| |
| #include "libcflat.h" |
| #include "desc.h" |
| #include "processor.h" |
| #include "asm/page.h" |
| #include "x86/vm.h" |
| |
| #define smp_id() 0 |
| |
| #define true 1 |
| #define false 0 |
| |
| static _Bool verbose = false; |
| |
| typedef unsigned long pt_element_t; |
| static int invalid_mask; |
| static int page_table_levels; |
| |
| #define PT_BASE_ADDR_MASK ((pt_element_t)((((pt_element_t)1 << 36) - 1) & PAGE_MASK)) |
| #define PT_PSE_BASE_ADDR_MASK (PT_BASE_ADDR_MASK & ~(1ull << 21)) |
| |
| #define CR0_WP_MASK (1UL << 16) |
| #define CR4_SMEP_MASK (1UL << 20) |
| |
| #define PFERR_PRESENT_MASK (1U << 0) |
| #define PFERR_WRITE_MASK (1U << 1) |
| #define PFERR_USER_MASK (1U << 2) |
| #define PFERR_RESERVED_MASK (1U << 3) |
| #define PFERR_FETCH_MASK (1U << 4) |
| #define PFERR_PK_MASK (1U << 5) |
| |
| #define MSR_EFER 0xc0000080 |
| #define EFER_NX_MASK (1ull << 11) |
| |
| #define PT_INDEX(address, level) \ |
| ((address) >> (12 + ((level)-1) * 9)) & 511 |
| |
| /* |
| * page table access check tests |
| */ |
| |
| enum { |
| AC_PTE_PRESENT_BIT, |
| AC_PTE_WRITABLE_BIT, |
| AC_PTE_USER_BIT, |
| AC_PTE_ACCESSED_BIT, |
| AC_PTE_DIRTY_BIT, |
| AC_PTE_NX_BIT, |
| AC_PTE_BIT51_BIT, |
| AC_PTE_BIT36_BIT, |
| |
| AC_PDE_PRESENT_BIT, |
| AC_PDE_WRITABLE_BIT, |
| AC_PDE_USER_BIT, |
| AC_PDE_ACCESSED_BIT, |
| AC_PDE_DIRTY_BIT, |
| AC_PDE_PSE_BIT, |
| AC_PDE_NX_BIT, |
| AC_PDE_BIT51_BIT, |
| AC_PDE_BIT36_BIT, |
| AC_PDE_BIT13_BIT, |
| |
| AC_PKU_AD_BIT, |
| AC_PKU_WD_BIT, |
| AC_PKU_PKEY_BIT, |
| |
| AC_ACCESS_USER_BIT, |
| AC_ACCESS_WRITE_BIT, |
| AC_ACCESS_FETCH_BIT, |
| AC_ACCESS_TWICE_BIT, |
| |
| AC_CPU_EFER_NX_BIT, |
| AC_CPU_CR0_WP_BIT, |
| AC_CPU_CR4_SMEP_BIT, |
| AC_CPU_CR4_PKE_BIT, |
| |
| NR_AC_FLAGS |
| }; |
| |
| #define AC_PTE_PRESENT_MASK (1 << AC_PTE_PRESENT_BIT) |
| #define AC_PTE_WRITABLE_MASK (1 << AC_PTE_WRITABLE_BIT) |
| #define AC_PTE_USER_MASK (1 << AC_PTE_USER_BIT) |
| #define AC_PTE_ACCESSED_MASK (1 << AC_PTE_ACCESSED_BIT) |
| #define AC_PTE_DIRTY_MASK (1 << AC_PTE_DIRTY_BIT) |
| #define AC_PTE_NX_MASK (1 << AC_PTE_NX_BIT) |
| #define AC_PTE_BIT51_MASK (1 << AC_PTE_BIT51_BIT) |
| #define AC_PTE_BIT36_MASK (1 << AC_PTE_BIT36_BIT) |
| |
| #define AC_PDE_PRESENT_MASK (1 << AC_PDE_PRESENT_BIT) |
| #define AC_PDE_WRITABLE_MASK (1 << AC_PDE_WRITABLE_BIT) |
| #define AC_PDE_USER_MASK (1 << AC_PDE_USER_BIT) |
| #define AC_PDE_ACCESSED_MASK (1 << AC_PDE_ACCESSED_BIT) |
| #define AC_PDE_DIRTY_MASK (1 << AC_PDE_DIRTY_BIT) |
| #define AC_PDE_PSE_MASK (1 << AC_PDE_PSE_BIT) |
| #define AC_PDE_NX_MASK (1 << AC_PDE_NX_BIT) |
| #define AC_PDE_BIT51_MASK (1 << AC_PDE_BIT51_BIT) |
| #define AC_PDE_BIT36_MASK (1 << AC_PDE_BIT36_BIT) |
| #define AC_PDE_BIT13_MASK (1 << AC_PDE_BIT13_BIT) |
| |
| #define AC_PKU_AD_MASK (1 << AC_PKU_AD_BIT) |
| #define AC_PKU_WD_MASK (1 << AC_PKU_WD_BIT) |
| #define AC_PKU_PKEY_MASK (1 << AC_PKU_PKEY_BIT) |
| |
| #define AC_ACCESS_USER_MASK (1 << AC_ACCESS_USER_BIT) |
| #define AC_ACCESS_WRITE_MASK (1 << AC_ACCESS_WRITE_BIT) |
| #define AC_ACCESS_FETCH_MASK (1 << AC_ACCESS_FETCH_BIT) |
| #define AC_ACCESS_TWICE_MASK (1 << AC_ACCESS_TWICE_BIT) |
| |
| #define AC_CPU_EFER_NX_MASK (1 << AC_CPU_EFER_NX_BIT) |
| #define AC_CPU_CR0_WP_MASK (1 << AC_CPU_CR0_WP_BIT) |
| #define AC_CPU_CR4_SMEP_MASK (1 << AC_CPU_CR4_SMEP_BIT) |
| #define AC_CPU_CR4_PKE_MASK (1 << AC_CPU_CR4_PKE_BIT) |
