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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Ptrace test for Memory Protection Key registers4 *5 * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.6 * Copyright (C) 2018 IBM Corporation.7 */8#include "ptrace.h"9#include "child.h"10 11#ifndef __NR_pkey_alloc12#define __NR_pkey_alloc 38413#endif14 15#ifndef __NR_pkey_free16#define __NR_pkey_free 38517#endif18 19#ifndef NT_PPC_PKEY20#define NT_PPC_PKEY 0x11021#endif22 23#ifndef PKEY_DISABLE_EXECUTE24#define PKEY_DISABLE_EXECUTE 0x425#endif26 27#define AMR_BITS_PER_PKEY 228#define PKEY_REG_BITS (sizeof(u64) * 8)29#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey + 1) * AMR_BITS_PER_PKEY))30 31static const char user_read[] = "[User Read (Running)]";32static const char user_write[] = "[User Write (Running)]";33static const char ptrace_read_running[] = "[Ptrace Read (Running)]";34static const char ptrace_write_running[] = "[Ptrace Write (Running)]";35 36/* Information shared between the parent and the child. */37struct shared_info {38 struct child_sync child_sync;39 40 /* AMR value the parent expects to read from the child. */41 unsigned long amr1;42 43 /* AMR value the parent is expected to write to the child. */44 unsigned long amr2;45 46 /* AMR value that ptrace should refuse to write to the child. */47 unsigned long invalid_amr;48 49 /* IAMR value the parent expects to read from the child. */50 unsigned long expected_iamr;51 52 /* UAMOR value the parent expects to read from the child. */53 unsigned long expected_uamor;54 55 /*56 * IAMR and UAMOR values that ptrace should refuse to write to the child57 * (even though they're valid ones) because userspace doesn't have58 * access to those registers.59 */60 unsigned long invalid_iamr;61 unsigned long invalid_uamor;62};63 64static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)65{66 return syscall(__NR_pkey_alloc, flags, init_access_rights);67}68 69static int child(struct shared_info *info)70{71 unsigned long reg;72 bool disable_execute = true;73 int pkey1, pkey2, pkey3;74 int ret;75 76 /* Wait until parent fills out the initial register values. */77 ret = wait_parent(&info->child_sync);78 if (ret)79 return ret;80 81 /* Get some pkeys so that we can change their bits in the AMR. */82 pkey1 = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);83 if (pkey1 < 0) {84 pkey1 = sys_pkey_alloc(0, 0);85 CHILD_FAIL_IF(pkey1 < 0, &info->child_sync);86 87 disable_execute = false;88 }89 90 pkey2 = sys_pkey_alloc(0, 0);91 CHILD_FAIL_IF(pkey2 < 0, &info->child_sync);92 93 pkey3 = sys_pkey_alloc(0, 0);94 CHILD_FAIL_IF(pkey3 < 0, &info->child_sync);95 96 info->amr1 |= 3ul << pkeyshift(pkey1);97 info->amr2 |= 3ul << pkeyshift(pkey2);98 /*99 * invalid amr value where we try to force write100 * things which are deined by a uamor setting.101 */102 info->invalid_amr = info->amr2 | (~0x0UL & ~info->expected_uamor);103 104 /*105 * if PKEY_DISABLE_EXECUTE succeeded we should update the expected_iamr106 */107 if (disable_execute)108 info->expected_iamr |= 1ul << pkeyshift(pkey1);109 else110 info->expected_iamr &= ~(1ul << pkeyshift(pkey1));111 112 /*113 * We allocated pkey2 and pkey 3 above. Clear the IAMR bits.114 */115 info->expected_iamr &= ~(1ul << pkeyshift(pkey2));116 info->expected_iamr &= ~(1ul << pkeyshift(pkey3));117 118 /*119 * Create an IAMR value different from expected value.120 * Kernel will reject an IAMR and UAMOR change.121 */122 info->invalid_iamr = info->expected_iamr | (1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2));123 info->invalid_uamor = info->expected_uamor & ~(0x3ul << pkeyshift(pkey1));124 125 printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",126 user_write, info->amr1, pkey1, pkey2, pkey3);127 128 set_amr(info->amr1);129 130 /* Wait for parent to read our AMR value and write a new one. */131 ret = prod_parent(&info->child_sync);132 CHILD_FAIL_IF(ret, &info->child_sync);133 134 ret = wait_parent(&info->child_sync);135 if (ret)136 return ret;137 138 reg = mfspr(SPRN_AMR);139 140 printf("%-30s AMR: %016lx\n", user_read, reg);141 142 CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);143 144 /*145 * Wait for parent to try to write an invalid AMR value.146 */147 ret = prod_parent(&info->child_sync);148 CHILD_FAIL_IF(ret, &info->child_sync);149 150 ret = wait_parent(&info->child_sync);151 if (ret)152 return ret;153 154 reg = mfspr(SPRN_AMR);155 156 printf("%-30s AMR: %016lx\n", user_read, reg);157 158 CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);159 160 /*161 * Wait for parent to try to write an IAMR and a UAMOR value. We can't162 * verify them, but we can verify that the AMR didn't change.163 */164 ret = prod_parent(&info->child_sync);165 