* [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
@ 2022-03-02 14:33 ` Zheyu Ma
0 siblings, 0 replies; 8+ messages in thread
From: Zheyu Ma @ 2022-03-02 14:33 UTC (permalink / raw)
To: deller, sudipm.mukherjee, teddy.wang
Cc: linux-fbdev, dri-devel, linux-kernel, Zheyu Ma
When the sm712fb driver writes three bytes to the framebuffer, the
driver will crash:
BUG: unable to handle page fault for address: ffffc90001ffffff
RIP: 0010:smtcfb_write+0x454/0x5b0
Call Trace:
vfs_write+0x291/0xd60
? do_sys_openat2+0x27d/0x350
? __fget_light+0x54/0x340
ksys_write+0xce/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix it by removing the open-coded endianness fixup-code.
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
drivers/video/fbdev/sm712fb.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)
diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
index 0dbc6bf8268a..e355089ac7d6 100644
--- a/drivers/video/fbdev/sm712fb.c
+++ b/drivers/video/fbdev/sm712fb.c
@@ -1130,7 +1130,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
count = total_size - p;
}
- buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
+ buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
@@ -1148,24 +1148,11 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
break;
}
- for (i = c >> 2; i--;) {
- fb_writel(big_swap(*src), dst++);
+ for (i = (c + 3) >> 2; i--;) {
+ fb_writel(big_swap(*src), dst);
+ dst++;
src++;
}
- if (c & 3) {
- u8 *src8 = (u8 *)src;
- u8 __iomem *dst8 = (u8 __iomem *)dst;
-
- for (i = c & 3; i--;) {
- if (i & 1) {
- fb_writeb(*src8++, ++dst8);
- } else {
- fb_writeb(*src8++, --dst8);
- dst8 += 2;
- }
- }
- dst = (u32 __iomem *)dst8;
- }
*ppos += c;
buf += c;
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
@ 2022-03-02 14:33 ` Zheyu Ma
0 siblings, 0 replies; 8+ messages in thread
From: Zheyu Ma @ 2022-03-02 14:33 UTC (permalink / raw)
To: deller, sudipm.mukherjee, teddy.wang
Cc: linux-fbdev, Zheyu Ma, linux-kernel, dri-devel
When the sm712fb driver writes three bytes to the framebuffer, the
driver will crash:
BUG: unable to handle page fault for address: ffffc90001ffffff
RIP: 0010:smtcfb_write+0x454/0x5b0
Call Trace:
vfs_write+0x291/0xd60
? do_sys_openat2+0x27d/0x350
? __fget_light+0x54/0x340
ksys_write+0xce/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix it by removing the open-coded endianness fixup-code.
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
drivers/video/fbdev/sm712fb.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)
diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
index 0dbc6bf8268a..e355089ac7d6 100644
--- a/drivers/video/fbdev/sm712fb.c
+++ b/drivers/video/fbdev/sm712fb.c
@@ -1130,7 +1130,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
count = total_size - p;
}
- buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
+ buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
@@ -1148,24 +1148,11 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
break;
}
- for (i = c >> 2; i--;) {
- fb_writel(big_swap(*src), dst++);
+ for (i = (c + 3) >> 2; i--;) {
+ fb_writel(big_swap(*src), dst);
+ dst++;
src++;
}
- if (c & 3) {
- u8 *src8 = (u8 *)src;
- u8 __iomem *dst8 = (u8 __iomem *)dst;
-
- for (i = c & 3; i--;) {
- if (i & 1) {
- fb_writeb(*src8++, ++dst8);
- } else {
- fb_writeb(*src8++, --dst8);
- dst8 += 2;
- }
- }
- dst = (u32 __iomem *)dst8;
- }
*ppos += c;
buf += c;
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
2022-03-02 14:33 ` Zheyu Ma
@ 2022-03-02 16:48 ` Helge Deller
-1 siblings, 0 replies; 8+ messages in thread
From: Helge Deller @ 2022-03-02 16:48 UTC (permalink / raw)
To: Zheyu Ma, sudipm.mukherjee, teddy.wang
Cc: linux-fbdev, dri-devel, linux-kernel
On 3/2/22 15:33, Zheyu Ma wrote:
> When the sm712fb driver writes three bytes to the framebuffer, the
> driver will crash:
>
> BUG: unable to handle page fault for address: ffffc90001ffffff
> RIP: 0010:smtcfb_write+0x454/0x5b0
> Call Trace:
> vfs_write+0x291/0xd60
> ? do_sys_openat2+0x27d/0x350
> ? __fget_light+0x54/0x340
> ksys_write+0xce/0x190
> do_syscall_64+0x43/0x90
> entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Fix it by removing the open-coded endianness fixup-code.
