Fix for the panic("vm_thread_new: kstack allocation failed") and

silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with:	Peter Holm
Reviewed by:	jhb

7 files changed, 8 insertions, 7 deletions

diff --git a/sys/arm/arm/pmap.c b/sys/arm/arm/pmap.c
index 2dbbe6e..4978460 100644
--- a/sys/arm/arm/pmap.c
+++ b/sys/arm/arm/pmap.c
@@ -3813,7 +3813,7 @@ pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
  * such as one in a vmspace structure.
  */
 
-void
+int
 pmap_pinit(pmap_t pmap)
 {
 	PDEBUG(1, printf("pmap_pinit: pmap = %08x\n", (uint32_t) pmap));
@@ -3832,6 +3832,7 @@ pmap_pinit(pmap_t pmap)
 		pmap_enter(pmap, vector_page, PHYS_TO_VM_PAGE(systempage.pv_pa),
 		    VM_PROT_READ, 1);
 	} 
+	return (1);
 }
 
 
diff --git a/sys/arm/at91/kb920x_machdep.c b/sys/arm/at91/kb920x_machdep.c
index 2647e61..f58a327 100644
--- a/sys/arm/at91/kb920x_machdep.c
+++ b/sys/arm/at91/kb920x_machdep.c
@@ -449,7 +449,7 @@ initarm(void *arg, void *arg2)
 	undefined_handler_address = (u_int)undefinedinstruction_bounce;
 	undefined_init();
 				
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
 		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
diff --git a/sys/arm/sa11x0/assabet_machdep.c b/sys/arm/sa11x0/assabet_machdep.c
index 482f3a5..195a4fb 100644
--- a/sys/arm/sa11x0/assabet_machdep.c
+++ b/sys/arm/sa11x0/assabet_machdep.c
@@ -422,7 +422,7 @@ initarm(void *arg, void *arg2)
 
 	/* Set stack for exception handlers */
 	
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
 		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
diff --git a/sys/arm/xscale/i80321/ep80219_machdep.c b/sys/arm/xscale/i80321/ep80219_machdep.c
index 2eee7e1..c0dda49 100644
--- a/sys/arm/xscale/i80321/ep80219_machdep.c
+++ b/sys/arm/xscale/i80321/ep80219_machdep.c
@@ -426,7 +426,7 @@ initarm(void *arg, void *arg2)
 	undefined_handler_address = (u_int)undefinedinstruction_bounce;
 	undefined_init();
 				
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
 		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
diff --git a/sys/arm/xscale/i80321/iq31244_machdep.c b/sys/arm/xscale/i80321/iq31244_machdep.c
index 2e4433e..ef8d0eb 100644
--- a/sys/arm/xscale/i80321/iq31244_machdep.c
+++ b/sys/arm/xscale/i80321/iq31244_machdep.c
@@ -424,7 +424,7 @@ initarm(void *arg, void *arg2)
 	undefined_handler_address = (u_int)undefinedinstruction_bounce;
 	undefined_init();
 				
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
 		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
diff --git a/sys/arm/xscale/i8134x/crb_machdep.c b/sys/arm/xscale/i8134x/crb_machdep.c
index d29693f..0c6475a 100644
--- a/sys/arm/xscale/i8134x/crb_machdep.c
+++ b/sys/arm/xscale/i8134x/crb_machdep.c
@@ -409,7 +409,7 @@ initarm(void *arg, void *arg2)
 #ifdef KSE
 	proc_linkup(&proc0, &ksegrp0, &thread0);
 #else
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 #endif
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
diff --git a/sys/arm/xscale/ixp425/avila_machdep.c b/sys/arm/xscale/ixp425/avila_machdep.c
index c02ddd3..71d7f71 100644
--- a/sys/arm/xscale/ixp425/avila_machdep.c
+++ b/sys/arm/xscale/ixp425/avila_machdep.c
@@ -490,7 +490,7 @@ initarm(void *arg, void *arg2)
 	undefined_handler_address = (u_int)undefinedinstruction_bounce;
 	undefined_init();
 				
-	proc_linkup(&proc0, &thread0);
+	proc_linkup0(&proc0, &thread0);
 	thread0.td_kstack = kernelstack.pv_va;
 	thread0.td_pcb = (struct pcb *)
 		(thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;