[PATCH] ASoC: SOF: Fix function topology name check in profile info output

[Chen-Yu Tsai <wenst@chromium.org>]

The function topology feature, and the plat_data->machine field that
specifies this feature, is ACPI specific. The check didn't take this
into consideration, which causes a NULL pointer dereference splat on
OF platforms:

    BUG: KASAN: null-ptr-deref in sof_create_ipc_file_profile (sound/soc/sof/fw-file-profile.c:291 sound/soc/sof/fw-file-profile.c:340) snd_sof
    Read of size 8 at addr 00000000000000c8 by task (udev-worker)/247

    CPU: 7 UID: 0 PID: 247 Comm: (udev-worker) Not tainted 6.18.0-rc2-next-20251023-03804-g93b191bc0c26-dirty #747 PREEMPT  ba3c303a11d89508de4087cb5b4f8985b6d87b6f
    Hardware name: Google Ciri sku2 board (DT)
    Call trace:
    [KASAN stuff]
    sof_create_ipc_file_profile (sound/soc/sof/fw-file-profile.c:291 sound/soc/sof/fw-file-profile.c:340) snd_sof
    snd_sof_device_probe (sound/soc/sof/core.c:304 sound/soc/sof/core.c:388 sound/soc/sof/core.c:460 sound/soc/sof/core.c:719) snd_sof
    sof_of_probe (sound/soc/sof/sof-of-dev.c:84) snd_sof_of
     platform_probe (drivers/base/platform.c:1405)
    [...]

Check that the ACPI specific field is actually valid before accessing
it.

This was seen on a MediaTek based Chromebook.

Fixes: 2b92b98cc476 ("ASoC: SOF: Don't print the monolithic topology name if function topology may be used")
Cc: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 sound/soc/sof/fw-file-profile.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sof/fw-file-profile.c b/sound/soc/sof/fw-file-profile.c
index 4a2afc04f338..76bde2e0be1d 100644
--- a/sound/soc/sof/fw-file-profile.c
+++ b/sound/soc/sof/fw-file-profile.c
@@ -288,7 +288,8 @@ static void sof_print_profile_info(struct snd_sof_dev *sdev,
 	if (profile->fw_lib_path)
 		dev_info(dev, " Firmware lib path: %s\n", profile->fw_lib_path);
 
-	if (plat_data->machine->get_function_tplg_files && !plat_data->disable_function_topology)
+	if (plat_data->machine && plat_data->machine->get_function_tplg_files &&
+	    !plat_data->disable_function_topology)
 		dev_info(dev, " Topology file:     function topologies\n");
 	else
 		dev_info(dev, " Topology file:     %s/%s\n",
-- 
2.51.1.814.gb8fa24458f-goog