[PATCH v1 0/7] Expand selftest utils

[PATCH v1 0/7] Expand selftest utils

[Benjamin Gray]

Started this when writing tests for a feature I'm working on, needing a way to
read/write numbers to system files. After writing some utils to safely handle
file IO and parsing, I realised I'd made the ~6th file read/write implementation
and only(?) number parser that checks all the failure modes when expecting to
parse a single number from a file.

So these utils ended up becoming this series. I also modified some other test
utils I came across while doing so. My understanding is selftests are not expected
to be backported, so I wasn't concerned about only introducing new utils and leaving
the existing implementations be.

Changes:
- Use the mtfspr/mfspr macros where possible over inline asm
- Fix potential non-null terminated buffer in ptrace tests
- Add read_file / write_file to read and write raw bytes given appropriate
  path and buffers. Replace hand rolled read/write with this where easy.
- Make read/write_debugfs_file work on byte buffers and introduce
  read/write_debugfs_int for int specific contents. This more naturally aligns
  with the read/write_file functions, and allows for future *_long, *_ulong
  variants when required.
- Add an error checking number parser. It's an ugly function generating macro.
  The issue is the result param type can't be made generic, so there needs to
  be a separate definition per type (or at least for signed/unsigned). Also
  can't seem to use generics with the variable type declaration, so the max
  sized type for the input sign has to be specified manually.
  It's at least grep-able and language servers recognise it as defining
  parse_int, etc., though.
- Add the read_long, write_long, etc., utils that combine file IO and parsing.
  These are the utils I really wanted, useful for system files that are just
  numbers.
- Add an allocating file read for when the buffer is potentially too big to
  preallocate on the stack or needs to live especially long.


Benjamin Gray (7):
  selftests/powerpc: Use mfspr/mtspr macros
  selftests/powerpc: Add ptrace setup_core_pattern() null-terminator
  selftests/powerpc: Add generic read/write file util
  selftests/powerpc: Add read/write debugfs file, int
  selftests/powerpc: Parse long/unsigned long value safely
  selftests/powerpc: Add {read,write}_{long,ulong}
  selftests/powerpc: Add automatically allocating read_file

 tools/testing/selftests/powerpc/dscr/dscr.h   |  56 +---
 .../selftests/powerpc/dscr/dscr_sysfs_test.c  |  23 +-
 .../testing/selftests/powerpc/include/utils.h |  18 +-
 .../selftests/powerpc/nx-gzip/gzfht_test.c    |  52 +--
 tools/testing/selftests/powerpc/pmu/lib.c     |  35 +-
 .../selftests/powerpc/ptrace/core-pkey.c      |  28 +-
 .../selftests/powerpc/ptrace/ptrace-hwbreak.c |   6 +-
 .../testing/selftests/powerpc/ptrace/ptrace.h |   5 +-
 .../selftests/powerpc/security/entry_flush.c  |  12 +-
 .../selftests/powerpc/security/flush_utils.c  |   3 +-
 .../selftests/powerpc/security/rfi_flush.c    |  12 +-
 .../powerpc/security/uaccess_flush.c          |  18 +-
 .../selftests/powerpc/syscalls/Makefile       |   2 +-
 .../selftests/powerpc/syscalls/rtas_filter.c  |  80 +----
 tools/testing/selftests/powerpc/utils.c       | 314 ++++++++++++++----
 15 files changed, 341 insertions(+), 323 deletions(-)


base-commit: 247f34f7b80357943234f93f247a1ae6b6c3a740
--
2.38.1

[PATCH v1 1/7] selftests/powerpc: Use mfspr/mtspr macros

[Benjamin Gray]

No need to write inline asm for mtspr/mfspr, we have macros for this
in reg.h
---
 tools/testing/selftests/powerpc/dscr/dscr.h     | 17 +++++------------
 .../selftests/powerpc/ptrace/ptrace-hwbreak.c   |  6 ++----
 tools/testing/selftests/powerpc/ptrace/ptrace.h |  5 +----
 .../selftests/powerpc/security/flush_utils.c    |  3 ++-
 4 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h
index 13e9b9e28e2c..b703714e7d98 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr.h
+++ b/tools/testing/selftests/powerpc/dscr/dscr.h
@@ -23,6 +23,7 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 
+#include "reg.h"
 #include "utils.h"
 
