A number of bug fixes from UML 2.4.19-6 -

Fixed the net crash seen when slab debugging is enabled
Fixed PROT_NONE
Fixed the 'tracing myself' bug seen on umlcoop.  This was caused by
a number of SIGALRM handlers nesting on the idle thread stack because
the system was busy enough that UML couldn't clear one before the
next arrived.

arch/um/drivers/net_kern.c

@@ -280,11 +280,6 @@ static int eth_configure(struct uml_net *device, int n)
 	device->dev = dev;
 
 	(*device->kern->init)(dev, device->transport_index);
-	rtnl_lock();
-	err = register_netdevice(dev);
-	rtnl_unlock();
-	if(err)
-		return(1);
 
 	dev->mtu = device->user->max_packet;
 	dev->open = uml_net_open;
@@ -298,7 +293,36 @@ static int eth_configure(struct uml_net *device, int n)
 	dev->do_ioctl = uml_net_ioctl;
 	dev->watchdog_timeo = (HZ >> 1);
 	dev->irq = UM_ETH_IRQ;
+	dev->init = NULL;
+	dev->master = NULL;
+	dev->neigh_setup = NULL;
+	dev->owner = NULL;
+	dev->state = 0;
+	dev->next_sched = 0;
+	dev->get_wireless_stats = 0;
+	dev->wireless_handlers = 0;
+	dev->gflags = 0;
+	dev->mc_list = NULL;
+	dev->mc_count = 0;
+	dev->promiscuity = 0;
+	dev->atalk_ptr = NULL;
+	dev->ip_ptr = NULL;
+	dev->dn_ptr = NULL;
+	dev->ip6_ptr = NULL;
+	dev->ec_ptr = NULL;
+	atomic_set(&dev->refcnt, 0);
+	dev->features = 0;
+	dev->uninit = NULL;
+	dev->destructor = NULL;
+	dev->set_config = NULL;
+	dev->accept_fastpath = 0;
+	dev->br_port = 0;
 
+	rtnl_lock();
+	err = register_netdevice(dev);
+	rtnl_unlock();
+	if(err)
+		return(1);
 	lp = dev->priv;
 
 	/* lp.user is the first four bytes of the transport data, which

arch/um/drivers/port_kern.c

@@ -53,7 +53,7 @@ static void pipe_interrupt(int irq, void *data, struct pt_regs *regs)
 
  	fd = os_rcv_fd(conn->socket[0], &conn->helper_pid);
 	if(fd < 0){
-		printk("os_accept_connection returned %d\n", -fd);
+		printk("os_rcv_fd returned %d\n", -fd);
 		os_close_file(conn->fd);
 	}
 	conn->fd = fd;

arch/um/include/kern.h

@@ -25,6 +25,7 @@ extern void *sbrk(int increment);
 extern void *malloc(int size);
 extern void perror(char *err);
 extern int kill(int pid, int sig);
+extern int getpid(void);
 extern int getuid(void);
 extern int pause(void);
 extern int write(int, const void *, int);

arch/um/include/time_user.h

+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#ifndef __TIME_USER_H__
+#define __TIME_USER_H__
+
+extern void timer(void);
+extern void get_profile_timer(void);
+extern void disable_profile_timer(void);
+extern void switch_timers(int to_real);
+extern void user_time_init(void);
+extern void set_timers(int set_signal);
+extern void idle_sleep(int secs);
+
+#endif

arch/um/kernel/process.c

@@ -35,6 +35,7 @@
 #include "irq_user.h"
 #include "syscall_user.h"
 #include "ptrace_user.h"
+#include "time_user.h"
 #include "init.h"
 #include "os.h"
 

arch/um/kernel/process_kern.c

@@ -34,6 +34,7 @@
 #include "init.h"
 #include "irq_user.h"
 #include "mem_user.h"
+#include "time_user.h"
 #include "tlb.h"
 #include "frame_kern.h"
 #include "sigcontext.h"

arch/um/kernel/time.c

@@ -53,6 +53,28 @@ static void set_interval(int timer_type)
 		panic("setitimer failed - errno = %d\n", errno);
 }
 
+void switch_timers(int to_real)
+{
+	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
+							{ 0, 1000000/hz() }});
+	int old, new;
+
+	if(to_real){
+		old = ITIMER_VIRTUAL;
+		new = ITIMER_REAL;
+	}
+	else {
+		old = ITIMER_REAL;
+		new = ITIMER_VIRTUAL;
+	}
+
+	if((setitimer(old, &disable, NULL) < 0) ||
+	   (setitimer(new, &enable, NULL)))
+		printk("switch_timers - setitimer failed, errno = %d\n",
+		       errno);
+}
+
 void idle_timer(void)
 {
 	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)

arch/um/kernel/time_kern.c

@@ -16,6 +16,7 @@
 #include "asm/current.h"
 #include "kern_util.h"
 #include "user_util.h"
+#include "time_user.h"
 
 u64 jiffies_64;
 

arch/um/kernel/tlb.c

@@ -99,7 +99,7 @@ void flush_kernel_range(unsigned long start, unsigned long end, int update_seq)
 	int updated = 0, err;
 
 	mm = &init_mm;
-	for(addr = start_vm; addr < end_vm;){
+	for(addr = start; addr < end;){
 		pgd = pgd_offset(mm, addr);
 		pmd = pmd_offset(pgd, addr);
 		if(pmd_present(*pmd)){

arch/um/kernel/trap_user.c

@@ -34,6 +34,7 @@
 #include "frame_user.h"
 #include "syscall_user.h"
 #include "ptrace_user.h"
+#include "time_user.h"
 #include "task.h"
 #include "os.h"
 
@@ -517,7 +518,14 @@ void alarm_handler(int sig, struct sigcontext sc)
 	user = user_context(SC_SP(&sc));
 	if(!user && !kern_timer_on) return;
 	if(!user && jail_timer_off) return;
+
+	if(sig == SIGALRM)
+		switch_timers(0);
+
 	sig_handler_common(sig, &sc);
+
+	if(sig == SIGALRM)
+		switch_timers(1);
 }
 
 void do_longjmp(void *p)

include/asm-um/pgtable.h

@@ -226,11 +226,25 @@ static inline void set_pte(pte_t *pteptr, pte_t pteval)
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
  */
-static inline int pte_read(pte_t pte)	{ return pte_val(pte) & _PAGE_USER; }
-static inline int pte_exec(pte_t pte)	{ return pte_val(pte) & _PAGE_USER; }
+static inline int pte_read(pte_t pte)
+{ 
+	return((pte_val(pte) & _PAGE_USER) && 
+	       !(pte_val(pte) & _PAGE_PROTNONE));
+}
+
+static inline int pte_exec(pte_t pte){
+	return((pte_val(pte) & _PAGE_USER) &&
+	       !(pte_val(pte) & _PAGE_PROTNONE));
+}
+
+static inline int pte_write(pte_t pte)
+{
+	return((pte_val(pte) & _PAGE_RW) &&
+	       !(pte_val(pte) & _PAGE_PROTNONE));
+}
+
 static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_DIRTY; }
 static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
-static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_RW; }
 static inline int pte_newpage(pte_t pte) { return pte_val(pte) & _PAGE_NEWPAGE; }
 static inline int pte_newprot(pte_t pte)
 {