>
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Thanks... it's already in the fbdev git tree and queued up for v5.18...
https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
Helge
> ---
> drivers/video/fbdev/sm712fb.c | 21 ++++-----------------
> 1 file changed, 4 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
> index 0dbc6bf8268a..e355089ac7d6 100644
> --- a/drivers/video/fbdev/sm712fb.c
> +++ b/drivers/video/fbdev/sm712fb.c
> @@ -1130,7 +1130,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
> count = total_size - p;
> }
>
> - buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
> + buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
> if (!buffer)
> return -ENOMEM;
>
> @@ -1148,24 +1148,11 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
> break;
> }
>
> - for (i = c >> 2; i--;) {
> - fb_writel(big_swap(*src), dst++);
> + for (i = (c + 3) >> 2; i--;) {
> + fb_writel(big_swap(*src), dst);
> + dst++;
> src++;
> }
> - if (c & 3) {
> - u8 *src8 = (u8 *)src;
> - u8 __iomem *dst8 = (u8 __iomem *)dst;
> -
> - for (i = c & 3; i--;) {
> - if (i & 1) {
> - fb_writeb(*src8++, ++dst8);
> - } else {
> - fb_writeb(*src8++, --dst8);
> - dst8 += 2;
> - }
> - }
> - dst = (u32 __iomem *)dst8;
> - }
>
> *ppos += c;
> buf += c;
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
@ 2022-03-02 16:48 ` Helge Deller
0 siblings, 0 replies; 8+ messages in thread
From: Helge Deller @ 2022-03-02 16:48 UTC (permalink / raw)
To: Zheyu Ma, sudipm.mukherjee, teddy.wang
Cc: linux-fbdev, linux-kernel, dri-devel
On 3/2/22 15:33, Zheyu Ma wrote:
> When the sm712fb driver writes three bytes to the framebuffer, the
> driver will crash:
>
> BUG: unable to handle page fault for address: ffffc90001ffffff
> RIP: 0010:smtcfb_write+0x454/0x5b0
> Call Trace:
> vfs_write+0x291/0xd60
> ? do_sys_openat2+0x27d/0x350
> ? __fget_light+0x54/0x340
> ksys_write+0xce/0x190
> do_syscall_64+0x43/0x90
> entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Fix it by removing the open-coded endianness fixup-code.
>
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Thanks... it's already in the fbdev git tree and queued up for v5.18...
