Hello all,
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
Typing Greg's email correct this time. My apologies.
Eugene
-----Original Message-----
From: Eugene Bordenkircher
Sent: Friday, October 29, 2021 10:14 AM
To: linux-usb@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
Cc: leoyang.li@nxp.com; balbi@kernel.org; gregkh@linuxfoundataion.org
Subject: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
Hello all,
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
On Fri, Oct 29, 2021 at 4:27 PM Eugene Bordenkircher
[off-list ref] wrote:
Typing Greg's email correct this time. My apologies.
Eugene
-----Original Message-----
From: Eugene Bordenkircher
Sent: Friday, October 29, 2021 10:14 AM
To: linux-usb@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
Cc: leoyang.li@nxp.com; balbi@kernel.org; gregkh@linuxfoundataion.org
Subject: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
Hello all,
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I agree with you that this looks problematic. This is probably
introduced by f79a60b8785 "usb: fsl_udc_core: prime status stage once
data stage has primed" that it didn't consider that the status_req has
been re-used for the DATA phase.
I think the proper fix should be having a separate request allocated
for the data phase after the above change.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
Hello all,
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Jocke
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
Hello all,
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Jocke
Curious, did my patches help? Good to known once we upgrade as well.
Jocke
Hi, this is your Linux kernel regression tracker speaking.
This looks stalled, as afaics nothing to get this regression fixed
happened since below mail. How can we things rolling again?
Eugene, were you able to look into the patch from Joakim?
Or did I miss anything and some progress to fix this was made elsewhere?
Please let me know if that's the case.
Ciao, Thorsten (carrying his Linux kernel regression tracker hat)
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
on my table. I can only look briefly into most of them. Unfortunately
therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply. That's in everyone's interest, as
what I wrote above might be misleading to everyone reading this; any
suggestion I gave they thus might sent someone reading this down the
wrong rabbit hole, which none of us wants.
P.P.S.: Feel free to ignore the following lines, they are only meant for
regzbot, my Linux kernel regression tracking bot
(https://linux-regtracking.leemhuis.info/regzbot/):
#regzbot poke
On 02.11.21 22:15, Joakim Tjernlund wrote:
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Jocke
Curious, did my patches help? Good to known once we upgrade as well.
Jocke
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Eugene
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Jocke
Curious, did my patches help? Good to known once we upgrade as well.
Jocke
There's good news and bad news.
The good news is that this appears to stop the driver from entering an infinite loop, which prevents the Linux system from locking up and never recovering. So I'm willing to say we've made the behavior better.
The bad news is that once we get past this point, there is new bad behavior. What is on top of this driver in our system is the RNDIS gadget driver communicating to a Laptop running Win10 -1809. Everything appears to work fine with the Linux system until there is a USB disconnect. After the disconnect, the Linux side appears to continue on just fine, but the Windows side doesn't seem to recognize the disconnect, which causes the USB driver on that side to hang forever and eventually blue screen the box. This doesn't happen on all machines, just a select few. I think we can isolate the behavior to a specific antivirus/security software driver that is inserting itself into the USB stack and filtering the disconnect message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call this patchset good, at least for our test setup. My only hesitation is if the Linux side is sending a set of responses that are confusing the Windows side (specifically this antivirus) or not. I'd be content calling that a separate defect though and letting this one close up with that patchset.
Eugene
Hi, this is your Linux kernel regression tracker speaking.
Top-posting for once, to make this easy to process for everyone:
Li Yang and Felipe Balbi: how to move on with this? It's quite an old
regression, but nevertheless it is one and thus should be fixed. Part of
my position is to make that happen and thus remind developers and
maintainers about this until the regression is resolved.
Ciao, Thorsten
On 16.11.21 20:11, Eugene Bordenkircher wrote:
On 02.11.21 22:15, Joakim Tjernlund wrote:
quoted
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Curious, did my patches help? Good to known once we upgrade as well.
There's good news and bad news.
The good news is that this appears to stop the driver from entering
an infinite loop, which prevents the Linux system from locking up and
never recovering. So I'm willing to say we've made the behavior
better.
The bad news is that once we get past this point, there is new bad
behavior. What is on top of this driver in our system is the RNDIS
gadget driver communicating to a Laptop running Win10 -1809.
Everything appears to work fine with the Linux system until there is
a USB disconnect. After the disconnect, the Linux side appears to
continue on just fine, but the Windows side doesn't seem to recognize
the disconnect, which causes the USB driver on that side to hang
forever and eventually blue screen the box. This doesn't happen on
all machines, just a select few. I think we can isolate the
behavior to a specific antivirus/security software driver that is
inserting itself into the USB stack and filtering the disconnect
message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call
this patchset good, at least for our test setup. My only hesitation
is if the Linux side is sending a set of responses that are confusing
the Windows side (specifically this antivirus) or not. I'd be
content calling that a separate defect though and letting this one
close up with that patchset.
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
on my table. I can only look briefly into most of them. Unfortunately
therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply. That's in everyone's interest, as
what I wrote above might be misleading to everyone reading this; any
suggestion I gave they thus might sent someone reading this down the
wrong rabbit hole, which none of us wants.
BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting
this mail to get things rolling again and hence don't need to be CC on
all further activities wrt to this regression.
#regzbot title: usb: fsl_udc_core: corrupted request list leads to
unrecoverable loop
The final result of our testing is that the patch set posted seems to address all known defects in the Linux kernel. The mentioned additional problems are entirely caused by the antivirus solution on the windows box. The antivirus solution blocks the disconnect messages from reaching the RNDIS driver so it has no idea the USB device went away. There is nothing we can do to address this in the Linux kernel.
I propose we move forward with the patchset.
Eugene T. Bordenkircher
-----Original Message-----
From: Thorsten Leemhuis <redacted>
Sent: Thursday, November 25, 2021 5:59 AM
To: Eugene Bordenkircher <redacted>; Thorsten Leemhuis <redacted>; Joakim Tjernlund <redacted>; linuxppc-dev@lists.ozlabs.org; linux-usb@vger.kernel.org
Cc: leoyang.li@nxp.com; gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
Hi, this is your Linux kernel regression tracker speaking.
Top-posting for once, to make this easy to process for everyone:
Li Yang and Felipe Balbi: how to move on with this? It's quite an old regression, but nevertheless it is one and thus should be fixed. Part of my position is to make that happen and thus remind developers and maintainers about this until the regression is resolved.
Ciao, Thorsten
On 16.11.21 20:11, Eugene Bordenkircher wrote:
On 02.11.21 22:15, Joakim Tjernlund wrote:
quoted
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver (drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the request queue, but the queue has been corrupted at some point so it loops infinitely. I believe we have narrowed into the offending code, but we are in need of assistance trying to find an appropriate fix for the problem. The identified code appears to be in all versions of the Linux kernel the driver exists in.
The problem appears to be when handling a USB_REQ_GET_STATUS request. The driver gets this request and then calls the ch9getstatus() function. In this function, it starts a request by "borrowing" the per device status_req, filling it in, and then queuing it with a call to list_add_tail() to add the request to the endpoint queue. Right before it exits the function however, it's calling ep0_prime_status(), which is filling out that same status_req structure and then queuing it with another call to list_add_tail() to add the request to the endpoint queue. This adds two instances of the exact same LIST_HEAD to the endpoint queue, which breaks the list since the prev and next pointers end up pointing to the wrong things. This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
I'm not sure what the appropriate fix to this problem is, mostly due to my lack of expertise in USB and this driver stack. The code has been this way in the kernel for a very long time, which suggests that it has been working, unless USB_REQ_GET_STATUS requests are never made. This further suggests that there is something else going on that I don't understand. Deleting the call to ep0_prime_status() and the following ep0stall() call appears, on the surface, to get the device working again, but may have side effects that I'm not seeing.
I'm hopeful someone in the community can help provide some information on what I may be missing or help come up with a solution to the problem. A big thank you to anyone who would like to help out.
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Curious, did my patches help? Good to known once we upgrade as well.
There's good news and bad news.
The good news is that this appears to stop the driver from entering an
infinite loop, which prevents the Linux system from locking up and
never recovering. So I'm willing to say we've made the behavior
better.
The bad news is that once we get past this point, there is new bad
behavior. What is on top of this driver in our system is the RNDIS
gadget driver communicating to a Laptop running Win10 -1809.
Everything appears to work fine with the Linux system until there is a
USB disconnect. After the disconnect, the Linux side appears to
continue on just fine, but the Windows side doesn't seem to recognize
the disconnect, which causes the USB driver on that side to hang
forever and eventually blue screen the box. This doesn't happen on
all machines, just a select few. I think we can isolate the
behavior to a specific antivirus/security software driver that is
inserting itself into the USB stack and filtering the disconnect
message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call this
patchset good, at least for our test setup. My only hesitation is if
the Linux side is sending a set of responses that are confusing the
Windows side (specifically this antivirus) or not. I'd be content
calling that a separate defect though and letting this one close up
with that patchset.
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them. Unfortunately therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to tell me about it in a public reply. That's in everyone's interest, as what I wrote above might be misleading to everyone reading this; any suggestion I gave they thus might sent someone reading this down the wrong rabbit hole, which none of us wants.
BTW, I have no personal interest in this issue, which is tracked using regzbot, my Linux kernel regression tracking bot (https://urldefense.com/v3/__https://linux-regtracking.leemhuis.info/regzbot/__;!!O7uE89YCNVw!aHa5_mLMnBeDjINlAtV19tBHm-He9jbusXucMA5h7oonHvNFwYpOHAaaqqewPOuGK9HAzJUz$ ). I'm only posting this mail to get things rolling again and hence don't need to be CC on all further activities wrt to this regression.
#regzbot title: usb: fsl_udc_core: corrupted request list leads to unrecoverable loop
-----Original Message-----
From: Eugene Bordenkircher <redacted>
Sent: Monday, November 29, 2021 11:25 AM
To: Thorsten Leemhuis <redacted>; jocke@infinera.com
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: Leo Li <redacted>; gregkh@linuxfoundation.org;
balbi@kernel.org
Subject: RE: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
The final result of our testing is that the patch set posted seems to address all
known defects in the Linux kernel. The mentioned additional problems are
entirely caused by the antivirus solution on the windows box. The antivirus
solution blocks the disconnect messages from reaching the RNDIS driver so it
has no idea the USB device went away. There is nothing we can do to
address this in the Linux kernel.
