X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fum%2Fsys-x86_64%2Fsyscalls.c;h=6d5605b7b2dd385b614317a3e22ae9a687b5b000;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=9cf624fa169e69d1836b9f3bb3afa914253fdbc6;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 9cf624fa1..6d5605b7b 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -9,7 +9,6 @@
 #include "linux/shm.h"
 #include "linux/utsname.h"
 #include "linux/personality.h"
-#include "linux/vs_cvirt.h"
 #include "asm/uaccess.h"
 #define __FRAME_OFFSETS
 #include "asm/ptrace.h"
@@ -17,12 +16,13 @@
 #include "asm/prctl.h" /* XXX This should get the constants from libc */
 #include "choose-mode.h"
 #include "kern.h"
+#include "os.h"
 
 asmlinkage long sys_uname64(struct new_utsname __user * name)
 {
 	int err;
 	down_read(&uts_sem);
-	err = copy_to_user(name, vx_new_utsname(), sizeof (*name));
+	err = copy_to_user(name, utsname(), sizeof (*name));
 	up_read(&uts_sem);
 	if (personality(current->personality) == PER_LINUX32)
 		err |= copy_to_user(&name->machine, "i686", 5);
@@ -46,7 +46,7 @@ static long arch_prctl_tt(int code, unsigned long addr)
 	case ARCH_GET_GS:
 		ret = arch_prctl(code, (unsigned long) &tmp);
 		if(!ret)
-			ret = put_user(tmp, &addr);
+			ret = put_user(tmp, (long __user *)addr);
 		break;
 	default:
 		ret = -EINVAL;
@@ -59,40 +59,70 @@ static long arch_prctl_tt(int code, unsigned long addr)
 
 #ifdef CONFIG_MODE_SKAS
 
-/* XXX: Must also call arch_prctl in the host, beside saving the segment bases! */
-static long arch_prctl_skas(int code, unsigned long addr)
+static long arch_prctl_skas(int code, unsigned long __user *addr)
 {
-	long ret = 0;
+	unsigned long *ptr = addr, tmp;
+	long ret;
+	int pid = current->mm->context.skas.id.u.pid;
+
+	/*
+	 * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
+	 * be safe), we need to call arch_prctl on the host because
+	 * setting %fs may result in something else happening (like a
+	 * GDT being set instead).  So, we let the host fiddle the
+	 * registers and restore them afterwards.
+	 *
+	 * So, the saved registers are stored to the process (this
+	 * needed because a stub may have been the last thing to run),
+	 * arch_prctl is run on the host, then the registers are read
+	 * back.
+	 */
+	switch(code){
+	case ARCH_SET_FS:
+	case ARCH_SET_GS:
+		restore_registers(pid, &current->thread.regs.regs);
+		break;
+	case ARCH_GET_FS:
+	case ARCH_GET_GS:
+		/*
+		 * With these two, we read to a local pointer and
+		 * put_user it to the userspace pointer that we were
+		 * given.  If addr isn't valid (because it hasn't been
+		 * faulted in or is just bogus), we want put_user to
+		 * fault it in (or return -EFAULT) instead of having
+		 * the host return -EFAULT.
+		 */
+		ptr = &tmp;
+	}
+
+	ret = os_arch_prctl(pid, code, ptr);
+	if(ret)
+		return ret;
 
 	switch(code){
 	case ARCH_SET_FS:
-		current->thread.regs.regs.skas.regs[FS_BASE / sizeof(unsigned long)] = addr;
+		current->thread.arch.fs = (unsigned long) ptr;
+		save_registers(pid, &current->thread.regs.regs);
 		break;
 	case ARCH_SET_GS:
-		current->thread.regs.regs.skas.regs[GS_BASE / sizeof(unsigned long)] = addr;
+		save_registers(pid, &current->thread.regs.regs);
 		break;
 	case ARCH_GET_FS:
-		ret = put_user(current->thread.regs.regs.skas.
-				regs[FS_BASE / sizeof(unsigned long)],
-				(unsigned long __user *)addr);
-	        break;
+		ret = put_user(tmp, addr);
+		break;
 	case ARCH_GET_GS:
-		ret = put_user(current->thread.regs.regs.skas.
-				regs[GS_BASE / sizeof(unsigned long)],
-				(unsigned long __user *)addr);
-	        break;
-	default:
-		ret = -EINVAL;
+		ret = put_user(tmp, addr);
 		break;
 	}
 
-	return(ret);
+	return ret;
 }
 #endif
 
 long sys_arch_prctl(int code, unsigned long addr)
 {
-	return(CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code, addr));
+	return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code,
+				(unsigned long __user *) addr);
 }
 
 long sys_clone(unsigned long clone_flags, unsigned long newsp,
@@ -106,5 +136,14 @@ long sys_clone(unsigned long clone_flags, unsigned long newsp,
 	ret = do_fork(clone_flags, newsp, &current->thread.regs, 0, parent_tid,
 		      child_tid);
 	current->thread.forking = 0;
-	return(ret);
+	return ret;
 }
+
+void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
+{
+	if((to->thread.arch.fs == 0) || (to->mm == NULL))
+		return;
+
+	arch_prctl_skas(ARCH_SET_FS, (void __user *) to->thread.arch.fs);
+}
+