 #define THREADS		100	/* Max threads */
@@ -41,31 +42,23 @@
 /* Prilvilege state DSCR access */
 inline unsigned long get_dscr(void)
 {
-	unsigned long ret;
-
-	asm volatile("mfspr %0,%1" : "=r" (ret) : "i" (SPRN_DSCR_PRIV));
-
-	return ret;
+	return mfspr(SPRN_DSCR_PRIV);
 }
 
 inline void set_dscr(unsigned long val)
 {
-	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR_PRIV));
+	mtspr(SPRN_DSCR_PRIV, val);
 }
 
 /* Problem state DSCR access */
 inline unsigned long get_dscr_usr(void)
 {
-	unsigned long ret;
-
-	asm volatile("mfspr %0,%1" : "=r" (ret) : "i" (SPRN_DSCR));
-
-	return ret;
+	return mfspr(SPRN_DSCR);
 }
 
 inline void set_dscr_usr(unsigned long val)
 {
-	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
+	mtspr(SPRN_DSCR, val);
 }
 
 /* Default DSCR access */
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
index a0635a3819aa..1345e9b9af0f 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
@@ -23,6 +23,7 @@
 #include <sys/syscall.h>
 #include <linux/limits.h>
 #include "ptrace.h"
+#include "reg.h"
 
 #define SPRN_PVR	0x11F
 #define PVR_8xx		0x00500000
@@ -620,10 +621,7 @@ static int ptrace_hwbreak(void)
 
 int main(int argc, char **argv, char **envp)
 {
-	int pvr = 0;
-	asm __volatile__ ("mfspr %0,%1" : "=r"(pvr) : "i"(SPRN_PVR));
-	if (pvr == PVR_8xx)
-		is_8xx = true;
+	is_8xx = mfspr(SPRN_PVR) == PVR_8xx;
 
 	return test_harness(ptrace_hwbreak, "ptrace-hwbreak");
 }
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace.h b/tools/testing/selftests/powerpc/ptrace/ptrace.h
index 4e0233c0f2b3..04788e5fc504 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace.h
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace.h
@@ -745,10 +745,7 @@ int show_tm_spr(pid_t child, struct tm_spr_regs *out)
 /* Analyse TEXASR after TM failure */
 inline unsigned long get_tfiar(void)
 {
-	unsigned long ret;
-
-	asm volatile("mfspr %0,%1" : "=r" (ret) : "i" (SPRN_TFIAR));
-	return ret;
+	return mfspr(SPRN_TFIAR);
 }
 
 void analyse_texasr(unsigned long texasr)
diff --git a/tools/testing/selftests/powerpc/security/flush_utils.c b/tools/testing/selftests/powerpc/security/flush_utils.c
index 4d95965cb751..9c5c00e04f63 100644
--- a/tools/testing/selftests/powerpc/security/flush_utils.c
+++ b/tools/testing/selftests/powerpc/security/flush_utils.c
@@ -14,6 +14,7 @@
 #include <string.h>
 #include <stdio.h>
 #include <sys/utsname.h>
+#include "reg.h"
 #include "utils.h"
 #include "flush_utils.h"
 
@@ -79,5 +80,5 @@ void set_dscr(unsigned long val)
 		init = 1;
 	}
 
-	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
+	mtspr(SPRN_DSCR, val);
 }
-- 
2.38.1

[PATCH v1 2/7] selftests/powerpc: Add ptrace setup_core_pattern() null-terminator

[Benjamin Gray]

- malloc() does not zero the buffer,
- fread() does not null-terminate it's output,
- `cat /proc/sys/kernel/core_pattern | hexdump -C` shows the file is
  not inherently null-terminated

So using string operations on the buffer is risky. Explicitly add a null
character to the end to make it safer.
---
 tools/testing/selftests/powerpc/ptrace/core-pkey.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index bbc05ffc5860..5c82ed9e7c65 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -383,7 +383,7 @@ static int setup_core_pattern(char **core_pattern_, bool *changed_)
 		goto out;
 	}
 
-	ret = fread(core_pattern, 1, PATH_MAX, f);
+	ret = fread(core_pattern, 1, PATH_MAX - 1, f);
 	fclose(f);
 	if (!ret) {
 		perror("Error reading core_pattern file");
@@ -391,6 +391,8 @@ static int setup_core_pattern(char **core_pattern_, bool *changed_)
 		goto out;
 	}
 
+	core_pattern[ret] = '\0';
+
 	/* Check whether we can predict the name of the core file. */
 	if (!strcmp(core_pattern, "core") || !strcmp(core_pattern, "core.%p"))
 		*changed_ = false;
-- 
2.38.1

[PATCH v1 3/7] selftests/powerpc: Add generic read/write file util

[Benjamin Gray]

File read/write is reimplemented in about 5 different ways in the
various PowerPC selftests. This indicates it should be a common util.

