15 files changed, 435 insertions, 303 deletions

diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h
index b703714e7d98..2c54998d4715 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr.h
+++ b/tools/testing/selftests/powerpc/dscr/dscr.h
@@ -64,48 +64,26 @@ inline void set_dscr_usr(unsigned long val)
 /* Default DSCR access */
 unsigned long get_default_dscr(void)
 {
-	int fd = -1, ret;
-	char buf[16];
+	int err;
 	unsigned long val;
 
-	if (fd == -1) {
-		fd = open(DSCR_DEFAULT, O_RDONLY);
-		if (fd == -1) {
-			perror("open() failed");
-			exit(1);
-		}
-	}
-	memset(buf, 0, sizeof(buf));
-	lseek(fd, 0, SEEK_SET);
-	ret = read(fd, buf, sizeof(buf));
-	if (ret == -1) {
+	err = read_ulong(DSCR_DEFAULT, &val, 16);
+	if (err) {
 		perror("read() failed");
 		exit(1);
 	}
-	sscanf(buf, "%lx", &val);
-	close(fd);
 	return val;
 }
 
 void set_default_dscr(unsigned long val)
 {
-	int fd = -1, ret;
-	char buf[16];
+	int err;
 
-	if (fd == -1) {
-		fd = open(DSCR_DEFAULT, O_RDWR);
-		if (fd == -1) {
-			perror("open() failed");
-			exit(1);
-		}
-	}
-	sprintf(buf, "%lx\n", val);
-	ret = write(fd, buf, strlen(buf));
-	if (ret == -1) {
+	err = write_ulong(DSCR_DEFAULT, val, 16);
+	if (err) {
 		perror("write() failed");
 		exit(1);
 	}
-	close(fd);
 }
 
 double uniform_deviate(int seed)
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
index f20d1c166d1e..4f1fef6198fc 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
@@ -12,27 +12,16 @@
 
 static int check_cpu_dscr_default(char *file, unsigned long val)
 {
-	char buf[10];
-	int fd, rc;
+	unsigned long cpu_dscr;
+	int err;
 
-	fd = open(file, O_RDWR);
-	if (fd == -1) {
-		perror("open() failed");
-		return 1;
-	}
-
-	rc = read(fd, buf, sizeof(buf));
-	if (rc == -1) {
-		perror("read() failed");
-		close(fd);
-		return 1;
-	}
-	close(fd);
+	err = read_ulong(file, &cpu_dscr, 16);
+	if (err)
+		return err;
 
-	buf[rc] = '\0';
-	if (strtol(buf, NULL, 16) != val) {
+	if (cpu_dscr != val) {
 		printf("DSCR match failed: %ld (system) %ld (cpu)\n",
-					val, strtol(buf, NULL, 16));
+					val, cpu_dscr);
 		return 1;
 	}
 	return 0;
diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index e222a5858450..eed7dd7582b2 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -33,8 +33,24 @@ void *get_auxv_entry(int type);
 
 int pick_online_cpu(void);
 
-int read_debugfs_file(char *debugfs_file, int *result);
-int write_debugfs_file(char *debugfs_file, int result);
+int parse_intmax(const char *buffer, size_t count, intmax_t *result, int base);
+int parse_uintmax(const char *buffer, size_t count, uintmax_t *result, int base);
+int parse_int(const char *buffer, size_t count, int *result, int base);
+int parse_uint(const char *buffer, size_t count, unsigned int *result, int base);
+int parse_long(const char *buffer, size_t count, long *result, int base);
+int parse_ulong(const char *buffer, size_t count, unsigned long *result, int base);
+
+int read_file(const char *path, char *buf, size_t count, size_t *len);
+int write_file(const char *path, const char *buf, size_t count);
+int read_file_alloc(const char *path, char **buf, size_t *len);
+int read_long(const char *path, long *result, int base);
+int write_long(const char *path, long result, int base);
+int read_ulong(const char *path, unsigned long *result, int base);
+int write_ulong(const char *path, unsigned long result, int base);
+int read_debugfs_file(const char *debugfs_file, char *buf, size_t count);
+int write_debugfs_file(const char *debugfs_file, const char *buf, size_t count);
+int read_debugfs_int(const char *debugfs_file, int *result);
+int write_debugfs_int(const char *debugfs_file, int result);
 int read_sysfs_file(char *debugfs_file, char *result, size_t result_size);
 int perf_event_open_counter(unsigned int type,
 			    unsigned long config, int group_fd);
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
index 095195a25687..4de079923ccb 100644
--- a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
+++ b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
@@ -143,54 +143,6 @@ int gzip_header_blank(char *buf)
 	return i;
 }
 