CHILD_FAIL_IF(ret, &info->child_sync);166 167 ret = wait_parent(&info->child_sync);168 if (ret)169 return ret;170 171 reg = mfspr(SPRN_AMR);172 173 printf("%-30s AMR: %016lx\n", user_read, reg);174 175 CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);176 177 /* Now let parent now that we are finished. */178 179 ret = prod_parent(&info->child_sync);180 CHILD_FAIL_IF(ret, &info->child_sync);181 182 return TEST_PASS;183}184 185static int parent(struct shared_info *info, pid_t pid)186{187 unsigned long regs[3];188 int ret, status;189 190 /*191 * Get the initial values for AMR, IAMR and UAMOR and communicate them192 * to the child.193 */194 ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);195 PARENT_SKIP_IF_UNSUPPORTED(ret, &info->child_sync, "PKEYs not supported");196 PARENT_FAIL_IF(ret, &info->child_sync);197 198 info->amr1 = info->amr2 = regs[0];199 info->expected_iamr = regs[1];200 info->expected_uamor = regs[2];201 202 /* Wake up child so that it can set itself up. */203 ret = prod_child(&info->child_sync);204 PARENT_FAIL_IF(ret, &info->child_sync);205 206 ret = wait_child(&info->child_sync);207 if (ret)208 return ret;209 210 /* Verify that we can read the pkey registers from the child. */211 ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);212 PARENT_FAIL_IF(ret, &info->child_sync);213 214 printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",215 ptrace_read_running, regs[0], regs[1], regs[2]);216 217 PARENT_FAIL_IF(regs[0] != info->amr1, &info->child_sync);218 PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);219 PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);220 221 /* Write valid AMR value in child. */222 ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr2, 1);223 PARENT_FAIL_IF(ret, &info->child_sync);224 225 printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr2);226 227 /* Wake up child so that it can verify it changed. */228 ret = prod_child(&info->child_sync);229 PARENT_FAIL_IF(ret, &info->child_sync);230 231 ret = wait_child(&info->child_sync);232 if (ret)233 return ret;234 235 /* Write invalid AMR value in child. */236 ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->invalid_amr, 1);237 PARENT_FAIL_IF(ret, &info->child_sync);238 239 printf("%-30s AMR: %016lx\n", ptrace_write_running, info->invalid_amr);240 241 /* Wake up child so that it can verify it didn't change. */242 ret = prod_child(&info->child_sync);243 PARENT_FAIL_IF(ret, &info->child_sync);244 245 ret = wait_child(&info->child_sync);246 if (ret)247 return ret;248 249 /* Try to write to IAMR. */250 regs[0] = info->amr1;251 regs[1] = info->invalid_iamr;252 ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);253 PARENT_FAIL_IF(!ret, &info->child_sync);254 255 printf("%-30s AMR: %016lx IAMR: %016lx\n",256 ptrace_write_running, regs[0], regs[1]);257 258 /* Try to write to IAMR and UAMOR. */259 regs[2] = info->invalid_uamor;260 ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);261 PARENT_FAIL_IF(!ret, &info->child_sync);262 263 printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",264 ptrace_write_running, regs[0], regs[1], regs[2]);265 266 /* Verify that all registers still have their expected values. */267 ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);268 PARENT_FAIL_IF(ret, &info->child_sync);269 270 printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",271 ptrace_read_running, regs[0], regs[1], regs[2]);272 273 PARENT_FAIL_IF(regs[0] != info->amr2, &info->child_sync);274 PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);275 PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);276 277 /* Wake up child so that it can verify AMR didn't change and wrap up. */278 ret = prod_child(&info->child_sync);279 PARENT_FAIL_IF(ret, &info->child_sync);280 281 ret = wait(&status);282 if (ret != pid) {283 printf("Child's exit status not captured\n");284 ret = TEST_PASS;285 } else if (!WIFEXITED(status)) {286 printf("Child exited abnormally\n");287 ret = TEST_FAIL;288 } else289 ret = WEXITSTATUS(status) ? TEST_FAIL : TEST_PASS;290 291 return ret;292}293 294static int ptrace_pkey(void)295{296 struct shared_info *info;297 int shm_id;298 int ret;299 pid_t pid;300 301 shm_id = shmget(IPC_PRIVATE, sizeof(*info), 0777 | IPC_CREAT);302 info = shmat(shm_id, NULL, 0);303 304 ret = init_child_sync(&info->child_sync);305 if (ret)306 return ret;307 308 pid = fork();309 if (pid < 0) {310 perror("fork() failed");311 ret = TEST_FAIL;312 } else if (pid == 0)313 ret = child(info);314 else315 ret = parent(info, pid);316 317 shmdt(info);318 319 if (pid) {320 destroy_child_sync(&info->child_sync);321 shmctl(shm_id, IPC_RMID, NULL);322 }323 324 return ret;325}326 327int main(int argc, char *argv[])328{329 return test_harness(ptrace_pkey, "ptrace_pkey");330}331