Add a common read_file / write_file implementation and convert users
to it where (easily) possible.
---
 tools/testing/selftests/powerpc/dscr/dscr.h   |  36 ++----
 .../selftests/powerpc/dscr/dscr_sysfs_test.c  |  19 +--
 .../testing/selftests/powerpc/include/utils.h |   2 +
 .../selftests/powerpc/nx-gzip/gzfht_test.c    |  49 +++-----
 tools/testing/selftests/powerpc/pmu/lib.c     |  27 +----
 .../selftests/powerpc/ptrace/core-pkey.c      |  30 ++---
 tools/testing/selftests/powerpc/utils.c       | 108 ++++++++++--------
 7 files changed, 107 insertions(+), 164 deletions(-)

diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h
index b703714e7d98..9a69d473ffdf 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr.h
+++ b/tools/testing/selftests/powerpc/dscr/dscr.h
@@ -64,48 +64,30 @@ 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;
+	char buf[16] = {0};
 	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) {
-		perror("read() failed");
+	if ((err = read_file(DSCR_DEFAULT, buf, sizeof(buf) - 1, NULL))) {
+		fprintf(stderr, "get_default_dscr() read failed: %s\n", strerror(err));
 		exit(1);
 	}
+
 	sscanf(buf, "%lx", &val);
-	close(fd);
 	return val;
 }
 
 void set_default_dscr(unsigned long val)
 {
-	int fd = -1, ret;
+	int err;
 	char buf[16];
 
-	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) {
-		perror("write() failed");
+
+	if ((err = write_file(DSCR_DEFAULT, buf, strlen(buf)))) {
+		fprintf(stderr, "set_default_dscr() write failed: %s\n", strerror(err));
 		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 fbbdffdb2e5d..310946262a24 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
@@ -12,23 +12,12 @@
 
 static int check_cpu_dscr_default(char *file, unsigned long val)
 {
-	char buf[10];
-	int fd, rc;
+	char buf[10] = {0};
+	int rc;
 
-	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");
-		return 1;
-	}
-	close(fd);
+	if ((rc = read_file(file, buf, sizeof(buf) - 1, NULL)))
+		return rc;
 
-	buf[rc] = '\0';
 	if (strtol(buf, NULL, 16) != val) {
 		printf("DSCR match failed: %ld (system) %ld (cpu)\n",
 					val, strtol(buf, NULL, 16));
diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index e222a5858450..70885e5814a8 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -33,6 +33,8 @@ void *get_auxv_entry(int type);
 
 int pick_online_cpu(void);
 
+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_debugfs_file(char *debugfs_file, int *result);
 int write_debugfs_file(char *debugfs_file, int result);
 int read_sysfs_file(char *debugfs_file, char *result, size_t result_size);
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
index 095195a25687..a6a226e1b8ba 100644
--- a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
+++ b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
@@ -146,49 +146,36 @@ int gzip_header_blank(char *buf)
 /* Caller must free the allocated buffer return nonzero on error. */
 int read_alloc_input_file(char *fname, char **buf, size_t *bufsize)
 {
+	int err;
 	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);
+		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);
+
+	if ((err = read_file(fname, p, statbuf.st_size, &num_bytes))) {
+		fprintf(stderr, "Failed to read file: %s\n", strerror(err));
+		goto fail;
 	}
+
+	if (num_bytes != statbuf.st_size) {
+		fprintf(stderr, "Actual bytes != expected bytes\n");
+		err = -1;
+		goto fail;
+	}
+
 	*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;
+fail:
+	free(p);
+	return err;
 }
 
