2018-01-26 05:56:43

by Thiago Jung Bauermann

[permalink] [raw]
Subject: [PATCH 0/2] Testcases for protection keys feature in powerpc/next

Ram Pai submitted a separate series containing the rework of the x86 test and
also the powerpc-specific tests:

https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=24741

There's a bug in the powerpc tests where they expect the AMR, IAMR and UAMOR
registers to be zeroed when a process starts. This is currently true on powernv
but isn't on LPARs, where key 31 is reserved and its bits are set. This causes
the tests to fail on that platform.

This series fixes the bug and now the tests pass on both powernv and LPAR
machines running powerpc/next. I think it's worth submitting these tests
separately from the one coming from x86 so here they are.

Thiago Jung Bauermann (2):
selftests/powerpc: Add ptrace tests for Protection Key registers
selftests/powerpc: Add core file test for Protection Key registers

tools/testing/selftests/powerpc/include/reg.h | 1 +
tools/testing/selftests/powerpc/ptrace/Makefile | 8 +-
tools/testing/selftests/powerpc/ptrace/child.h | 130 ++++++
tools/testing/selftests/powerpc/ptrace/core-pkey.c | 460 +++++++++++++++++++++
.../testing/selftests/powerpc/ptrace/ptrace-pkey.c | 326 +++++++++++++++
tools/testing/selftests/powerpc/ptrace/ptrace.h | 37 ++
6 files changed, 961 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/ptrace/child.h
create mode 100644 tools/testing/selftests/powerpc/ptrace/core-pkey.c
create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c



2018-01-26 05:56:43

by Thiago Jung Bauermann

[permalink] [raw]
Subject: [PATCH 2/2] selftests/powerpc: Add core file test for Protection Key registers

This test verifies that the AMR, IAMR and UAMOR are being written to a
process' core file.

Signed-off-by: Thiago Jung Bauermann <[email protected]>
---
tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
tools/testing/selftests/powerpc/ptrace/core-pkey.c | 460 +++++++++++++++++++++
2 files changed, 464 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/ptrace/core-pkey.c

diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
index 707ba734faf2..a10916c3f3e1 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
- ptrace-tm-spd-vsx ptrace-tm-spr ptrace-pkey
+ ptrace-tm-spd-vsx ptrace-tm-spr ptrace-pkey core-pkey

include ../../lib.mk

@@ -12,6 +12,9 @@ CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
ptrace-pkey: ../harness.c ../utils.c ../lib/reg.S ptrace.h child.h ptrace-pkey.c
$(LINK.c) $^ $(LDLIBS) -pthread -o $@

+core-pkey: ../harness.c ../utils.c ../lib/reg.S ptrace.h child.h core-pkey.c
+ $(LINK.c) $^ $(LDLIBS) -pthread -o $@
+
$(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h

