linux-kernel - [PATCH] drm/amdgpu: Avoid printing of stack contents on firmware load error

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Message-ID: <nycvar.YFH.7.76.2106241135440.18969@cbobk.fhfr.pm>
Date:   Thu, 24 Jun 2021 11:37:18 +0200 (CEST)
From:   Jiri Kosina <jikos@...nel.org>
To:     Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        David Airlie <airlied@...ux.ie>
cc:     amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, Vojtech Pavlik <vojtech@....cz>
Subject: [PATCH] drm/amdgpu: Avoid printing of stack contents on firmware
 load error

From: Jiri Kosina <jkosina@...e.cz>

In case when psp_init_asd_microcode() fails to load ASD microcode file, 
psp_v12_0_init_microcode() tries to print the firmware filename that 
failed to load before bailing out.

This is wrong because:

- the firmware filename it would want it print is an incorrect one as
  psp_init_asd_microcode() and psp_v12_0_init_microcode() are loading
  different filenames
- it tries to print fw_name, but that's not yet been initialized by that
  time, so it prints random stack contents, e.g.

    amdgpu 0000:04:00.0: Direct firmware load for amdgpu/renoir_asd.bin failed with error -2
    amdgpu 0000:04:00.0: amdgpu: fail to initialize asd microcode
    amdgpu 0000:04:00.0: amdgpu: psp v12.0: Failed to load firmware "\xfeTO\x8e\xff\xff"

Fix that by bailing out immediately, instead of priting the bogus error 
message.

Reported-by: Vojtech Pavlik <vojtech@....cz>
Signed-off-by: Jiri Kosina <jkosina@...e.cz>
---
 drivers/gpu/drm/amd/amdgpu/psp_v12_0.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c b/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
index c4828bd3264b..5b21e22ad4b9 100644
--- a/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
@@ -67,7 +67,7 @@ static int psp_v12_0_init_microcode(struct psp_context *psp)
 
 	err = psp_init_asd_microcode(psp, chip_name);
 	if (err)
-		goto out;
+		return err;
 
 	snprintf(fw_name, sizeof(fw_name), "amdgpu/%s_ta.bin", chip_name);
 	err = request_firmware(&adev->psp.ta_fw, fw_name, adev->dev);
-- 
2.12.3


-- 
Jiri Kosina
SUSE Labs