 /*
@@ -399,7 +386,7 @@ 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..e8960e7a1271 100644
--- a/tools/testing/selftests/powerpc/pmu/lib.c
+++ b/tools/testing/selftests/powerpc/pmu/lib.c
@@ -190,38 +190,21 @@ 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)) {
+	if ((err = read_file(PARANOID_PATH, buf, sizeof(buf), NULL))) {
 		printf("Couldn't read " PARANOID_PATH "?\n");
-		goto out_close;
+		return false;
 	}
 
 	current = strtol(buf, &end, 10);
 
 	if (end == buf) {
 		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/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index 5c82ed9e7c65..46e0695ed8b0 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -348,16 +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) {
-		perror("Error writing to core_pattern file");
+	if ((err = write_file(core_pattern_file, core_pattern, strlen(core_pattern)))) {
+		SKIP_IF_MSG(err == -EPERM, "Try with root privileges");
+		fprintf(stderr, "Error writing core_pattern file: %s\n", strerror(err));
 		return TEST_FAIL;
 	}
 
@@ -366,8 +361,8 @@ 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 +371,13 @@ 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) {
-		perror("Error reading core_pattern file");
+	if ((ret = read_file(core_pattern_file, core_pattern, PATH_MAX - 1, &len))) {
+		fprintf(stderr, "Error reading core_pattern file: %s\n", strerror(ret));
 		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/utils.c b/tools/testing/selftests/powerpc/utils.c
index 1f36ee1a909a..7ebbaa09f69d 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -26,34 +26,73 @@
 
 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;
+
+	if ((fd = open(path, O_RDONLY)) < 0)
+		return errno;
 
-	fd = open("/proc/self/auxv", O_RDONLY);
-	if (fd == -1) {
-		perror("open");
-		return -errno;
+	if ((rc = read(fd, buf, count)) < 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)) != 0) {
+		err = EOVERFLOW;
 		goto out;
 	}
 
-	if (num > buf_size) {
-		printf("overflowed auxv buffer\n");
-		rc = -EOVERFLOW;
+	err = 0;
+
+out:
+	close(fd);
+	return err;
+}
+
+int write_file(const char *path, const char *buf, size_t count)
+{
+	int fd;
+	int err;
+	ssize_t rc;
+
+	if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC)) < 0)
+		return errno;
+
+	if ((rc = write(fd, buf, count)) < 0) {
+		err = errno;
 		goto out;
 	}
 
-	rc = 0;
+	if (rc != count) {
+		err = EOVERFLOW;
+		goto out;
+	}
+
+	err = 0;
+
 out:
 	close(fd);
-	return rc;
+	return err;
+}
+
+int read_auxv(char *buf, ssize_t buf_size)
+{
+	int err;
+
+	if ((err = read_file("/proc/self/auxv", buf, buf_size, NULL))) {
+		fprintf(stderr, "Error reading auxv: %s\n", strerror(err));
+		return err;
+	}
+
+	return 0;
 }
 
 void *find_auxv_entry(int type, char *auxv)
@@ -142,65 +181,40 @@ 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 rc = -1, fd;
+	int err;
 	char path[PATH_MAX];
-	char value[16];
+	char value[16] = {0};
 
 	strcpy(path, "/sys/kernel/debug/");
 	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
 
-	if ((fd = open(path, O_RDONLY)) < 0)
-		return rc;
-
-	if ((rc = read(fd, value, sizeof(value))) < 0)
-		return rc;
+	if ((err = read_file(path, value, sizeof(value) - 1, NULL)))
+		return err;
 
-	value[15] = 0;
 	*result = atoi(value);
-	close(fd);
 
 	return 0;
 }
 
 int write_debugfs_file(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_file(path, value, strlen(value));
 }
 
 static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
-- 
2.38.1

[PATCH v1 4/7] selftests/powerpc: Add read/write debugfs file, int

[Benjamin Gray]

Debugfs files are not always integers, so make *_file return/write a
byte buffer, and *_int deal with int values specifically. This increases
consistency with the other file read/write helpers.
---
 .../testing/selftests/powerpc/include/utils.h |  6 ++--
 .../selftests/powerpc/security/entry_flush.c  | 12 +++----
 .../selftests/powerpc/security/rfi_flush.c    | 12 +++----
 .../powerpc/security/uaccess_flush.c          | 18 +++++-----
 tools/testing/selftests/powerpc/utils.c       | 34 ++++++++++++-------
 5 files changed, 47 insertions(+), 35 deletions(-)