| |
| const char *ac_names[] = { |
| [AC_PTE_PRESENT_BIT] = "pte.p", |
| [AC_PTE_ACCESSED_BIT] = "pte.a", |
| [AC_PTE_WRITABLE_BIT] = "pte.rw", |
| [AC_PTE_USER_BIT] = "pte.user", |
| [AC_PTE_DIRTY_BIT] = "pte.d", |
| [AC_PTE_NX_BIT] = "pte.nx", |
| [AC_PTE_BIT51_BIT] = "pte.51", |
| [AC_PTE_BIT36_BIT] = "pte.36", |
| [AC_PDE_PRESENT_BIT] = "pde.p", |
| [AC_PDE_ACCESSED_BIT] = "pde.a", |
| [AC_PDE_WRITABLE_BIT] = "pde.rw", |
| [AC_PDE_USER_BIT] = "pde.user", |
| [AC_PDE_DIRTY_BIT] = "pde.d", |
| [AC_PDE_PSE_BIT] = "pde.pse", |
| [AC_PDE_NX_BIT] = "pde.nx", |
| [AC_PDE_BIT51_BIT] = "pde.51", |
| [AC_PDE_BIT36_BIT] = "pde.36", |
| [AC_PDE_BIT13_BIT] = "pde.13", |
| [AC_PKU_AD_BIT] = "pkru.ad", |
| [AC_PKU_WD_BIT] = "pkru.wd", |
| [AC_PKU_PKEY_BIT] = "pkey=1", |
| [AC_ACCESS_WRITE_BIT] = "write", |
| [AC_ACCESS_USER_BIT] = "user", |
| [AC_ACCESS_FETCH_BIT] = "fetch", |
| [AC_ACCESS_TWICE_BIT] = "twice", |
| [AC_CPU_EFER_NX_BIT] = "efer.nx", |
| [AC_CPU_CR0_WP_BIT] = "cr0.wp", |
| [AC_CPU_CR4_SMEP_BIT] = "cr4.smep", |
| [AC_CPU_CR4_PKE_BIT] = "cr4.pke", |
| }; |
| |
| static inline void *va(pt_element_t phys) |
| { |
| return (void *)phys; |
| } |
| |
| typedef struct { |
| pt_element_t pt_pool; |
| unsigned pt_pool_size; |
| unsigned pt_pool_current; |
| } ac_pool_t; |
| |
| typedef struct { |
| unsigned flags; |
| void *virt; |
| pt_element_t phys; |
| pt_element_t *ptep; |
| pt_element_t expected_pte; |
| pt_element_t *pdep; |
| pt_element_t expected_pde; |
| pt_element_t ignore_pde; |
| int expected_fault; |
| unsigned expected_error; |
| } ac_test_t; |
| |
| typedef struct { |
| unsigned short limit; |
| unsigned long linear_addr; |
| } __attribute__((packed)) descriptor_table_t; |
| |
| |
| static void ac_test_show(ac_test_t *at); |
| |
| static unsigned long shadow_cr0; |
| static unsigned long shadow_cr4; |
| static unsigned long long shadow_efer; |
| |
| static void set_cr0_wp(int wp) |
| { |
| unsigned long cr0 = shadow_cr0; |
| |
| cr0 &= ~CR0_WP_MASK; |
| if (wp) |
| cr0 |= CR0_WP_MASK; |
| if (cr0 != shadow_cr0) { |
| write_cr0(cr0); |
| shadow_cr0 = cr0; |
| } |
| } |
| |
| static unsigned set_cr4_smep(int smep) |
| { |
| unsigned long cr4 = shadow_cr4; |
| extern u64 ptl2[]; |
| unsigned r; |
| |
| cr4 &= ~CR4_SMEP_MASK; |
| if (smep) |
| cr4 |= CR4_SMEP_MASK; |
| if (cr4 == shadow_cr4) |
| return 0; |
| |
| if (smep) |
| ptl2[2] &= ~PT_USER_MASK; |
| r = write_cr4_checking(cr4); |
| if (r || !smep) |
| ptl2[2] |= PT_USER_MASK; |
| if (!r) |
| shadow_cr4 = cr4; |
| return r; |
| } |
| |
| static void set_cr4_pke(int pke) |
| { |
| unsigned long cr4 = shadow_cr4; |
| |
| cr4 &= ~X86_CR4_PKE; |
| if (pke) |
| cr4 |= X86_CR4_PKE; |
| if (cr4 == shadow_cr4) |
| return; |
| |
| /* Check that protection keys do not affect accesses when CR4.PKE=0. */ |
| if ((shadow_cr4 & X86_CR4_PKE) && !pke) |
| write_pkru(0xfffffffc); |
| write_cr4(cr4); |
| shadow_cr4 = cr4; |
| } |
| |
| static void set_efer_nx(int nx) |
| { |
| unsigned long long efer = shadow_efer; |
| |
| efer &= ~EFER_NX_MASK; |
| if (nx) |
| efer |= EFER_NX_MASK; |
| if (efer != shadow_efer) { |
| wrmsr(MSR_EFER, efer); |
| shadow_efer = efer; |
| } |
| } |
| |
| static void ac_env_int(ac_pool_t *pool) |
| { |
| extern char page_fault, kernel_entry; |
| set_idt_entry(14, &page_fault, 0); |
| set_idt_entry(0x20, &kernel_entry, 3); |