Thanks for the confirmation.
I propose we move forward with the patchset.
I think that we should proceed to merge the patchset but it seems to need some cleanup for coding style issues and better description before submitted formally.
Eugene T. Bordenkircher
-----Original Message-----
From: Thorsten Leemhuis <redacted>
Sent: Thursday, November 25, 2021 5:59 AM
To: Eugene Bordenkircher <redacted>; Thorsten
Leemhuis [off-list ref]; Joakim Tjernlund
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: leoyang.li@nxp.com; gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
Hi, this is your Linux kernel regression tracker speaking.
Top-posting for once, to make this easy to process for everyone:
Li Yang and Felipe Balbi: how to move on with this? It's quite an old
regression, but nevertheless it is one and thus should be fixed. Part of my
position is to make that happen and thus remind developers and maintainers
about this until the regression is resolved.
Ciao, Thorsten
On 16.11.21 20:11, Eugene Bordenkircher wrote:
quoted
On 02.11.21 22:15, Joakim Tjernlund wrote:
quoted
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver
(drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating over the
request queue, but the queue has been corrupted at some point so it loops
infinitely. I believe we have narrowed into the offending code, but we are in
need of assistance trying to find an appropriate fix for the problem. The
identified code appears to be in all versions of the Linux kernel the driver
exists in.
quoted
quoted
quoted
quoted
The problem appears to be when handling a USB_REQ_GET_STATUS
request. The driver gets this request and then calls the ch9getstatus()
function. In this function, it starts a request by "borrowing" the per device
status_req, filling it in, and then queuing it with a call to list_add_tail() to add
the request to the endpoint queue. Right before it exits the function
however, it's calling ep0_prime_status(), which is filling out that same
status_req structure and then queuing it with another call to list_add_tail() to
add the request to the endpoint queue. This adds two instances of the exact
same LIST_HEAD to the endpoint queue, which breaks the list since the prev
and next pointers end up pointing to the wrong things. This ends up causing
a hard loop the next time nuke() gets called, which happens on the next
setup IRQ.
quoted
quoted
quoted
quoted
I'm not sure what the appropriate fix to this problem is, mostly due to
my lack of expertise in USB and this driver stack. The code has been this way
in the kernel for a very long time, which suggests that it has been working,
unless USB_REQ_GET_STATUS requests are never made. This further
suggests that there is something else going on that I don't understand.
Deleting the call to ep0_prime_status() and the following ep0stall() call
appears, on the surface, to get the device working again, but may have side
effects that I'm not seeing.
quoted
quoted
quoted
quoted
I'm hopeful someone in the community can help provide some
information on what I may be missing or help come up with a solution to the
problem. A big thank you to anyone who would like to help out.
quoted
quoted
quoted
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Curious, did my patches help? Good to known once we upgrade as well.
There's good news and bad news.
The good news is that this appears to stop the driver from entering an
infinite loop, which prevents the Linux system from locking up and
never recovering. So I'm willing to say we've made the behavior
better.
The bad news is that once we get past this point, there is new bad
behavior. What is on top of this driver in our system is the RNDIS
gadget driver communicating to a Laptop running Win10 -1809.
Everything appears to work fine with the Linux system until there is a
USB disconnect. After the disconnect, the Linux side appears to
continue on just fine, but the Windows side doesn't seem to recognize
the disconnect, which causes the USB driver on that side to hang
forever and eventually blue screen the box. This doesn't happen on
all machines, just a select few. I think we can isolate the
behavior to a specific antivirus/security software driver that is
inserting itself into the USB stack and filtering the disconnect
message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call this
patchset good, at least for our test setup. My only hesitation is if
the Linux side is sending a set of responses that are confusing the
Windows side (specifically this antivirus) or not. I'd be content
calling that a separate defect though and letting this one close up
with that patchset.
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports on my
table. I can only look briefly into most of them. Unfortunately therefore I
sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to tell me
about it in a public reply. That's in everyone's interest, as what I wrote above
might be misleading to everyone reading this; any suggestion I gave they
thus might sent someone reading this down the wrong rabbit hole, which
none of us wants.
BTW, I have no personal interest in this issue, which is tracked using regzbot,
my Linux kernel regression tracking bot
(https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld
efense.com%2Fv3%2F__https%3A%2F%2Flinux-
regtracking.leemhuis.info%2Fregzbot%2F__%3B!!O7uE89YCNVw!aHa5_mLM
nBeDjINlAtV19tBHm-
He9jbusXucMA5h7oonHvNFwYpOHAaaqqewPOuGK9HAzJUz%24&data
=04%7C01%7Cleoyang.li%40nxp.com%7C859ce1560a7344729cea08d9b35d2e
67%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6377380350721308
84%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ONQZyAKXNgok
6LgYvnaAL7LVY%2B5Wl7pXglZDqWUJZMc%3D&reserved=0 ). I'm only
posting this mail to get things rolling again and hence don't need to be CC on
all further activities wrt to this regression.