-/* Caller must free the allocated buffer return nonzero on error. */
-int read_alloc_input_file(char *fname, char **buf, size_t *bufsize)
-{
-	struct stat statbuf;
-	FILE *fp;
-	char *p;
-	size_t num_bytes;
-
-	if (stat(fname, &statbuf)) {
-		perror(fname);
-		return(-1);
-	}
-	fp = fopen(fname, "r");
-	if (fp == NULL) {
-		perror(fname);
-		return(-1);
-	}
-	assert(NULL != (p = (char *) malloc(statbuf.st_size)));
-	num_bytes = fread(p, 1, statbuf.st_size, fp);
-	if (ferror(fp) || (num_bytes != statbuf.st_size)) {
-		perror(fname);
-		return(-1);
-	}
-	*buf = p;
-	*bufsize = num_bytes;
-	return 0;
-}
-
-/* Returns nonzero on error */
-int write_output_file(char *fname, char *buf, size_t bufsize)
-{
-	FILE *fp;
-	size_t num_bytes;
-
-	fp = fopen(fname, "w");
-	if (fp == NULL) {
-		perror(fname);
-		return(-1);
-	}
-	num_bytes = fwrite(buf, 1, bufsize, fp);
-	if (ferror(fp) || (num_bytes != bufsize)) {
-		perror(fname);
-		return(-1);
-	}
-	fclose(fp);
-	return 0;
-}
-
 /*
  * Z_SYNC_FLUSH as described in zlib.h.
  * Returns number of appended bytes
@@ -257,7 +209,7 @@ int compress_file(int argc, char **argv, void *handle)
 		fprintf(stderr, "usage: %s <fname>\n", argv[0]);
 		exit(-1);
 	}
-	if (read_alloc_input_file(argv[1], &inbuf, &inlen))
+	if (read_file_alloc(argv[1], &inbuf, &inlen))
 		exit(-1);
 	fprintf(stderr, "file %s read, %ld bytes\n", argv[1], inlen);
 
@@ -399,7 +351,7 @@ int compress_file(int argc, char **argv, void *handle)
 	assert(FNAME_MAX > (strlen(argv[1]) + strlen(FEXT)));
 	strcpy(outname, argv[1]);
 	strcat(outname, FEXT);
-	if (write_output_file(outname, outbuf, dsttotlen)) {
+	if (write_file(outname, outbuf, dsttotlen)) {
 		fprintf(stderr, "write error: %s\n", outname);
 		exit(-1);
 	}
diff --git a/tools/testing/selftests/powerpc/pmu/lib.c b/tools/testing/selftests/powerpc/pmu/lib.c
index 88690b97b7b9..719f94f10d41 100644
--- a/tools/testing/selftests/powerpc/pmu/lib.c
+++ b/tools/testing/selftests/powerpc/pmu/lib.c
@@ -190,38 +190,14 @@ int parse_proc_maps(void)
 
 bool require_paranoia_below(int level)
 {
+	int err;
 	long current;
-	char *end, buf[16];
-	FILE *f;
-	bool rc;
-
-	rc = false;
-
-	f = fopen(PARANOID_PATH, "r");
-	if (!f) {
-		perror("fopen");
-		goto out;
-	}
 
-	if (!fgets(buf, sizeof(buf), f)) {
-		printf("Couldn't read " PARANOID_PATH "?\n");
-		goto out_close;
-	}
-
-	current = strtol(buf, &end, 10);
-
-	if (end == buf) {
+	err = read_long(PARANOID_PATH, &current, 10);
+	if (err) {
 		printf("Couldn't parse " PARANOID_PATH "?\n");
-		goto out_close;
+		return false;
 	}
 