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index 70885e5814a8..de5e3790f397 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -35,8 +35,10 @@ int pick_online_cpu(void);
 
 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_debugfs_file(char *debugfs_file, int *result);
-int write_debugfs_file(char *debugfs_file, int result);
+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/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 @@ int entry_flush_test(void)
 
 	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 @@ int entry_flush_test(void)
 
 	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 @@ int rfi_flush_test(void)
 
 	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 @@ int rfi_flush_test(void)
 
 	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 @@ int uaccess_flush_test(void)
 
 	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 @@ int uaccess_flush_test(void)
 
 	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/utils.c b/tools/testing/selftests/powerpc/utils.c
index 7ebbaa09f69d..22a255cd43d1 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -95,6 +95,24 @@ int read_auxv(char *buf, ssize_t buf_size)
 	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);
+}
+
 void *find_auxv_entry(int type, char *auxv)
 {
 	ElfW(auxv_t) *p;
@@ -187,16 +205,12 @@ int read_sysfs_file(char *fpath, char *result, size_t result_size)
 	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 err;
-	char path[PATH_MAX];
 	char value[16] = {0};
 
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
-
-	if ((err = read_file(path, value, sizeof(value) - 1, NULL)))
+	if ((err = read_debugfs_file(debugfs_file, value, sizeof(value) - 1)))
 		return err;
 
 	*result = atoi(value);
@@ -204,17 +218,13 @@ int read_debugfs_file(char *debugfs_file, int *result)
 	return 0;
 }
 
-int write_debugfs_file(char *debugfs_file, int result)
+int write_debugfs_int(const char *debugfs_file, int result)
 {
-	char path[PATH_MAX];
 	char value[16];
 
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
-
 	snprintf(value, 16, "%d", result);
 
-	return write_file(path, value, strlen(value));
+	return write_debugfs_file(debugfs_file, value, strlen(value));
 }
 
 static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
-- 
2.38.1

[PATCH v1 5/7] selftests/powerpc: Parse long/unsigned long value safely

[Benjamin Gray]

Often a file is expected to hold an integral value. Existing functions
will use a C stdlib function like atoi or strtol to parse the file.
These operations are error prone, with complicated error conditions
(atoi returns 0 if not a number, and is undefined behaviour if not in
range. strtol returns 0 if not a number, and LONG_MIN/MAX if not in
range + sets errno to ERANGE).

Add a dedicated parse function that accounts for these error conditions
so tests can safely parse numbers without undetected bad data. It's a
bit ugly to generate the functions through a macro, but it beats copying
the error check logic multiple times over.

define_parse_number
---
 .../testing/selftests/powerpc/include/utils.h |  5 ++
 tools/testing/selftests/powerpc/pmu/lib.c     |  9 ++--
 tools/testing/selftests/powerpc/utils.c       | 53 +++++++++++++++++--
 3 files changed, 59 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index de5e3790f397..b82e143a07c6 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -33,6 +33,11 @@ void *get_auxv_entry(int type);
 
 int pick_online_cpu(void);
 
+int parse_int(const char *buffer, size_t count, int *result, int base);
+int parse_long(const char *buffer, size_t count, long *result, int base);
+int parse_uint(const char *buffer, size_t count, unsigned int *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_debugfs_file(const char *debugfs_file, char *buf, size_t count);
diff --git a/tools/testing/selftests/powerpc/pmu/lib.c b/tools/testing/selftests/powerpc/pmu/lib.c
index e8960e7a1271..771658278f55 100644
--- a/tools/testing/selftests/powerpc/pmu/lib.c
+++ b/tools/testing/selftests/powerpc/pmu/lib.c
@@ -192,16 +192,15 @@ bool require_paranoia_below(int level)
 {
 	int err;
 	long current;
-	char *end, buf[16];
+	char buf[16] = {0};
+	char *end;
 
-	if ((err = read_file(PARANOID_PATH, buf, sizeof(buf), NULL))) {
+	if ((err = read_file(PARANOID_PATH, buf, sizeof(buf) - 1, NULL))) {
 		printf("Couldn't read " PARANOID_PATH "?\n");
 		return false;
 	}
 