#regzbot title: usb: fsl_udc_core: corrupted request list leads to
unrecoverable loop
Agreed,
We are happy pick up the torch on this, but I'd like to try and hear from Joakim first before we do. The patch set is his, so I'd like to give him the opportunity. I think he's the only one that can add a truly proper description as well because he mentioned that this includes a "few more fixes" than just the one we ran into. I'd rather hear from him than try to reverse engineer what was being addressed.
Joakim, if you are still watching the thread, would you like to take a stab at it? If I don't hear from you in a couple days, we'll pick up the torch and do what we can.
Eugene T. Bordenkircher
-----Original Message-----
From: Leo Li <redacted>
Sent: Monday, November 29, 2021 3:37 PM
To: Eugene Bordenkircher <redacted>; Thorsten Leemhuis <redacted>; jocke@infinera.com <redacted>; linuxppc-dev@lists.ozlabs.org; linux-usb@vger.kernel.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: RE: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
[Caution - External]
-----Original Message-----
From: Eugene Bordenkircher <redacted>
Sent: Monday, November 29, 2021 11:25 AM
To: Thorsten Leemhuis <redacted>; jocke@infinera.com
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: Leo Li <redacted>; gregkh@linuxfoundation.org;
balbi@kernel.org
Subject: RE: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
The final result of our testing is that the patch set posted seems to
address all known defects in the Linux kernel. The mentioned
additional problems are entirely caused by the antivirus solution on
the windows box. The antivirus solution blocks the disconnect
messages from reaching the RNDIS driver so it has no idea the USB
device went away. There is nothing we can do to address this in the Linux kernel.
Thanks for the confirmation.
I propose we move forward with the patchset.
I think that we should proceed to merge the patchset but it seems to need some cleanup for coding style issues and better description before submitted formally.
Eugene T. Bordenkircher
-----Original Message-----
From: Thorsten Leemhuis <redacted>
Sent: Thursday, November 25, 2021 5:59 AM
To: Eugene Bordenkircher <redacted>; Thorsten
Leemhuis [off-list ref]; Joakim Tjernlund
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: leoyang.li@nxp.com; gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
Hi, this is your Linux kernel regression tracker speaking.
Top-posting for once, to make this easy to process for everyone:
Li Yang and Felipe Balbi: how to move on with this? It's quite an old
regression, but nevertheless it is one and thus should be fixed. Part
of my position is to make that happen and thus remind developers and
maintainers about this until the regression is resolved.
Ciao, Thorsten
On 16.11.21 20:11, Eugene Bordenkircher wrote:
quoted
On 02.11.21 22:15, Joakim Tjernlund wrote:
quoted
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver
(drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating
over the request queue, but the queue has been corrupted at some point
so it loops infinitely. I believe we have narrowed into the offending
code, but we are in need of assistance trying to find an appropriate
fix for the problem. The identified code appears to be in all
versions of the Linux kernel the driver exists in.
quoted
quoted
quoted
quoted
The problem appears to be when handling a USB_REQ_GET_STATUS
request. The driver gets this request and then calls the
ch9getstatus() function. In this function, it starts a request by
"borrowing" the per device status_req, filling it in, and then queuing
it with a call to list_add_tail() to add the request to the endpoint
queue. Right before it exits the function however, it's calling
ep0_prime_status(), which is filling out that same status_req
structure and then queuing it with another call to list_add_tail() to
add the request to the endpoint queue. This adds two instances of the
exact same LIST_HEAD to the endpoint queue, which breaks the list
since the prev and next pointers end up pointing to the wrong things.
This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
quoted
quoted
quoted
quoted
I'm not sure what the appropriate fix to this problem is, mostly
due to
my lack of expertise in USB and this driver stack. The code has been
this way in the kernel for a very long time, which suggests that it
has been working, unless USB_REQ_GET_STATUS requests are never made.
This further suggests that there is something else going on that I don't understand.
Deleting the call to ep0_prime_status() and the following ep0stall()
call appears, on the surface, to get the device working again, but may
have side effects that I'm not seeing.
quoted
quoted
quoted
quoted
I'm hopeful someone in the community can help provide some
information on what I may be missing or help come up with a solution
to the problem. A big thank you to anyone who would like to help out.
quoted
quoted
quoted
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Curious, did my patches help? Good to known once we upgrade as well.
There's good news and bad news.
The good news is that this appears to stop the driver from entering
an infinite loop, which prevents the Linux system from locking up
and never recovering. So I'm willing to say we've made the behavior
better.
The bad news is that once we get past this point, there is new bad
behavior. What is on top of this driver in our system is the RNDIS
gadget driver communicating to a Laptop running Win10 -1809.
Everything appears to work fine with the Linux system until there is
a USB disconnect. After the disconnect, the Linux side appears to
continue on just fine, but the Windows side doesn't seem to
recognize the disconnect, which causes the USB driver on that side
to hang forever and eventually blue screen the box. This doesn't happen on
all machines, just a select few. I think we can isolate the
behavior to a specific antivirus/security software driver that is
inserting itself into the USB stack and filtering the disconnect
message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call
this patchset good, at least for our test setup. My only hesitation
is if the Linux side is sending a set of responses that are
confusing the Windows side (specifically this antivirus) or not.
