Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 261 insertions, 0 deletions

diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
new file mode 100644
index 000000000..a25588ad7
--- /dev/null
+++ b/arch/x86/mm/pageattr-test.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * self test for change_page_attr.
+ *
+ * Clears the a test pte bit on random pages in the direct mapping,
+ * then reverts and compares page tables forwards and afterwards.
+ */
+#include <linux/bootmem.h>
+#include <linux/kthread.h>
+#include <linux/random.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+#include <asm/kdebug.h>
+
+/*
+ * Only print the results of the first pass:
+ */
+static __read_mostly int print = 1;
+
+enum {
+	NTEST			= 400,
+#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)
+};
+
+#define PAGE_CPA_TEST	__pgprot(_PAGE_CPA_TEST)
+
+static int pte_testbit(pte_t pte)
+{
+	return pte_flags(pte) & _PAGE_SOFTW1;
+}
+
+struct split_state {
+	long lpg, gpg, spg, exec;
+	long min_exec, max_exec;
+};
+
+static int print_split(struct split_state *s)
+{
+	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_pfn_mapped; ) {
+		unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
+		unsigned int level;
+		pte_t *pte;
+
+		pte = lookup_address(addr, &level);
+		if (!pte) {
+			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_PRESENT) && !(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;
+		}
+	}
+	if (print) {
+		printk(KERN_INFO
+			" 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 addr[NTEST];
+static unsigned int len[NTEST];
+
+/* Change the global bit on random pages in the direct mapping */
+static int pageattr_test(void)
+{
+	struct split_state sa, sb, sc;
+	unsigned long *bm;
+	pte_t *pte, pte0;
+	int failed = 0;
+	unsigned int level;
+	int i, k;
+	int err;
+	unsigned long test_addr;
+
+	if (print)
+		printk(KERN_INFO "CPA self-test:\n");
+
+	bm = vzalloc((max_pfn_mapped + 7) / 8);
+	if (!bm) {
+		printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
+		return -ENOMEM;
+	}
+
+	failed += print_split(&sa);
+
+	for (i = 0; i < NTEST; i++) {
+		unsigned long pfn = prandom_u32() % max_pfn_mapped;
+
+		addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
+		len[i] = prandom_u32() % 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 ||
+			    !(pte_val(*pte) & _PAGE_PRESENT)) {
+				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;
+		}
+
+		test_addr = addr[i];
+		err = change_page_attr_set(&test_addr, len[i], PAGE_CPA_TEST, 0);
+		if (err < 0) {
+			printk(KERN_ERR "CPA %d failed %d\n", i, err);
+			failed++;
+		}
+
+		pte = lookup_address(addr[i], &level);
+		if (!pte || !pte_testbit(*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);
+
+	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;
+		}
+		test_addr = addr[i];
+		err = change_page_attr_clear(&test_addr, len[i], PAGE_CPA_TEST, 0);
+		if (err < 0) {
+			printk(KERN_ERR "CPA reverting failed: %d\n", err);
+			failed++;
+		}
+		pte = lookup_address(addr[i], &level);
+		if (!pte || pte_testbit(*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) {
+		WARN(1, KERN_ERR "NOT PASSED. Please report.\n");
+		return -EINVAL;
+	} else {
+		if (print)
+			printk(KERN_INFO "ok.\n");
+	}
+
+	return 0;
+}
+
+static int do_pageattr_test(void *__unused)
+{
+	while (!kthread_should_stop()) {
+		schedule_timeout_interruptible(HZ*30);
+		if (pageattr_test() < 0)
+			break;
+		if (print)
+			print--;
+	}
+	return 0;
+}
+
+static int start_pageattr_test(void)
+{
+	struct task_struct *p;
+
+	p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
+	if (!IS_ERR(p))
+		wake_up_process(p);
+	else
+		WARN_ON(1);
+
+	return 0;
+}
+device_initcall(start_pageattr_test);