clean:
diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
new file mode 100644
index 000000000000..ddbe0f2caf70
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Ptrace test for Memory Protection Key registers
+ *
+ * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
+ * Copyright (C) 2018 IBM Corporation.
+ */
+#include <limits.h>
+#include <linux/kernel.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "ptrace.h"
+#include "child.h"
+
+#ifndef __NR_pkey_alloc
+#define __NR_pkey_alloc 384
+#endif
+
+#ifndef __NR_pkey_free
+#define __NR_pkey_free 385
+#endif
+
+#ifndef NT_PPC_PKEY
+#define NT_PPC_PKEY 0x110
+#endif
+
+#ifndef PKEY_DISABLE_EXECUTE
+#define PKEY_DISABLE_EXECUTE 0x4
+#endif
+
+#define AMR_BITS_PER_PKEY 2
+#define PKEY_REG_BITS (sizeof(u64) * 8)
+#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey + 1) * AMR_BITS_PER_PKEY))
+
+#define CORE_FILE_LIMIT (5 * 1024 * 1024) /* 5 MB should be enough */
+
+static const char core_pattern_file[] = "/proc/sys/kernel/core_pattern";
+
+static const char user_write[] = "[User Write (Running)]";
+static const char core_read_running[] = "[Core Read (Running)]";
+
+/* Information shared between the parent and the child. */
+struct shared_info {
+ struct child_sync child_sync;
+
+ /* AMR value the parent expects to read in the core file. */
+ unsigned long amr;
+
+ /* IAMR value the parent expects to read in the core file. */
+ unsigned long iamr;
+
+ /* UAMOR value the parent expects to read in the core file. */
+ unsigned long uamor;
+
+ /* When the child crashed. */
+ time_t core_time;
+};
+
+static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
+{
+ return syscall(__NR_pkey_alloc, flags, init_access_rights);
+}
+
+static int sys_pkey_free(int pkey)
+{
+ return syscall(__NR_pkey_free, pkey);
+}
+
+static int increase_core_file_limit(void)
+{
+ struct rlimit rlim;
+ int ret;
+
+ ret = getrlimit(RLIMIT_CORE, &rlim);
+ FAIL_IF(ret);
+
+ if (rlim.rlim_cur != RLIM_INFINITY && rlim.rlim_cur < CORE_FILE_LIMIT) {
+ rlim.rlim_cur = CORE_FILE_LIMIT;
+
+ if (rlim.rlim_max != RLIM_INFINITY &&
+ rlim.rlim_max < CORE_FILE_LIMIT)
+ rlim.rlim_max = CORE_FILE_LIMIT;
+
+ ret = setrlimit(RLIMIT_CORE, &rlim);
+ FAIL_IF(ret);
+ }
+
+ ret = getrlimit(RLIMIT_FSIZE, &rlim);
+ FAIL_IF(ret);
+
+ if (rlim.rlim_cur != RLIM_INFINITY && rlim.rlim_cur < CORE_FILE_LIMIT) {
+ rlim.rlim_cur = CORE_FILE_LIMIT;
+
+ if (rlim.rlim_max != RLIM_INFINITY &&
+ rlim.rlim_max < CORE_FILE_LIMIT)
+ rlim.rlim_max = CORE_FILE_LIMIT;
+
+ ret = setrlimit(RLIMIT_FSIZE, &rlim);
+ FAIL_IF(ret);
+ }
+
+ return TEST_PASS;
+}
+
+static int child(struct shared_info *info)
+{
+ bool disable_execute = true;
+ int pkey1, pkey2, pkey3;
+ int *ptr, ret;
+
+ /* Wait until parent fills out the initial register values. */
+ ret = wait_parent(&info->child_sync);
+ if (ret)
+ return ret;
+
+ ret = increase_core_file_limit();
+ FAIL_IF(ret);
+
+ /* Get some pkeys so that we can change their bits in the AMR. */
+ pkey1 = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
+ if (pkey1 < 0) {
+ pkey1 = sys_pkey_alloc(0, 0);
+ FAIL_IF(pkey1 < 0);
+
+ disable_execute = false;
+ }
+
+ pkey2 = sys_pkey_alloc(0, 0);
+ FAIL_IF(pkey2 < 0);
+
+ pkey3 = sys_pkey_alloc(0, 0);
+ FAIL_IF(pkey3 < 0);
+
+ info->amr |= 3ul << pkeyshift(pkey1) | 2ul << pkeyshift(pkey2);
+
+ if (disable_execute)
+ info->iamr |= 1ul << pkeyshift(pkey1);
+
+ info->uamor |= 3ul << pkeyshift(pkey1) | 3ul << pkeyshift(pkey2);
+
+ printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
+ user_write, info->amr, pkey1, pkey2, pkey3);
+
+ mtspr(SPRN_AMR, info->amr);
+
+ /*
+ * We won't use pkey3. This tests whether the kernel restores the UAMOR
+ * permissions after a key is freed.
+ */
+ sys_pkey_free(pkey3);
+
+ info->core_time = time(NULL);
+
+ /* Crash. */
+ ptr = 0;
+ *ptr = 1;
+
+ /* Shouldn't get here. */
+ FAIL_IF(true);
+
+ return TEST_FAIL;
+}
+
+/* Return file size if filename exists and pass sanity check, or zero if not. */
+static off_t try_core_file(const char *filename, struct shared_info *info,
+ pid_t pid)
+{
+ struct stat buf;
+ int ret;
+
+ ret = stat(filename, &buf);
+ if (ret == -1)
+ return TEST_FAIL;
+
+ /* Make sure we're not using a stale core file. */
+ return buf.st_mtime >= info->core_time ? buf.st_size : TEST_FAIL;
+}
+
+static Elf64_Nhdr *next_note(Elf64_Nhdr *nhdr)
+{
+ return (void *) nhdr + sizeof(*nhdr) +
+ __ALIGN_KERNEL(nhdr->n_namesz, 4) +
+ __ALIGN_KERNEL(nhdr->n_descsz, 4);
+}
+
+static int check_core_file(struct shared_info *info, Elf64_Ehdr *ehdr,
+ off_t core_size)
+{
+ unsigned long *regs;
+ Elf64_Phdr *phdr;
+ Elf64_Nhdr *nhdr;
+ size_t phdr_size;
+ void *p = ehdr, *note;
+ int ret;
+
+ ret = memcmp(ehdr->e_ident, ELFMAG, SELFMAG);
+ FAIL_IF(ret);
+
+ FAIL_IF(ehdr->e_type != ET_CORE);
+ FAIL_IF(ehdr->e_machine != EM_PPC64);
+ FAIL_IF(ehdr->e_phoff == 0 || ehdr->e_phnum == 0);
+
+ /*
+ * e_phnum is at most 65535 so calculating the size of the
+ * program header cannot overflow.
+ */
+ phdr_size = sizeof(*phdr) * ehdr->e_phnum;
+
+ /* Sanity check the program header table location. */
+ FAIL_IF(ehdr->e_phoff + phdr_size < ehdr->e_phoff);
+ FAIL_IF(ehdr->e_phoff + phdr_size > core_size);
+
+ /* Find the PT_NOTE segment. */
+ for (phdr = p + ehdr->e_phoff;
+ (void *) phdr < p + ehdr->e_phoff + phdr_size;
+ phdr += ehdr->e_phentsize)
+ if (phdr->p_type == PT_NOTE)
+ break;
+
+ FAIL_IF((void *) phdr >= p + ehdr->e_phoff + phdr_size);
+
+ /* Find the NT_PPC_PKEY note. */
+ for (nhdr = p + phdr->p_offset;
+ (void *) nhdr < p + phdr->p_offset + phdr->p_filesz;
+ nhdr = next_note(nhdr))
+ if (nhdr->n_type == NT_PPC_PKEY)
+ break;
+
+ FAIL_IF((void *) nhdr >= p + phdr->p_offset + phdr->p_filesz);
+ FAIL_IF(nhdr->n_descsz == 0);
+
+ p = nhdr;
+ note = p + sizeof(*nhdr) + __ALIGN_KERNEL(nhdr->n_namesz, 4);
+
+ regs = (unsigned long *) note;
+
+ printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
+ core_read_running, regs[0], regs[1], regs[2]);
+
+ FAIL_IF(regs[0] != info->amr);
+ FAIL_IF(regs[1] != info->iamr);
+ FAIL_IF(regs[2] != info->uamor);
+
+ return TEST_PASS;
+}
+
+static int parent(struct shared_info *info, pid_t pid)
+{
+ char *filenames, *filename[3];
+ int fd, i, ret, status;
+ unsigned long regs[3];
+ off_t core_size;
+ void *core;
+
+ /*
+ * Get the initial values for AMR, IAMR and UAMOR and communicate them
+ * to the child.
+ */
+ ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ info->amr = regs[0];
+ info->iamr = regs[1];
+ info->uamor = regs[2];
+
+ /* Wake up child so that it can set itself up. */
+ ret = prod_child(&info->child_sync);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait(&status);
+ if (ret != pid) {
+ printf("Child's exit status not captured\n");
+ return TEST_FAIL;
+ } else if (!WIFSIGNALED(status) || !WCOREDUMP(status)) {
+ printf("Child didn't dump core\n");
+ return TEST_FAIL;
+ }
+
+ /* Construct array of core file names to try. */
+
+ filename[0] = filenames = malloc(PATH_MAX);
+ if (!filenames) {
+ perror("Error allocating memory");
+ return TEST_FAIL;
+ }
+
+ ret = snprintf(filename[0], PATH_MAX, "core-pkey.%d", pid);
+ if (ret < 0 || ret >= PATH_MAX) {
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ filename[1] = filename[0] + ret + 1;
+ ret = snprintf(filename[1], PATH_MAX - ret - 1, "core.%d", pid);
+ if (ret < 0 || ret >= PATH_MAX - ret - 1) {
+ ret = TEST_FAIL;
+ goto out;
+ }
+ filename[2] = "core";
+
+ for (i = 0; i < 3; i++) {
+ core_size = try_core_file(filename[i], info, pid);
+ if (core_size != TEST_FAIL)
+ break;
+ }
+
+ if (i == 3) {
+ printf("Couldn't find core file\n");
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ fd = open(filename[i], O_RDONLY);
+ if (fd == -1) {
+ perror("Error opening core file");
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ core = mmap(NULL, core_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (core == (void *) -1) {
+ perror("Error mmaping core file");
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ ret = check_core_file(info, core, core_size);
+
+ munmap(core, core_size);
+ close(fd);
+ unlink(filename[i]);
+
+ out:
+ free(filenames);
+
+ return ret;
+}
+
+static int write_core_pattern(const char *core_pattern)
+{
+ size_t len = strlen(core_pattern), ret;
+ FILE *f;
+
+ f = fopen(core_pattern_file, "w");
+ if (!f) {
+ perror("Error writing to core_pattern file");
+ return TEST_FAIL;
+ }
+
+ ret = fwrite(core_pattern, 1, len, f);
+ fclose(f);
+ if (ret != len) {
+ perror("Error writing to core_pattern file");
+ return TEST_FAIL;
+ }
+
+ return TEST_PASS;
+}
+
+static int setup_core_pattern(char **core_pattern_, bool *changed_)
+{
+ FILE *f;
+ char *core_pattern;
+ int ret;
+
+ core_pattern = malloc(PATH_MAX);
+ if (!core_pattern) {
+ perror("Error allocating memory");
+ return TEST_FAIL;
+ }
+
+ f = fopen(core_pattern_file, "r");
+ if (!f) {
+ perror("Error opening core_pattern file");
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ ret = fread(core_pattern, 1, PATH_MAX, f);
+ fclose(f);
+ if (!ret) {
+ perror("Error reading core_pattern file");
+ ret = TEST_FAIL;
+ goto out;
+ }
+
+ /* Check whether we can predict the name of the core file. */
+ if (!strcmp(core_pattern, "core") || !strcmp(core_pattern, "core.%p"))
+ *changed_ = false;
+ else {
+ ret = write_core_pattern("core-pkey.%p");
+ if (ret)
+ goto out;
+
+ *changed_ = true;
+ }
+
+ *core_pattern_ = core_pattern;
+ ret = TEST_PASS;
+
+ out:
+ if (ret)
+ free(core_pattern);
+
+ return ret;
+}
+
+static int core_pkey(void)
+{
+ char *core_pattern;
+ bool changed_core_pattern;
+ struct shared_info *info;
+ int shm_id;
+ int ret;
+ pid_t pid;
+
+ ret = setup_core_pattern(&core_pattern, &changed_core_pattern);
+ if (ret)
+ return ret;
+
+ shm_id = shmget(IPC_PRIVATE, sizeof(*info), 0777 | IPC_CREAT);
+ info = shmat(shm_id, NULL, 0);
+
+ ret = init_child_sync(&info->child_sync);
+ if (ret)
+ return ret;
+
+ pid = fork();
+ if (pid < 0) {
+ perror("fork() failed");
+ ret = TEST_FAIL;
+ } else if (pid == 0)
+ ret = child(info);
+ else
+ ret = parent(info, pid);
+
+ shmdt(info);
+
+ if (pid) {
+ destroy_child_sync(&info->child_sync);
+ shmctl(shm_id, IPC_RMID, NULL);
+
+ if (changed_core_pattern)
+ write_core_pattern(core_pattern);
+ }
+
+ free(core_pattern);
+
+ return ret;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(core_pkey, "core_pkey");
+}


2018-01-26 05:57:14

by Thiago Jung Bauermann

[permalink] [raw]
Subject: [PATCH 1/2] selftests/powerpc: Add ptrace tests for Protection Key registers

This test exercises read and write access to the AMR, IAMR and UAMOR.