-	if (current >= level)
-		goto out_close;
-
-	rc = true;
-out_close:
-	fclose(f);
-out:
-	return rc;
+	return current < level;
 }
-
diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
index 2f02cb54224d..cbeeaeae8837 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -33,7 +33,7 @@ TESTS_64 := $(patsubst %,$(OUTPUT)/%,$(TESTS_64))
 $(TESTS_64): CFLAGS += -m64
 $(TM_TESTS): CFLAGS += -I../tm -mhtm
 
-CFLAGS += -I../../../../../usr/include -fno-pie
+CFLAGS += $(KHDR_INCLUDES) -fno-pie
 
 $(OUTPUT)/ptrace-gpr: ptrace-gpr.S
 $(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: LDLIBS += -pthread
diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index 4e8d0ce1ff58..f6f8596ce8e1 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -348,15 +348,11 @@ static int parent(struct shared_info *info, pid_t pid)
 
 static int write_core_pattern(const char *core_pattern)
 {
-	size_t len = strlen(core_pattern), ret;
-	FILE *f;
+	int err;
 
-	f = fopen(core_pattern_file, "w");
-	SKIP_IF_MSG(!f, "Try with root privileges");
-
-	ret = fwrite(core_pattern, 1, len, f);
-	fclose(f);
-	if (ret != len) {
+	err = write_file(core_pattern_file, core_pattern, strlen(core_pattern));
+	if (err) {
+		SKIP_IF_MSG(err == -EPERM, "Try with root privileges");
 		perror("Error writing to core_pattern file");
 		return TEST_FAIL;
 	}
@@ -366,8 +362,8 @@ static int write_core_pattern(const char *core_pattern)
 
 static int setup_core_pattern(char **core_pattern_, bool *changed_)
 {
-	FILE *f;
 	char *core_pattern;
+	size_t len;
 	int ret;
 
 	core_pattern = malloc(PATH_MAX);
@@ -376,22 +372,14 @@ static int setup_core_pattern(char **core_pattern_, bool *changed_)
 		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 - 1, f);
-	fclose(f);
-	if (!ret) {
+	ret = read_file(core_pattern_file, core_pattern, PATH_MAX - 1, &len);
+	if (ret) {
 		perror("Error reading core_pattern file");
 		ret = TEST_FAIL;
 		goto out;
 	}
 
-	core_pattern[ret] = '\0';
+	core_pattern[len] = '\0';
 
 	/* Check whether we can predict the name of the core file. */
 	if (!strcmp(core_pattern, "core") || !strcmp(core_pattern, "core.%p"))
diff --git a/tools/testing/selftests/powerpc/security/Makefile b/tools/testing/selftests/powerpc/security/Makefile
index 7488315fd847..e0d979ab0204 100644
--- a/tools/testing/selftests/powerpc/security/Makefile
+++ b/tools/testing/selftests/powerpc/security/Makefile
@@ -5,7 +5,7 @@ TEST_PROGS := mitigation-patching.sh
 
 top_srcdir = ../../../../..
 
-CFLAGS += -I../../../../../usr/include
+CFLAGS += $(KHDR_INCLUDES)
 
 include ../../lib.mk
 
diff --git a/tools/testing/selftests/powerpc/security/entry_flush.c b/tools/testing/selftests/powerpc/security/entry_flush.c
index 68ce377b205e..e01c573deadd 100644
--- a/tools/testing/selftests/powerpc/security/entry_flush.c
+++ b/tools/testing/selftests/powerpc/security/entry_flush.c
@@ -34,18 +34,18 @@ int entry_flush_test(void)
 	// The PMU event we use only works on Power7 or later
 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
 
-	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
 		perror("Unable to read powerpc/rfi_flush debugfs file");
 		SKIP_IF(1);
 	}
 