I'd be content calling that a separate defect though and letting
this one close up with that patchset.
P.S.: As a Linux kernel regression tracker I'm getting a lot of
reports on my table. I can only look briefly into most of them.
Unfortunately therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply. That's in everyone's interest, as
what I wrote above might be misleading to everyone reading this; any
suggestion I gave they thus might sent someone reading this down the
wrong rabbit hole, which none of us wants.
BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://urldefense.com/v3/__https://eur01.safelinks.protection.outloo
k.com/?url=https*3A*2F*2Furld__;JSUl!!O7uE89YCNVw!a6nsIMfn544OIzmshw3H
bMBVcbwor4cV2Q5OsST7-86jy_YZKvDsN-558Ris4wh8Zawz4puN$
efense.com%2Fv3%2F__https%3A%2F%2Flinux-
regtracking.leemhuis.info%2Fregzbot%2F__%3B!!O7uE89YCNVw!aHa5_mLM
nBeDjINlAtV19tBHm-
He9jbusXucMA5h7oonHvNFwYpOHAaaqqewPOuGK9HAzJUz%24&data
=04%7C01%7Cleoyang.li%40nxp.com%7C859ce1560a7344729cea08d9b35d2e
67%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6377380350721308
84%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ONQZyAKXNgok
6LgYvnaAL7LVY%2B5Wl7pXglZDqWUJZMc%3D&reserved=0 ). I'm only
posting this mail to get things rolling again and hence don't need to
be CC on all further activities wrt to this regression.
#regzbot title: usb: fsl_udc_core: corrupted request list leads to
unrecoverable loop
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
Agreed,
We are happy pick up the torch on this, but I'd like to try and hear from Joakim first before we do. The patch set is his, so I'd like to give him the opportunity. I think he's the only one that can add a truly proper description as well because he mentioned that this includes a "few more fixes" than just the one we ran into. I'd rather hear from him than try to reverse engineer what was being addressed.
Joakim, if you are still watching the thread, would you like to take a stab at it? If I don't hear from you in a couple days, we'll pick up the torch and do what we can.
I am far away from this now and still on 4.19. I don't mind if you tweak tweak the patches for better "upstreamability"
Regards
Joakim
Eugene T. Bordenkircher
-----Original Message-----
From: Leo Li <redacted>
Sent: Monday, November 29, 2021 3:37 PM
To: Eugene Bordenkircher <redacted>; Thorsten Leemhuis <redacted>; jocke@infinera.com <redacted>; linuxppc-dev@lists.ozlabs.org; linux-usb@vger.kernel.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: RE: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
[Caution - External]
quoted
-----Original Message-----
From: Eugene Bordenkircher <redacted>
Sent: Monday, November 29, 2021 11:25 AM
To: Thorsten Leemhuis <redacted>; jocke@infinera.com
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: Leo Li <redacted>; gregkh@linuxfoundation.org;
balbi@kernel.org
Subject: RE: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
The final result of our testing is that the patch set posted seems to
address all known defects in the Linux kernel. The mentioned
additional problems are entirely caused by the antivirus solution on
the windows box. The antivirus solution blocks the disconnect
messages from reaching the RNDIS driver so it has no idea the USB
device went away. There is nothing we can do to address this in the Linux kernel.
Thanks for the confirmation.
quoted
I propose we move forward with the patchset.
I think that we should proceed to merge the patchset but it seems to need some cleanup for coding style issues and better description before submitted formally.
quoted
Eugene T. Bordenkircher
-----Original Message-----
From: Thorsten Leemhuis <redacted>
Sent: Thursday, November 25, 2021 5:59 AM
To: Eugene Bordenkircher <redacted>; Thorsten
Leemhuis [off-list ref]; Joakim Tjernlund
[off-list ref]; linuxppc-dev@lists.ozlabs.org; linux-
usb@vger.kernel.org
Cc: leoyang.li@nxp.com; gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
Hi, this is your Linux kernel regression tracker speaking.
Top-posting for once, to make this easy to process for everyone:
Li Yang and Felipe Balbi: how to move on with this? It's quite an old
regression, but nevertheless it is one and thus should be fixed. Part
of my position is to make that happen and thus remind developers and
maintainers about this until the regression is resolved.
Ciao, Thorsten
On 16.11.21 20:11, Eugene Bordenkircher wrote:
quoted
On 02.11.21 22:15, Joakim Tjernlund wrote:
quoted
On Sat, 2021-10-30 at 14:20 +0000, Joakim Tjernlund wrote:
quoted
On Fri, 2021-10-29 at 17:14 +0000, Eugene Bordenkircher wrote:
quoted
quoted
We've discovered a situation where the FSL udc driver
(drivers/usb/gadget/udc/fsl_udc_core.c) will enter a loop iterating
over the request queue, but the queue has been corrupted at some point
so it loops infinitely. I believe we have narrowed into the offending
code, but we are in need of assistance trying to find an appropriate
fix for the problem. The identified code appears to be in all
versions of the Linux kernel the driver exists in.
quoted
quoted
quoted
quoted
The problem appears to be when handling a USB_REQ_GET_STATUS
request. The driver gets this request and then calls the
ch9getstatus() function. In this function, it starts a request by
"borrowing" the per device status_req, filling it in, and then queuing
it with a call to list_add_tail() to add the request to the endpoint
queue. Right before it exits the function however, it's calling
ep0_prime_status(), which is filling out that same status_req
structure and then queuing it with another call to list_add_tail() to
add the request to the endpoint queue. This adds two instances of the
exact same LIST_HEAD to the endpoint queue, which breaks the list
since the prev and next pointers end up pointing to the wrong things.
