x86: c_p_a(), add simple self test at boot (fa2d8369) · Commits · 戴 / test

arch/x86/mm/Makefile_32

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/mm/Makefile_64

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/mm/pageattr-test.c

0 → 100644

+233 −0

Original line number	Diff line number	Diff line
		/*
		* 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->gpgGPS + s->lpgLPS)/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);

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