-	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/entry_flush", &entry_flush_orig) < 0) {
 		perror("Unable to read powerpc/entry_flush debugfs file");
 		SKIP_IF(1);
 	}
 
 	if (rfi_flush_orig != 0) {
-		if (write_debugfs_file("powerpc/rfi_flush", 0) < 0) {
+		if (write_debugfs_int("powerpc/rfi_flush", 0) < 0) {
 			perror("error writing to powerpc/rfi_flush debugfs file");
 			FAIL_IF(1);
 		}
@@ -105,7 +105,7 @@ again:
 
 	if (entry_flush == entry_flush_orig) {
 		entry_flush = !entry_flush_orig;
-		if (write_debugfs_file("powerpc/entry_flush", entry_flush) < 0) {
+		if (write_debugfs_int("powerpc/entry_flush", entry_flush) < 0) {
 			perror("error writing to powerpc/entry_flush debugfs file");
 			return 1;
 		}
@@ -120,12 +120,12 @@ again:
 
 	set_dscr(0);
 
-	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/rfi_flush", rfi_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
 		return 1;
 	}
 
-	if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/entry_flush", entry_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/entry_flush debugfs file");
 		return 1;
 	}
diff --git a/tools/testing/selftests/powerpc/security/rfi_flush.c b/tools/testing/selftests/powerpc/security/rfi_flush.c
index f73484a6470f..6bedc86443a6 100644
--- a/tools/testing/selftests/powerpc/security/rfi_flush.c
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -34,18 +34,18 @@ int rfi_flush_test(void)
 	// The PMU event we use only works on Power7 or later
 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
 
-	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
 		perror("Unable to read powerpc/rfi_flush debugfs file");
 		SKIP_IF(1);
 	}
 
-	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/entry_flush", &entry_flush_orig) < 0) {
 		have_entry_flush = 0;
 	} else {
 		have_entry_flush = 1;
 
 		if (entry_flush_orig != 0) {
-			if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
+			if (write_debugfs_int("powerpc/entry_flush", 0) < 0) {
 				perror("error writing to powerpc/entry_flush debugfs file");
 				return 1;
 			}
@@ -105,7 +105,7 @@ again:
 
 	if (rfi_flush == rfi_flush_orig) {
 		rfi_flush = !rfi_flush_orig;
-		if (write_debugfs_file("powerpc/rfi_flush", rfi_flush) < 0) {
+		if (write_debugfs_int("powerpc/rfi_flush", rfi_flush) < 0) {
 			perror("error writing to powerpc/rfi_flush debugfs file");
 			return 1;
 		}
@@ -120,13 +120,13 @@ again:
 
 	set_dscr(0);
 
-	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/rfi_flush", rfi_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
 		return 1;
 	}
 
 	if (have_entry_flush) {
-		if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+		if (write_debugfs_int("powerpc/entry_flush", entry_flush_orig) < 0) {
 			perror("unable to restore original value of powerpc/entry_flush "
 			       "debugfs file");
 			return 1;
diff --git a/tools/testing/selftests/powerpc/security/uaccess_flush.c b/tools/testing/selftests/powerpc/security/uaccess_flush.c
index cf80f960e38a..fcf23ea9b183 100644
--- a/tools/testing/selftests/powerpc/security/uaccess_flush.c
+++ b/tools/testing/selftests/powerpc/security/uaccess_flush.c
@@ -36,30 +36,30 @@ int uaccess_flush_test(void)
 	// The PMU event we use only works on Power7 or later
 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
 
-	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
 		perror("Unable to read powerpc/rfi_flush debugfs file");
 		SKIP_IF(1);
 	}
 
-	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/entry_flush", &entry_flush_orig) < 0) {
 		perror("Unable to read powerpc/entry_flush debugfs file");
 		SKIP_IF(1);
 	}
 
-	if (read_debugfs_file("powerpc/uaccess_flush", &uaccess_flush_orig) < 0) {
+	if (read_debugfs_int("powerpc/uaccess_flush", &uaccess_flush_orig) < 0) {
 		perror("Unable to read powerpc/entry_flush debugfs file");
 		SKIP_IF(1);
 	}
 
 	if (rfi_flush_orig != 0) {
-		if (write_debugfs_file("powerpc/rfi_flush", 0) < 0) {
+		if (write_debugfs_int("powerpc/rfi_flush", 0) < 0) {
 			perror("error writing to powerpc/rfi_flush debugfs file");
 			FAIL_IF(1);
 		}
 	}
 
 	if (entry_flush_orig != 0) {
-		if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
+		if (write_debugfs_int("powerpc/entry_flush", 0) < 0) {
 			perror("error writing to powerpc/entry_flush debugfs file");
 			FAIL_IF(1);
 		}
@@ -119,7 +119,7 @@ again:
 
 	if (uaccess_flush == uaccess_flush_orig) {
 		uaccess_flush = !uaccess_flush_orig;
-		if (write_debugfs_file("powerpc/uaccess_flush", uaccess_flush) < 0) {
+		if (write_debugfs_int("powerpc/uaccess_flush", uaccess_flush) < 0) {
 			perror("error writing to powerpc/uaccess_flush debugfs file");
 			return 1;
 		}
@@ -134,17 +134,17 @@ again:
 
 	set_dscr(0);
 
