diff options
Diffstat (limited to 'arch/x86/mm/pageattr-test.c')
| -rw-r--r-- | arch/x86/mm/pageattr-test.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c new file mode 100644 index 000000000000..4b22eb47f23a --- /dev/null +++ b/arch/x86/mm/pageattr-test.c @@ -0,0 +1,233 @@ +/* + * self test for change_page_attr. + * + * Clears the global bit on random pages in the direct mapping, then reverts + * and compares page tables forwards and afterwards. + */ + +#include <linux/mm.h> +#include <linux/random.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/bootmem.h> +#include <asm/cacheflush.h> +#include <asm/pgtable.h> +#include <asm/kdebug.h> + +enum { + NTEST = 400, +#ifdef CONFIG_X86_64 + LOWEST_LEVEL = 4, + LPS = (1 << PMD_SHIFT), +#elif defined(CONFIG_X86_PAE) + LOWEST_LEVEL = 3, + LPS = (1 << PMD_SHIFT), +#else + LOWEST_LEVEL = 3, /* lookup_address lies here */ + LPS = (1 << 22), +#endif + GPS = (1<<30) +}; + +#ifdef CONFIG_X86_64 +#include <asm/proto.h> +#define max_mapped end_pfn_map +#else +#define max_mapped max_low_pfn +#endif + +struct split_state { + long lpg, gpg, spg, exec; + long min_exec, max_exec; +}; + +static __init int print_split(struct split_state *s) +{ + int printed = 0; + long i, expected, missed = 0; + int err = 0; + + s->lpg = s->gpg = s->spg = s->exec = 0; + s->min_exec = ~0UL; + s->max_exec = 0; + for (i = 0; i < max_mapped; ) { + int level; + pte_t *pte; + unsigned long adr = (unsigned long)__va(i << PAGE_SHIFT); + + pte = lookup_address(adr, &level); + if (!pte) { + if (!printed) { + dump_pagetable(adr); + printk("CPA %lx no pte level %d\n", adr, level); + printed = 1; + } + missed++; + i++; + continue; + } + + if (level == 2 && sizeof(long) == 8) { + s->gpg++; + i += GPS/PAGE_SIZE; + } else if (level != LOWEST_LEVEL) { + if (!(pte_val(*pte) & _PAGE_PSE)) { + printk("%lx level %d but not PSE %Lx\n", + adr, level, (u64)pte_val(*pte)); + err = 1; + } + s->lpg++; + i += LPS/PAGE_SIZE; + } else { + s->spg++; + i++; + } + if (!(pte_val(*pte) & _PAGE_NX)) { + s->exec++; + if (adr < s->min_exec) + s->min_exec = adr; + if (adr > s->max_exec) + s->max_exec = adr; + } + } + printk("CPA mapping 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n", + s->spg, s->lpg, s->gpg, s->exec, + s->min_exec != ~0UL ? s->min_exec : 0, s->max_exec, missed); + expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed; + if (expected != i) { + printk("CPA max_mapped %lu but expected %lu\n", + max_mapped, expected); + return 1; + } + return err; +} + +static __init int state_same(struct split_state *a, struct split_state *b) +{ + return a->lpg == b->lpg && a->gpg == b->gpg && a->spg == b->spg && + a->exec == b->exec; +} + +static unsigned long addr[NTEST] __initdata; +static unsigned len[NTEST] __initdata; + +/* Change the global bit on random pages in the direct mapping */ +static __init int exercise_pageattr(void) +{ + int i, k; + pte_t *pte, pte0; + int level; + int err; + struct split_state sa, sb, sc; + int failed = 0; + unsigned long *bm; + + printk("CPA exercising pageattr\n"); + + bm = vmalloc((max_mapped + 7) / 8); + if (!bm) { + printk("CPA Cannot vmalloc bitmap\n"); + return -ENOMEM; + } + memset(bm, 0, (max_mapped + 7) / 8); + + failed += print_split(&sa); + srandom32(100); + for (i = 0; i < NTEST; i++) { + unsigned long pfn = random32() % max_mapped; + addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT); + len[i] = random32() % 100; + len[i] = min_t(unsigned long, len[i], max_mapped - pfn - 1); + if (len[i] == 0) + len[i] = 1; + + pte = NULL; + pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */ + for (k = 0; k < len[i]; k++) { + pte = lookup_address(addr[i] + k*PAGE_SIZE, &level); + if (!pte || pgprot_val(pte_pgprot(*pte)) == 0) { + addr[i] = 0; + break; + } + if (k == 0) + pte0 = *pte; + else if (pgprot_val(pte_pgprot(*pte)) != + pgprot_val(pte_pgprot(pte0))) { + len[i] = k; + break; + } + if (test_bit(pfn + k, bm)) { + len[i] = k; + break; + } + __set_bit(pfn + k, bm); + } + if (!addr[i] || !pte || !k) { + addr[i] = 0; + continue; + } + + err = change_page_attr(virt_to_page(addr[i]), len[i], + pte_pgprot(pte_clrhuge(pte_clrglobal(pte0)))); + if (err < 0) { + printk("CPA %d failed %d\n", i, err); + failed++; + } + + pte = lookup_address(addr[i], &level); + if (!pte || pte_global(*pte) || pte_huge(*pte)) { + printk("CPA %lx: bad pte %Lx\n", addr[i], + pte ? (u64)pte_val(*pte) : 0ULL); + failed++; + } + if (level != LOWEST_LEVEL) { + printk("CPA %lx: unexpected level %d\n", addr[i], + level); + failed++; + } + + } + vfree(bm); + global_flush_tlb(); + + failed += print_split(&sb); + + printk("CPA reverting everything\n"); + for (i = 0; i < NTEST; i++) { + if (!addr[i]) + continue; + pte = lookup_address(addr[i], &level); + if (!pte) { + printk("CPA lookup of %lx failed\n", addr[i]); + failed++; + continue; + } + err = change_page_attr(virt_to_page(addr[i]), len[i], + pte_pgprot(pte_mkglobal(*pte))); + if (err < 0) { + printk("CPA reverting failed: %d\n", err); + failed++; + } + pte = lookup_address(addr[i], &level); + if (!pte || !pte_global(*pte)) { + printk("CPA %lx: bad pte after revert %Lx\n", addr[i], + pte ? (u64)pte_val(*pte) : 0ULL); + failed++; + } + + } + global_flush_tlb(); + + failed += print_split(&sc); + if (!state_same(&sa, &sc)) + failed++; + + if (failed) + printk("CPA selftests NOT PASSED. Please report.\n"); + else + printk("CPA selftests PASSED\n"); + + return 0; +} + +module_init(exercise_pageattr); |