hw/sd/sdbus: Provide buffer size to sdbus_do_command()

We provide to sdbus_do_command() a pointer to a buffer to be
filled with a varying number of bytes. By not providing the
buffer size, the callee can not check the buffer is big enough.
Pass the buffer size as argument to follow good practices.

sdbus_do_command() doesn't return any error, only the size filled
in the buffer. Convert the returned type to unsigned and remove
the few unreachable lines in callers.

This allow to check for possible overflow in sd_do_command().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250804133406.17456-4-philmd@linaro.org>

1 files changed, 21 insertions, 2 deletions

diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index d6bad17513..55d363f58f 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -96,7 +96,17 @@ struct SDCardClass {
     DeviceClass parent_class;
     /*< public >*/
 
-    int (*do_command)(SDState *sd, SDRequest *req, uint8_t *response);
+    /**
+     * Process a SD command request.
+     * @sd: card
+     * @req: command request
+     * @resp: buffer to receive the command response
+     * @respsz: size of @resp buffer
+     *
+     * Return: size of the response
+     */
+    size_t (*do_command)(SDState *sd, SDRequest *req,
+                         uint8_t *resp, size_t respsz);
     /**
      * Write a byte to a SD card.
      * @sd: card
@@ -153,7 +163,16 @@ struct SDBusClass {
 void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts);
 uint8_t sdbus_get_dat_lines(SDBus *sdbus);
 bool sdbus_get_cmd_line(SDBus *sdbus);
-int sdbus_do_command(SDBus *sd, SDRequest *req, uint8_t *response);
+/**
+ * sdbus_do_command: Process a SD command request
+ * @sd: card
+ * @req: command request
+ * @resp: buffer to receive the command response
+ * @respsz: size of @resp buffer
+ *
+ * Return: size of the response
+ */
+size_t sdbus_do_command(SDBus *sd, SDRequest *req, uint8_t *resp, size_t respsz);
 /**
  * Write a byte to a SD bus.
  * @sd: bus