-	current = strtol(buf, &end, 10);
-
-	if (end == buf) {
+	if ((err = parse_long(buf, sizeof(buf), &current, 10))) {
 		printf("Couldn't parse " PARANOID_PATH "?\n");
 		return false;
 	}
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 22a255cd43d1..7c7d8aaa69fb 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>
@@ -113,6 +115,53 @@ int write_debugfs_file(const char *subpath, const char *buf, size_t count)
 	return write_file(path, buf, count);
 }
 
+#define TYPE_MIN(x)				\
+	_Generic((x),				\
+		int:		INT_MIN,	\
+		long:		LONG_MIN,	\
+		unsigned int:	0,		\
+		unsigned long:	0)
+
+#define TYPE_MAX(x)				\
+	_Generic((x),				\
+		int:		INT_MAX,	\
+		long:		LONG_MAX,	\
+		unsigned int:	INT_MAX,	\
+		unsigned long:	LONG_MAX)
+
+#define define_parse_number(fn, type, super_type)				\
+	int fn(const char *buffer, size_t count, type *result, int base)	\
+	{									\
+		char *end;							\
+		super_type parsed;						\
+										\
+		errno = 0;							\
+		parsed = _Generic(parsed,					\
+				  intmax_t:	strtoimax,			\
+				  uintmax_t:	strtoumax)(buffer, &end, base);	\
+										\
+		if (errno == ERANGE ||						\
+		    parsed < TYPE_MIN(*result) || parsed > TYPE_MAX(*result))	\
+			return ERANGE;						\
+										\
+		/* Require at least one digit */				\
+		if (end == buffer)						\
+			return EINVAL;						\
+										\
+		/* Require all remaining characters be whitespace-ish */	\
+		for (; end < buffer + count; end++)				\
+			if (!(*end == ' ' || *end == '\n' || *end == '\0'))	\
+				return EINVAL;					\
+										\
+		*result = parsed;						\
+		return 0;							\
+	}
+
+define_parse_number(parse_int, int, intmax_t);
+define_parse_number(parse_long, long, intmax_t);
+define_parse_number(parse_uint, unsigned int, uintmax_t);
+define_parse_number(parse_ulong, unsigned long, uintmax_t);
+
 void *find_auxv_entry(int type, char *auxv)
 {
 	ElfW(auxv_t) *p;
@@ -213,9 +262,7 @@ int read_debugfs_int(const char *debugfs_file, int *result)
 	if ((err = read_debugfs_file(debugfs_file, value, sizeof(value) - 1)))
 		return err;
 
-	*result = atoi(value);
-
-	return 0;
+	return parse_int(value, sizeof(value), result, 10);
 }
 
 int write_debugfs_int(const char *debugfs_file, int result)
-- 
2.38.1

[PATCH v1 6/7] selftests/powerpc: Add {read,write}_{long,ulong}

[Benjamin Gray]

Add helper functions to read and write (unsigned) long values directly
from/to files. One of the kernel interfaces uses hex strings, so we need
to allow passing a base too.

write_long

write_ulong
---
 tools/testing/selftests/powerpc/dscr/dscr.h   |  9 +--
 .../selftests/powerpc/dscr/dscr_sysfs_test.c  | 12 ++--
 .../testing/selftests/powerpc/include/utils.h |  4 ++
 tools/testing/selftests/powerpc/pmu/lib.c     | 11 +---
 tools/testing/selftests/powerpc/utils.c       | 62 +++++++++++++++++++
 5 files changed, 76 insertions(+), 22 deletions(-)

diff --git a/tools/testing/selftests/powerpc/dscr/dscr.h b/tools/testing/selftests/powerpc/dscr/dscr.h
index 9a69d473ffdf..b5166ddcf26a 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr.h
+++ b/tools/testing/selftests/powerpc/dscr/dscr.h
@@ -65,26 +65,21 @@ inline void set_dscr_usr(unsigned long val)
 unsigned long get_default_dscr(void)
 {
 	int err;
-	char buf[16] = {0};
 	unsigned long val;
 
-	if ((err = read_file(DSCR_DEFAULT, buf, sizeof(buf) - 1, NULL))) {
+	if ((err = read_ulong(DSCR_DEFAULT, &val, 16))) {
 		fprintf(stderr, "get_default_dscr() read failed: %s\n", strerror(err));
 		exit(1);
 	}
 
