diff options
Diffstat (limited to 'drivers/lguest/page_tables.c')
| -rw-r--r-- | drivers/lguest/page_tables.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index 576a8318221..a059cf9980f 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -199,7 +199,7 @@ static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd) * * If we fixed up the fault (ie. we mapped the address), this routine returns * true. Otherwise, it was a real fault and we need to tell the Guest. */ -int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) +bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) { pgd_t gpgd; pgd_t *spgd; @@ -211,7 +211,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t); /* Toplevel not present? We can't map it in. */ if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) - return 0; + return false; /* Now look at the matching shadow entry. */ spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr); @@ -222,7 +222,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) * simple for this corner case. */ if (!ptepage) { kill_guest(cpu, "out of memory allocating pte page"); - return 0; + return false; } /* We check that the Guest pgd is OK. */ check_gpgd(cpu, gpgd); @@ -238,16 +238,16 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) /* If this page isn't in the Guest page tables, we can't page it in. */ if (!(pte_flags(gpte) & _PAGE_PRESENT)) - return 0; + return false; /* Check they're not trying to write to a page the Guest wants * read-only (bit 2 of errcode == write). */ if ((errcode & 2) && !(pte_flags(gpte) & _PAGE_RW)) - return 0; + return false; /* User access to a kernel-only page? (bit 3 == user access) */ if ((errcode & 4) && !(pte_flags(gpte) & _PAGE_USER)) - return 0; + return false; /* Check that the Guest PTE flags are OK, and the page number is below * the pfn_limit (ie. not mapping the Launcher binary). */ @@ -283,7 +283,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) * manipulated, the result returned and the code complete. A small * delay and a trace of alliteration are the only indications the Guest * has that a page fault occurred at all. */ - return 1; + return true; } /*H:360 @@ -296,7 +296,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) * * This is a quick version which answers the question: is this virtual address * mapped by the shadow page tables, and is it writable? */ -static int page_writable(struct lg_cpu *cpu, unsigned long vaddr) +static bool page_writable(struct lg_cpu *cpu, unsigned long vaddr) { pgd_t *spgd; unsigned long flags; @@ -304,7 +304,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr) /* Look at the current top level entry: is it present? */ spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr); if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) - return 0; + return false; /* Check the flags on the pte entry itself: it must be present and * writable. */ @@ -373,8 +373,10 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr) /* 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)) + if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) { kill_guest(cpu, "Bad address %#lx", vaddr); + return -1UL; + } gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t); if (!(pte_flags(gpte) & _PAGE_PRESENT)) |