Signed-off-by: Thiago Jung Bauermann <[email protected]>
---
tools/testing/selftests/powerpc/include/reg.h | 1 +
tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
tools/testing/selftests/powerpc/ptrace/child.h | 130 ++++++++
.../testing/selftests/powerpc/ptrace/ptrace-pkey.c | 326 +++++++++++++++++++++
tools/testing/selftests/powerpc/ptrace/ptrace.h | 37 +++
5 files changed, 498 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/ptrace/child.h
create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c

diff --git a/tools/testing/selftests/powerpc/include/reg.h b/tools/testing/selftests/powerpc/include/reg.h
index 4afdebcce4cd..7f348c059bc2 100644
--- a/tools/testing/selftests/powerpc/include/reg.h
+++ b/tools/testing/selftests/powerpc/include/reg.h
@@ -54,6 +54,7 @@
#define SPRN_DSCR_PRIV 0x11 /* Privilege State DSCR */
#define SPRN_DSCR 0x03 /* Data Stream Control Register */
#define SPRN_PPR 896 /* Program Priority Register */
+#define SPRN_AMR 13 /* Authority Mask Register - problem state */

/* TEXASR register bits */
#define TEXASR_FC 0xFE00000000000000
diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
index 480305266504..707ba734faf2 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
- ptrace-tm-spd-vsx ptrace-tm-spr
+ ptrace-tm-spd-vsx ptrace-tm-spr ptrace-pkey

include ../../lib.mk

@@ -9,6 +9,9 @@ all: $(TEST_PROGS)

CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie

+ptrace-pkey: ../harness.c ../utils.c ../lib/reg.S ptrace.h child.h ptrace-pkey.c
+ $(LINK.c) $^ $(LDLIBS) -pthread -o $@
+
$(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h

clean:
diff --git a/tools/testing/selftests/powerpc/ptrace/child.h b/tools/testing/selftests/powerpc/ptrace/child.h
new file mode 100644
index 000000000000..40c1a6d92111
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/child.h
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Helper functions to sync execution between parent and child processes.
+ *
+ * Copyright 2018, Thiago Jung Bauermann, IBM Corporation.
+ */
+#include <stdio.h>
+#include <stdbool.h>
+#include <semaphore.h>
+
+/*
+ * Information in a shared memory location for synchronization between child and
+ * parent.
+ */
+struct child_sync {
+ /* The parent waits on this semaphore. */
+ sem_t sem_parent;
+
+ /* If true, the child should give up as well. */
+ bool parent_gave_up;
+
+ /* The child waits on this semaphore. */
+ sem_t sem_child;
+
+ /* If true, the parent should give up as well. */
+ bool child_gave_up;
+};
+
+#define CHILD_FAIL_IF(x, sync) \
+ do { \
+ if (x) { \
+ fprintf(stderr, \
+ "[FAIL] Test FAILED on line %d\n", __LINE__); \
+ (sync)->child_gave_up = true; \
+ prod_parent(sync); \
+ return 1; \
+ } \
+ } while (0)
+
+#define PARENT_FAIL_IF(x, sync) \
+ do { \
+ if (x) { \
+ fprintf(stderr, \
+ "[FAIL] Test FAILED on line %d\n", __LINE__); \
+ (sync)->parent_gave_up = true; \
+ prod_child(sync); \
+ return 1; \
+ } \
+ } while (0)
+
+int init_child_sync(struct child_sync *sync)
+{
+ int ret;
+
+ ret = sem_init(&sync->sem_parent, 1, 0);
+ if (ret) {
+ perror("Semaphore initialization failed");
+ return 1;
+ }
+
+ ret = sem_init(&sync->sem_child, 1, 0);
+ if (ret) {
+ perror("Semaphore initialization failed");
+ return 1;
+ }
+
+ return 0;
+}
+
+void destroy_child_sync(struct child_sync *sync)
+{
+ sem_destroy(&sync->sem_parent);
+ sem_destroy(&sync->sem_child);
+}
+
+int wait_child(struct child_sync *sync)
+{
+ int ret;
+
+ /* Wait until the child prods us. */
+ ret = sem_wait(&sync->sem_parent);
+ if (ret) {
+ perror("Error waiting for child");
+ return 1;
+ }
+
+ return sync->child_gave_up;
+}
+
+int prod_child(struct child_sync *sync)
+{
+ int ret;
+
+ /* Unblock the child now. */
+ ret = sem_post(&sync->sem_child);
+ if (ret) {
+ perror("Error prodding child");
+ return 1;
+ }
+
+ return 0;
+}
+
+int wait_parent(struct child_sync *sync)
+{
+ int ret;
+
+ /* Wait until the parent prods us. */
+ ret = sem_wait(&sync->sem_child);
+ if (ret) {
+ perror("Error waiting for parent");
+ return 1;
+ }
+
+ return sync->parent_gave_up;
+}
+
+int prod_parent(struct child_sync *sync)
+{
+ int ret;
+
+ /* Unblock the parent now. */
+ ret = sem_post(&sync->sem_parent);
+ if (ret) {
+ perror("Error prodding parent");
+ return 1;
+ }
+
+ return 0;
+}
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
new file mode 100644
index 000000000000..8332b9338d39
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Ptrace test for Memory Protection Key registers
+ *
+ * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
+ * Copyright (C) 2018 IBM Corporation.
+ */
+#include "ptrace.h"
+#include "child.h"
+
+#ifndef __NR_pkey_alloc
+#define __NR_pkey_alloc 384
+#endif
+
+#ifndef __NR_pkey_free
+#define __NR_pkey_free 385
+#endif
+
+#ifndef NT_PPC_PKEY
+#define NT_PPC_PKEY 0x110
+#endif
+
+#ifndef PKEY_DISABLE_EXECUTE
+#define PKEY_DISABLE_EXECUTE 0x4
+#endif
+
+#define AMR_BITS_PER_PKEY 2
+#define PKEY_REG_BITS (sizeof(u64) * 8)
+#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey + 1) * AMR_BITS_PER_PKEY))
+
+static const char user_read[] = "[User Read (Running)]";
+static const char user_write[] = "[User Write (Running)]";
+static const char ptrace_read_running[] = "[Ptrace Read (Running)]";
+static const char ptrace_write_running[] = "[Ptrace Write (Running)]";
+
+/* Information shared between the parent and the child. */
+struct shared_info {
+ struct child_sync child_sync;
+
+ /* AMR value the parent expects to read from the child. */
+ unsigned long amr1;
+
+ /* AMR value the parent is expected to write to the child. */
+ unsigned long amr2;
+
+ /* AMR value that ptrace should refuse to write to the child. */
+ unsigned long amr3;
+
+ /* IAMR value the parent expects to read from the child. */
+ unsigned long expected_iamr;
+
+ /* UAMOR value the parent expects to read from the child. */
+ unsigned long expected_uamor;
+
+ /*
+ * IAMR and UAMOR values that ptrace should refuse to write to the child
+ * (even though they're valid ones) because userspace doesn't have
+ * access to those registers.
+ */
+ unsigned long new_iamr;
+ unsigned long new_uamor;
+};
+
+static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
+{
+ return syscall(__NR_pkey_alloc, flags, init_access_rights);
+}
+
+static int sys_pkey_free(int pkey)
+{
+ return syscall(__NR_pkey_free, pkey);
+}
+
+static int child(struct shared_info *info)
+{
+ unsigned long reg;
+ bool disable_execute = true;
+ int pkey1, pkey2, pkey3;
+ int ret;
+
+ /* Wait until parent fills out the initial register values. */
+ ret = wait_parent(&info->child_sync);
+ if (ret)
+ return ret;
+
+ /* Get some pkeys so that we can change their bits in the AMR. */
+ pkey1 = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
+ if (pkey1 < 0) {
+ pkey1 = sys_pkey_alloc(0, 0);
+ CHILD_FAIL_IF(pkey1 < 0, &info->child_sync);
+
+ disable_execute = false;
+ }
+
+ pkey2 = sys_pkey_alloc(0, 0);
+ CHILD_FAIL_IF(pkey2 < 0, &info->child_sync);
+
+ pkey3 = sys_pkey_alloc(0, 0);
+ CHILD_FAIL_IF(pkey3 < 0, &info->child_sync);
+
+ info->amr1 |= 3ul << pkeyshift(pkey1);
+ info->amr2 |= 3ul << pkeyshift(pkey2);
+ info->amr3 |= info->amr2 | 3ul << pkeyshift(pkey3);
+
+ if (disable_execute)
+ info->expected_iamr |= 1ul << pkeyshift(pkey1);
+
+ info->expected_uamor |= 3ul << pkeyshift(pkey1) |
+ 3ul << pkeyshift(pkey2);
+ info->new_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
+ info->new_uamor |= 3ul << pkeyshift(pkey1);
+
+ /*
+ * We won't use pkey3. We just want a plausible but invalid key to test
+ * whether ptrace will let us write to AMR bits we are not supposed to.
+ *
+ * This also tests whether the kernel restores the UAMOR permissions
+ * after a key is freed.
+ */
+ sys_pkey_free(pkey3);
+
+ printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
+ user_write, info->amr1, pkey1, pkey2, pkey3);
+
+ mtspr(SPRN_AMR, info->amr1);
+
+ /* Wait for parent to read our AMR value and write a new one. */
+ ret = prod_parent(&info->child_sync);
+ CHILD_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_parent(&info->child_sync);
+ if (ret)
+ return ret;
+
+ reg = mfspr(SPRN_AMR);
+
+ printf("%-30s AMR: %016lx\n", user_read, reg);
+
+ CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
+
+ /*
+ * Wait for parent to try to write an invalid AMR value.
+ */
+ ret = prod_parent(&info->child_sync);
+ CHILD_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_parent(&info->child_sync);
+ if (ret)
+ return ret;
+
+ reg = mfspr(SPRN_AMR);
+
+ printf("%-30s AMR: %016lx\n", user_read, reg);
+
+ CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
+
+ /*
+ * Wait for parent to try to write an IAMR and a UAMOR value. We can't
+ * verify them, but we can verify that the AMR didn't change.
+ */
+ ret = prod_parent(&info->child_sync);
+ CHILD_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_parent(&info->child_sync);
+ if (ret)
+ return ret;
+
+ reg = mfspr(SPRN_AMR);
+
+ printf("%-30s AMR: %016lx\n", user_read, reg);
+
+ CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
+
+ /* Now let parent now that we are finished. */
+
+ ret = prod_parent(&info->child_sync);
+ CHILD_FAIL_IF(ret, &info->child_sync);
+
+ return TEST_PASS;
+}
+
+static int parent(struct shared_info *info, pid_t pid)
+{
+ unsigned long regs[3];
+ int ret, status;
+
+ /*
+ * Get the initial values for AMR, IAMR and UAMOR and communicate them
+ * to the child.
+ */
+ ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ info->amr1 = info->amr2 = info->amr3 = regs[0];
+ info->expected_iamr = info->new_iamr = regs[1];
+ info->expected_uamor = info->new_uamor = regs[2];
+
+ /* Wake up child so that it can set itself up. */
+ ret = prod_child(&info->child_sync);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_child(&info->child_sync);
+ if (ret)
+ return ret;
+
+ /* Verify that we can read the pkey registers from the child. */
+ ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
+ ptrace_read_running, regs[0], regs[1], regs[2]);
+
+ PARENT_FAIL_IF(regs[0] != info->amr1, &info->child_sync);
+ PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
+ PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
+
+ /* Write valid AMR value in child. */
+ ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr2, 1);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr2);
+
+ /* Wake up child so that it can verify it changed. */
+ ret = prod_child(&info->child_sync);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_child(&info->child_sync);
+ if (ret)
+ return ret;
+
+ /* Write invalid AMR value in child. */
+ ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr3, 1);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr3);
+
+ /* Wake up child so that it can verify it didn't change. */
+ ret = prod_child(&info->child_sync);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait_child(&info->child_sync);
+ if (ret)
+ return ret;
+
+ /* Try to write to IAMR. */
+ regs[0] = info->amr1;
+ regs[1] = info->new_iamr;
+ ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);
+ PARENT_FAIL_IF(!ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx IAMR: %016lx\n",
+ ptrace_write_running, regs[0], regs[1]);
+
+ /* Try to write to IAMR and UAMOR. */
+ regs[2] = info->new_uamor;
+ ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);
+ PARENT_FAIL_IF(!ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
+ ptrace_write_running, regs[0], regs[1], regs[2]);
+
+ /* Verify that all registers still have their expected values. */
+ ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
+ ptrace_read_running, regs[0], regs[1], regs[2]);
+
+ PARENT_FAIL_IF(regs[0] != info->amr2, &info->child_sync);
+ PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
+ PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
+
+ /* Wake up child so that it can verify AMR didn't change and wrap up. */
+ ret = prod_child(&info->child_sync);
+ PARENT_FAIL_IF(ret, &info->child_sync);
+
+ ret = wait(&status);
+ if (ret != pid) {
+ printf("Child's exit status not captured\n");
+ ret = TEST_PASS;
+ } else if (!WIFEXITED(status)) {
+ printf("Child exited abnormally\n");
+ ret = TEST_FAIL;
+ } else
+ ret = WEXITSTATUS(status) ? TEST_FAIL : TEST_PASS;
+
+ return ret;
+}
+
+static int ptrace_pkey(void)
+{
+ struct shared_info *info;
+ int shm_id;
+ int ret;
+ pid_t pid;
+
+ shm_id = shmget(IPC_PRIVATE, sizeof(*info), 0777 | IPC_CREAT);
+ info = shmat(shm_id, NULL, 0);
+
+ ret = init_child_sync(&info->child_sync);
+ if (ret)
+ return ret;
+
+ pid = fork();
+ if (pid < 0) {
+ perror("fork() failed");
+ ret = TEST_FAIL;
+ } else if (pid == 0)
+ ret = child(info);
+ else
+ ret = parent(info, pid);
+
+ shmdt(info);
+
+ if (pid) {
+ destroy_child_sync(&info->child_sync);
+ shmctl(shm_id, IPC_RMID, NULL);
+ }
+
+ return ret;
+}
+
+int main(int argc, char *argv[])
+{
+ return test_harness(ptrace_pkey, "ptrace_pkey");
+}
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace.h b/tools/testing/selftests/powerpc/ptrace/ptrace.h
index 19fb825270a1..d2c9c4c2b5ee 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace.h
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace.h
@@ -102,6 +102,43 @@ int cont_trace(pid_t child)
return TEST_PASS;
}