This ends up causing a hard loop the next time nuke() gets called, which happens on the next setup IRQ.
quoted
quoted
quoted
quoted
I'm not sure what the appropriate fix to this problem is, mostly
due to
my lack of expertise in USB and this driver stack. The code has been
this way in the kernel for a very long time, which suggests that it
has been working, unless USB_REQ_GET_STATUS requests are never made.
This further suggests that there is something else going on that I don't understand.
Deleting the call to ep0_prime_status() and the following ep0stall()
call appears, on the surface, to get the device working again, but may
have side effects that I'm not seeing.
quoted
quoted
quoted
quoted
I'm hopeful someone in the community can help provide some
information on what I may be missing or help come up with a solution
to the problem. A big thank you to anyone who would like to help out.
quoted
quoted
quoted
Run into this to a while ago. Found the bug and a few more fixes.
This is against 4.19 so you may have to tweak them a bit.
Feel free to upstream them.
Curious, did my patches help? Good to known once we upgrade as well.
There's good news and bad news.
The good news is that this appears to stop the driver from entering
an infinite loop, which prevents the Linux system from locking up
and never recovering. So I'm willing to say we've made the behavior
better.
The bad news is that once we get past this point, there is new bad
behavior. What is on top of this driver in our system is the RNDIS
gadget driver communicating to a Laptop running Win10 -1809.
Everything appears to work fine with the Linux system until there is
a USB disconnect. After the disconnect, the Linux side appears to
continue on just fine, but the Windows side doesn't seem to
recognize the disconnect, which causes the USB driver on that side
to hang forever and eventually blue screen the box. This doesn't happen on
all machines, just a select few. I think we can isolate the
behavior to a specific antivirus/security software driver that is
inserting itself into the USB stack and filtering the disconnect
message, but we're still proving that.
I'm about 90% certain this is a different problem and we can call
this patchset good, at least for our test setup. My only hesitation
is if the Linux side is sending a set of responses that are
confusing the Windows side (specifically this antivirus) or not.
I'd be content calling that a separate defect though and letting
this one close up with that patchset.
P.S.: As a Linux kernel regression tracker I'm getting a lot of
reports on my table. I can only look briefly into most of them.
Unfortunately therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply. That's in everyone's interest, as
what I wrote above might be misleading to everyone reading this; any
suggestion I gave they thus might sent someone reading this down the
wrong rabbit hole, which none of us wants.
BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2F%2Feur01.safelinks.protection.outloo&data=04%7C01%7Cjoakim.tjernlund%40infinera.com%7Cb302ff817a8f4b3184c408d9b392bd1c%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637738265108962168%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=D2TOGHLaeLnnmbJQG5VEY3CQ66GKtkpBOkFZ16WeW%2F4%3D&reserved=0
k.com/?url=https*3A*2F*2Furld__;JSUl!!O7uE89YCNVw!a6nsIMfn544OIzmshw3H
bMBVcbwor4cV2Q5OsST7-86jy_YZKvDsN-558Ris4wh8Zawz4puN$
efense.com%2Fv3%2F__https%3A%2F%2Flinux-
regtracking.leemhuis.info%2Fregzbot%2F__%3B!!O7uE89YCNVw!aHa5_mLM
nBeDjINlAtV19tBHm-
He9jbusXucMA5h7oonHvNFwYpOHAaaqqewPOuGK9HAzJUz%24&data
=04%7C01%7Cleoyang.li%40nxp.com%7C859ce1560a7344729cea08d9b35d2e
67%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6377380350721308
84%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ONQZyAKXNgok
6LgYvnaAL7LVY%2B5Wl7pXglZDqWUJZMc%3D&reserved=0 ). I'm only
posting this mail to get things rolling again and hence don't need to
be CC on all further activities wrt to this regression.
#regzbot title: usb: fsl_udc_core: corrupted request list leads to
unrecoverable loop
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and hear from Joakim first before we do. The patch set is his, so I'd like to give him the opportunity. I think he's the only one that can add a truly proper description as well because he mentioned that this includes a "few more fixes" than just the one we ran into. I'd rather hear from him than try to reverse engineer what was being addressed.
Joakim, if you are still watching the thread, would you like to take a stab at it? If I don't hear from you in a couple days, we'll pick up the torch and do what we can.
I am far away from this now and still on 4.19. I don't mind if you tweak tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told just a few tweaks are needed but this is probably
something NXP should do as they have access to other SOC's using chipidea.
Leo ?