-	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/rfi_flush", rfi_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
 		return 1;
 	}
 
-	if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/entry_flush", entry_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/entry_flush debugfs file");
 		return 1;
 	}
 
-	if (write_debugfs_file("powerpc/uaccess_flush", uaccess_flush_orig) < 0) {
+	if (write_debugfs_int("powerpc/uaccess_flush", uaccess_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/uaccess_flush debugfs file");
 		return 1;
 	}
diff --git a/tools/testing/selftests/powerpc/syscalls/Makefile b/tools/testing/selftests/powerpc/syscalls/Makefile
index b63f8459c704..ee1740ddfb0c 100644
--- a/tools/testing/selftests/powerpc/syscalls/Makefile
+++ b/tools/testing/selftests/powerpc/syscalls/Makefile
@@ -1,9 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-only
 TEST_GEN_PROGS := ipc_unmuxed rtas_filter
 
-CFLAGS += -I../../../../../usr/include
+CFLAGS += $(KHDR_INCLUDES)
 
 top_srcdir = ../../../../..
 include ../../lib.mk
 
-$(TEST_GEN_PROGS): ../harness.c
+$(TEST_GEN_PROGS): ../harness.c ../utils.c
diff --git a/tools/testing/selftests/powerpc/syscalls/rtas_filter.c b/tools/testing/selftests/powerpc/syscalls/rtas_filter.c
index 03b487f18d00..9b17780f0b18 100644
--- a/tools/testing/selftests/powerpc/syscalls/rtas_filter.c
+++ b/tools/testing/selftests/powerpc/syscalls/rtas_filter.c
@@ -8,6 +8,7 @@
 #include <byteswap.h>
 #include <stdint.h>
 #include <inttypes.h>
+#include <linux/limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/syscall.h>
@@ -50,70 +51,16 @@ struct region {
 	struct region *next;
 };
 
-int read_entire_file(int fd, char **buf, size_t *len)
-{
-	size_t buf_size = 0;
-	size_t off = 0;
-	int rc;
-
-	*buf = NULL;
-	do {
-		buf_size += BLOCK_SIZE;
-		if (*buf == NULL)
-			*buf = malloc(buf_size);
-		else
-			*buf = realloc(*buf, buf_size);
-
-		if (*buf == NULL)
-			return -ENOMEM;
-
-		rc = read(fd, *buf + off, BLOCK_SIZE);
-		if (rc < 0)
-			return -EIO;
-
-		off += rc;
-	} while (rc == BLOCK_SIZE);
-
-	if (len)
-		*len = off;
-
-	return 0;
-}
-
-static int open_prop_file(const char *prop_path, const char *prop_name, int *fd)
-{
-	char *path;
-	int len;
-
-	/* allocate enough for two string, a slash and trailing NULL */
-	len = strlen(prop_path) + strlen(prop_name) + 1 + 1;
-	path = malloc(len);
-	if (path == NULL)
-		return -ENOMEM;
-
-	snprintf(path, len, "%s/%s", prop_path, prop_name);
-
-	*fd = open(path, O_RDONLY);
-	free(path);
-	if (*fd < 0)
-		return -errno;
-
-	return 0;
-}
-
 static int get_property(const char *prop_path, const char *prop_name,
 			char **prop_val, size_t *prop_len)
 {
-	int rc, fd;
-
-	rc = open_prop_file(prop_path, prop_name, &fd);
-	if (rc)
-		return rc;
+	char path[PATH_MAX];
 