+int ptrace_read_regs(pid_t child, unsigned long type, unsigned long regs[],
+ int n)
+{
+ struct iovec iov;
+ long ret;
+
+ FAIL_IF(start_trace(child));
+
+ iov.iov_base = regs;
+ iov.iov_len = n * sizeof(unsigned long);
+
+ ret = ptrace(PTRACE_GETREGSET, child, type, &iov);
+ FAIL_IF(ret != 0);
+
+ FAIL_IF(stop_trace(child));
+
+ return TEST_PASS;
+}
+
+long ptrace_write_regs(pid_t child, unsigned long type, unsigned long regs[],
+ int n)
+{
+ struct iovec iov;
+ long ret;
+
+ FAIL_IF(start_trace(child));
+
+ iov.iov_base = regs;
+ iov.iov_len = n * sizeof(unsigned long);
+
+ ret = ptrace(PTRACE_SETREGSET, child, type, &iov);
+
+ FAIL_IF(stop_trace(child));
+
+ return ret;
+}
+
/* TAR, PPR, DSCR */
int show_tar_registers(pid_t child, unsigned long *out)
{


2018-02-23 19:29:34

by Ram Pai

[permalink] [raw]
Subject: Re: [PATCH 2/2] selftests/powerpc: Add core file test for Protection Key registers

On Fri, Feb 23, 2018 at 03:33:44PM -0300, Thiago Jung Bauermann wrote:
> This test verifies that the AMR, IAMR and UAMOR are being written to a
> process' core file.
>

Acked-by: Ram Pai <[email protected]>
Tested-by: Ram Pai <[email protected]>

> Signed-off-by: Thiago Jung Bauermann <[email protected]>
> ---
> tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
> tools/testing/selftests/powerpc/ptrace/core-pkey.c | 460 +++++++++++++++++++++
> 2 files changed, 464 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/powerpc/ptrace/core-pkey.c
>
.snip...

