[PATCH v3 3/5] crypto: ccp: Fix DBC sample application error handling

Mario Limonciello
2023-08-29T17:34:47Z

The sample application was taking values from ioctl() and treating
those as the error codes to present to a user.

This is incorrect when ret is non-zero, the error is stored to `errno`.
Use this value instead.

Fixes: f40d42f116cf ("crypto: ccp - Add a sample python script for Dynamic Boost Control")
Fixes: febe3ed3222f ("crypto: ccp - Add a sample library for ioctl use")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
tools/crypto/ccp/dbc.c | 16 ++++++++--------
tools/crypto/ccp/dbc.py | 3 +--
2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/tools/crypto/ccp/dbc.c b/tools/crypto/ccp/dbc.c
index 37e813175642..7774e981849f 100644
--- a/tools/crypto/ccp/dbc.c
+++ b/tools/crypto/ccp/dbc.c
@@ -8,6 +8,7 @@
*/

#include <assert.h>
+#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>

@@ -22,16 +23,14 @@ int get_nonce(int fd, void *nonce_out, void *signature)
struct dbc_user_nonce tmp = {
.auth_needed = !!signature,
};
- int ret;

assert(nonce_out);

if (signature)
memcpy(tmp.signature, signature, sizeof(tmp.signature));

- ret = ioctl(fd, DBCIOCNONCE, &tmp);
- if (ret)
- return ret;
+ if (ioctl(fd, DBCIOCNONCE, &tmp))
+ return errno;
memcpy(nonce_out, tmp.nonce, sizeof(tmp.nonce));

return 0;
@@ -47,7 +46,9 @@ int set_uid(int fd, __u8 *uid, __u8 *signature)
memcpy(tmp.uid, uid, sizeof(tmp.uid));
memcpy(tmp.signature, signature, sizeof(tmp.signature));

- return ioctl(fd, DBCIOCUID, &tmp);
+ if (ioctl(fd, DBCIOCUID, &tmp))
+ return errno;
+ return 0;
}

int process_param(int fd, int msg_index, __u8 *signature, int *data)
@@ -63,9 +64,8 @@ int process_param(int fd, int msg_index, __u8 *signature, int *data)

memcpy(tmp.signature, signature, sizeof(tmp.signature));

- ret = ioctl(fd, DBCIOCPARAM, &tmp);
- if (ret)
- return ret;
+ if (ioctl(fd, DBCIOCPARAM, &tmp))
+ return errno;

*data = tmp.param;
return 0;
diff --git a/tools/crypto/ccp/dbc.py b/tools/crypto/ccp/dbc.py
index 3f6a825ffc9e..3956efe7537a 100644
--- a/tools/crypto/ccp/dbc.py
+++ b/tools/crypto/ccp/dbc.py
@@ -27,8 +27,7 @@ lib = ctypes.CDLL("./dbc_library.so", mode=ctypes.RTLD_GLOBAL)

def handle_error(code):
- val = code * -1
- raise OSError(val, os.strerror(val))
+ raise OSError(code, os.strerror(code))

def get_nonce(device, signature):
--
2.34.1