diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/mm/protection_keys.c (renamed from tools/testing/selftests/vm/protection_keys.c) | 267 |
1 files changed, 250 insertions, 17 deletions
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c index fdbb602ecf32..f822ae31af22 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/mm/protection_keys.c @@ -18,12 +18,13 @@ * do a plain mprotect() to a mprotect_pkey() area and make sure the pkey sticks * * Compile like this: - * gcc -o protection_keys -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm - * gcc -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm + * gcc -mxsave -o protection_keys -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm + * gcc -mxsave -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm */ #define _GNU_SOURCE #define __SANE_USERSPACE_TYPES__ #include <errno.h> +#include <linux/elf.h> #include <linux/futex.h> #include <time.h> #include <sys/time.h> @@ -53,6 +54,7 @@ int test_nr; u64 shadow_pkey_reg; int dprint_in_signal; char dprint_in_signal_buffer[DPRINT_IN_SIGNAL_BUF_SIZE]; +char buf[256]; void cat_into_file(char *str, char *file) { @@ -97,7 +99,7 @@ int tracing_root_ok(void) void tracing_on(void) { #if CONTROL_TRACING > 0 -#define TRACEDIR "/sys/kernel/debug/tracing" +#define TRACEDIR "/sys/kernel/tracing" char pidstr[32]; if (!tracing_root_ok()) @@ -123,7 +125,7 @@ void tracing_off(void) #if CONTROL_TRACING > 0 if (!tracing_root_ok()) return; - cat_into_file("0", "/sys/kernel/debug/tracing/tracing_on"); + cat_into_file("0", "/sys/kernel/tracing/tracing_on"); #endif } @@ -293,15 +295,6 @@ void pkey_access_deny(int pkey) pkey_disable_set(pkey, PKEY_DISABLE_ACCESS); } -/* Failed address bound checks: */ -#ifndef SEGV_BNDERR -# define SEGV_BNDERR 3 -#endif - -#ifndef SEGV_PKUERR -# define SEGV_PKUERR 4 -#endif - static char *si_code_str(int si_code) { if (si_code == SEGV_MAPERR) @@ -475,7 +468,7 @@ int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot, ptr, size, orig_prot, pkey); errno = 0; - sret = syscall(SYS_mprotect_key, ptr, size, orig_prot, pkey); + sret = syscall(__NR_pkey_mprotect, ptr, size, orig_prot, pkey); if (errno) { dprintf2("SYS_mprotect_key sret: %d\n", sret); dprintf2("SYS_mprotect_key prot: 0x%lx\n", orig_prot); @@ -510,7 +503,7 @@ int alloc_pkey(void) " shadow: 0x%016llx\n", __func__, __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg); - if (ret) { + if (ret > 0) { /* clear both the bits: */ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret, ~PKEY_MASK); @@ -561,7 +554,6 @@ int alloc_random_pkey(void) int nr_alloced = 0; int random_index; memset(alloced_pkeys, 0, sizeof(alloced_pkeys)); - srand((unsigned int)time(NULL)); /* allocate every possible key and make a note of which ones we got */ max_nr_pkey_allocs = NR_PKEYS; @@ -1278,6 +1270,78 @@ void test_pkey_alloc_exhaust(int *ptr, u16 pkey) } } +void arch_force_pkey_reg_init(void) +{ +#if defined(__i386__) || defined(__x86_64__) /* arch */ + u64 *buf; + + /* + * All keys should be allocated and set to allow reads and + * writes, so the register should be all 0. If not, just + * skip the test. + */ + if (read_pkey_reg()) + return; + + /* + * Just allocate an absurd about of memory rather than + * doing the XSAVE size enumeration dance. + */ + buf = mmap(NULL, 1*MB, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); + + /* These __builtins require compiling with -mxsave */ + + /* XSAVE to build a valid buffer: */ + __builtin_ia32_xsave(buf, XSTATE_PKEY); + /* Clear XSTATE_BV[PKRU]: */ + buf[XSTATE_BV_OFFSET/sizeof(u64)] &= ~XSTATE_PKEY; + /* XRSTOR will likely get PKRU back to the init state: */ + __builtin_ia32_xrstor(buf, XSTATE_PKEY); + + munmap(buf, 1*MB); +#endif +} + + +/* + * This is mostly useless on ppc for now. But it will not + * hurt anything and should give some better coverage as + * a long-running test that continually checks the pkey + * register. + */ +void test_pkey_init_state(int *ptr, u16 pkey) +{ + int err; + int allocated_pkeys[NR_PKEYS] = {0}; + int nr_allocated_pkeys = 0; + int i; + + for (i = 0; i < NR_PKEYS; i++) { + int new_pkey = alloc_pkey(); + + if (new_pkey < 0) + continue; + allocated_pkeys[nr_allocated_pkeys++] = new_pkey; + } + + dprintf3("%s()::%d\n", __func__, __LINE__); + + arch_force_pkey_reg_init(); + + /* + * Loop for a bit, hoping to get exercise the kernel + * context switch code. + */ + for (i = 0; i < 1000000; i++) + read_pkey_reg(); + + for (i = 0; i < nr_allocated_pkeys; i++) { + err = sys_pkey_free(allocated_pkeys[i]); + pkey_assert(!err); + read_pkey_reg(); /* for shadow checking */ + } +} + /* * pkey 0 is special. It is allocated by default, so you do not * have to call pkey_alloc() to use it first. Make sure that it @@ -1449,6 +1513,13 @@ void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) ret = mprotect(p1, PAGE_SIZE, PROT_EXEC); pkey_assert(!ret); + /* + * Reset the shadow, assuming that the above mprotect() + * correctly changed PKRU, but to an unknown value since + * the actual allocated pkey is unknown. + */ + shadow_pkey_reg = __read_pkey_reg(); + dprintf2("pkey_reg: %016llx\n", read_pkey_reg()); /* Make sure this is an *instruction* fault */ @@ -1472,6 +1543,129 @@ void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) do_not_expect_pkey_fault("plain read on recently PROT_EXEC area"); } +#if defined(__i386__) || defined(__x86_64__) +void test_ptrace_modifies_pkru(int *ptr, u16 pkey) +{ + u32 new_pkru; + pid_t child; + int status, ret; + int pkey_offset = pkey_reg_xstate_offset(); + size_t xsave_size = cpu_max_xsave_size(); + void *xsave; + u32 *pkey_register; + u64 *xstate_bv; + struct iovec iov; + + new_pkru = ~read_pkey_reg(); + /* Don't make PROT_EXEC mappings inaccessible */ + new_pkru &= ~3; + + child = fork(); + pkey_assert(child >= 0); + dprintf3("[%d] fork() ret: %d\n", getpid(), child); + if (!child) { + ptrace(PTRACE_TRACEME, 0, 0, 0); + /* Stop and allow the tracer to modify PKRU directly */ + raise(SIGSTOP); + + /* + * need __read_pkey_reg() version so we do not do shadow_pkey_reg + * checking + */ + if (__read_pkey_reg() != new_pkru) + exit(1); + + /* Stop and allow the tracer to clear XSTATE_BV for PKRU */ + raise(SIGSTOP); + + if (__read_pkey_reg() != 0) + exit(1); + + /* Stop and allow the tracer to examine PKRU */ + raise(SIGSTOP); + + exit(0); + } + + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + xsave = (void *)malloc(xsave_size); + pkey_assert(xsave > 0); + + /* Modify the PKRU register directly */ + iov.iov_base = xsave; + iov.iov_len = xsave_size; + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + pkey_register = (u32 *)(xsave + pkey_offset); + pkey_assert(*pkey_register == read_pkey_reg()); + + *pkey_register = new_pkru; + + ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + /* Test that the modification is visible in ptrace before any execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == new_pkru); + + /* Execute the tracee */ + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + + /* Test that the tracee saw the PKRU value change */ + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + /* Test that the modification is visible in ptrace after execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == new_pkru); + + /* Clear the PKRU bit from XSTATE_BV */ + xstate_bv = (u64 *)(xsave + 512); + *xstate_bv &= ~(1 << 9); + + ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + /* Test that the modification is visible in ptrace before any execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == 0); + + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + + /* Test that the tracee saw the PKRU value go to 0 */ + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + /* Test that the modification is visible in ptrace after execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == 0); + + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFEXITED(status)); + pkey_assert(WEXITSTATUS(status) == 0); + free(xsave); +} +#endif + void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) { int size = PAGE_SIZE; @@ -1482,7 +1676,7 @@ void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) return; } - sret = syscall(SYS_mprotect_key, ptr, size, PROT_READ, pkey); + sret = syscall(__NR_pkey_mprotect, ptr, size, PROT_READ, pkey); pkey_assert(sret < 0); } @@ -1502,10 +1696,14 @@ void (*pkey_tests[])(int *ptr, u16 pkey) = { test_implicit_mprotect_exec_only_memory, test_mprotect_with_pkey_0, test_ptrace_of_child, + test_pkey_init_state, test_pkey_syscalls_on_non_allocated_pkey, test_pkey_syscalls_bad_args, test_pkey_alloc_exhaust, test_pkey_alloc_free_attach_pkey0, +#if defined(__i386__) || defined(__x86_64__) + test_ptrace_modifies_pkru, +#endif }; void run_tests_once(void) @@ -1547,11 +1745,46 @@ void pkey_setup_shadow(void) shadow_pkey_reg = __read_pkey_reg(); } +void restore_settings_atexit(void) +{ + cat_into_file(buf, "/proc/sys/vm/nr_hugepages"); +} + +void save_settings(void) +{ + int fd; + int err; + + if (geteuid()) + return; + + fd = open("/proc/sys/vm/nr_hugepages", O_RDONLY); + if (fd < 0) { + fprintf(stderr, "error opening\n"); + perror("error: "); + exit(__LINE__); + } + + /* -1 to guarantee leaving the trailing \0 */ + err = read(fd, buf, sizeof(buf)-1); + if (err < 0) { + fprintf(stderr, "error reading\n"); + perror("error: "); + exit(__LINE__); + } + + atexit(restore_settings_atexit); + close(fd); +} + int main(void) { int nr_iterations = 22; int pkeys_supported = is_pkeys_supported(); + srand((unsigned int)time(NULL)); + + save_settings(); setup_handlers(); printf("has pkeys: %d\n", pkeys_supported); |