RP


2018-02-23 19:36:57

by Ram Pai

[permalink] [raw]
Subject: Re: [PATCH 1/2] selftests/powerpc: Add ptrace tests for Protection Key registers

On Fri, Feb 23, 2018 at 03:33:43PM -0300, Thiago Jung Bauermann wrote:
> This test exercises read and write access to the AMR, IAMR and UAMOR.
>

Tested-by: Ram Pai <[email protected]>
Acked-by: Ram Pai <[email protected]>

> Signed-off-by: Thiago Jung Bauermann <[email protected]>
> ---
> tools/testing/selftests/powerpc/include/reg.h | 1 +
> tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
> tools/testing/selftests/powerpc/ptrace/child.h | 130 ++++++++
> .../testing/selftests/powerpc/ptrace/ptrace-pkey.c | 326 +++++++++++++++++++++
> tools/testing/selftests/powerpc/ptrace/ptrace.h | 37 +++
> 5 files changed, 498 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/powerpc/ptrace/child.h
> create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
>
> diff --git a/tools/testing/selftests/powerpc/include/reg.h b/tools/testing/selftests/powerpc/include/reg.h
> index 4afdebcce4cd..7f348c059bc2 100644
> --- a/tools/testing/selftests/powerpc/include/reg.h
> +++ b/tools/testing/selftests/powerpc/include/reg.h
> @@ -54,6 +54,7 @@
> #define SPRN_DSCR_PRIV 0x11 /* Privilege State DSCR */
> #define SPRN_DSCR 0x03 /* Data Stream Control Register */
> #define SPRN_PPR 896 /* Program Priority Register */
> +#define SPRN_AMR 13 /* Authority Mask Register - problem state */
>
> /* TEXASR register bits */
> #define TEXASR_FC 0xFE00000000000000
> diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
> index 480305266504..707ba734faf2 100644
> --- a/tools/testing/selftests/powerpc/ptrace/Makefile
> +++ b/tools/testing/selftests/powerpc/ptrace/Makefile
> @@ -1,7 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
> ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
> - ptrace-tm-spd-vsx ptrace-tm-spr
> + ptrace-tm-spd-vsx ptrace-tm-spr ptrace-pkey
>
> include ../../lib.mk
>
> @@ -9,6 +9,9 @@ all: $(TEST_PROGS)
>
> CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
>
> +ptrace-pkey: ../harness.c ../utils.c ../lib/reg.S ptrace.h child.h ptrace-pkey.c
> + $(LINK.c) $^ $(LDLIBS) -pthread -o $@
> +
> $(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
>
> clean:
> diff --git a/tools/testing/selftests/powerpc/ptrace/child.h b/tools/testing/selftests/powerpc/ptrace/child.h
> new file mode 100644
> index 000000000000..40c1a6d92111
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/ptrace/child.h
> @@ -0,0 +1,130 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Helper functions to sync execution between parent and child processes.
> + *
> + * Copyright 2018, Thiago Jung Bauermann, IBM Corporation.
> + */
> +#include <stdio.h>
> +#include <stdbool.h>
> +#include <semaphore.h>
> +
> +/*
> + * Information in a shared memory location for synchronization between child and
> + * parent.
> + */
> +struct child_sync {
> + /* The parent waits on this semaphore. */
> + sem_t sem_parent;
> +
> + /* If true, the child should give up as well. */
> + bool parent_gave_up;
> +
> + /* The child waits on this semaphore. */
> + sem_t sem_child;
> +
> + /* If true, the parent should give up as well. */
> + bool child_gave_up;
> +};
> +
> +#define CHILD_FAIL_IF(x, sync) \
> + do { \
> + if (x) { \
> + fprintf(stderr, \
> + "[FAIL] Test FAILED on line %d\n", __LINE__); \
> + (sync)->child_gave_up = true; \
> + prod_parent(sync); \
> + return 1; \
> + } \
> + } while (0)
> +
> +#define PARENT_FAIL_IF(x, sync) \
> + do { \
> + if (x) { \
> + fprintf(stderr, \
> + "[FAIL] Test FAILED on line %d\n", __LINE__); \
> + (sync)->parent_gave_up = true; \
> + prod_child(sync); \
> + return 1; \
> + } \
> + } while (0)
> +
> +int init_child_sync(struct child_sync *sync)
> +{
> + int ret;
> +
> + ret = sem_init(&sync->sem_parent, 1, 0);
> + if (ret) {
> + perror("Semaphore initialization failed");
> + return 1;
> + }
> +
> + ret = sem_init(&sync->sem_child, 1, 0);
> + if (ret) {
> + perror("Semaphore initialization failed");
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +void destroy_child_sync(struct child_sync *sync)
> +{
> + sem_destroy(&sync->sem_parent);
> + sem_destroy(&sync->sem_child);
> +}
> +
> +int wait_child(struct child_sync *sync)
> +{
> + int ret;
> +
> + /* Wait until the child prods us. */
> + ret = sem_wait(&sync->sem_parent);
> + if (ret) {
> + perror("Error waiting for child");
> + return 1;
> + }
> +
> + return sync->child_gave_up;
> +}
> +
> +int prod_child(struct child_sync *sync)
> +{
> + int ret;
> +
> + /* Unblock the child now. */
> + ret = sem_post(&sync->sem_child);
> + if (ret) {
> + perror("Error prodding child");
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +int wait_parent(struct child_sync *sync)
> +{
> + int ret;
> +
> + /* Wait until the parent prods us. */
> + ret = sem_wait(&sync->sem_child);
> + if (ret) {
> + perror("Error waiting for parent");
> + return 1;
> + }
> +
> + return sync->parent_gave_up;
> +}
> +
> +int prod_parent(struct child_sync *sync)
> +{
> + int ret;
> +
> + /* Unblock the parent now. */
> + ret = sem_post(&sync->sem_parent);
> + if (ret) {
> + perror("Error prodding parent");
> + return 1;
> + }
> +
> + return 0;
> +}
> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
> new file mode 100644
> index 000000000000..8332b9338d39
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
> @@ -0,0 +1,326 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Ptrace test for Memory Protection Key registers
> + *
> + * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
> + * Copyright (C) 2018 IBM Corporation.
> + */
> +#include "ptrace.h"
> +#include "child.h"
> +
> +#ifndef __NR_pkey_alloc
> +#define __NR_pkey_alloc 384
> +#endif
> +
> +#ifndef __NR_pkey_free
> +#define __NR_pkey_free 385
> +#endif
> +
> +#ifndef NT_PPC_PKEY
> +#define NT_PPC_PKEY 0x110
> +#endif
> +
> +#ifndef PKEY_DISABLE_EXECUTE
> +#define PKEY_DISABLE_EXECUTE 0x4
> +#endif
> +
> +#define AMR_BITS_PER_PKEY 2
> +#define PKEY_REG_BITS (sizeof(u64) * 8)
> +#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey + 1) * AMR_BITS_PER_PKEY))
> +
> +static const char user_read[] = "[User Read (Running)]";
> +static const char user_write[] = "[User Write (Running)]";
> +static const char ptrace_read_running[] = "[Ptrace Read (Running)]";
> +static const char ptrace_write_running[] = "[Ptrace Write (Running)]";
> +
> +/* Information shared between the parent and the child. */
> +struct shared_info {
> + struct child_sync child_sync;
> +
> + /* AMR value the parent expects to read from the child. */
> + unsigned long amr1;
> +
> + /* AMR value the parent is expected to write to the child. */
> + unsigned long amr2;
> +
> + /* AMR value that ptrace should refuse to write to the child. */
> + unsigned long amr3;
> +
> + /* IAMR value the parent expects to read from the child. */
> + unsigned long expected_iamr;
> +
> + /* UAMOR value the parent expects to read from the child. */
> + unsigned long expected_uamor;
> +
> + /*
> + * IAMR and UAMOR values that ptrace should refuse to write to the child
> + * (even though they're valid ones) because userspace doesn't have
> + * access to those registers.
> + */
> + unsigned long new_iamr;
> + unsigned long new_uamor;
> +};
> +
> +static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
> +{
> + return syscall(__NR_pkey_alloc, flags, init_access_rights);
> +}
> +
> +static int sys_pkey_free(int pkey)
> +{
> + return syscall(__NR_pkey_free, pkey);
> +}
> +
> +static int child(struct shared_info *info)
> +{
> + unsigned long reg;
> + bool disable_execute = true;
> + int pkey1, pkey2, pkey3;
> + int ret;
> +
> + /* Wait until parent fills out the initial register values. */
> + ret = wait_parent(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + /* Get some pkeys so that we can change their bits in the AMR. */