Joakim
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and hear from
Joakim first before we do. The patch set is his, so I'd like to give him the
opportunity. I think he's the only one that can add a truly proper description
as well because he mentioned that this includes a "few more fixes" than just
the one we ran into. I'd rather hear from him than try to reverse engineer
what was being addressed.
quoted
quoted
Joakim, if you are still watching the thread, would you like to take a stab
at it? If I don't hear from you in a couple days, we'll pick up the torch and do
what we can.
quoted
quoted
I am far away from this now and still on 4.19. I don't mind if you tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told just a few
tweaks are needed but this is probably something NXP should do as they
have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this controller was only used on legacy platforms, it is harder to justify new effort on it now.
Regards,
Leo
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and hear from
Joakim first before we do. The patch set is his, so I'd like to give him the
opportunity. I think he's the only one that can add a truly proper description
as well because he mentioned that this includes a "few more fixes" than just
the one we ran into. I'd rather hear from him than try to reverse engineer
what was being addressed.
quoted
quoted
Joakim, if you are still watching the thread, would you like to take a stab
at it? If I don't hear from you in a couple days, we'll pick up the torch and do
what we can.
quoted
quoted
I am far away from this now and still on 4.19. I don't mind if you tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told just a few
tweaks are needed but this is probably something NXP should do as they
have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this controller was only used on legacy platforms, it is harder to justify new effort on it now.
Legacy? All PPC is legacy and not supported now?
Jocke
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Thursday, December 2, 2021 4:45 PM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Thu, 2021-12-02 at 20:35 +0000, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org;
linuxppc- dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and
hear from
Joakim first before we do. The patch set is his, so I'd like to
give him the opportunity. I think he's the only one that can add a
truly proper description as well because he mentioned that this
includes a "few more fixes" than just the one we ran into. I'd
rather hear from him than try to reverse engineer what was being
addressed.
quoted
quoted
quoted
quoted
Joakim, if you are still watching the thread, would you like to
take a stab
at it? If I don't hear from you in a couple days, we'll pick up the
torch and do what we can.
quoted
quoted
I am far away from this now and still on 4.19. I don't mind if you
tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told
just a few tweaks are needed but this is probably something NXP
should do as they have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this
controller was only used on legacy platforms, it is harder to justify new effort
on it now.
quoted
Legacy? All PPC is legacy and not supported now?
I'm not saying that they are not supported, but they are in maintenance only mode.
Regards,
Leo
Hi, this is your Linux kernel regression tracker speaking.
On 04.12.21 01:40, Leo Li wrote:
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Thursday, December 2, 2021 4:45 PM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Thu, 2021-12-02 at 20:35 +0000, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org;
linuxppc- dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and
hear from
Joakim first before we do. The patch set is his, so I'd like to
give him the opportunity. I think he's the only one that can add a
truly proper description as well because he mentioned that this
includes a "few more fixes" than just the one we ran into. I'd
rather hear from him than try to reverse engineer what was being
addressed.
quoted
quoted
quoted
quoted
Joakim, if you are still watching the thread, would you like to
take a stab
at it? If I don't hear from you in a couple days, we'll pick up the
torch and do what we can.
Did anything happen? Sure, it's a old regression from the v3.4-rc4 days,
but there iirc was already a tested proto-patch in that thread that
fixes the issue. Or was progress made and I just missed it?
Ciao, Thorsten
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
on my table. I can only look briefly into most of them. Unfortunately
therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply, that's in everyone's interest.
BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting
this mail to get things rolling again and hence don't need to be CC on
all further activities wrt to this regression.
#regzbot ignore-activity
quoted
quoted
quoted
quoted
I am far away from this now and still on 4.19. I don't mind if you
tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told
just a few tweaks are needed but this is probably something NXP
should do as they have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this
controller was only used on legacy platforms, it is harder to justify new effort
on it now.
Legacy? All PPC is legacy and not supported now?
I'm not saying that they are not supported, but they are in maintenance only mode.
Hi, this is your Linux kernel regression tracker speaking. Top-posting
for once, to make this easy accessible to everyone.
Sadly it looks to me like nobody is going to address this (quite old)
regression (that afaic only very few people will hit), despite the rough
patch to fix it that was already posted and tested in this thread.
Well, guess that's how it is sometimes. Marking it as "on back burner"
in regzbot to reduce the noise there:
#regzbot backburner: Tested patch available, but things nevertheless got
stuck
Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
P.S.: As the Linux kernel's regression tracker I'm getting a lot of
reports on my table. I can only look briefly into most of them and lack
knowledge about most of the areas they concern. I thus unfortunately
will sometimes get things wrong or miss something important. I hope
that's not the case here; if you think it is, don't hesitate to tell me
in a public reply, it's in everyone's interest to set the public record
straight.
#regzbot poke
On 20.01.22 13:54, Thorsten Leemhuis wrote:
Hi, this is your Linux kernel regression tracker speaking.
On 04.12.21 01:40, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Thursday, December 2, 2021 4:45 PM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Thu, 2021-12-02 at 20:35 +0000, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org;
linuxppc- dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and
hear from
Joakim first before we do. The patch set is his, so I'd like to
give him the opportunity. I think he's the only one that can add a
truly proper description as well because he mentioned that this
includes a "few more fixes" than just the one we ran into. I'd
rather hear from him than try to reverse engineer what was being
addressed.
quoted
quoted
quoted
quoted
Joakim, if you are still watching the thread, would you like to
take a stab
at it? If I don't hear from you in a couple days, we'll pick up the
torch and do what we can.
