From: Andi Kleen Date: Wed, 30 Jan 2008 12:33:43 +0000 (+0100) Subject: x86: c_p_a(), add simple self test at boot X-Git-Tag: v2.6.25-rc1~1143^2~137 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa2d8369a1e0e5dd0fdaaba9d40ca5187f4cd20b;p=linux-2.6 x86: c_p_a(), add simple self test at boot Since change_page_attr() is tricky code it is good to have some regression test code. This patch maps and unmaps some random pages in the direct mapping at boot and then dumps the state and does some simple sanity checks. Add it with a CONFIG option. Signed-off-by: Andi Kleen Acked-by: Jan Beulich Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/mm/Makefile_32 b/arch/x86/mm/Makefile_32 index 6a5e981981..be2f55160b 100644 --- a/arch/x86/mm/Makefile_32 +++ b/arch/x86/mm/Makefile_32 @@ -4,6 +4,7 @@ obj-y := init_32.o pgtable_32.o fault_32.o ioremap_32.o extable.o pageattr_32.o mmap.o +obj-$(CONFIG_CPA_DEBUG) += pageattr-test.o obj-$(CONFIG_NUMA) += discontig_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_HIGHMEM) += highmem_32.o diff --git a/arch/x86/mm/Makefile_64 b/arch/x86/mm/Makefile_64 index 09c997fe58..cb72316763 100644 --- a/arch/x86/mm/Makefile_64 +++ b/arch/x86/mm/Makefile_64 @@ -7,3 +7,4 @@ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_NUMA) += numa_64.o obj-$(CONFIG_K8_NUMA) += k8topology_64.o obj-$(CONFIG_ACPI_NUMA) += srat_64.o +obj-$(CONFIG_CPA_DEBUG) += pageattr-test.o diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c new file mode 100644 index 0000000000..4b22eb47f2 --- /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 +#include +#include +#include +#include +#include +#include +#include + +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 +#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);