> + pkey1 = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
> + if (pkey1 < 0) {
> + pkey1 = sys_pkey_alloc(0, 0);
> + CHILD_FAIL_IF(pkey1 < 0, &info->child_sync);
> +
> + disable_execute = false;
> + }
> +
> + pkey2 = sys_pkey_alloc(0, 0);
> + CHILD_FAIL_IF(pkey2 < 0, &info->child_sync);
> +
> + pkey3 = sys_pkey_alloc(0, 0);
> + CHILD_FAIL_IF(pkey3 < 0, &info->child_sync);
> +
> + info->amr1 |= 3ul << pkeyshift(pkey1);
> + info->amr2 |= 3ul << pkeyshift(pkey2);
> + info->amr3 |= info->amr2 | 3ul << pkeyshift(pkey3);
> +
> + if (disable_execute)
> + info->expected_iamr |= 1ul << pkeyshift(pkey1);
> +
> + info->expected_uamor |= 3ul << pkeyshift(pkey1) |
> + 3ul << pkeyshift(pkey2);
> + info->new_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
> + info->new_uamor |= 3ul << pkeyshift(pkey1);
> +
> + /*
> + * We won't use pkey3. We just want a plausible but invalid key to test
> + * whether ptrace will let us write to AMR bits we are not supposed to.
> + *
> + * This also tests whether the kernel restores the UAMOR permissions
> + * after a key is freed.
> + */
> + sys_pkey_free(pkey3);
> +
> + printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
> + user_write, info->amr1, pkey1, pkey2, pkey3);
> +
> + mtspr(SPRN_AMR, info->amr1);
> +
> + /* Wait for parent to read our AMR value and write a new one. */
> + ret = prod_parent(&info->child_sync);
> + CHILD_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_parent(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + reg = mfspr(SPRN_AMR);
> +
> + printf("%-30s AMR: %016lx\n", user_read, reg);
> +
> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
> +
> + /*
> + * Wait for parent to try to write an invalid AMR value.
> + */
> + ret = prod_parent(&info->child_sync);
> + CHILD_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_parent(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + reg = mfspr(SPRN_AMR);
> +
> + printf("%-30s AMR: %016lx\n", user_read, reg);
> +
> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
> +
> + /*
> + * Wait for parent to try to write an IAMR and a UAMOR value. We can't
> + * verify them, but we can verify that the AMR didn't change.
> + */
> + ret = prod_parent(&info->child_sync);
> + CHILD_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_parent(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + reg = mfspr(SPRN_AMR);
> +
> + printf("%-30s AMR: %016lx\n", user_read, reg);
> +
> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
> +
> + /* Now let parent now that we are finished. */
> +
> + ret = prod_parent(&info->child_sync);
> + CHILD_FAIL_IF(ret, &info->child_sync);
> +
> + return TEST_PASS;
> +}
> +
> +static int parent(struct shared_info *info, pid_t pid)
> +{
> + unsigned long regs[3];
> + int ret, status;
> +
> + /*
> + * Get the initial values for AMR, IAMR and UAMOR and communicate them
> + * to the child.
> + */
> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + info->amr1 = info->amr2 = info->amr3 = regs[0];
> + info->expected_iamr = info->new_iamr = regs[1];
> + info->expected_uamor = info->new_uamor = regs[2];
> +
> + /* Wake up child so that it can set itself up. */
> + ret = prod_child(&info->child_sync);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_child(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + /* Verify that we can read the pkey registers from the child. */
> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
> + ptrace_read_running, regs[0], regs[1], regs[2]);
> +
> + PARENT_FAIL_IF(regs[0] != info->amr1, &info->child_sync);
> + PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
> + PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
> +
> + /* Write valid AMR value in child. */
> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr2, 1);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr2);
> +
> + /* Wake up child so that it can verify it changed. */
> + ret = prod_child(&info->child_sync);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_child(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + /* Write invalid AMR value in child. */
> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr3, 1);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr3);
> +
> + /* Wake up child so that it can verify it didn't change. */
> + ret = prod_child(&info->child_sync);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait_child(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + /* Try to write to IAMR. */
> + regs[0] = info->amr1;
> + regs[1] = info->new_iamr;
> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);
> + PARENT_FAIL_IF(!ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx IAMR: %016lx\n",
> + ptrace_write_running, regs[0], regs[1]);
> +
> + /* Try to write to IAMR and UAMOR. */
> + regs[2] = info->new_uamor;
> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);
> + PARENT_FAIL_IF(!ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
> + ptrace_write_running, regs[0], regs[1], regs[2]);
> +
> + /* Verify that all registers still have their expected values. */
> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
> + ptrace_read_running, regs[0], regs[1], regs[2]);
> +
> + PARENT_FAIL_IF(regs[0] != info->amr2, &info->child_sync);
> + PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
> + PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
> +
> + /* Wake up child so that it can verify AMR didn't change and wrap up. */
> + ret = prod_child(&info->child_sync);
> + PARENT_FAIL_IF(ret, &info->child_sync);
> +
> + ret = wait(&status);
> + if (ret != pid) {
> + printf("Child's exit status not captured\n");
> + ret = TEST_PASS;
> + } else if (!WIFEXITED(status)) {
> + printf("Child exited abnormally\n");
> + ret = TEST_FAIL;
> + } else
> + ret = WEXITSTATUS(status) ? TEST_FAIL : TEST_PASS;
> +
> + return ret;
> +}
> +
> +static int ptrace_pkey(void)
> +{
> + struct shared_info *info;
> + int shm_id;
> + int ret;
> + pid_t pid;
> +
> + shm_id = shmget(IPC_PRIVATE, sizeof(*info), 0777 | IPC_CREAT);
> + info = shmat(shm_id, NULL, 0);
> +
> + ret = init_child_sync(&info->child_sync);
> + if (ret)
> + return ret;
> +
> + pid = fork();
> + if (pid < 0) {
> + perror("fork() failed");
> + ret = TEST_FAIL;
> + } else if (pid == 0)
> + ret = child(info);
> + else
> + ret = parent(info, pid);
> +
> + shmdt(info);
> +
> + if (pid) {
> + destroy_child_sync(&info->child_sync);
> + shmctl(shm_id, IPC_RMID, NULL);
> + }
> +
> + return ret;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + return test_harness(ptrace_pkey, "ptrace_pkey");
> +}
> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace.h b/tools/testing/selftests/powerpc/ptrace/ptrace.h
> index 19fb825270a1..d2c9c4c2b5ee 100644
> --- a/tools/testing/selftests/powerpc/ptrace/ptrace.h
> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace.h
> @@ -102,6 +102,43 @@ int cont_trace(pid_t child)
> return TEST_PASS;
> }
>
> +int ptrace_read_regs(pid_t child, unsigned long type, unsigned long regs[],
> + int n)
> +{
> + struct iovec iov;
> + long ret;
> +
> + FAIL_IF(start_trace(child));
> +
> + iov.iov_base = regs;
> + iov.iov_len = n * sizeof(unsigned long);
> +
> + ret = ptrace(PTRACE_GETREGSET, child, type, &iov);
> + FAIL_IF(ret != 0);
> +
> + FAIL_IF(stop_trace(child));
> +
> + return TEST_PASS;
> +}
> +
> +long ptrace_write_regs(pid_t child, unsigned long type, unsigned long regs[],
> + int n)
> +{
> + struct iovec iov;
> + long ret;
> +
> + FAIL_IF(start_trace(child));
> +
> + iov.iov_base = regs;
> + iov.iov_len = n * sizeof(unsigned long);
> +
> + ret = ptrace(PTRACE_SETREGSET, child, type, &iov);
> +
> + FAIL_IF(stop_trace(child));
> +
> + return ret;
> +}
> +
> /* TAR, PPR, DSCR */
> int show_tar_registers(pid_t child, unsigned long *out)
> {