Did anything happen? Sure, it's a old regression from the v3.4-rc4 days,
but there iirc was already a tested proto-patch in that thread that
fixes the issue. Or was progress made and I just missed it?
Ciao, Thorsten
P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
on my table. I can only look briefly into most of them. Unfortunately
therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply, that's in everyone's interest.
BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting
this mail to get things rolling again and hence don't need to be CC on
all further activities wrt to this regression.
#regzbot ignore-activity
quoted
quoted
quoted
quoted
quoted
I am far away from this now and still on 4.19. I don't mind if you
tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told
just a few tweaks are needed but this is probably something NXP
should do as they have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this
controller was only used on legacy platforms, it is harder to justify new effort
on it now.
Legacy? All PPC is legacy and not supported now?
I'm not saying that they are not supported, but they are in maintenance only mode.
I think you could apply them as is, only criticism was the commit msgs.
Jocke
________________________________________
From: Thorsten Leemhuis <redacted>
Sent: 18 February 2022 08:11
To: Leo Li; Joakim Tjernlund; Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
Hi, this is your Linux kernel regression tracker speaking. Top-posting
for once, to make this easy accessible to everyone.
Sadly it looks to me like nobody is going to address this (quite old)
regression (that afaic only very few people will hit), despite the rough
patch to fix it that was already posted and tested in this thread.
Well, guess that's how it is sometimes. Marking it as "on back burner"
in regzbot to reduce the noise there:
#regzbot backburner: Tested patch available, but things nevertheless got
stuck
Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
P.S.: As the Linux kernel's regression tracker I'm getting a lot of
reports on my table. I can only look briefly into most of them and lack
knowledge about most of the areas they concern. I thus unfortunately
will sometimes get things wrong or miss something important. I hope
that's not the case here; if you think it is, don't hesitate to tell me
in a public reply, it's in everyone's interest to set the public record
straight.
#regzbot poke
On 20.01.22 13:54, Thorsten Leemhuis wrote:
Hi, this is your Linux kernel regression tracker speaking.
On 04.12.21 01:40, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Thursday, December 2, 2021 4:45 PM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-
dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to
unrecoverable loop.
On Thu, 2021-12-02 at 20:35 +0000, Leo Li wrote:
quoted
quoted
-----Original Message-----
From: Joakim Tjernlund <redacted>
Sent: Wednesday, December 1, 2021 8:19 AM
To: regressions@leemhuis.info; Leo Li <redacted>;
Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org;
linuxppc- dev@lists.ozlabs.org
Cc: gregkh@linuxfoundation.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list
leads to unrecoverable loop.
On Tue, 2021-11-30 at 12:56 +0100, Joakim Tjernlund wrote:
quoted
On Mon, 2021-11-29 at 23:48 +0000, Eugene Bordenkircher wrote:
quoted
Agreed,
We are happy pick up the torch on this, but I'd like to try and
hear from
Joakim first before we do. The patch set is his, so I'd like to
give him the opportunity. I think he's the only one that can add a
truly proper description as well because he mentioned that this
includes a "few more fixes" than just the one we ran into. I'd
rather hear from him than try to reverse engineer what was being
addressed.
quoted
quoted
quoted
quoted
Joakim, if you are still watching the thread, would you like to
take a stab
at it? If I don't hear from you in a couple days, we'll pick up the
torch and do what we can.
I am far away from this now and still on 4.19. I don't mind if you
tweak
tweak the patches for better "upstreamability"
Even better would be to migrate to the chipidea driver, I am told
just a few tweaks are needed but this is probably something NXP
should do as they have access to other SOC's using chipidea.
I agree with this direction but the problem was with bandwidth. As this
controller was only used on legacy platforms, it is harder to justify new effort
on it now.
Legacy? All PPC is legacy and not supported now?
I'm not saying that they are not supported, but they are in maintenance only mode.
On Fri, Feb 18, 2022 at 10:21:12AM +0000, Joakim Tjernlund wrote:
I think you could apply them as is, only criticism was the commit msgs.
That is always a good reason to reject a change. Please resubmit them
with the commit message cleaned up and I will be glad to review it
again.
thanks,
greg k-h
I was happy with commit msgs and I don't know what the criticism was.
________________________________________
From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
Sent: 18 February 2022 11:39
To: Joakim Tjernlund
Cc: Thorsten Leemhuis; Leo Li; Eugene_Bordenkircher@selinc.com; linux-usb@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; balbi@kernel.org
Subject: Re: bug: usb: gadget: FSL_UDC_CORE Corrupted request list leads to unrecoverable loop.
On Fri, Feb 18, 2022 at 10:21:12AM +0000, Joakim Tjernlund wrote:
I think you could apply them as is, only criticism was the commit msgs.
That is always a good reason to reject a change. Please resubmit them
with the commit message cleaned up and I will be glad to review it
again.
thanks,
greg k-h