bitkeeper revision 1.191 (3ead448eiWx9DnIJDafKeaW69PFN8g)

Merge scramble.cl.cam.ac.uk:/auto/groups/xeno/BK/xeno.bk
into scramble.cl.cam.ac.uk:/local/scratch/kaf24/ach-xeno

4 files changed, 39 insertions, 6 deletions

diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/ioport.c b/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/ioport.c
index 798c5c5c1f..c43daee3fd 100644
--- a/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/ioport.c
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/ioport.c
@@ -7,13 +7,30 @@
 
 asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 {
-    /* No IO permission! */
-		return -EPERM;
+    /* No IO permission! Selective IO perms aren't virtualised yet. */
+    return -EPERM;
 }
 
 
 asmlinkage int sys_iopl(unsigned long unused)
 {
-    /* The hypervisor won't allow it! */
-			return -EPERM;
+    struct pt_regs *regs = (struct pt_regs *)&unused;
+    unsigned int level = regs->ebx;
+    unsigned int old = (regs->eflags >> 12) & 3;
+
+    if ( !(start_info.flags & SIF_PRIVILEGED) )
+        return -EPERM;
+
+    if ( level > 3 )
+        return -EINVAL;
+    if ( (level > old) && !capable(CAP_SYS_RAWIO) )
+        return -EPERM;
+    
+    /* Change the one on our stack for sanity's sake. */
+    regs->eflags = (regs->eflags & 0xffffcfff) | (level << 12);
+
+    /* Force the change at ring 0. */
+    HYPERVISOR_iopl(level);
+
+    return 0;
 }
diff --git a/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/process.c b/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/process.c
index d4db667474..a7c0755d38 100644
--- a/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/process.c
+++ b/xenolinux-2.4.21-pre4-sparse/arch/xeno/kernel/process.c
@@ -363,7 +363,12 @@ void __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
     }
 
     if ( next->esp0 != 0 )
+    {
         queue_multicall2(__HYPERVISOR_stack_switch, __KERNEL_DS, next->esp0);
+        /* Next call will silently fail if we are a non-privileged guest OS. */
+        queue_multicall1(__HYPERVISOR_iopl, 
+                         ((((struct pt_regs *)next->esp0)-1)->eflags>>12)&3);
+    }
 
     /* EXECUTE ALL TASK SWITCH XEN SYSCALLS AT THIS POINT. */
     execute_multicall_list();
diff --git a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
index 935ea3a6ef..887a01b231 100644
--- a/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
+++ b/xenolinux-2.4.21-pre4-sparse/include/asm-xeno/hypervisor.h
@@ -11,7 +11,7 @@
 
 #include <asm/hypervisor-ifs/hypervisor-if.h>
 #include <asm/ptrace.h>
-#include <asm/page.h>
+//#include <asm/page.h>
 
 /* arch/xeno/kernel/setup.c */
 union start_info_union
@@ -353,7 +353,6 @@ static inline int HYPERVISOR_multicall(void *call_list, int nr_calls)
     return ret;
 }
 
-
 static inline long HYPERVISOR_kbd_op(unsigned char op, unsigned char val)
 {
     int ret;
@@ -365,4 +364,15 @@ static inline long HYPERVISOR_kbd_op(unsigned char op, unsigned char val)
     return ret;
 }
 
+static inline long HYPERVISOR_iopl(unsigned int new_iopl)
+{
+    int ret;
+    __asm__ __volatile__ (
+        TRAP_INSTR
+        : "=a" (ret) : "0" (__HYPERVISOR_iopl),
+        "b" (new_iopl) );
+
+    return ret;
+}
+
 #endif /* __HYPERVISOR_H__ */
diff --git a/xenolinux-2.4.21-pre4-sparse/mkbuildtree b/xenolinux-2.4.21-pre4-sparse/mkbuildtree
index 8749150889..38f76d7e2b 100755
--- a/xenolinux-2.4.21-pre4-sparse/mkbuildtree
+++ b/xenolinux-2.4.21-pre4-sparse/mkbuildtree
@@ -23,6 +23,7 @@ rm -f ${D}/mkbuildtree
 ## subdirectories.
 
 # This first symlink is special: it links to shared files in Xen's source tree
+rm -f ${D}/include/asm-xeno/hypervisor-ifs
 ln -sf `pwd`/../xen/include/hypervisor-ifs ${D}/include/asm-xeno/hypervisor-ifs
 
 # The remainder are the i386 -> xeno-i386 links