<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="#467886" vlink="#96607D" style="word-wrap:break-word"> <p style="font-family:Calibri;font-size:10pt;color:#008000;margin:5pt;font-style:normal;font-weight:normal;text-decoration:none;" align="Left"> [Public]<br> </p> <br> <div> <div class="WordSection1"> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif">I seem to recall -ENOTSUPP being frowned upon for IOCTLs.<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif">Alex<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> McRae, Geoffrey <Geoffrey.McRae@amd.com> <br> <b>Sent:</b> Tuesday, July 8, 2025 5:13 AM<br> <b>To:</b> Koenig, Christian <Christian.Koenig@amd.com>; Kuehling, Felix <Felix.Kuehling@amd.com><br> <b>Cc:</b> Deucher, Alexander <Alexander.Deucher@amd.com>; amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org<br> <b>Subject:</b> Re: [PATCH v2 1/1] drm/amdkfd: return -ENOTTY for unsupported IOCTLs<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <p style="margin:5.0pt"><span style="font-size:10.0pt;font-family:"Calibri",sans-serif;color:blue">[AMD Official Use Only - AMD Internal Distribution Only]<o:p></o:p></span></p> <p class="MsoNormal"><o:p> </o:p></p> <div> <div> <p class="MsoNormal"><span style="color:black">I am happy to use EOPNOTSUPP but I must point out that this is not the pattern used across the kernel, the standard is to use ENOTTY, which is also the default that fs/ioctl.c returns when no handler is present. Userspace tooling such as strace and glibc specifically expectect ENOTTY to indicate invalid or unsupported IOCTL.<o:p></o:p></span></p> </div> <div class="MsoNormal" align="center" style="text-align:center"> <hr size="2" width="98%" align="center"> </div> <div id="divRplyFwdMsg"> <p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"> Koenig, Christian <<a href="mailto:Christian.Koenig@amd.com">Christian.Koenig@amd.com</a>><br> <b>Sent:</b> Tuesday, 8 July 2025 5:01 PM<br> <b>To:</b> McRae, Geoffrey <<a href="mailto:Geoffrey.McRae@amd.com">Geoffrey.McRae@amd.com</a>>; Kuehling, Felix <<a href="mailto:Felix.Kuehling@amd.com">Felix.Kuehling@amd.com</a>><br> <b>Cc:</b> Deucher, Alexander <<a href="mailto:Alexander.Deucher@amd.com">Alexander.Deucher@amd.com</a>>; <a href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a> <<a href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>>; <a href="mailto:dri-devel@lists.freedesktop.org">dri-devel@lists.freedesktop.org</a> <<a href="mailto:dri-devel@lists.freedesktop.org">dri-devel@lists.freedesktop.org</a>><br> <b>Subject:</b> Re: [PATCH v2 1/1] drm/amdkfd: return -ENOTTY for unsupported IOCTLs</span> <o:p></o:p></p> <div> <p class="MsoNormal"> <o:p></o:p></p> </div> </div> <div> <div> <p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt">On 08.07.25 06:22, Geoffrey McRae wrote:<br> > Some kfd ioctls may not be available depending on the kernel version the<br> > user is running, as such we need to report -ENOTTY so userland can<br> > determine the cause of the ioctl failure.<br> <br> In general sounds like a good idea, but ENOTTY is potentially a bit misleading.<br> <br> We usually use EOPNOTSUPP for that even if its not the original meaning of that error code.<br> <br> Regards,<br> Christian.<br> <br> > <br> > Signed-off-by: Geoffrey McRae <<a href="mailto:geoffrey.mcrae@amd.com">geoffrey.mcrae@amd.com</a>><br> > ---<br> > drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 8 ++++++--<br> > 1 file changed, 6 insertions(+), 2 deletions(-)<br> > <br> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c<br> > index a2149afa5803..36396b7318e7 100644<br> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c<br> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c<br> > @@ -3253,8 +3253,10 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)<br> > int retcode = -EINVAL;<br> > bool ptrace_attached = false;<br> > <br> > - if (nr >= AMDKFD_CORE_IOCTL_COUNT)<br> > + if (nr >= AMDKFD_CORE_IOCTL_COUNT) {<br> > + retcode = -ENOTTY;<br> > goto err_i1;<br> > + }<br> > <br> > if ((nr >= AMDKFD_COMMAND_START) && (nr < AMDKFD_COMMAND_END)) {<br> > u32 amdkfd_size;<br> > @@ -3267,8 +3269,10 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)<br> > asize = amdkfd_size;<br> > <br> > cmd = ioctl->cmd;<br> > - } else<br> > + } else {<br> > + retcode = -ENOTTY;<br> > goto err_i1;<br> > + }<br> > <br> > dev_dbg(kfd_device, "ioctl cmd 0x%x (#0x%x), arg 0x%lx\n", cmd, nr, arg);<br> > <o:p></o:p></span></p> </div> </div> </div> </div> </div> </div> </body> </html>