| |
| pool->pt_pool = 33 * 1024 * 1024; |
| pool->pt_pool_size = 120 * 1024 * 1024 - pool->pt_pool; |
| pool->pt_pool_current = 0; |
| } |
| |
| static void ac_test_init(ac_test_t *at, void *virt) |
| { |
| set_efer_nx(1); |
| set_cr0_wp(1); |
| at->flags = 0; |
| at->virt = virt; |
| at->phys = 32 * 1024 * 1024; |
| } |
| |
| static int ac_test_bump_one(ac_test_t *at) |
| { |
| at->flags = ((at->flags | invalid_mask) + 1) & ~invalid_mask; |
| return at->flags < (1 << NR_AC_FLAGS); |
| } |
| |
| #define F(x) ((flags & x##_MASK) != 0) |
| |
| static _Bool ac_test_legal(ac_test_t *at) |
| { |
| int flags = at->flags; |
| |
| if (F(AC_ACCESS_FETCH) && F(AC_ACCESS_WRITE)) |
| return false; |
| |
| /* |
| * Since we convert current page to kernel page when cr4.smep=1, |
| * we can't switch to user mode. |
| */ |
| if (F(AC_ACCESS_USER) && F(AC_CPU_CR4_SMEP)) |
| return false; |
| |
| /* |
| * Only test protection key faults if CR4.PKE=1. |
| */ |
| if (!F(AC_CPU_CR4_PKE) && |
| (F(AC_PKU_AD) || F(AC_PKU_WD))) { |
| return false; |
| } |
| |
| /* |
| * pde.bit13 checks handling of reserved bits in largepage PDEs. It is |
| * meaningless if there is a PTE. |
| */ |
| if (!F(AC_PDE_PSE) && F(AC_PDE_BIT13)) |
| return false; |
| |
| /* |
| * Shorten the test by avoiding testing too many reserved bit combinations |
| */ |
| if ((F(AC_PDE_BIT51) + F(AC_PDE_BIT36) + F(AC_PDE_BIT13)) > 1) |
| return false; |
| if ((F(AC_PTE_BIT51) + F(AC_PTE_BIT36)) > 1) |
| return false; |
| |
| return true; |
| } |
| |
| static int ac_test_bump(ac_test_t *at) |
| { |
| int ret; |
| |
| ret = ac_test_bump_one(at); |
| while (ret && !ac_test_legal(at)) |
| ret = ac_test_bump_one(at); |
| return ret; |
| } |
| |
| static pt_element_t ac_test_alloc_pt(ac_pool_t *pool) |
| { |
| pt_element_t ret = pool->pt_pool + pool->pt_pool_current; |
| pool->pt_pool_current += PAGE_SIZE; |
| return ret; |
| } |
| |
| static _Bool ac_test_enough_room(ac_pool_t *pool) |
| { |
| return pool->pt_pool_current + 5 * PAGE_SIZE <= pool->pt_pool_size; |
| } |
| |
| static void ac_test_reset_pt_pool(ac_pool_t *pool) |
| { |
| pool->pt_pool_current = 0; |
| } |
| |
| static pt_element_t ac_test_permissions(ac_test_t *at, unsigned flags, |
| bool writable, bool user, |
| bool executable) |
| { |
| bool kwritable = !F(AC_CPU_CR0_WP) && !F(AC_ACCESS_USER); |
| pt_element_t expected = 0; |
| |
| if (F(AC_ACCESS_USER) && !user) |
| at->expected_fault = 1; |
| |
| if (F(AC_ACCESS_WRITE) && !writable && !kwritable) |
| at->expected_fault = 1; |
| |
| if (F(AC_ACCESS_FETCH) && !executable) |
| at->expected_fault = 1; |
| |
| if (F(AC_ACCESS_FETCH) && user && F(AC_CPU_CR4_SMEP)) |
| at->expected_fault = 1; |
| |
| if (user && !F(AC_ACCESS_FETCH) && F(AC_PKU_PKEY) && F(AC_CPU_CR4_PKE)) { |
| if (F(AC_PKU_AD)) { |
| at->expected_fault = 1; |
| at->expected_error |= PFERR_PK_MASK; |
| } else if (F(AC_ACCESS_WRITE) && F(AC_PKU_WD) && !kwritable) { |
| at->expected_fault = 1; |
| at->expected_error |= PFERR_PK_MASK; |
| } |
| } |
| |
| if (!at->expected_fault) { |
| expected |= PT_ACCESSED_MASK; |
| if (F(AC_ACCESS_WRITE)) |
| expected |= PT_DIRTY_MASK; |
| } |
| |
| return expected; |
| } |
| |
| static void ac_emulate_access(ac_test_t *at, unsigned flags) |
| { |
| bool pde_valid, pte_valid; |
| bool user, writable, executable; |
| |
| if (F(AC_ACCESS_USER)) |