-	sscanf(buf, "%lx", &val);
 	return val;
 }
 
 void set_default_dscr(unsigned long val)
 {
 	int err;
-	char buf[16];
 
-	sprintf(buf, "%lx\n", val);
-
-	if ((err = write_file(DSCR_DEFAULT, buf, strlen(buf)))) {
+	if ((err = write_ulong(DSCR_DEFAULT, val, 16))) {
 		fprintf(stderr, "set_default_dscr() write failed: %s\n", strerror(err));
 		exit(1);
 	}
diff --git a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
index 310946262a24..3ac176888feb 100644
--- a/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
+++ b/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c
@@ -12,15 +12,15 @@
 
 static int check_cpu_dscr_default(char *file, unsigned long val)
 {
-	char buf[10] = {0};
-	int rc;
+	unsigned long cpu_dscr;
+	int err;
 
-	if ((rc = read_file(file, buf, sizeof(buf) - 1, NULL)))
-		return rc;
+	if ((err = read_ulong(file, &cpu_dscr, 16)))
+		return err;
 
-	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 b82e143a07c6..044b0236df38 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -40,6 +40,10 @@ int parse_ulong(const char *buffer, size_t count, unsigned long *result, int bas
 
 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_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);
diff --git a/tools/testing/selftests/powerpc/pmu/lib.c b/tools/testing/selftests/powerpc/pmu/lib.c
index 771658278f55..55481c5b6995 100644
--- a/tools/testing/selftests/powerpc/pmu/lib.c
+++ b/tools/testing/selftests/powerpc/pmu/lib.c
@@ -192,16 +192,9 @@ bool require_paranoia_below(int level)
 {
 	int err;
 	long current;
-	char buf[16] = {0};
-	char *end;
 
-	if ((err = read_file(PARANOID_PATH, buf, sizeof(buf) - 1, NULL))) {
-		printf("Couldn't read " PARANOID_PATH "?\n");
-		return false;
-	}
-
-	if ((err = parse_long(buf, sizeof(buf), &current, 10))) {
-		printf("Couldn't parse " PARANOID_PATH "?\n");
+	if ((err = read_long(PARANOID_PATH, &current, 10))) {
+		fprintf(stderr, "Couldn't read " PARANOID_PATH ": %s\n", strerror(err));
 		return false;
 	}
 
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 7c7d8aaa69fb..32a96c8967ac 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -162,6 +162,68 @@ define_parse_number(parse_long, long, intmax_t);
 define_parse_number(parse_uint, unsigned int, uintmax_t);
 define_parse_number(parse_ulong, unsigned long, uintmax_t);
 
+int read_long(const char *path, long *result, int base)
+{
+	int err;
+	char buffer[32] = {0};
+
+	if ((err = read_file(path, buffer, sizeof(buffer) - 1, NULL)))
+		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};
+
+	if ((err = read_file(path, buffer, sizeof(buffer) - 1, NULL)))
+		return err;
+
+	return parse_ulong(buffer, sizeof(buffer), result, base);
+}
+
+int write_long(const char *path, long result, int base)
+{
+	int len;
+	char buffer[32];
+
+	/* Decimal only; we don't have a format specifier for signed hex values */
+	if (base != 10)
+		return EINVAL;
+
+	len = snprintf(buffer, sizeof(buffer), "%ld", result);
+	if (len < 0 || len >= sizeof(buffer))
+		return EOVERFLOW;
+
+	return write_file(path, buffer, len);
+}
+
+int write_ulong(const char *path, unsigned long result, int base)
+{
+	int len;
+	char buffer[32];
+	char *fmt;
+
+	switch (base) {
+	case 10:
+		fmt = "%lu";
+		break;
+	case 16:
+		fmt = "%lx";
+		break;
+	default:
+		return EINVAL;
+	}
+
+	len = snprintf(buffer, sizeof(buffer), fmt, result);
+	if (len < 0 || len >= sizeof(buffer))
+		return -1;
+
+	return write_file(path, buffer, len);
+}
+
 void *find_auxv_entry(int type, char *auxv)
 {
 	ElfW(auxv_t) *p;
-- 
2.38.1

[PATCH v1 7/7] selftests/powerpc: Add automatically allocating read_file

[Benjamin Gray]

A couple of tests roll their own auto-allocating file read logic.

