From: David van Moolenbroek <david@minix3.org>
Date: Sun, 8 Jan 2012 23:38:29 +0000 (+0100)
Subject: Kernel: introduce vm_check_range
X-Git-Tag: v3.2.1~652
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=2a395dd8b49deafabdf073460786ad8873fde762;p=minix.git

Kernel: introduce vm_check_range
---

diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index 9fceb45ac..ba369bcb4 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -531,6 +531,34 @@ PRIVATE void vm_suspend(struct proc *caller, const struct proc *target,
 	vmrequest = caller;
 }
 
+/*===========================================================================*
+ *				vm_check_range				     *
+ *===========================================================================*/
+PUBLIC int vm_check_range(struct proc *caller, struct proc *target,
+	vir_bytes vir_addr, size_t bytes)
+{
+	/* Public interface to vm_suspend(), for use by kernel calls. On behalf
+	 * of 'caller', call into VM to check linear virtual address range of
+	 * process 'target', starting at 'vir_addr', for 'bytes' bytes. This
+	 * function assumes that it will called twice if VM returned an error
+	 * the first time (since nothing has changed in that case), and will
+	 * then return the error code resulting from the first call. Upon the
+	 * first call, a non-success error code is returned as well.
+	 */
+	int r;
+
+	if (!vm_running)
+		return EFAULT;
+
+	if ((caller->p_misc_flags & MF_KCALL_RESUME) &&
+			(r = caller->p_vmrequest.vmresult) != OK)
+		return r;
+
+	vm_suspend(caller, target, vir_addr, bytes, VMSTYPE_KERNELCALL);
+
+	return VMSUSPEND;
+}
+
 /*===========================================================================*
  *                              delivermsg                                *
  *===========================================================================*/
diff --git a/kernel/proto.h b/kernel/proto.h
index 4ba3328b3..764341e74 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -211,6 +211,8 @@ _PROTOTYPE( void proc_stacktrace, (struct proc *proc)	         );
 _PROTOTYPE( int vm_lookup, (const struct proc *proc, vir_bytes virtual, phys_bytes *result, u32_t *ptent));
 _PROTOTYPE( size_t vm_lookup_range, (const struct proc *proc,
 	vir_bytes vir_addr, phys_bytes *phys_addr, size_t bytes)	);
+_PROTOTYPE( int vm_check_range, (struct proc *caller,
+	struct proc *target, vir_bytes vir_addr, size_t bytes)		);
 _PROTOTYPE( void delivermsg, (struct proc *target));
 _PROTOTYPE( void arch_do_syscall, (struct proc *proc)			);
 _PROTOTYPE( int arch_phys_map, (int index, phys_bytes *addr,