| at->expected_error |= PFERR_USER_MASK; |
| |
| if (F(AC_ACCESS_WRITE)) |
| at->expected_error |= PFERR_WRITE_MASK; |
| |
| if (F(AC_ACCESS_FETCH)) |
| at->expected_error |= PFERR_FETCH_MASK; |
| |
| if (!F(AC_PDE_ACCESSED)) |
| at->ignore_pde = PT_ACCESSED_MASK; |
| |
| pde_valid = F(AC_PDE_PRESENT) |
| && !F(AC_PDE_BIT51) && !F(AC_PDE_BIT36) && !F(AC_PDE_BIT13) |
| && !(F(AC_PDE_NX) && !F(AC_CPU_EFER_NX)); |
| |
| if (!pde_valid) { |
| at->expected_fault = 1; |
| if (F(AC_PDE_PRESENT)) { |
| at->expected_error |= PFERR_RESERVED_MASK; |
| } else { |
| at->expected_error &= ~PFERR_PRESENT_MASK; |
| } |
| goto fault; |
| } |
| |
| writable = F(AC_PDE_WRITABLE); |
| user = F(AC_PDE_USER); |
| executable = !F(AC_PDE_NX); |
| |
| if (F(AC_PDE_PSE)) { |
| at->expected_pde |= ac_test_permissions(at, flags, writable, user, |
| executable); |
| goto no_pte; |
| } |
| |
| at->expected_pde |= PT_ACCESSED_MASK; |
| |
| pte_valid = F(AC_PTE_PRESENT) |
| && !F(AC_PTE_BIT51) && !F(AC_PTE_BIT36) |
| && !(F(AC_PTE_NX) && !F(AC_CPU_EFER_NX)); |
| |
| if (!pte_valid) { |
| at->expected_fault = 1; |
| if (F(AC_PTE_PRESENT)) { |
| at->expected_error |= PFERR_RESERVED_MASK; |
| } else { |
| at->expected_error &= ~PFERR_PRESENT_MASK; |
| } |
| goto fault; |
| } |
| |
| writable &= F(AC_PTE_WRITABLE); |
| user &= F(AC_PTE_USER); |
| executable &= !F(AC_PTE_NX); |
| |
| at->expected_pte |= ac_test_permissions(at, flags, writable, user, |
| executable); |
| |
| no_pte: |
| fault: |
| if (!at->expected_fault) |
| at->ignore_pde = 0; |
| if (!F(AC_CPU_EFER_NX) && !F(AC_CPU_CR4_SMEP)) |
| at->expected_error &= ~PFERR_FETCH_MASK; |
| } |
| |
| static void ac_set_expected_status(ac_test_t *at) |
| { |
| invlpg(at->virt); |
| |
| if (at->ptep) |
| at->expected_pte = *at->ptep; |
| at->expected_pde = *at->pdep; |
| at->ignore_pde = 0; |
| at->expected_fault = 0; |
| at->expected_error = PFERR_PRESENT_MASK; |
| |
| if (at->flags & AC_ACCESS_TWICE_MASK) { |
| ac_emulate_access(at, at->flags & ~AC_ACCESS_WRITE_MASK |
| & ~AC_ACCESS_FETCH_MASK & ~AC_ACCESS_USER_MASK); |
| at->expected_fault = 0; |
| at->expected_error = PFERR_PRESENT_MASK; |
| at->ignore_pde = 0; |
| } |
| |
| ac_emulate_access(at, at->flags); |
| } |
| |
| static void __ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, |
| u64 pd_page, u64 pt_page) |
| |
| { |
| unsigned long root = read_cr3(); |
| int flags = at->flags; |
| bool skip = true; |
| |
| if (!ac_test_enough_room(pool)) |
| ac_test_reset_pt_pool(pool); |
| |
| at->ptep = 0; |
| for (int i = page_table_levels; i >= 1 && (i >= 2 || !F(AC_PDE_PSE)); --i) { |
| pt_element_t *vroot = va(root & PT_BASE_ADDR_MASK); |
| unsigned index = PT_INDEX((unsigned long)at->virt, i); |
| pt_element_t pte = 0; |
| |
| /* |
| * Reuse existing page tables along the path to the test code and data |
| * (which is in the bottom 2MB). |
| */ |
| if (skip && i >= 2 && index == 0) { |
| goto next; |
| } |
| skip = false; |
| |
| switch (i) { |
| case 5: |
| case 4: |
| case 3: |
| pte = pd_page ? pd_page : ac_test_alloc_pt(pool); |
| pte |= PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK; |
| break; |
| case 2: |
| if (!F(AC_PDE_PSE)) { |
| pte = pt_page ? pt_page : ac_test_alloc_pt(pool); |
| /* The protection key is ignored on non-leaf entries. */ |
| if (F(AC_PKU_PKEY)) |
| pte |= 2ull << 59; |
| } else { |
