diff options
| -rw-r--r-- | arch/x86/include/asm/lguest.h | 7 | ||||
| -rw-r--r-- | drivers/lguest/core.c | 9 | ||||
| -rw-r--r-- | drivers/lguest/lg.h | 2 | ||||
| -rw-r--r-- | drivers/lguest/page_tables.c | 21 | ||||
| -rw-r--r-- | drivers/lguest/x86/core.c | 5 |
5 files changed, 21 insertions, 23 deletions
diff --git a/arch/x86/include/asm/lguest.h b/arch/x86/include/asm/lguest.h index 85ecdb80d121..74edebd010ab 100644 --- a/arch/x86/include/asm/lguest.h +++ b/arch/x86/include/asm/lguest.h @@ -11,11 +11,8 @@ #define GUEST_PL 1 -/* Every guest maps the core switcher code. */ -#define SHARED_SWITCHER_PAGES \ - DIV_ROUND_UP(end_switcher_text - start_switcher_text, PAGE_SIZE) -/* Pages for switcher itself, then two pages per cpu */ -#define TOTAL_SWITCHER_PAGES (SHARED_SWITCHER_PAGES + 2 * nr_cpu_ids) +/* Page for Switcher text itself, then two pages per cpu */ +#define TOTAL_SWITCHER_PAGES (1 + 2 * nr_cpu_ids) /* We map at -4M (-2M for PAE) for ease of mapping (one PTE page). */ #ifdef CONFIG_X86_PAE diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 211d8267992b..4209065b9b1e 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -52,6 +52,13 @@ static __init int map_switcher(void) * easy. */ + /* We assume Switcher text fits into a single page. */ + if (end_switcher_text - start_switcher_text > PAGE_SIZE) { + printk(KERN_ERR "lguest: switcher text too large (%zu)\n", + end_switcher_text - start_switcher_text); + return -EINVAL; + } + /* * We allocate an array of struct page pointers. map_vm_area() wants * this, rather than just an array of pages. @@ -326,7 +333,7 @@ static int __init init(void) goto out; /* Now we set up the pagetable implementation for the Guests. */ - err = init_pagetables(switcher_pages, SHARED_SWITCHER_PAGES); + err = init_pagetables(switcher_pages); if (err) goto unmap; diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 8bf68c54ff7f..4c3e532d50d6 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -15,7 +15,7 @@ #include <asm/lguest.h> void free_pagetables(void); -int init_pagetables(struct page **switcher_pages, unsigned int pages); +int init_pagetables(struct page **switcher_pages); struct pgdir { unsigned long gpgdir; diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index 21685580eb9f..758466299b0d 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -1079,25 +1079,20 @@ static void free_switcher_pte_pages(void) /*H:520 * Setting up the Switcher PTE page for given CPU is fairly easy, given - * the CPU number and the "struct page"s for the Switcher code itself. - * - * Currently the Switcher is less than a page long, so "pages" is always 1. + * the CPU number and the "struct page"s for the Switcher and per-cpu pages. */ static __init void populate_switcher_pte_page(unsigned int cpu, - struct page *switcher_pages[], - unsigned int pages) + struct page *switcher_pages[]) { - unsigned int i; pte_t *pte = switcher_pte_page(cpu); + int i; - /* The first entries are easy: they map the Switcher code. */ - for (i = 0; i < pages; i++) { - set_pte(&pte[i], mk_pte(switcher_pages[i], + /* The first entries maps the Switcher code. */ + set_pte(&pte[0], mk_pte(switcher_pages[0], __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED))); - } /* The only other thing we map is this CPU's pair of pages. */ - i = pages + cpu*2; + i = 1 + cpu*2; /* First page (Guest registers) is writable from the Guest */ set_pte(&pte[i], pfn_pte(page_to_pfn(switcher_pages[i]), @@ -1128,7 +1123,7 @@ static __init void populate_switcher_pte_page(unsigned int cpu, * At boot or module load time, init_pagetables() allocates and populates * the Switcher PTE page for each CPU. */ -__init int init_pagetables(struct page **switcher_pages, unsigned int pages) +__init int init_pagetables(struct page **switcher_pages) { unsigned int i; @@ -1138,7 +1133,7 @@ __init int init_pagetables(struct page **switcher_pages, unsigned int pages) free_switcher_pte_pages(); return -ENOMEM; } - populate_switcher_pte_page(i, switcher_pages, pages); + populate_switcher_pte_page(i, switcher_pages); } return 0; } diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 20fae765d600..f0a3347b6441 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -62,11 +62,10 @@ static unsigned long switcher_offset(void) return switcher_addr - (unsigned long)start_switcher_text; } -/* This cpu's struct lguest_pages. */ +/* This cpu's struct lguest_pages (after the Switcher text page) */ static struct lguest_pages *lguest_pages(unsigned int cpu) { - return &(((struct lguest_pages *) - (switcher_addr + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]); + return &(((struct lguest_pages *)(switcher_addr + PAGE_SIZE))[cpu]); } static DEFINE_PER_CPU(struct lg_cpu *, lg_last_cpu); |