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References: <20220225164231.904173-1-broonie@kernel.org>
In-Reply-To: <20220225164231.904173-1-broonie@kernel.org>
From:   Hsin-Yi Wang <hsinyi@chromium.org>
Date:   Mon, 28 Feb 2022 14:44:05 +0800
Message-ID: <CAJMQK-jGCX6Zp0gkfgqeA6=0zuWiSbWbytUixH3VFiwX9wtLNQ@mail.gmail.com>
Subject: Re: linux-next: build failure after merge of the drm tree
To:     broonie@kernel.org
Cc:     Dave Airlie <airlied@linux.ie>,
        DRI <dri-devel@lists.freedesktop.org>,
        Allen Chen <allen.chen@ite.com.tw>,
        Hermes Wu <Hermes.Wu@ite.com.tw>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Robert Foss <robert.foss@linaro.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Next Mailing List <linux-next@vger.kernel.org>
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On Sat, Feb 26, 2022 at 12:43 AM <broonie@kernel.org> wrote:
>
> Hi all,
>
> After merging the drm tree, today's linux-next build (x86 allmodconfig)
> failed like this:
>
> lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x10b: call to do_strncpy_from_user() with UACCESS enabled
> lib/strnlen_user.o: warning: objtool: strnlen_user()+0xbb: call to do_strnlen_user() with UACCESS enabled
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c: In function 'receive_timing_debugfs_show':
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3077:23: error: array subscript 4096 is outside array bounds of 'u8[200]' {aka 'unsigned char[200]'} [-Werror=array-bounds]
>  3077 |  u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
>       |                       ^~~
> /tmp/next/build/drivers/gpu/drm/bridge/ite-it6505.c:3076:5: note: while referencing 'read_buf'
>  3076 |  u8 read_buf[READ_BUFFER_SIZE];
>       |     ^~~~~~~~
> cc1: all warnings being treated as errors
>
> Caused by commit
>
>   b5c84a9edcd418 ("drm/bridge: add it6505 driver")
>
> I have used the drm tree from yesterday instead.

hi all,

The following fix should be able to address the errors. Should it be
squashed into b5c84a9edcd418 ("drm/bridge: add it6505 driver")?

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c
b/drivers/gpu/drm/bridge/ite-it6505.c
index fb16a176822d81..f2f101220ade94 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -289,7 +289,7 @@
 #define WORD_LENGTH_20BIT 2
 #define WORD_LENGTH_24BIT 3
 #define DEBUGFS_DIR_NAME "it6505-debugfs"
-#define READ_BUFFER_SIZE 200
+#define READ_BUFFER_SIZE 400

 /* Vendor option */
 #define HDCP_DESIRED 1
@@ -3074,7 +3074,7 @@ static ssize_t
receive_timing_debugfs_show(struct file *file, char __user *buf,
        struct it6505 *it6505 = file->private_data;
        struct drm_display_mode *vid = &it6505->video_info;
        u8 read_buf[READ_BUFFER_SIZE];
-       u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
+       u8 *str = read_buf, *end = read_buf + READ_BUFFER_SIZE;
        ssize_t ret, count;

        if (!it6505)