Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / x86 / vdso / vdso32-setup.c

diff --git a/kernel/arch/x86/vdso/vdso32-setup.c b/kernel/arch/x86/vdso/vdso32-setup.c
new file mode 100644 (file)
index 0000000..e904c27
--- /dev/null
+++ b/kernel/arch/x86/vdso/vdso32-setup.c
@@ -0,0 +1,120 @@
+/*
+ * (C) Copyright 2002 Linus Torvalds
+ * Portions based on the vdso-randomization code from exec-shield:
+ * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
+ *
+ * This file contains the needed initializations to support sysenter.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
+
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+#include <asm/vdso.h>
+
+#ifdef CONFIG_COMPAT_VDSO
+#define VDSO_DEFAULT   0
+#else
+#define VDSO_DEFAULT   1
+#endif
+
+/*
+ * Should the kernel map a VDSO page into processes and pass its
+ * address down to glibc upon exec()?
+ */
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
+
+static int __init vdso32_setup(char *s)
+{
+       vdso32_enabled = simple_strtoul(s, NULL, 0);
+
+       if (vdso32_enabled > 1)
+               pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
+
+       return 1;
+}
+
+/*
+ * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
+ * behavior on both 64-bit and 32-bit kernels.
+ * On 32-bit kernels, vdso=[012] means the same thing.
+ */
+__setup("vdso32=", vdso32_setup);
+
+#ifdef CONFIG_X86_32
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
+#endif
+
+#ifdef CONFIG_X86_64
+
+#define        vdso32_sysenter()       (boot_cpu_has(X86_FEATURE_SYSENTER32))
+#define        vdso32_syscall()        (boot_cpu_has(X86_FEATURE_SYSCALL32))
+
+#else  /* CONFIG_X86_32 */
+
+#define vdso32_sysenter()      (boot_cpu_has(X86_FEATURE_SEP))
+#define vdso32_syscall()       (0)
+
+#endif /* CONFIG_X86_64 */
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+const struct vdso_image *selected_vdso32;
+#endif
+
+int __init sysenter_setup(void)
+{
+#ifdef CONFIG_COMPAT
+       if (vdso32_syscall())
+               selected_vdso32 = &vdso_image_32_syscall;
+       else
+#endif
+       if (vdso32_sysenter())
+               selected_vdso32 = &vdso_image_32_sysenter;
+       else
+               selected_vdso32 = &vdso_image_32_int80;
+
+       init_vdso_image(selected_vdso32);
+
+       return 0;
+}
+
+#ifdef CONFIG_X86_64
+
+subsys_initcall(sysenter_setup);
+
+#ifdef CONFIG_SYSCTL
+/* Register vsyscall32 into the ABI table */
+#include <linux/sysctl.h>
+
+static struct ctl_table abi_table2[] = {
+       {
+               .procname       = "vsyscall32",
+               .data           = &vdso32_enabled,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec
+       },
+       {}
+};
+
+static struct ctl_table abi_root_table2[] = {
+       {
+               .procname = "abi",
+               .mode = 0555,
+               .child = abi_table2
+       },
+       {}
+};
+
+static __init int ia32_binfmt_init(void)
+{
+       register_sysctl_table(abi_root_table2);
+       return 0;
+}
+__initcall(ia32_binfmt_init);
+#endif /* CONFIG_SYSCTL */
+
+#endif /* CONFIG_X86_64 */