https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
Helge
> ---
> drivers/video/fbdev/sm712fb.c | 21 ++++-----------------
> 1 file changed, 4 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c
> index 0dbc6bf8268a..e355089ac7d6 100644
> --- a/drivers/video/fbdev/sm712fb.c
> +++ b/drivers/video/fbdev/sm712fb.c
> @@ -1130,7 +1130,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
> count = total_size - p;
> }
>
> - buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
> + buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
> if (!buffer)
> return -ENOMEM;
>
> @@ -1148,24 +1148,11 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf,
> break;
> }
>
> - for (i = c >> 2; i--;) {
> - fb_writel(big_swap(*src), dst++);
> + for (i = (c + 3) >> 2; i--;) {
> + fb_writel(big_swap(*src), dst);
> + dst++;
> src++;
> }
> - if (c & 3) {
> - u8 *src8 = (u8 *)src;
> - u8 __iomem *dst8 = (u8 __iomem *)dst;
> -
> - for (i = c & 3; i--;) {
> - if (i & 1) {
> - fb_writeb(*src8++, ++dst8);
> - } else {
> - fb_writeb(*src8++, --dst8);
> - dst8 += 2;
> - }
> - }
> - dst = (u32 __iomem *)dst8;
> - }
>
> *ppos += c;
> buf += c;
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
2022-03-02 16:48 ` Helge Deller
@ 2022-03-03 1:34 ` Zheyu Ma
-1 siblings, 0 replies; 8+ messages in thread
From: Zheyu Ma @ 2022-03-03 1:34 UTC (permalink / raw)
To: Helge Deller
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, dri-devel,
Linux Kernel Mailing List
Hi,
On Thu, Mar 3, 2022 at 12:49 AM Helge Deller <deller@gmx.de> wrote:
>
> On 3/2/22 15:33, Zheyu Ma wrote:
> > When the sm712fb driver writes three bytes to the framebuffer, the
> > driver will crash:
> >
> > BUG: unable to handle page fault for address: ffffc90001ffffff
> > RIP: 0010:smtcfb_write+0x454/0x5b0
> > Call Trace:
> > vfs_write+0x291/0xd60
> > ? do_sys_openat2+0x27d/0x350
> > ? __fget_light+0x54/0x340
> > ksys_write+0xce/0x190
> > do_syscall_64+0x43/0x90
> > entry_SYSCALL_64_after_hwframe+0x44/0xae
> >
> > Fix it by removing the open-coded endianness fixup-code.
> >
> > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
>
> Thanks... it's already in the fbdev git tree and queued up for v5.18...
> https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
This patch fixes the crash in smtcfb_read(), but there is a similar
bug in smtcfb_write(), and I mocked up your patch a wrote a new patch
for it.
So we should fix two bugs with two patches.
Regards,
Zheyu Ma
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
@ 2022-03-03 1:34 ` Zheyu Ma
0 siblings, 0 replies; 8+ messages in thread
From: Zheyu Ma @ 2022-03-03 1:34 UTC (permalink / raw)
To: Helge Deller
Cc: Linux Kernel Mailing List, linux-fbdev, sudipm.mukherjee,
dri-devel, teddy.wang
Hi,
On Thu, Mar 3, 2022 at 12:49 AM Helge Deller <deller@gmx.de> wrote:
>
> On 3/2/22 15:33, Zheyu Ma wrote:
> > When the sm712fb driver writes three bytes to the framebuffer, the
> > driver will crash:
> >
> > BUG: unable to handle page fault for address: ffffc90001ffffff
> > RIP: 0010:smtcfb_write+0x454/0x5b0
> > Call Trace:
> > vfs_write+0x291/0xd60
> > ? do_sys_openat2+0x27d/0x350
> > ? __fget_light+0x54/0x340
> > ksys_write+0xce/0x190
> > do_syscall_64+0x43/0x90
> > entry_SYSCALL_64_after_hwframe+0x44/0xae
> >
> > Fix it by removing the open-coded endianness fixup-code.
> >
> > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
>
> Thanks... it's already in the fbdev git tree and queued up for v5.18...
> https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
This patch fixes the crash in smtcfb_read(), but there is a similar
bug in smtcfb_write(), and I mocked up your patch a wrote a new patch
for it.
So we should fix two bugs with two patches.