| pte = at->phys & PT_PSE_BASE_ADDR_MASK; |
| pte |= PT_PAGE_SIZE_MASK; |
| if (F(AC_PKU_PKEY)) |
| pte |= 1ull << 59; |
| } |
| if (F(AC_PDE_PRESENT)) |
| pte |= PT_PRESENT_MASK; |
| if (F(AC_PDE_WRITABLE)) |
| pte |= PT_WRITABLE_MASK; |
| if (F(AC_PDE_USER)) |
| pte |= PT_USER_MASK; |
| if (F(AC_PDE_ACCESSED)) |
| pte |= PT_ACCESSED_MASK; |
| if (F(AC_PDE_DIRTY)) |
| pte |= PT_DIRTY_MASK; |
| if (F(AC_PDE_NX)) |
| pte |= PT64_NX_MASK; |
| if (F(AC_PDE_BIT51)) |
| pte |= 1ull << 51; |
| if (F(AC_PDE_BIT36)) |
| pte |= 1ull << 36; |
| if (F(AC_PDE_BIT13)) |
| pte |= 1ull << 13; |
| at->pdep = &vroot[index]; |
| break; |
| case 1: |
| pte = at->phys & PT_BASE_ADDR_MASK; |
| if (F(AC_PKU_PKEY)) |
| pte |= 1ull << 59; |
| if (F(AC_PTE_PRESENT)) |
| pte |= PT_PRESENT_MASK; |
| if (F(AC_PTE_WRITABLE)) |
| pte |= PT_WRITABLE_MASK; |
| if (F(AC_PTE_USER)) |
| pte |= PT_USER_MASK; |
| if (F(AC_PTE_ACCESSED)) |
| pte |= PT_ACCESSED_MASK; |
| if (F(AC_PTE_DIRTY)) |
| pte |= PT_DIRTY_MASK; |
| if (F(AC_PTE_NX)) |
| pte |= PT64_NX_MASK; |
| if (F(AC_PTE_BIT51)) |
| pte |= 1ull << 51; |
| if (F(AC_PTE_BIT36)) |
| pte |= 1ull << 36; |
| at->ptep = &vroot[index]; |
| break; |
| } |
| vroot[index] = pte; |
| next: |
| root = vroot[index]; |
| } |
| ac_set_expected_status(at); |
| } |
| |
| static void ac_test_setup_pte(ac_test_t *at, ac_pool_t *pool) |
| { |
| __ac_setup_specific_pages(at, pool, 0, 0); |
| } |
| |
| static void ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, |
| u64 pd_page, u64 pt_page) |
| { |
| return __ac_setup_specific_pages(at, pool, pd_page, pt_page); |
| } |
| |
| static void dump_mapping(ac_test_t *at) |
| { |
| unsigned long root = read_cr3(); |
| int flags = at->flags; |
| int i; |
| |
| printf("Dump mapping: address: %p\n", at->virt); |
| for (i = page_table_levels ; i >= 1 && (i >= 2 || !F(AC_PDE_PSE)); --i) { |
| pt_element_t *vroot = va(root & PT_BASE_ADDR_MASK); |
| unsigned index = PT_INDEX((unsigned long)at->virt, i); |
| pt_element_t pte = vroot[index]; |
| |
| printf("------L%d: %lx\n", i, pte); |
| root = vroot[index]; |
| } |
| } |
| |
| static void ac_test_check(ac_test_t *at, _Bool *success_ret, _Bool cond, |
| const char *fmt, ...) |
| { |
| va_list ap; |
| char buf[500]; |
| |
| if (!*success_ret) { |
| return; |
| } |
| |
| if (!cond) { |
| return; |
| } |
| |
| *success_ret = false; |
| |
| if (!verbose) { |
| puts("\n"); |
| ac_test_show(at); |
| } |
| |
| va_start(ap, fmt); |
| vsnprintf(buf, sizeof(buf), fmt, ap); |
| va_end(ap); |
| printf("FAIL: %s\n", buf); |
| dump_mapping(at); |
| } |
| |
| static int pt_match(pt_element_t pte1, pt_element_t pte2, pt_element_t ignore) |
| { |
| pte1 &= ~ignore; |
| pte2 &= ~ignore; |
| return pte1 == pte2; |
| } |
| |
| static int ac_test_do_access(ac_test_t *at) |
| { |
| static unsigned unique = 42; |
| int fault = 0; |
| unsigned e; |
| static unsigned char user_stack[4096]; |
| unsigned long rsp; |
| _Bool success = true; |
| int flags = at->flags; |
| |
| ++unique; |
| if (!(unique & 65535)) { |
| puts("."); |
| } |
| |
| *((unsigned char *)at->phys) = 0xc3; /* ret */ |
| |
| unsigned r = unique; |
| set_cr0_wp(F(AC_CPU_CR0_WP)); |
| set_efer_nx(F(AC_CPU_EFER_NX)); |
| set_cr4_pke(F(AC_CPU_CR4_PKE)); |
| if (F(AC_CPU_CR4_PKE)) { |
| /* WD2=AD2=1, WD1=F(AC_PKU_WD), AD1=F(AC_PKU_AD) */ |
| write_pkru(0x30 | (F(AC_PKU_WD) ? 8 : 0) | |
