selftests/powerpc: Parse long/unsigned long value safely

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).

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230203003947.38033-4-bgray@linux.ibm.com

1 files changed, 7 insertions, 0 deletions

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index de5e3790f397..7c1fa385824c 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -33,6 +33,13 @@ void *get_auxv_entry(int type);
 
 int pick_online_cpu(void);
 
+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_debugfs_file(const char *debugfs_file, char *buf, size_t count);