Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 225 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
new file mode 100644
index 00000000000..b4b8dc59663
--- /dev/null
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -0,0 +1,225 @@
+/*
+ *  linux/arch/x86_64/kernel/vsyscall.c
+ *
+ *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
+ *  Copyright 2003 Andi Kleen, SuSE Labs.
+ *
+ *  Thanks to hpa@transmeta.com for some useful hint.
+ *  Special thanks to Ingo Molnar for his early experience with
+ *  a different vsyscall implementation for Linux/IA32 and for the name.
+ *
+ *  vsyscall 1 is located at -10Mbyte, vsyscall 2 is located
+ *  at virtual address -10Mbyte+1024bytes etc... There are at max 4
+ *  vsyscalls. One vsyscall can reserve more than 1 slot to avoid
+ *  jumping out of line if necessary. We cannot add more with this
+ *  mechanism because older kernels won't return -ENOSYS.
+ *  If we want more than four we need a vDSO.
+ *
+ *  Note: the concept clashes with user mode linux. If you use UML and
+ *  want per guest time just set the kernel.vsyscall64 sysctl to 0.
+ */
+
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/seqlock.h>
+#include <linux/jiffies.h>
+#include <linux/sysctl.h>
+
+#include <asm/vsyscall.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/fixmap.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+
+#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
+#define force_inline __attribute__((always_inline)) inline
+
+int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
+seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
+
+#include <asm/unistd.h>
+
+static force_inline void timeval_normalize(struct timeval * tv)
+{
+	time_t __sec;
+
+	__sec = tv->tv_usec / 1000000;
+	if (__sec) {
+		tv->tv_usec %= 1000000;
+		tv->tv_sec += __sec;
+	}
+}
+
+static force_inline void do_vgettimeofday(struct timeval * tv)
+{
+	long sequence, t;
+	unsigned long sec, usec;
+
+	do {
+		sequence = read_seqbegin(&__xtime_lock);
+		
+		sec = __xtime.tv_sec;
+		usec = (__xtime.tv_nsec / 1000) +
+			(__jiffies - __wall_jiffies) * (1000000 / HZ);
+
+		if (__vxtime.mode == VXTIME_TSC) {
+			sync_core();
+			rdtscll(t);
+			if (t < __vxtime.last_tsc)
+				t = __vxtime.last_tsc;
+			usec += ((t - __vxtime.last_tsc) *
+				 __vxtime.tsc_quot) >> 32;
+			/* See comment in x86_64 do_gettimeofday. */
+		} else {
+			usec += ((readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0) -
+				  __vxtime.last) * __vxtime.quot) >> 32;
+		}
+	} while (read_seqretry(&__xtime_lock, sequence));
+
+	tv->tv_sec = sec + usec / 1000000;
+	tv->tv_usec = usec % 1000000;
+}
+
+/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
+static force_inline void do_get_tz(struct timezone * tz)
+{
+	*tz = __sys_tz;
+}
+
+static force_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+	int ret;
+	asm volatile("vsysc2: syscall"
+		: "=a" (ret)
+		: "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber );
+	return ret;
+}
+
+static force_inline long time_syscall(long *t)
+{
+	long secs;
+	asm volatile("vsysc1: syscall"
+		: "=a" (secs)
+		: "0" (__NR_time),"D" (t) : __syscall_clobber);
+	return secs;
+}
+
+static int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz)
+{
+	if (unlikely(!__sysctl_vsyscall))
+		return gettimeofday(tv,tz);
+	if (tv)
+		do_vgettimeofday(tv);
+	if (tz)
+		do_get_tz(tz);
+	return 0;
+}
+
+/* This will break when the xtime seconds get inaccurate, but that is
+ * unlikely */
+static time_t __vsyscall(1) vtime(time_t *t)
+{
+	if (unlikely(!__sysctl_vsyscall))
+		return time_syscall(t);
+	else if (t)
+		*t = __xtime.tv_sec;		
+	return __xtime.tv_sec;
+}
+
+static long __vsyscall(2) venosys_0(void)
+{
+	return -ENOSYS;
+}
+
+static long __vsyscall(3) venosys_1(void)
+{
+	return -ENOSYS;
+}
+
+#ifdef CONFIG_SYSCTL
+
+#define SYSCALL 0x050f
+#define NOP2    0x9090
+
+/*
+ * NOP out syscall in vsyscall page when not needed.
+ */
+static int vsyscall_sysctl_change(ctl_table *ctl, int write, struct file * filp,
+                        void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	extern u16 vsysc1, vsysc2;
+	u16 *map1, *map2;
+	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+	if (!write)
+		return ret;
+	/* gcc has some trouble with __va(__pa()), so just do it this
+	   way. */
+	map1 = ioremap(__pa_symbol(&vsysc1), 2);
+	if (!map1)
+		return -ENOMEM;
+	map2 = ioremap(__pa_symbol(&vsysc2), 2);
+	if (!map2) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	if (!sysctl_vsyscall) {
+		*map1 = SYSCALL;
+		*map2 = SYSCALL;
+	} else {
+		*map1 = NOP2;
+		*map2 = NOP2;
+	}
+	iounmap(map2);
+out:
+	iounmap(map1);
+	return ret;
+}
+
+static int vsyscall_sysctl_nostrat(ctl_table *t, int __user *name, int nlen,
+				void __user *oldval, size_t __user *oldlenp,
+				void __user *newval, size_t newlen,
+				void **context)
+{
+	return -ENOSYS;
+}
+
+static ctl_table kernel_table2[] = {
+	{ .ctl_name = 99, .procname = "vsyscall64",
+	  .data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644,
+	  .strategy = vsyscall_sysctl_nostrat,
+	  .proc_handler = vsyscall_sysctl_change },
+	{ 0, }
+};
+
+static ctl_table kernel_root_table2[] = {
+	{ .ctl_name = CTL_KERN, .procname = "kernel", .mode = 0555,
+	  .child = kernel_table2 },
+	{ 0 },
+};
+
+#endif
+
+static void __init map_vsyscall(void)
+{
+	extern char __vsyscall_0;
+	unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0);
+
+	__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
+}
+
+static int __init vsyscall_init(void)
+{
+	BUG_ON(((unsigned long) &vgettimeofday !=
+			VSYSCALL_ADDR(__NR_vgettimeofday)));
+	BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime));
+	BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE)));
+	map_vsyscall();
+	sysctl_vsyscall = 1;
+	register_sysctl_table(kernel_root_table2, 0);
+	return 0;
+}
+
+__initcall(vsyscall_init);