| (F(AC_PKU_AD) ? 4 : 0)); |
| } |
| |
| set_cr4_smep(F(AC_CPU_CR4_SMEP)); |
| |
| if (F(AC_ACCESS_TWICE)) { |
| asm volatile ( |
| "mov $fixed2, %%rsi \n\t" |
| "mov (%[addr]), %[reg] \n\t" |
| "fixed2:" |
| : [reg]"=r"(r), [fault]"=a"(fault), "=b"(e) |
| : [addr]"r"(at->virt) |
| : "rsi" |
| ); |
| fault = 0; |
| } |
| |
| asm volatile ("mov $fixed1, %%rsi \n\t" |
| "mov %%rsp, %%rdx \n\t" |
| "cmp $0, %[user] \n\t" |
| "jz do_access \n\t" |
| "push %%rax; mov %[user_ds], %%ax; mov %%ax, %%ds; pop %%rax \n\t" |
| "pushq %[user_ds] \n\t" |
| "pushq %[user_stack_top] \n\t" |
| "pushfq \n\t" |
| "pushq %[user_cs] \n\t" |
| "pushq $do_access \n\t" |
| "iretq \n" |
| "do_access: \n\t" |
| "cmp $0, %[fetch] \n\t" |
| "jnz 2f \n\t" |
| "cmp $0, %[write] \n\t" |
| "jnz 1f \n\t" |
| "mov (%[addr]), %[reg] \n\t" |
| "jmp done \n\t" |
| "1: mov %[reg], (%[addr]) \n\t" |
| "jmp done \n\t" |
| "2: call *%[addr] \n\t" |
| "done: \n" |
| "fixed1: \n" |
| "int %[kernel_entry_vector] \n\t" |
| "back_to_kernel:" |
| : [reg]"+r"(r), "+a"(fault), "=b"(e), "=&d"(rsp) |
| : [addr]"r"(at->virt), |
| [write]"r"(F(AC_ACCESS_WRITE)), |
| [user]"r"(F(AC_ACCESS_USER)), |
| [fetch]"r"(F(AC_ACCESS_FETCH)), |
| [user_ds]"i"(USER_DS), |
| [user_cs]"i"(USER_CS), |
| [user_stack_top]"r"(user_stack + sizeof user_stack), |
| [kernel_entry_vector]"i"(0x20) |
| : "rsi"); |
| |
| asm volatile (".section .text.pf \n\t" |
| "page_fault: \n\t" |
| "pop %rbx \n\t" |
| "mov %rsi, (%rsp) \n\t" |
| "movl $1, %eax \n\t" |
| "iretq \n\t" |
| ".section .text"); |
| |
| asm volatile (".section .text.entry \n\t" |
| "kernel_entry: \n\t" |
| "mov %rdx, %rsp \n\t" |
| "jmp back_to_kernel \n\t" |
| ".section .text"); |
| |
| ac_test_check(at, &success, fault && !at->expected_fault, |
| "unexpected fault"); |
| ac_test_check(at, &success, !fault && at->expected_fault, |
| "unexpected access"); |
| ac_test_check(at, &success, fault && e != at->expected_error, |
| "error code %x expected %x", e, at->expected_error); |
| if (at->ptep) |
| ac_test_check(at, &success, *at->ptep != at->expected_pte, |
| "pte %x expected %x", *at->ptep, at->expected_pte); |
| ac_test_check(at, &success, |
| !pt_match(*at->pdep, at->expected_pde, at->ignore_pde), |
| "pde %x expected %x", *at->pdep, at->expected_pde); |
| |
| if (success && verbose) { |
| if (at->expected_fault) { |
| printf("PASS (%x)\n", at->expected_error); |
| } else { |
| printf("PASS\n"); |
| } |
| } |
| return success; |
| } |
| |
| static void ac_test_show(ac_test_t *at) |
| { |
| char line[5000]; |
| |
| *line = 0; |
| strcat(line, "test"); |
| for (int i = 0; i < NR_AC_FLAGS; ++i) |
| if (at->flags & (1 << i)) { |
| strcat(line, " "); |
| strcat(line, ac_names[i]); |
| } |
| |
| strcat(line, ": "); |
| printf("%s", line); |
| } |
| |
| /* |
| * This test case is used to triger the bug which is fixed by |
| * commit e09e90a5 in the kvm tree |
| */ |
| static int corrupt_hugepage_triger(ac_pool_t *pool) |
| { |
| ac_test_t at1, at2; |
| |
| ac_test_init(&at1, (void *)(0x123400000000)); |
| ac_test_init(&at2, (void *)(0x666600000000)); |
| |
| at2.flags = AC_CPU_CR0_WP_MASK | AC_PDE_PSE_MASK | AC_PDE_PRESENT_MASK; |
| ac_test_setup_pte(&at2, pool); |
| if (!ac_test_do_access(&at2)) |
| goto err; |
| |
| at1.flags = at2.flags | AC_PDE_WRITABLE_MASK; |
| ac_test_setup_pte(&at1, pool); |
