diff options
Diffstat (limited to 'arch/x86/mm/pageattr-test.c')
| -rw-r--r-- | arch/x86/mm/pageattr-test.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c new file mode 100644 index 00000000000..06353d43f72 --- /dev/null +++ b/arch/x86/mm/pageattr-test.c @@ -0,0 +1,224 @@ +/* + * 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/bootmem.h> +#include <linux/random.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> +#include <asm/pgtable.h> +#include <asm/kdebug.h> + +enum { + NTEST = 4000, +#ifdef CONFIG_X86_64 + LPS = (1 << PMD_SHIFT), +#elif defined(CONFIG_X86_PAE) + LPS = (1 << PMD_SHIFT), +#else + LPS = (1 << 22), +#endif + GPS = (1<<30) +}; + +struct split_state { + long lpg, gpg, spg, exec; + long min_exec, max_exec; +}; + +static __init int print_split(struct split_state *s) +{ + long i, expected, missed = 0; + int printed = 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_pfn_mapped; ) { + unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT); + int level; + pte_t *pte; + + pte = lookup_address(addr, &level); + if (!pte) { + if (!printed) { + dump_pagetable(addr); + printk(KERN_INFO "CPA %lx no pte level %d\n", + addr, level); + printed = 1; + } + missed++; + i++; + continue; + } + + if (level == PG_LEVEL_1G && sizeof(long) == 8) { + s->gpg++; + i += GPS/PAGE_SIZE; + } else if (level == PG_LEVEL_2M) { + if (!(pte_val(*pte) & _PAGE_PSE)) { + printk(KERN_ERR + "%lx level %d but not PSE %Lx\n", + addr, 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 (addr < s->min_exec) + s->min_exec = addr; + if (addr > s->max_exec) + s->max_exec = addr; + } + } + printk(KERN_INFO + "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(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n", + max_pfn_mapped, expected); + return 1; + } + return err; +} + +static unsigned long __initdata addr[NTEST]; +static unsigned int __initdata len[NTEST]; + +/* Change the global bit on random pages in the direct mapping */ +static __init int exercise_pageattr(void) +{ + struct split_state sa, sb, sc; + unsigned long *bm; + pte_t *pte, pte0; + int failed = 0; + int level; + int i, k; + int err; + + printk(KERN_INFO "CPA exercising pageattr\n"); + + bm = vmalloc((max_pfn_mapped + 7) / 8); + if (!bm) { + printk(KERN_ERR "CPA Cannot vmalloc bitmap\n"); + return -ENOMEM; + } + memset(bm, 0, (max_pfn_mapped + 7) / 8); + + failed += print_split(&sa); + srandom32(100); + + for (i = 0; i < NTEST; i++) { + unsigned long pfn = random32() % max_pfn_mapped; + + addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT); + len[i] = random32() % 100; + len[i] = min_t(unsigned long, len[i], max_pfn_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_clear(addr[i], len[i], + __pgprot(_PAGE_GLOBAL)); + if (err < 0) { + printk(KERN_ERR "CPA %d failed %d\n", i, err); + failed++; + } + + pte = lookup_address(addr[i], &level); + if (!pte || pte_global(*pte) || pte_huge(*pte)) { + printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i], + pte ? (u64)pte_val(*pte) : 0ULL); + failed++; + } + if (level != PG_LEVEL_4K) { + printk(KERN_ERR "CPA %lx: unexpected level %d\n", + addr[i], level); + failed++; + } + + } + vfree(bm); + + failed += print_split(&sb); + + printk(KERN_INFO "CPA reverting everything\n"); + for (i = 0; i < NTEST; i++) { + if (!addr[i]) + continue; + pte = lookup_address(addr[i], &level); + if (!pte) { + printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]); + failed++; + continue; + } + err = change_page_attr_set(addr[i], len[i], + __pgprot(_PAGE_GLOBAL)); + if (err < 0) { + printk(KERN_ERR "CPA reverting failed: %d\n", err); + failed++; + } + pte = lookup_address(addr[i], &level); + if (!pte || !pte_global(*pte)) { + printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n", + addr[i], pte ? (u64)pte_val(*pte) : 0ULL); + failed++; + } + + } + + failed += print_split(&sc); + + if (failed) { + printk(KERN_ERR "CPA selftests NOT PASSED. Please report.\n"); + WARN_ON(1); + } else { + printk(KERN_INFO "CPA selftests PASSED\n"); + } + + return 0; +} +module_init(exercise_pageattr); |