提交 ee5c2ab0 编写于 作者: L Linus Torvalds

Merge branch 'x86-fixes-for-linus' of...

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  xen: don't drop NX bit
  xen: mask unwanted pte bits in __supported_pte_mask
  xen: Use wmb instead of rmb in xen_evtchn_do_upcall().
  x86: fix NULL pointer deref in __switch_to
......@@ -1228,6 +1228,11 @@ asmlinkage void __init xen_start_kernel(void)
if (xen_feature(XENFEAT_supervisor_mode_kernel))
pv_info.kernel_rpl = 0;
/* Prevent unwanted bits from being set in PTEs. */
__supported_pte_mask &= ~_PAGE_GLOBAL;
if (!is_initial_xendomain())
__supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
/* set the limit of our address space */
xen_reserve_top();
......
......@@ -179,48 +179,54 @@ void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
preempt_enable();
}
pteval_t xen_pte_val(pte_t pte)
/* Assume pteval_t is equivalent to all the other *val_t types. */
static pteval_t pte_mfn_to_pfn(pteval_t val)
{
pteval_t ret = pte.pte;
if (val & _PAGE_PRESENT) {
unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT;
pteval_t flags = val & ~PTE_MASK;
val = (mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
}
return val;
}
static pteval_t pte_pfn_to_mfn(pteval_t val)
{
if (val & _PAGE_PRESENT) {
unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT;
pteval_t flags = val & ~PTE_MASK;
val = (pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
}
if (ret & _PAGE_PRESENT)
ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
return val;
}
return ret;
pteval_t xen_pte_val(pte_t pte)
{
return pte_mfn_to_pfn(pte.pte);
}
pgdval_t xen_pgd_val(pgd_t pgd)
{
pgdval_t ret = pgd.pgd;
if (ret & _PAGE_PRESENT)
ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
return ret;
return pte_mfn_to_pfn(pgd.pgd);
}
pte_t xen_make_pte(pteval_t pte)
{
if (pte & _PAGE_PRESENT) {
pte = phys_to_machine(XPADDR(pte)).maddr;
pte &= ~(_PAGE_PCD | _PAGE_PWT);
}
return (pte_t){ .pte = pte };
pte = pte_pfn_to_mfn(pte);
return native_make_pte(pte);
}
pgd_t xen_make_pgd(pgdval_t pgd)
{
if (pgd & _PAGE_PRESENT)
pgd = phys_to_machine(XPADDR(pgd)).maddr;
return (pgd_t){ pgd };
pgd = pte_pfn_to_mfn(pgd);
return native_make_pgd(pgd);
}
pmdval_t xen_pmd_val(pmd_t pmd)
{
pmdval_t ret = native_pmd_val(pmd);
if (ret & _PAGE_PRESENT)
ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
return ret;
return pte_mfn_to_pfn(pmd.pmd);
}
#ifdef CONFIG_X86_PAE
void xen_set_pud(pud_t *ptr, pud_t val)
......@@ -267,9 +273,7 @@ void xen_pmd_clear(pmd_t *pmdp)
pmd_t xen_make_pmd(pmdval_t pmd)
{
if (pmd & _PAGE_PRESENT)
pmd = phys_to_machine(XPADDR(pmd)).maddr;
pmd = pte_pfn_to_mfn(pmd);
return native_make_pmd(pmd);
}
#else /* !PAE */
......
......@@ -17,7 +17,7 @@ ENTRY(startup_xen)
__FINIT
.pushsection .bss.page_aligned
.pushsection .text
.align PAGE_SIZE_asm
ENTRY(hypercall_page)
.skip 0x1000
......
......@@ -176,7 +176,7 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
* we set it now, so we can trap and pass that trap to the Guest if it
* uses the FPU. */
if (cpu->ts)
lguest_set_ts();
unlazy_fpu(current);
/* SYSENTER is an optimized way of doing system calls. We can't allow
* it because it always jumps to privilege level 0. A normal Guest
......@@ -196,6 +196,10 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
* trap made the switcher code come back, and an error code which some
* traps set. */
/* Restore SYSENTER if it's supposed to be on. */
if (boot_cpu_has(X86_FEATURE_SEP))
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
/* If the Guest page faulted, then the cr2 register will tell us the
* bad virtual address. We have to grab this now, because once we
* re-enable interrupts an interrupt could fault and thus overwrite
......@@ -203,13 +207,12 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
if (cpu->regs->trapnum == 14)
cpu->arch.last_pagefault = read_cr2();
/* Similarly, if we took a trap because the Guest used the FPU,
* we have to restore the FPU it expects to see. */
* we have to restore the FPU it expects to see.
* math_state_restore() may sleep and we may even move off to
* a different CPU. So all the critical stuff should be done
* before this. */
else if (cpu->regs->trapnum == 7)
math_state_restore();
/* Restore SYSENTER if it's supposed to be on. */
if (boot_cpu_has(X86_FEATURE_SEP))
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
}
/*H:130 Now we've examined the hypercall code; our Guest can make requests.
......
......@@ -529,7 +529,7 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
/* Clear master flag /before/ clearing selector flag. */
rmb();
wmb();
#endif
pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
while (pending_words != 0) {
......
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