| if (!ac_test_do_access(&at1)) |
| goto err; |
| |
| at1.flags |= AC_ACCESS_WRITE_MASK; |
| ac_set_expected_status(&at1); |
| if (!ac_test_do_access(&at1)) |
| goto err; |
| |
| at2.flags |= AC_ACCESS_WRITE_MASK; |
| ac_set_expected_status(&at2); |
| if (!ac_test_do_access(&at2)) |
| goto err; |
| |
| return 1; |
| |
| err: |
| printf("corrupt_hugepage_triger test fail\n"); |
| return 0; |
| } |
| |
| /* |
| * This test case is used to triger the bug which is fixed by |
| * commit 3ddf6c06e13e in the kvm tree |
| */ |
| static int check_pfec_on_prefetch_pte(ac_pool_t *pool) |
| { |
| ac_test_t at1, at2; |
| |
| ac_test_init(&at1, (void *)(0x123406001000)); |
| ac_test_init(&at2, (void *)(0x123406003000)); |
| |
| at1.flags = AC_PDE_PRESENT_MASK | AC_PTE_PRESENT_MASK; |
| ac_setup_specific_pages(&at1, pool, 30 * 1024 * 1024, 30 * 1024 * 1024); |
| |
| at2.flags = at1.flags | AC_PTE_NX_MASK; |
| ac_setup_specific_pages(&at2, pool, 30 * 1024 * 1024, 30 * 1024 * 1024); |
| |
| if (!ac_test_do_access(&at1)) { |
| printf("%s: prepare fail\n", __FUNCTION__); |
| goto err; |
| } |
| |
| if (!ac_test_do_access(&at2)) { |
| printf("%s: check PFEC on prefetch pte path fail\n", |
| __FUNCTION__); |
| goto err; |
| } |
| |
| return 1; |
| |
| err: |
| return 0; |
| } |
| |
| /* |
| * If the write-fault access is from supervisor and CR0.WP is not set on the |
| * vcpu, kvm will fix it by adjusting pte access - it sets the W bit on pte |
| * and clears U bit. This is the chance that kvm can change pte access from |
| * readonly to writable. |
| * |
| * Unfortunately, the pte access is the access of 'direct' shadow page table, |
| * means direct sp.role.access = pte_access, then we will create a writable |
| * spte entry on the readonly shadow page table. It will cause Dirty bit is |
| * not tracked when two guest ptes point to the same large page. Note, it |
| * does not have other impact except Dirty bit since cr0.wp is encoded into |
| * sp.role. |
| * |
| * Note: to trigger this bug, hugepage should be disabled on host. |
| */ |
| static int check_large_pte_dirty_for_nowp(ac_pool_t *pool) |
| { |
| ac_test_t at1, at2; |
| |
| ac_test_init(&at1, (void *)(0x123403000000)); |
| ac_test_init(&at2, (void *)(0x666606000000)); |
| |
| at2.flags = AC_PDE_PRESENT_MASK | AC_PDE_PSE_MASK; |
| ac_test_setup_pte(&at2, pool); |
| if (!ac_test_do_access(&at2)) { |
| printf("%s: read on the first mapping fail.\n", __FUNCTION__); |
| goto err; |
| } |
| |
| at1.flags = at2.flags | AC_ACCESS_WRITE_MASK; |
| ac_test_setup_pte(&at1, pool); |
| if (!ac_test_do_access(&at1)) { |
| printf("%s: write on the second mapping fail.\n", __FUNCTION__); |
| goto err; |
| } |
| |
| at2.flags |= AC_ACCESS_WRITE_MASK; |
| ac_set_expected_status(&at2); |
| if (!ac_test_do_access(&at2)) { |
| printf("%s: write on the first mapping fail.\n", __FUNCTION__); |
| goto err; |
| } |
| |
| return 1; |
| |
| err: |
| return 0; |
| } |
| |
| static int check_smep_andnot_wp(ac_pool_t *pool) |
| { |
| ac_test_t at1; |
| int err_prepare_andnot_wp, err_smep_andnot_wp; |
| |
| if (!this_cpu_has(X86_FEATURE_SMEP)) { |
| return 1; |
| } |
| |
| ac_test_init(&at1, (void *)(0x123406001000)); |
| |
| at1.flags = AC_PDE_PRESENT_MASK | AC_PTE_PRESENT_MASK | |
| AC_PDE_USER_MASK | AC_PTE_USER_MASK | |
| AC_PDE_ACCESSED_MASK | AC_PTE_ACCESSED_MASK | |
| AC_CPU_CR4_SMEP_MASK | |
