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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/um/syscalls_64.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/um/syscalls_64.c')
-rw-r--r--kernel/arch/x86/um/syscalls_64.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/arch/x86/um/syscalls_64.c b/kernel/arch/x86/um/syscalls_64.c
new file mode 100644
index 000000000..adb08eb5c
--- /dev/null
+++ b/kernel/arch/x86/um/syscalls_64.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright 2003 PathScale, Inc.
+ *
+ * Licensed under the GPL
+ */
+
+#include <linux/sched.h>
+#include <asm/prctl.h> /* XXX This should get the constants from libc */
+#include <os.h>
+
+long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
+{
+ unsigned long *ptr = addr, tmp;
+ long ret;
+ int pid = task->mm->context.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 or thread.fs being set instead). So, we let the host
+ * fiddle the registers and thread struct and restore the
+ * registers 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:
+ ret = restore_registers(pid, &current->thread.regs.regs);
+ if (ret)
+ return ret;
+ 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.arch.fs = (unsigned long) ptr;
+ ret = save_registers(pid, &current->thread.regs.regs);
+ break;
+ case ARCH_SET_GS:
+ ret = save_registers(pid, &current->thread.regs.regs);
+ break;
+ case ARCH_GET_FS:
+ ret = put_user(tmp, addr);
+ break;
+ case ARCH_GET_GS:
+ ret = put_user(tmp, addr);
+ break;
+ }
+
+ return ret;
+}
+
+long sys_arch_prctl(int code, unsigned long addr)
+{
+ return arch_prctl(current, code, (unsigned long __user *) addr);
+}
+
+void arch_switch_to(struct task_struct *to)
+{
+ if ((to->thread.arch.fs == 0) || (to->mm == NULL))
+ return;
+
+ arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
+}