-	rc = read_entire_file(fd, prop_val, prop_len);
-	close(fd);
+	int len = snprintf(path, sizeof(path), "%s/%s", prop_path, prop_name);
+	if (len < 0 || len >= sizeof(path))
+		return -ENOMEM;
 
-	return rc;
+	return read_file_alloc(path, prop_val, prop_len);
 }
 
 int rtas_token(const char *call_name)
@@ -138,22 +85,14 @@ err:
 static int read_kregion_bounds(struct region *kregion)
 {
 	char *buf;
-	int fd;
-	int rc;
+	int err;
 
-	fd = open("/proc/ppc64/rtas/rmo_buffer", O_RDONLY);
-	if (fd < 0) {
-		printf("Could not open rmo_buffer file\n");
+	err = read_file_alloc("/proc/ppc64/rtas/rmo_buffer", &buf, NULL);
+	if (err) {
+		perror("Could not open rmo_buffer file");
 		return RTAS_IO_ASSERT;
 	}
 
-	rc = read_entire_file(fd, &buf, NULL);
-	close(fd);
-	if (rc) {
-		free(buf);
-		return rc;
-	}
-
 	sscanf(buf, "%" SCNx64 " %x", &kregion->addr, &kregion->size);
 	free(buf);
 
diff --git a/tools/testing/selftests/powerpc/tm/Makefile b/tools/testing/selftests/powerpc/tm/Makefile
index 5881e97c73c1..3876805c2f31 100644
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -17,7 +17,7 @@ $(TEST_GEN_PROGS): ../harness.c ../utils.c
 CFLAGS += -mhtm
 
 $(OUTPUT)/tm-syscall: tm-syscall-asm.S
-$(OUTPUT)/tm-syscall: CFLAGS += -I../../../../../usr/include
+$(OUTPUT)/tm-syscall: CFLAGS += $(KHDR_INCLUDES)
 $(OUTPUT)/tm-tmspr: CFLAGS += -pthread
 $(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64
 $(OUTPUT)/tm-resched-dscr: ../pmu/lib.c
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 1f36ee1a909a..7c8cfedb012a 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -8,6 +8,8 @@
 #include <elf.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
 #include <link.h>
 #include <sched.h>
 #include <stdio.h>
@@ -26,34 +28,360 @@
 
 static char auxv[4096];
 
-int read_auxv(char *buf, ssize_t buf_size)
+int read_file(const char *path, char *buf, size_t count, size_t *len)
 {
-	ssize_t num;
-	int rc, fd;
+	ssize_t rc;
+	int fd;
+	int err;
+	char eof;
 
-	fd = open("/proc/self/auxv", O_RDONLY);
-	if (fd == -1) {
-		perror("open");
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
 		return -errno;
+
+	rc = read(fd, buf, count);
+	if (rc < 0) {
+		err = -errno;
+		goto out;
 	}
 
-	num = read(fd, buf, buf_size);
-	if (num < 0) {
-		perror("read");
-		rc = -EIO;
+	if (len)
+		*len = rc;
+
+	/* Overflow if there are still more bytes after filling the buffer */
+	if (rc == count) {
+		rc = read(fd, &eof, 1);
+		if (rc != 0) {
+			err = -EOVERFLOW;
+			goto out;
+		}
+	}
+
+	err = 0;
+
+out:
+	close(fd);
+	errno = -err;
+	return err;
+}
+
+int read_file_alloc(const char *path, char **buf, size_t *len)
+{
+	size_t read_offset = 0;
+	size_t buffer_len = 0;
+	char *buffer = NULL;
+	int err;
+	int fd;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+
+	/*
+	 * We don't use stat & preallocate st_size because some non-files
+	 * report 0 file size. Instead just dynamically grow the buffer
+	 * as needed.
+	 */
+	while (1) {
+		ssize_t rc;
+
+		if (read_offset >= buffer_len / 2) {
+			char *next_buffer;
+
+			buffer_len = buffer_len ? buffer_len * 2 : 4096;
+			next_buffer = realloc(buffer, buffer_len);
+			if (!next_buffer) {
+				err = -errno;
+				goto out;
+			}
+			buffer = next_buffer;
+		}
+
+		rc = read(fd, buffer + read_offset, buffer_len - read_offset);
+		if (rc < 0) {
+			err = -errno;
+			goto out;
+		}
+
+		if (rc == 0)
+			break;
+
+		read_offset += rc;
+	}
+
+	*buf = buffer;
+	if (len)
+		*len = read_offset;
+
+	err = 0;
+
+out:
+	close(fd);
+	if (err)
+		free(buffer);
+	errno = -err;
+	return err;
+}
+
+int write_file(const char *path, const char *buf, size_t count)
+{
+	int fd;
+	int err;
+	ssize_t rc;
+
+	fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd < 0)
+		return -errno;
+
+	rc = write(fd, buf, count);
+	if (rc < 0) {
+		err = -errno;
 		goto out;
 	}
 
