include kernels >= 5.1.0 (CentOS Stream release 9)

[amichelotti]

On my mrf delivered with CentOS Stream release 9:
/opt/epics/modules/mrfioc2/mrmShared/linux/uio_mrf.c:129:19: error: assignment of read-only member ‘vm_flags’
129 | vma->vm_flags |= VM_IO | VM_RESERVED;

Fixed just applying the patch also to kernels >= 5.1.0

[gabrielfedel]

@amichelotti , it seems something is not right. I have being compiling the kernel driver for kernel 5.15 without problem.
You can see with your change the build fails on kernel 5.9.6 : https://github.com/epics-modules/mrfioc2/actions/runs/11590754198/job/32285612288?pr=191

Which exactly version is your kernel ?

[amichelotti]

Hello here: ``` Linux plsparcmrf003 5.14.0-522.el9.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Oct 20 13:04:34 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux ``` Regards, Andrea Il giorno mer 30 ott 2024 alle ore 16:04 Gabriel Fedel < ***@***.***> ha scritto:

…

@amichelotti <https://github.com/amichelotti> , it seems something is not right. I have being compiling the kernel driver for kernel 5.15 without problem. You can see that it fails with your change : https://github.com/epics-modules/mrfioc2/actions/runs/11590754198/job/32285612288?pr=191 Which exactly version is your kernel ? — Reply to this email directly, view it on GitHub <#191 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAW6KTD2E5MPJOELH3X4OE3Z6DYRJAVCNFSM6AAAAABQ3WQYJWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDINBXGQ2DQNZTGQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

-- --------------------------------------------------- Andrea Michelotti http://it.linkedin.com/in/michelotti skype:a.michelotti

[mdavidsaver]

I think vm_flags_set() was introduced by torvalds/linux@bc292ab before v6.3-rc1.

Now the story may be more complicated if this change has been backported by some distributor. Since it is an inline function, not a macro, I don't see a simple way to test for this possibility.

[amichelotti]

Hi @mdavidsaver, you’re absolutely right! Apologies for submitting such an incorrect patch. I hadn’t realized that distributors can create customized versions of the Linux kernel in such a way. I've just received three utca crates with unfortunately centos 9, previous were centos 7.9 (everything ok).

this is one of the lines of the 'customized'  kernel by Centos where they introduced vm_flags_set:

/usr/src/kernels/5.14.0-522.el9.x86_64/include/linux/mm.h:static inline void vm_flags_set(struct vm_area_struct *vma,

that as @gabrielfedel detected is not present in the kernels 5.9 (also following).
Probably the best thing to capture also this situation could be to introduce a macro USE_VM_FLAGS_SET that can be set in the makefile to avoid compilation errors with this distribution (maybe other do this things?):

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)) || defined(USE_VM_FLAGS_SET)
   vm_flags_set(vma, VM_IO | VM_RESERVED);
#else
   vma->vm_flags |= VM_IO | VM_RESERVED;
#endif