Regards,
Zheyu Ma
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
2022-03-03 1:34 ` Zheyu Ma
@ 2022-03-03 10:16 ` Helge Deller
-1 siblings, 0 replies; 8+ messages in thread
From: Helge Deller @ 2022-03-03 10:16 UTC (permalink / raw)
To: Zheyu Ma
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, dri-devel,
Linux Kernel Mailing List
On 3/3/22 02:34, Zheyu Ma wrote:
> Hi,
>
> On Thu, Mar 3, 2022 at 12:49 AM Helge Deller <deller@gmx.de> wrote:
>>
>> On 3/2/22 15:33, Zheyu Ma wrote:
>>> When the sm712fb driver writes three bytes to the framebuffer, the
>>> driver will crash:
>>>
>>> BUG: unable to handle page fault for address: ffffc90001ffffff
>>> RIP: 0010:smtcfb_write+0x454/0x5b0
>>> Call Trace:
>>> vfs_write+0x291/0xd60
>>> ? do_sys_openat2+0x27d/0x350
>>> ? __fget_light+0x54/0x340
>>> ksys_write+0xce/0x190
>>> do_syscall_64+0x43/0x90
>>> entry_SYSCALL_64_after_hwframe+0x44/0xae
>>>
>>> Fix it by removing the open-coded endianness fixup-code.
>>>
>>> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
>>
>> Thanks... it's already in the fbdev git tree and queued up for v5.18...
>> https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
>
> This patch fixes the crash in smtcfb_read(), but there is a similar
> bug in smtcfb_write(), and I mocked up your patch a wrote a new patch
> for it.
> So we should fix two bugs with two patches.
Right, I missed the read() code.
I applied your patch now to the fbdev for-next git tree.
Thanks!
Helge
>
> Regards,
> Zheyu Ma
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write()
@ 2022-03-03 10:16 ` Helge Deller
0 siblings, 0 replies; 8+ messages in thread
From: Helge Deller @ 2022-03-03 10:16 UTC (permalink / raw)
To: Zheyu Ma
Cc: Linux Kernel Mailing List, linux-fbdev, sudipm.mukherjee,
dri-devel, teddy.wang
On 3/3/22 02:34, Zheyu Ma wrote:
> Hi,
>
> On Thu, Mar 3, 2022 at 12:49 AM Helge Deller <deller@gmx.de> wrote:
>>
>> On 3/2/22 15:33, Zheyu Ma wrote:
>>> When the sm712fb driver writes three bytes to the framebuffer, the
>>> driver will crash:
>>>
>>> BUG: unable to handle page fault for address: ffffc90001ffffff
>>> RIP: 0010:smtcfb_write+0x454/0x5b0
>>> Call Trace:
>>> vfs_write+0x291/0xd60
>>> ? do_sys_openat2+0x27d/0x350
>>> ? __fget_light+0x54/0x340
>>> ksys_write+0xce/0x190
>>> do_syscall_64+0x43/0x90
>>> entry_SYSCALL_64_after_hwframe+0x44/0xae
>>>
>>> Fix it by removing the open-coded endianness fixup-code.
>>>
>>> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
>>
>> Thanks... it's already in the fbdev git tree and queued up for v5.18...
>> https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit/?h=for-next&id=bd771cf5c4254511cc4abb88f3dab3bd58bdf8e8
>
> This patch fixes the crash in smtcfb_read(), but there is a similar
> bug in smtcfb_write(), and I mocked up your patch a wrote a new patch
> for it.
> So we should fix two bugs with two patches.
Right, I missed the read() code.
I applied your patch now to the fbdev for-next git tree.
Thanks!
Helge
>
> Regards,
> Zheyu Ma
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-03-03 10:18 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-02 14:33 [PATCH] video: fbdev: sm712fb: Fix crash in smtcfb_write() Zheyu Ma
2022-03-02 14:33 ` Zheyu Ma
2022-03-02 16:48 ` Helge Deller
2022-03-02 16:48 ` Helge Deller
2022-03-03 1:34 ` Zheyu Ma
2022-03-03 1:34 ` Zheyu Ma
2022-03-03 10:16 ` Helge Deller
2022-03-03 10:16 ` Helge Deller
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.