-	if (num > buf_size) {
-		printf("overflowed auxv buffer\n");
-		rc = -EOVERFLOW;
+	if (rc != count) {
+		err = -EOVERFLOW;
 		goto out;
 	}
 
-	rc = 0;
+	err = 0;
+
 out:
 	close(fd);
-	return rc;
+	errno = -err;
+	return err;
+}
+
+int read_auxv(char *buf, ssize_t buf_size)
+{
+	int err;
+
+	err = read_file("/proc/self/auxv", buf, buf_size, NULL);
+	if (err) {
+		perror("Error reading /proc/self/auxv");
+		return err;
+	}
+
+	return 0;
+}
+
+int read_debugfs_file(const char *subpath, char *buf, size_t count)
+{
+	char path[PATH_MAX] = "/sys/kernel/debug/";
+
+	strncat(path, subpath, sizeof(path) - strlen(path) - 1);
+
+	return read_file(path, buf, count, NULL);
+}
+
+int write_debugfs_file(const char *subpath, const char *buf, size_t count)
+{
+	char path[PATH_MAX] = "/sys/kernel/debug/";
+
+	strncat(path, subpath, sizeof(path) - strlen(path) - 1);
+
+	return write_file(path, buf, count);
+}
+
+static int validate_int_parse(const char *buffer, size_t count, char *end)
+{
+	int err = 0;
+
+	/* Require at least one digit */
+	if (end == buffer) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Require all remaining characters be whitespace-ish */
+	for (; end < buffer + count; end++) {
+		if (*end == '\0')
+			break;
+
+		if (*end != ' ' && *end != '\n') {
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+out:
+	errno = -err;
+	return err;
+}
+
+static int parse_bounded_int(const char *buffer, size_t count, intmax_t *result,
+			     int base, intmax_t min, intmax_t max)
+{
+	int err;
+	char *end;
+
+	errno = 0;
+	*result = strtoimax(buffer, &end, base);
+
+	if (errno)
+		return -errno;
+
+	err = validate_int_parse(buffer, count, end);
+	if (err)
+		goto out;
+
+	if (*result < min || *result > max)
+		err = -EOVERFLOW;
+
+out:
+	errno = -err;
+	return err;
+}
+
+static int parse_bounded_uint(const char *buffer, size_t count, uintmax_t *result,
+			      int base, uintmax_t max)
+{
+	int err = 0;
+	char *end;
+
+	errno = 0;
+	*result = strtoumax(buffer, &end, base);
+
+	if (errno)
+		return -errno;
+
+	err = validate_int_parse(buffer, count, end);
+	if (err)
+		goto out;
+
+	if (*result > max)
+		err = -EOVERFLOW;
+
+out:
+	errno = -err;
+	return err;
+}
+
+int parse_intmax(const char *buffer, size_t count, intmax_t *result, int base)
+{
+	return parse_bounded_int(buffer, count, result, base, INTMAX_MIN, INTMAX_MAX);
+}
+
+int parse_uintmax(const char *buffer, size_t count, uintmax_t *result, int base)
+{
+	return parse_bounded_uint(buffer, count, result, base, UINTMAX_MAX);
+}
+
+int parse_int(const char *buffer, size_t count, int *result, int base)
+{
+	intmax_t parsed;
+	int err = parse_bounded_int(buffer, count, &parsed, base, INT_MIN, INT_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_uint(const char *buffer, size_t count, unsigned int *result, int base)
+{
+	uintmax_t parsed;
+	int err = parse_bounded_uint(buffer, count, &parsed, base, UINT_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_long(const char *buffer, size_t count, long *result, int base)
+{
+	intmax_t parsed;
+	int err = parse_bounded_int(buffer, count, &parsed, base, LONG_MIN, LONG_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_ulong(const char *buffer, size_t count, unsigned long *result, int base)
+{
+	uintmax_t parsed;
+	int err = parse_bounded_uint(buffer, count, &parsed, base, ULONG_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int read_long(const char *path, long *result, int base)
+{
+	int err;
+	char buffer[32] = {0};
+
+	err = read_file(path, buffer, sizeof(buffer) - 1, NULL);
+	if (err)
+		return err;
+
+	return parse_long(buffer, sizeof(buffer), result, base);
+}
+
+int read_ulong(const char *path, unsigned long *result, int base)
+{
+	int err;
+	char buffer[32] = {0};
+
+	err = read_file(path, buffer, sizeof(buffer) - 1, NULL);
+	if (err)
+		return err;
+
+	return parse_ulong(buffer, sizeof(buffer), result, base);
+}
+
+int write_long(const char *path, long result, int base)
+{
+	int err;
+	int len;
+	char buffer[32];
+
+	/* Decimal only for now: no format specifier for signed hex values */
+	if (base != 10) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	len = snprintf(buffer, sizeof(buffer), "%ld", result);
+	if (len < 0 || len >= sizeof(buffer)) {
+		err = -EOVERFLOW;
+		goto out;
+	}
+
+	err = write_file(path, buffer, len);
+
+out:
+	errno = -err;
+	return err;
+}
+
+int write_ulong(const char *path, unsigned long result, int base)
+{
+	int err;
+	int len;
+	char buffer[32];
+	char *fmt;
+
+	switch (base) {
+	case 10:
+		fmt = "%lu";
+		break;
+	case 16:
+		fmt = "%lx";
+		break;
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+
+	len = snprintf(buffer, sizeof(buffer), fmt, result);
+	if (len < 0 || len >= sizeof(buffer)) {
+		err = -errno;
+		goto out;
+	}
+
+	err = write_file(path, buffer, len);
+
+out:
+	errno = -err;
+	return err;
 }
 