--
Ram Pai


2018-03-27 17:38:17

by Thiago Jung Bauermann

[permalink] [raw]
Subject: Re: [PATCH 1/2] selftests/powerpc: Add ptrace tests for Protection Key registers


Ram Pai <[email protected]> writes:

> On Fri, Feb 23, 2018 at 03:33:43PM -0300, Thiago Jung Bauermann wrote:
>> This test exercises read and write access to the AMR, IAMR and UAMOR.
>>
>
> Tested-by: Ram Pai <[email protected]>
> Acked-by: Ram Pai <[email protected]>

Ping? Can this and patch 2/2 go in v4.17?

>> Signed-off-by: Thiago Jung Bauermann <[email protected]>
>> ---
>> tools/testing/selftests/powerpc/include/reg.h | 1 +
>> tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
>> tools/testing/selftests/powerpc/ptrace/child.h | 130 ++++++++
>> .../testing/selftests/powerpc/ptrace/ptrace-pkey.c | 326 +++++++++++++++++++++
>> tools/testing/selftests/powerpc/ptrace/ptrace.h | 37 +++
>> 5 files changed, 498 insertions(+), 1 deletion(-)
>> create mode 100644 tools/testing/selftests/powerpc/ptrace/child.h
>> create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
>>
>> diff --git a/tools/testing/selftests/powerpc/include/reg.h b/tools/testing/selftests/powerpc/include/reg.h
>> index 4afdebcce4cd..7f348c059bc2 100644
>> --- a/tools/testing/selftests/powerpc/include/reg.h
>> +++ b/tools/testing/selftests/powerpc/include/reg.h
>> @@ -54,6 +54,7 @@
>> #define SPRN_DSCR_PRIV 0x11 /* Privilege State DSCR */
>> #define SPRN_DSCR 0x03 /* Data Stream Control Register */
>> #define SPRN_PPR 896 /* Program Priority Register */
>> +#define SPRN_AMR 13 /* Authority Mask Register - problem state */
>>
>> /* TEXASR register bits */
>> #define TEXASR_FC 0xFE00000000000000
>> diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
>> index 480305266504..707ba734faf2 100644
>> --- a/tools/testing/selftests/powerpc/ptrace/Makefile
>> +++ b/tools/testing/selftests/powerpc/ptrace/Makefile
>> @@ -1,7 +1,7 @@
>> # SPDX-License-Identifier: GPL-2.0
>> TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
>> ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
>> - ptrace-tm-spd-vsx ptrace-tm-spr
>> + ptrace-tm-spd-vsx ptrace-tm-spr ptrace-pkey
>>
>> include ../../lib.mk
>>
>> @@ -9,6 +9,9 @@ all: $(TEST_PROGS)
>>
>> CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
>>
>> +ptrace-pkey: ../harness.c ../utils.c ../lib/reg.S ptrace.h child.h ptrace-pkey.c
>> + $(LINK.c) $^ $(LDLIBS) -pthread -o $@
>> +
>> $(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
>>
>> clean:
>> diff --git a/tools/testing/selftests/powerpc/ptrace/child.h b/tools/testing/selftests/powerpc/ptrace/child.h
>> new file mode 100644
>> index 000000000000..40c1a6d92111
>> --- /dev/null
>> +++ b/tools/testing/selftests/powerpc/ptrace/child.h
>> @@ -0,0 +1,130 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Helper functions to sync execution between parent and child processes.
>> + *
>> + * Copyright 2018, Thiago Jung Bauermann, IBM Corporation.
>> + */
>> +#include <stdio.h>
>> +#include <stdbool.h>
>> +#include <semaphore.h>
>> +
>> +/*
>> + * Information in a shared memory location for synchronization between child and
>> + * parent.
>> + */
>> +struct child_sync {
>> + /* The parent waits on this semaphore. */
>> + sem_t sem_parent;
>> +
>> + /* If true, the child should give up as well. */
>> + bool parent_gave_up;
>> +
>> + /* The child waits on this semaphore. */
>> + sem_t sem_child;
>> +
>> + /* If true, the parent should give up as well. */
>> + bool child_gave_up;
>> +};
>> +
>> +#define CHILD_FAIL_IF(x, sync) \
>> + do { \
>> + if (x) { \
>> + fprintf(stderr, \
>> + "[FAIL] Test FAILED on line %d\n", __LINE__); \
>> + (sync)->child_gave_up = true; \
>> + prod_parent(sync); \
>> + return 1; \
>> + } \
>> + } while (0)
>> +
>> +#define PARENT_FAIL_IF(x, sync) \
>> + do { \
>> + if (x) { \
>> + fprintf(stderr, \
>> + "[FAIL] Test FAILED on line %d\n", __LINE__); \
>> + (sync)->parent_gave_up = true; \
>> + prod_child(sync); \
>> + return 1; \
>> + } \
>> + } while (0)
>> +
>> +int init_child_sync(struct child_sync *sync)
>> +{
>> + int ret;
>> +
>> + ret = sem_init(&sync->sem_parent, 1, 0);
>> + if (ret) {
>> + perror("Semaphore initialization failed");
>> + return 1;
>> + }
>> +
>> + ret = sem_init(&sync->sem_child, 1, 0);
>> + if (ret) {
>> + perror("Semaphore initialization failed");
>> + return 1;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +void destroy_child_sync(struct child_sync *sync)
>> +{
>> + sem_destroy(&sync->sem_parent);
>> + sem_destroy(&sync->sem_child);
>> +}
>> +
>> +int wait_child(struct child_sync *sync)
>> +{
>> + int ret;
>> +
>> + /* Wait until the child prods us. */
>> + ret = sem_wait(&sync->sem_parent);
>> + if (ret) {
>> + perror("Error waiting for child");
>> + return 1;
>> + }
>> +
>> + return sync->child_gave_up;
>> +}
>> +
>> +int prod_child(struct child_sync *sync)
>> +{
>> + int ret;
>> +
>> + /* Unblock the child now. */
>> + ret = sem_post(&sync->sem_child);
>> + if (ret) {
>> + perror("Error prodding child");
>> + return 1;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +int wait_parent(struct child_sync *sync)
>> +{
>> + int ret;
>> +
>> + /* Wait until the parent prods us. */
>> + ret = sem_wait(&sync->sem_child);
>> + if (ret) {
>> + perror("Error waiting for parent");
>> + return 1;
>> + }
>> +
>> + return sync->parent_gave_up;
>> +}
>> +
>> +int prod_parent(struct child_sync *sync)
>> +{
>> + int ret;
>> +
>> + /* Unblock the parent now. */
>> + ret = sem_post(&sync->sem_parent);
>> + if (ret) {
>> + perror("Error prodding parent");
>> + return 1;
>> + }
>> +
>> + return 0;
>> +}
>> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
>> new file mode 100644
>> index 000000000000..8332b9338d39
>> --- /dev/null
>> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
>> @@ -0,0 +1,326 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Ptrace test for Memory Protection Key registers
>> + *
>> + * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
>> + * Copyright (C) 2018 IBM Corporation.
>> + */
>> +#include "ptrace.h"
>> +#include "child.h"
>> +
>> +#ifndef __NR_pkey_alloc
>> +#define __NR_pkey_alloc 384
>> +#endif
>> +
>> +#ifndef __NR_pkey_free
>> +#define __NR_pkey_free 385
>> +#endif
>> +
>> +#ifndef NT_PPC_PKEY
>> +#define NT_PPC_PKEY 0x110
>> +#endif
>> +
>> +#ifndef PKEY_DISABLE_EXECUTE
>> +#define PKEY_DISABLE_EXECUTE 0x4
>> +#endif
>> +
>> +#define AMR_BITS_PER_PKEY 2
>> +#define PKEY_REG_BITS (sizeof(u64) * 8)
>> +#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey + 1) * AMR_BITS_PER_PKEY))
>> +
>> +static const char user_read[] = "[User Read (Running)]";
>> +static const char user_write[] = "[User Write (Running)]";
>> +static const char ptrace_read_running[] = "[Ptrace Read (Running)]";
>> +static const char ptrace_write_running[] = "[Ptrace Write (Running)]";
>> +
>> +/* Information shared between the parent and the child. */
>> +struct shared_info {
>> + struct child_sync child_sync;
>> +
>> + /* AMR value the parent expects to read from the child. */
>> + unsigned long amr1;
>> +
>> + /* AMR value the parent is expected to write to the child. */
>> + unsigned long amr2;
>> +
>> + /* AMR value that ptrace should refuse to write to the child. */
>> + unsigned long amr3;
>> +
>> + /* IAMR value the parent expects to read from the child. */
>> + unsigned long expected_iamr;
>> +
>> + /* UAMOR value the parent expects to read from the child. */
>> + unsigned long expected_uamor;
>> +
>> + /*
>> + * IAMR and UAMOR values that ptrace should refuse to write to the child
>> + * (even though they're valid ones) because userspace doesn't have
>> + * access to those registers.
>> + */
>> + unsigned long new_iamr;
>> + unsigned long new_uamor;
>> +};
>> +
>> +static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
>> +{
>> + return syscall(__NR_pkey_alloc, flags, init_access_rights);
>> +}
>> +
>> +static int sys_pkey_free(int pkey)
>> +{
>> + return syscall(__NR_pkey_free, pkey);
>> +}
>> +
>> +static int child(struct shared_info *info)
>> +{
>> + unsigned long reg;
>> + bool disable_execute = true;
>> + int pkey1, pkey2, pkey3;
>> + int ret;
>> +
>> + /* Wait until parent fills out the initial register values. */
