diff options
Diffstat (limited to 'drivers/lguest/page_tables.c')
| -rw-r--r-- | drivers/lguest/page_tables.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index e8b55c3a6170..69c35caa955a 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -647,7 +647,7 @@ void guest_pagetable_flush_user(struct lg_cpu *cpu) /*:*/ /* We walk down the guest page tables to get a guest-physical address */ -unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr) +bool __guest_pa(struct lg_cpu *cpu, unsigned long vaddr, unsigned long *paddr) { pgd_t gpgd; pte_t gpte; @@ -656,31 +656,47 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr) #endif /* Still not set up? Just map 1:1. */ - if (unlikely(cpu->linear_pages)) - return vaddr; + if (unlikely(cpu->linear_pages)) { + *paddr = vaddr; + return true; + } /* First step: get the top-level Guest page table entry. */ gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t); /* Toplevel not present? We can't map it in. */ - if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) { - kill_guest(cpu, "Bad address %#lx", vaddr); - return -1UL; - } + if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) + goto fail; #ifdef CONFIG_X86_PAE gpmd = lgread(cpu, gpmd_addr(gpgd, vaddr), pmd_t); - if (!(pmd_flags(gpmd) & _PAGE_PRESENT)) { - kill_guest(cpu, "Bad address %#lx", vaddr); - return -1UL; - } + if (!(pmd_flags(gpmd) & _PAGE_PRESENT)) + goto fail; gpte = lgread(cpu, gpte_addr(cpu, gpmd, vaddr), pte_t); #else gpte = lgread(cpu, gpte_addr(cpu, gpgd, vaddr), pte_t); #endif if (!(pte_flags(gpte) & _PAGE_PRESENT)) - kill_guest(cpu, "Bad address %#lx", vaddr); + goto fail; + + *paddr = pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK); + return true; + +fail: + *paddr = -1UL; + return false; +} - return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK); +/* + * This is the version we normally use: kills the Guest if it uses a + * bad address + */ +unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr) +{ + unsigned long paddr; + + if (!__guest_pa(cpu, vaddr, &paddr)) + kill_guest(cpu, "Bad address %#lx", vaddr); + return paddr; } /* |