| AC_CPU_CR0_WP_MASK | |
| AC_ACCESS_WRITE_MASK; |
| ac_test_setup_pte(&at1, pool); |
| |
| /* |
| * Here we write the ro user page when |
| * cr0.wp=0, then we execute it and SMEP |
| * fault should happen. |
| */ |
| err_prepare_andnot_wp = ac_test_do_access(&at1); |
| if (!err_prepare_andnot_wp) { |
| printf("%s: SMEP prepare fail\n", __FUNCTION__); |
| goto clean_up; |
| } |
| |
| at1.flags &= ~AC_ACCESS_WRITE_MASK; |
| at1.flags |= AC_ACCESS_FETCH_MASK; |
| ac_set_expected_status(&at1); |
| err_smep_andnot_wp = ac_test_do_access(&at1); |
| |
| clean_up: |
| set_cr4_smep(0); |
| |
| if (!err_prepare_andnot_wp) |
| goto err; |
| if (!err_smep_andnot_wp) { |
| printf("%s: check SMEP without wp fail\n", __FUNCTION__); |
| goto err; |
| } |
| return 1; |
| |
| err: |
| return 0; |
| } |
| |
| static int ac_test_exec(ac_test_t *at, ac_pool_t *pool) |
| { |
| int r; |
| |
| if (verbose) { |
| ac_test_show(at); |
| } |
| ac_test_setup_pte(at, pool); |
| r = ac_test_do_access(at); |
| return r; |
| } |
| |
| typedef int (*ac_test_fn)(ac_pool_t *pool); |
| const ac_test_fn ac_test_cases[] = |
| { |
| corrupt_hugepage_triger, |
| check_pfec_on_prefetch_pte, |
| check_large_pte_dirty_for_nowp, |
| check_smep_andnot_wp |
| }; |
| |
| static int ac_test_run(void) |
| { |
| ac_test_t at; |
| ac_pool_t pool; |
| int i, tests, successes; |
| |
| printf("run\n"); |
| tests = successes = 0; |
| |
| shadow_cr0 = read_cr0(); |
| shadow_cr4 = read_cr4(); |
| shadow_efer = rdmsr(MSR_EFER); |
| |
| if (cpuid_maxphyaddr() >= 52) { |
| invalid_mask |= AC_PDE_BIT51_MASK; |
| invalid_mask |= AC_PTE_BIT51_MASK; |
| } |
| if (cpuid_maxphyaddr() >= 37) { |
| invalid_mask |= AC_PDE_BIT36_MASK; |
| invalid_mask |= AC_PTE_BIT36_MASK; |
| } |
| |
| if (this_cpu_has(X86_FEATURE_PKU)) { |
| set_cr4_pke(1); |
| set_cr4_pke(0); |
| /* Now PKRU = 0xFFFFFFFF. */ |
| } else { |
| tests++; |
| if (write_cr4_checking(shadow_cr4 | X86_CR4_PKE) == GP_VECTOR) { |
| successes++; |
| invalid_mask |= AC_PKU_AD_MASK; |
| invalid_mask |= AC_PKU_WD_MASK; |
| invalid_mask |= AC_PKU_PKEY_MASK; |
| invalid_mask |= AC_CPU_CR4_PKE_MASK; |
| printf("CR4.PKE not available, disabling PKE tests\n"); |
| } else { |
| printf("Set PKE in CR4 - expect #GP: FAIL!\n"); |
| set_cr4_pke(0); |
| } |
| } |
| |
| if (!this_cpu_has(X86_FEATURE_SMEP)) { |
| tests++; |
| if (set_cr4_smep(1) == GP_VECTOR) { |
| successes++; |
| invalid_mask |= AC_CPU_CR4_SMEP_MASK; |
| printf("CR4.SMEP not available, disabling SMEP tests\n"); |
| } else { |
| printf("Set SMEP in CR4 - expect #GP: FAIL!\n"); |
| set_cr4_smep(0); |
| } |
| } |
| |
| ac_env_int(&pool); |
| ac_test_init(&at, (void *)(0x123400000000 + 16 * smp_id())); |
| do { |
| ++tests; |
| successes += ac_test_exec(&at, &pool); |
| } while (ac_test_bump(&at)); |
| |
| for (i = 0; i < ARRAY_SIZE(ac_test_cases); i++) { |
| ++tests; |
| successes += ac_test_cases[i](&pool); |
| } |
| |
| printf("\n%d tests, %d failures\n", tests, tests - successes); |
| |
| return successes == tests; |
| } |
| |
| int main(void) |
| { |
| int r; |
| |
| printf("starting test\n\n"); |
| page_table_levels = 4; |
| r = ac_test_run(); |
| |
| if (this_cpu_has(X86_FEATURE_LA57)) { |
| page_table_levels = 5; |
| printf("starting 5-level paging test.\n\n"); |
| setup_5level_page_table(); |
| r = ac_test_run(); |
| } |
| |
| return r ? 0 : 1; |
| } |