Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: Do not append space to guests kernel command line
  lguest: Revert 1ce70c4fac, fix real problem.
  lguest: Sanitize the lguest clock.
  lguest: fix __get_vm_area usage.
  lguest: make sure cpu is initialized before accessing it
This commit is contained in:
Linus Torvalds 2008-03-10 18:03:20 -07:00
commit aeb24d2fb0
5 changed files with 50 additions and 46 deletions

View File

@ -486,9 +486,12 @@ static void concat(char *dst, char *args[])
unsigned int i, len = 0;
for (i = 0; args[i]; i++) {
strcpy(dst+len, args[i]);
if (i) {
strcat(dst+len, " ");
len += strlen(args[i]) + 1;
len++;
}
strcpy(dst+len, args[i]);
len += strlen(args[i]);
}
/* In case it's empty. */
dst[len] = '\0';

View File

@ -84,7 +84,6 @@ struct lguest_data lguest_data = {
.blocked_interrupts = { 1 }, /* Block timer interrupts */
.syscall_vec = SYSCALL_VECTOR,
};
static cycle_t clock_base;
/*G:037 async_hcall() is pretty simple: I'm quite proud of it really. We have a
* ring buffer of stored hypercalls which the Host will run though next time we
@ -327,8 +326,8 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx,
case 1: /* Basic feature request. */
/* We only allow kernel to see SSE3, CMPXCHG16B and SSSE3 */
*cx &= 0x00002201;
/* SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, FPU. */
*dx &= 0x07808101;
/* SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, TSC, FPU. */
*dx &= 0x07808111;
/* The Host can do a nice optimization if it knows that the
* kernel mappings (addresses above 0xC0000000 or whatever
* PAGE_OFFSET is set to) haven't changed. But Linux calls
@ -481,7 +480,7 @@ static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
*pmdp = pmdval;
lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK,
(__pa(pmdp)&(PAGE_SIZE-1)), 0);
(__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
}
/* There are a couple of legacy places where the kernel sets a PTE, but we
@ -595,19 +594,25 @@ static unsigned long lguest_get_wallclock(void)
return lguest_data.time.tv_sec;
}
/* The TSC is a Time Stamp Counter. The Host tells us what speed it runs at,
* or 0 if it's unusable as a reliable clock source. This matches what we want
* here: if we return 0 from this function, the x86 TSC clock will not register
* itself. */
static unsigned long lguest_cpu_khz(void)
{
return lguest_data.tsc_khz;
}
/* If we can't use the TSC, the kernel falls back to our "lguest_clock", where
* we read the time value given to us by the Host. */
static cycle_t lguest_clock_read(void)
{
unsigned long sec, nsec;
/* If the Host tells the TSC speed, we can trust that. */
if (lguest_data.tsc_khz)
return native_read_tsc();
/* If we can't use the TSC, we read the time value written by the Host.
* Since it's in two parts (seconds and nanoseconds), we risk reading
* it just as it's changing from 99 & 0.999999999 to 100 and 0, and
* getting 99 and 0. As Linux tends to come apart under the stress of
* time travel, we must be careful: */
/* Since the time is in two parts (seconds and nanoseconds), we risk
* reading it just as it's changing from 99 & 0.999999999 to 100 and 0,
* and getting 99 and 0. As Linux tends to come apart under the stress
* of time travel, we must be careful: */
do {
/* First we read the seconds part. */
sec = lguest_data.time.tv_sec;
@ -622,14 +627,14 @@ static cycle_t lguest_clock_read(void)
/* Now if the seconds part has changed, try again. */
} while (unlikely(lguest_data.time.tv_sec != sec));
/* Our non-TSC clock is in real nanoseconds. */
/* Our lguest clock is in real nanoseconds. */
return sec*1000000000ULL + nsec;
}
/* This is what we tell the kernel is our clocksource. */
/* This is the fallback clocksource: lower priority than the TSC clocksource. */
static struct clocksource lguest_clock = {
.name = "lguest",
.rating = 400,
.rating = 200,
.read = lguest_clock_read,
.mask = CLOCKSOURCE_MASK(64),
.mult = 1 << 22,
@ -637,12 +642,6 @@ static struct clocksource lguest_clock = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
/* The "scheduler clock" is just our real clock, adjusted to start at zero */
static unsigned long long lguest_sched_clock(void)
{
return cyc2ns(&lguest_clock, lguest_clock_read() - clock_base);
}
/* We also need a "struct clock_event_device": Linux asks us to set it to go
* off some time in the future. Actually, James Morris figured all this out, I
* just applied the patch. */
@ -712,19 +711,8 @@ static void lguest_time_init(void)
/* Set up the timer interrupt (0) to go to our simple timer routine */
set_irq_handler(0, lguest_time_irq);
/* Our clock structure looks like arch/x86/kernel/tsc_32.c if we can
* use the TSC, otherwise it's a dumb nanosecond-resolution clock.
* Either way, the "rating" is set so high that it's always chosen over
* any other clocksource. */
if (lguest_data.tsc_khz)
lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz,
lguest_clock.shift);
clock_base = lguest_clock_read();
clocksource_register(&lguest_clock);
/* Now we've set up our clock, we can use it as the scheduler clock */
pv_time_ops.sched_clock = lguest_sched_clock;
/* We can't set cpumask in the initializer: damn C limitations! Set it
* here and register our timer device. */
lguest_clockevent.cpumask = cpumask_of_cpu(0);
@ -995,6 +983,7 @@ __init void lguest_init(void)
/* time operations */
pv_time_ops.get_wallclock = lguest_get_wallclock;
pv_time_ops.time_init = lguest_time_init;
pv_time_ops.get_cpu_khz = lguest_cpu_khz;
/* Now is a good time to look at the implementations of these functions
* before returning to the rest of lguest_init(). */