Add a generic implementation and convert them to use it.
---
 .../testing/selftests/powerpc/include/utils.h |  1 +
 .../selftests/powerpc/nx-gzip/gzfht_test.c    | 37 +--------
 .../selftests/powerpc/syscalls/Makefile       |  2 +-
 .../selftests/powerpc/syscalls/rtas_filter.c  | 80 +++----------------
 tools/testing/selftests/powerpc/utils.c       | 63 +++++++++++++++
 5 files changed, 75 insertions(+), 108 deletions(-)

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index 044b0236df38..95f3a24a4569 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -40,6 +40,7 @@ int parse_ulong(const char *buffer, size_t count, unsigned long *result, int bas
 
 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);
diff --git a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
index a6a226e1b8ba..4de079923ccb 100644
--- a/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
+++ b/tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c
@@ -143,41 +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)
-{
-	int err;
-	struct stat statbuf;
-	char *p;
-	size_t num_bytes;
-
-	if (stat(fname, &statbuf)) {
-		perror(fname);
-		return -1;
-	}
-
-	assert(NULL != (p = (char *) malloc(statbuf.st_size)));
-
-	if ((err = read_file(fname, p, statbuf.st_size, &num_bytes))) {
-		fprintf(stderr, "Failed to read file: %s\n", strerror(err));
-		goto fail;
-	}
-
-	if (num_bytes != statbuf.st_size) {
-		fprintf(stderr, "Actual bytes != expected bytes\n");
-		err = -1;
-		goto fail;
-	}
-
-	*buf = p;
-	*bufsize = num_bytes;
-	return 0;
-
-fail:
-	free(p);
-	return err;
-}
-
 /*
  * Z_SYNC_FLUSH as described in zlib.h.
  * Returns number of appended bytes
@@ -244,7 +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);
 
diff --git a/tools/testing/selftests/powerpc/syscalls/Makefile b/tools/testing/selftests/powerpc/syscalls/Makefile
index b63f8459c704..54ff5cfffc63 100644
--- a/tools/testing/selftests/powerpc/syscalls/Makefile
+++ b/tools/testing/selftests/powerpc/syscalls/Makefile
@@ -6,4 +6,4 @@ CFLAGS += -I../../../../../usr/include
 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..05f25f12556f 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 +85,13 @@ int rtas_token(const char *call_name)
 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");
+	if ((err = read_file_alloc("/proc/ppc64/rtas/rmo_buffer", &buf, NULL))) {
+		fprintf(stderr, "Error reading rmo_buffer: %s\n", strerror(err));
 		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/utils.c b/tools/testing/selftests/powerpc/utils.c
index 32a96c8967ac..b8402d0de451 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -59,6 +59,69 @@ int read_file(const char *path, char *buf, size_t count, size_t *len)
 	return err;
 }
 
+int read_file_alloc(const char *path, char **buf, size_t *len)
+{
+	ssize_t rc;
+	char *buffer;
+	size_t read_offset;
+	size_t length;
+	int fd;
+	int err;
+
+
+	if ((fd = open(path, O_RDONLY)) < 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.
+	 */
+	length = 4096;
+	buffer = malloc(length);
+	read_offset = 0;
+
+	if (!buffer) {
+		err = errno;
+		goto out;
+	}
+
+	while (1) {
+		if ((rc = read(fd, buffer + read_offset, length - read_offset)) < 0) {
+			err = errno;
+			goto out;
+		}
+
+		if (rc == 0)
+			break;
+
+		read_offset += rc;
+
+		if (read_offset > length / 2) {
+			char *next_buffer;
+
+			length *= 2;
+			next_buffer = realloc(buffer, length);
+			if (!next_buffer) {
+				err = errno;
+				free(buffer);
+				goto out;
+			}
+			buffer = next_buffer;
+		}
+	}
+
+	*buf = buffer;
+	if (len)
+		*len = read_offset;
+
+	err = 0;
+
+out:
+	close(fd);
+	return err;
+}
+
 int write_file(const char *path, const char *buf, size_t count)
 {
 	int fd;
-- 
2.38.1

Re: [PATCH v1 0/7] Expand selftest utils

[Benjamin Gray]

And yes, I did realise last night I forgot signed-off-by's and a couple
of messages have extra squashed commit messages :(