| // 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); |