From: Arnd Bergmann <arnd@kernel.org>
To: "Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"David Airlie" <airlied@linux.ie>,
"Daniel Vetter" <daniel@ffwll.ch>
Cc: Arnd Bergmann <arnd@arndb.de>, Huang Rui <ray.huang@amd.com>,
Jinzhou Su <Jinzhou.Su@amd.com>,
amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] amdgpu: fix gcc -Wrestrict warning
Date: Tue, 23 Mar 2021 14:04:20 +0100 [thread overview]
Message-ID: <20210323130430.2250052-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
gcc warns about an sprintf() that uses the same buffer as source
and destination, which is undefined behavior in C99:
drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c: In function 'amdgpu_securedisplay_debugfs_write':
drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c:141:6: error: 'sprintf' argument 3 overlaps destination object 'i2c_output' [-Werror=restrict]
141 | sprintf(i2c_output, "%s 0x%X", i2c_output,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
142 | securedisplay_cmd->securedisplay_out_message.send_roi_crc.i2c_buf[i]);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c:97:7: note: destination object referenced by 'restrict'-qualified argument 1 was declared here
97 | char i2c_output[256];
| ^~~~~~~~~~
Rewrite it to remember the current offset into the buffer instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c
index 834440ab9ff7..69d7f6bff5d4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c
@@ -136,9 +136,10 @@ static ssize_t amdgpu_securedisplay_debugfs_write(struct file *f, const char __u
ret = psp_securedisplay_invoke(psp, TA_SECUREDISPLAY_COMMAND__SEND_ROI_CRC);
if (!ret) {
if (securedisplay_cmd->status == TA_SECUREDISPLAY_STATUS__SUCCESS) {
+ int pos = 0;
memset(i2c_output, 0, sizeof(i2c_output));
for (i = 0; i < TA_SECUREDISPLAY_I2C_BUFFER_SIZE; i++)
- sprintf(i2c_output, "%s 0x%X", i2c_output,
+ pos += sprintf(i2c_output + pos, " 0x%X",
securedisplay_cmd->securedisplay_out_message.send_roi_crc.i2c_buf[i]);
dev_info(adev->dev, "SECUREDISPLAY: I2C buffer out put is :%s\n", i2c_output);
} else {
--
2.29.2
next reply other threads:[~2021-03-23 13:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-23 13:04 Arnd Bergmann [this message]
2021-03-23 15:33 ` [PATCH] amdgpu: fix gcc -Wrestrict warning Alex Deucher
2021-03-23 15:57 ` Rasmus Villemoes
2021-03-24 13:33 ` Arnd Bergmann
2021-03-24 14:14 ` Rasmus Villemoes
2021-03-24 14:31 ` Joe Perches
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