 void *find_auxv_entry(int type, char *auxv)
@@ -142,65 +470,31 @@ bool is_ppc64le(void)
 int read_sysfs_file(char *fpath, char *result, size_t result_size)
 {
 	char path[PATH_MAX] = "/sys/";
-	int rc = -1, fd;
 
 	strncat(path, fpath, PATH_MAX - strlen(path) - 1);
 
-	if ((fd = open(path, O_RDONLY)) < 0)
-		return rc;
-
-	rc = read(fd, result, result_size);
-
-	close(fd);
-
-	if (rc < 0)
-		return rc;
-
-	return 0;
+	return read_file(path, result, result_size, NULL);
 }
 
-int read_debugfs_file(char *debugfs_file, int *result)
+int read_debugfs_int(const char *debugfs_file, int *result)
 {
-	int rc = -1, fd;
-	char path[PATH_MAX];
-	char value[16];
-
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
+	int err;
+	char value[16] = {0};
 
-	if ((fd = open(path, O_RDONLY)) < 0)
-		return rc;
+	err = read_debugfs_file(debugfs_file, value, sizeof(value) - 1);
+	if (err)
+		return err;
 
-	if ((rc = read(fd, value, sizeof(value))) < 0)
-		return rc;
-
-	value[15] = 0;
-	*result = atoi(value);
-	close(fd);
-
-	return 0;
+	return parse_int(value, sizeof(value), result, 10);
 }
 
-int write_debugfs_file(char *debugfs_file, int result)
+int write_debugfs_int(const char *debugfs_file, int result)
 {
-	int rc = -1, fd;
-	char path[PATH_MAX];
 	char value[16];
 
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
-
-	if ((fd = open(path, O_WRONLY)) < 0)
-		return rc;
-
 	snprintf(value, 16, "%d", result);
 
-	if ((rc = write(fd, value, strlen(value))) < 0)
-		return rc;
-
-	close(fd);
-
-	return 0;
+	return write_debugfs_file(debugfs_file, value, strlen(value));
 }
 
 static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,