View File

@ -69,11 +69,22 @@ static __init int map_switcher(void)
switcher_page[i] = virt_to_page(addr);
}
/* First we check that the Switcher won't overlap the fixmap area at
* the top of memory. It's currently nowhere near, but it could have
* very strange effects if it ever happened. */
if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
err = -ENOMEM;
printk("lguest: mapping switcher would thwack fixmap\n");
goto free_pages;
}
/* Now we reserve the "virtual memory area" we want: 0xFFC00000
* (SWITCHER_ADDR). We might not get it in theory, but in practice
* it's worked so far. */
* it's worked so far. The end address needs +1 because __get_vm_area
* allocates an extra guard page, so we need space for that. */
switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
VM_ALLOC, SWITCHER_ADDR, VMALLOC_END);
VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
+ (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
if (!switcher_vma) {
err = -ENOMEM;
printk("lguest: could not map switcher pages high\n");

View File

@ -241,15 +241,16 @@ static ssize_t write(struct file *file, const char __user *in,
cpu = &lg->cpus[cpu_id];
if (!cpu)
return -EINVAL;
}
/* Once the Guest is dead, all you can do is read() why it died. */
if (lg && lg->dead)
/* Once the Guest is dead, you can only read() why it died. */
if (lg->dead)
return -ENOENT;
/* If you're not the task which owns the Guest, you can only break */
if (lg && current != cpu->tsk && req != LHREQ_BREAK)
/* If you're not the task which owns the Guest, all you can do
* is break the Launcher out of running the Guest. */
if (current != cpu->tsk && req != LHREQ_BREAK)
return -EPERM;
}
switch (req) {
case LHREQ_INITIALIZE:

View File

@ -391,7 +391,7 @@ static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
if (lg->pgdirs[i].gpgdir == pgtable)
if (lg->pgdirs[i].pgdir && lg->pgdirs[i].gpgdir == pgtable)
break;
return i;
}