>> + ret = wait_parent(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + /* Get some pkeys so that we can change their bits in the AMR. */
>> + pkey1 = sys_pkey_alloc(0, PKEY_DISABLE_EXECUTE);
>> + if (pkey1 < 0) {
>> + pkey1 = sys_pkey_alloc(0, 0);
>> + CHILD_FAIL_IF(pkey1 < 0, &info->child_sync);
>> +
>> + disable_execute = false;
>> + }
>> +
>> + pkey2 = sys_pkey_alloc(0, 0);
>> + CHILD_FAIL_IF(pkey2 < 0, &info->child_sync);
>> +
>> + pkey3 = sys_pkey_alloc(0, 0);
>> + CHILD_FAIL_IF(pkey3 < 0, &info->child_sync);
>> +
>> + info->amr1 |= 3ul << pkeyshift(pkey1);
>> + info->amr2 |= 3ul << pkeyshift(pkey2);
>> + info->amr3 |= info->amr2 | 3ul << pkeyshift(pkey3);
>> +
>> + if (disable_execute)
>> + info->expected_iamr |= 1ul << pkeyshift(pkey1);
>> +
>> + info->expected_uamor |= 3ul << pkeyshift(pkey1) |
>> + 3ul << pkeyshift(pkey2);
>> + info->new_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
>> + info->new_uamor |= 3ul << pkeyshift(pkey1);
>> +
>> + /*
>> + * We won't use pkey3. We just want a plausible but invalid key to test
>> + * whether ptrace will let us write to AMR bits we are not supposed to.
>> + *
>> + * This also tests whether the kernel restores the UAMOR permissions
>> + * after a key is freed.
>> + */
>> + sys_pkey_free(pkey3);
>> +
>> + printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
>> + user_write, info->amr1, pkey1, pkey2, pkey3);
>> +
>> + mtspr(SPRN_AMR, info->amr1);
>> +
>> + /* Wait for parent to read our AMR value and write a new one. */
>> + ret = prod_parent(&info->child_sync);
>> + CHILD_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_parent(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + reg = mfspr(SPRN_AMR);
>> +
>> + printf("%-30s AMR: %016lx\n", user_read, reg);
>> +
>> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
>> +
>> + /*
>> + * Wait for parent to try to write an invalid AMR value.
>> + */
>> + ret = prod_parent(&info->child_sync);
>> + CHILD_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_parent(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + reg = mfspr(SPRN_AMR);
>> +
>> + printf("%-30s AMR: %016lx\n", user_read, reg);
>> +
>> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
>> +
>> + /*
>> + * Wait for parent to try to write an IAMR and a UAMOR value. We can't
>> + * verify them, but we can verify that the AMR didn't change.
>> + */
>> + ret = prod_parent(&info->child_sync);
>> + CHILD_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_parent(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + reg = mfspr(SPRN_AMR);
>> +
>> + printf("%-30s AMR: %016lx\n", user_read, reg);
>> +
>> + CHILD_FAIL_IF(reg != info->amr2, &info->child_sync);
>> +
>> + /* Now let parent now that we are finished. */
>> +
>> + ret = prod_parent(&info->child_sync);
>> + CHILD_FAIL_IF(ret, &info->child_sync);
>> +
>> + return TEST_PASS;
>> +}
>> +
>> +static int parent(struct shared_info *info, pid_t pid)
>> +{
>> + unsigned long regs[3];
>> + int ret, status;
>> +
>> + /*
>> + * Get the initial values for AMR, IAMR and UAMOR and communicate them
>> + * to the child.
>> + */
>> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + info->amr1 = info->amr2 = info->amr3 = regs[0];
>> + info->expected_iamr = info->new_iamr = regs[1];
>> + info->expected_uamor = info->new_uamor = regs[2];
>> +
>> + /* Wake up child so that it can set itself up. */
>> + ret = prod_child(&info->child_sync);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_child(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + /* Verify that we can read the pkey registers from the child. */
>> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
>> + ptrace_read_running, regs[0], regs[1], regs[2]);
>> +
>> + PARENT_FAIL_IF(regs[0] != info->amr1, &info->child_sync);
>> + PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
>> + PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
>> +
>> + /* Write valid AMR value in child. */
>> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr2, 1);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr2);
>> +
>> + /* Wake up child so that it can verify it changed. */
>> + ret = prod_child(&info->child_sync);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_child(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + /* Write invalid AMR value in child. */
>> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr3, 1);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr3);
>> +
>> + /* Wake up child so that it can verify it didn't change. */
>> + ret = prod_child(&info->child_sync);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait_child(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + /* Try to write to IAMR. */
>> + regs[0] = info->amr1;
>> + regs[1] = info->new_iamr;
>> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);
>> + PARENT_FAIL_IF(!ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx IAMR: %016lx\n",
>> + ptrace_write_running, regs[0], regs[1]);
>> +
>> + /* Try to write to IAMR and UAMOR. */
>> + regs[2] = info->new_uamor;
>> + ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);
>> + PARENT_FAIL_IF(!ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
>> + ptrace_write_running, regs[0], regs[1], regs[2]);
>> +
>> + /* Verify that all registers still have their expected values. */
>> + ret = ptrace_read_regs(pid, NT_PPC_PKEY, regs, 3);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + printf("%-30s AMR: %016lx IAMR: %016lx UAMOR: %016lx\n",
>> + ptrace_read_running, regs[0], regs[1], regs[2]);
>> +
>> + PARENT_FAIL_IF(regs[0] != info->amr2, &info->child_sync);
>> + PARENT_FAIL_IF(regs[1] != info->expected_iamr, &info->child_sync);
>> + PARENT_FAIL_IF(regs[2] != info->expected_uamor, &info->child_sync);
>> +
>> + /* Wake up child so that it can verify AMR didn't change and wrap up. */
>> + ret = prod_child(&info->child_sync);
>> + PARENT_FAIL_IF(ret, &info->child_sync);
>> +
>> + ret = wait(&status);
>> + if (ret != pid) {
>> + printf("Child's exit status not captured\n");
>> + ret = TEST_PASS;
>> + } else if (!WIFEXITED(status)) {
>> + printf("Child exited abnormally\n");
>> + ret = TEST_FAIL;
>> + } else
>> + ret = WEXITSTATUS(status) ? TEST_FAIL : TEST_PASS;
>> +
>> + return ret;
>> +}
>> +
>> +static int ptrace_pkey(void)
>> +{
>> + struct shared_info *info;
>> + int shm_id;
>> + int ret;
>> + pid_t pid;
>> +
>> + shm_id = shmget(IPC_PRIVATE, sizeof(*info), 0777 | IPC_CREAT);
>> + info = shmat(shm_id, NULL, 0);
>> +
>> + ret = init_child_sync(&info->child_sync);
>> + if (ret)
>> + return ret;
>> +
>> + pid = fork();
>> + if (pid < 0) {
>> + perror("fork() failed");
>> + ret = TEST_FAIL;
>> + } else if (pid == 0)
>> + ret = child(info);
>> + else
>> + ret = parent(info, pid);
>> +
>> + shmdt(info);
>> +
>> + if (pid) {
>> + destroy_child_sync(&info->child_sync);
>> + shmctl(shm_id, IPC_RMID, NULL);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + return test_harness(ptrace_pkey, "ptrace_pkey");
>> +}
>> diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace.h b/tools/testing/selftests/powerpc/ptrace/ptrace.h
>> index 19fb825270a1..d2c9c4c2b5ee 100644
>> --- a/tools/testing/selftests/powerpc/ptrace/ptrace.h
>> +++ b/tools/testing/selftests/powerpc/ptrace/ptrace.h
>> @@ -102,6 +102,43 @@ int cont_trace(pid_t child)
>> return TEST_PASS;
>> }
>>
>> +int ptrace_read_regs(pid_t child, unsigned long type, unsigned long regs[],
>> + int n)
>> +{
>> + struct iovec iov;
>> + long ret;
>> +
>> + FAIL_IF(start_trace(child));
>> +
>> + iov.iov_base = regs;
>> + iov.iov_len = n * sizeof(unsigned long);
>> +
>> + ret = ptrace(PTRACE_GETREGSET, child, type, &iov);
>> + FAIL_IF(ret != 0);
>> +
>> + FAIL_IF(stop_trace(child));
>> +
>> + return TEST_PASS;
>> +}
>> +
>> +long ptrace_write_regs(pid_t child, unsigned long type, unsigned long regs[],
>> + int n)
>> +{
>> + struct iovec iov;
>> + long ret;
>> +
>> + FAIL_IF(start_trace(child));
>> +
>> + iov.iov_base = regs;
>> + iov.iov_len = n * sizeof(unsigned long);
>> +
>> + ret = ptrace(PTRACE_SETREGSET, child, type, &iov);
>> +
>> + FAIL_IF(stop_trace(child));
>> +
>> + return ret;
>> +}
>> +
>> /* TAR, PPR, DSCR */
>> int show_tar_registers(pid_t child, unsigned long *out)
>> {


--
Thiago Jung Bauermann
IBM Linux Technology Center