_paramctl, (message *m_ptr) );	
 
 #endif	/* SYSTEM_H */
 

kernel/system/Makefile

@@ -35,6 +35,7 @@ OBJECTS	= \
 	$(SYSTEM)(do_vcopy.o) \
 	$(SYSTEM)(do_umap.o) \
 	$(SYSTEM)(do_memset.o) \
+	$(SYSTEM)(do_paramctl.o) \
 	$(SYSTEM)(do_privctl.o) \
 	$(SYSTEM)(do_segctl.o) \
 	$(SYSTEM)(do_safecopy.o) \
@@ -137,6 +138,9 @@ $(SYSTEM)(do_getinfo.o):	do_getinfo.c
 $(SYSTEM)(do_abort.o):	do_abort.c
 	$(CC) do_abort.c
 
+$(SYSTEM)(do_paramctl.o):	do_paramctl.c
+	$(CC) do_paramctl.c
+
 $(SYSTEM)(do_privctl.o):	do_privctl.c
 	$(CC) do_privctl.c
 

kernel/system/do_paramctl.c

@@ -0,0 +1,45 @@
+/* The kernel call implemented in this file:
+ *   m_type:	SYS_PARAMCTL
+ *
+ * The parameters for this kernel call are:
+ *      PCTL_REQ	request code (SYS_PARAM_*)
+ *      PCTL_INT[12]	integer parameters
+ *	PCTL_ADDR1	address parameter
+ */
+
+#include "../system.h"
+#include <minix/safecopies.h>
+
+/*===========================================================================*
+ *				do_paramctl				     *
+ *===========================================================================*/
+PUBLIC int do_paramctl(m_ptr)
+message *m_ptr;
+{
+	struct proc *rp;
+	int r;
+
+	/* Who wants to set a parameter? */
+	rp = proc_addr(who_p);
+
+	/* Which parameter is it? */
+	switch(m_ptr->PCTL_REQ) {
+
+		case SYS_PARAM_SET_GRANT:
+			/* Copy grant table set in priv. struct. */
+			if ((rp->p_rts_flags & NO_PRIV) || !(priv(rp))) {
+				r = EPERM;
+			} else {
+				_K_SET_GRANT_TABLE(rp, 
+					(vir_bytes) m_ptr->PCTL_ADDR1,
+					m_ptr->PCTL_INT1);
+				r = OK;
+			}
+			break;
+		default:
+			r = EINVAL;
+			break;
+	}
+
+	return r;
+}

kernel/system/do_privctl.c

@@ -163,12 +163,6 @@ message *m_ptr;			/* pointer to request message */
 	priv(rp)->s_nr_irq++;
 
 	return OK;
-  case SYS_PRIV_SET_GRANTS:
-	if ((rp->p_rts_flags & NO_PRIV) || !(priv(rp))) return(EPERM);
-	_K_SET_GRANT_TABLE(rp, 
-		(vir_bytes) m_ptr->CTL_ARG_PTR, m_ptr->CTL_MM_PRIV);
-	return OK;
-
   default:
 	kprintf("do_privctl: bad request %d\n", m_ptr->CTL_REQUEST);
 	return EINVAL;

kernel/system/do_safecopy.c

@@ -1,5 +1,5 @@
 /* The kernel call implemented in this file:
- *   m_type:	SYS_SAFECOPYFROM or SYS_SAFECOPYTO
+ *   m_type:	SYS_SAFECOPYFROM or SYS_SAFECOPYTO or SYS_VSAFECOPY
  *
  * The parameters for this kernel call are:
  *    	SCP_FROM_TO	other endpoint

lib/syslib/Makefile.in

@@ -49,6 +49,7 @@ libsys_FILES=" \
 	sys_sigreturn.c \
 	sys_sigsend.c \
 	sys_privctl.c \
+	sys_paramctl.c \
 	sys_times.c \
 	sys_trace.c \
 	sys_umap.c \

lib/syslib/safecopies.c

@@ -12,6 +12,8 @@
 #include <stdlib.h>
 #include <minix/syslib.h>
 #include <minix/safecopies.h>
+#include <minix/com.h>
+#include <string.h>
 
 PRIVATE cp_grant_t *grants = NULL;
 PRIVATE int ngrants = 0, dynamic = 1;
@@ -33,8 +35,7 @@ cpf_preallocate(cp_grant_t *new_grants, int new_ngrants)
 	}
 
 	/* Update kernel about the table. */
-	if((s=sys_privctl(SELF, SYS_PRIV_SET_GRANTS,
-		new_ngrants, new_grants))) {
+	if((s=sys_paramctl(SYS_PARAM_SET_GRANT, new_ngrants, new_grants, 0))) {
 		return -1;
 	}
 
@@ -79,7 +80,7 @@ cpf_grow(void)
 		new_grants[g].cp_flags = 0;
 
 	/* Inform kernel about new size (and possibly new location). */
-	if(sys_privctl(SELF, SYS_PRIV_SET_GRANTS, new_size, new_grants)) {
+	if((sys_paramctl(SYS_PARAM_SET_GRANT, new_size, new_grants, 0))) {
 		free(new_grants);
 		return;	/* Failed - don't grow then. */
 	}