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.
Signed-off-by: Benjamin Gray <bg...@linux.ibm.com>
---
.../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), ¤t, 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 8593e67ce779..c82539fd44f1 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
