X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=kitten%2Farch%2Fx86_64%2Fkernel%2Fsys_arch_prctl.c;fp=kitten%2Farch%2Fx86_64%2Fkernel%2Fsys_arch_prctl.c;h=5243162ee2e4ba93a6f7bfd716dc961c7fbe79ff;hb=66a1a4c7a9edcd7d8bc207aca093d694a6e6b5b2;hp=0000000000000000000000000000000000000000;hpb=f7cf9c19ecb0a589dd45ae0d2c91814bd3c2acc2;p=palacios-OLD.git

diff --git a/kitten/arch/x86_64/kernel/sys_arch_prctl.c b/kitten/arch/x86_64/kernel/sys_arch_prctl.c
new file mode 100644
index 0000000..5243162
--- /dev/null
+++ b/kitten/arch/x86_64/kernel/sys_arch_prctl.c
@@ -0,0 +1,84 @@
+#include <lwk/kernel.h>
+#include <lwk/task.h>
+#include <arch/prctl.h>
+#include <arch/uaccess.h>
+
+
+long
+do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
+{
+	int ret = 0; 
+	int doit = task == current;
+
+	switch (code) { 
+	case ARCH_SET_GS:
+		if (addr >= task->arch.addr_limit)
+			return -EPERM; 
+
+		task->arch.thread.gsindex = 0;
+		task->arch.thread.gs = addr;
+		if (doit) {
+			/* The kernel's %gs is currently loaded, so this
+			   call is needed to set the user version. */
+			load_gs_index(0);
+			ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
+		} 
+
+		break;
+	case ARCH_SET_FS:
+		/* Not strictly needed for fs, but do it for symmetry
+		   with gs */
+		if (addr >= task->arch.addr_limit)
+			return -EPERM; 
+
+		task->arch.thread.fsindex = 0;
+		task->arch.thread.fs = addr;
+		if (doit) {
+			/* The kernel doesn't use %fs so we can set it
+			   directly.  set the selector to 0 to not confuse
+			   __switch_to */
+			asm volatile("movl %0,%%fs" :: "r" (0));
+			ret = checking_wrmsrl(MSR_FS_BASE, addr);
+		}
+
+		break;
+	case ARCH_GET_FS: { 
+		unsigned long base; 
+		if (doit)
+			rdmsrl(MSR_FS_BASE, base);
+		else
+			base = task->arch.thread.fs;
+		ret = put_user(base, (unsigned long __user *)addr); 
+		break; 
+	}
+	case ARCH_GET_GS: { 
+		unsigned long base;
+		unsigned gsindex;
+		if (doit) {
+ 			asm("movl %%gs,%0" : "=r" (gsindex));
+			if (gsindex)
+				rdmsrl(MSR_KERNEL_GS_BASE, base);
+			else
+				base = task->arch.thread.gs;
+		}
+		else
+			base = task->arch.thread.gs;
+		ret = put_user(base, (unsigned long __user *)addr); 
+		break;
+	}
+
+	default:
+		ret = -EINVAL;
+		break;
+	} 
+
+	return ret;	
+}
+
+
+long
+sys_arch_prctl(int code, unsigned long addr)
+{
+	return do_arch_prctl(current, code, addr);
+}
+