On 15.10.21 17:47, David Hildenbrand wrote: > On 15.10.21 17:45, Shuah Khan wrote: >> On 9/18/21 1:41 AM, David Hildenbrand wrote: >>> On 18.09.21 00:45, Shuah Khan wrote: >>>> Hi David, >>>> >>>> I am running into the following warning when try to build this test: >>>> >>>> madv_populate.c:334:2: warning: #warning "missing MADV_POPULATE_READ or MADV_POPULATE_WRITE definition" [-Wcpp] >>>> 334 | #warning "missing MADV_POPULATE_READ or MADV_POPULATE_WRITE definition" >>>> | ^~~~~~~ >>>> >>>> >>>> I see that the following handling is in place. However there is no >>>> other information to explain why the check is necessary. >>>> >>>> #if defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) >>>> >>>> #else /* defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) */ >>>> >>>> #warning "missing MADV_POPULATE_READ or MADV_POPULATE_WRITE definition" >>>> >>>> I do see these defined in: >>>> >>>> include/uapi/asm-generic/mman-common.h:#define MADV_POPULATE_READ 22 >>>> include/uapi/asm-generic/mman-common.h:#define MADV_POPULATE_WRITE 23 >>>> >>>> Is this the case of missing include from madv_populate.c? >>> >>> Hi Shuan, >>> >>> note that we're including "#include <sys/mman.h>", which in my >>> understanding maps to the version installed on your system instead >>> of the one in our build environment.ing. >>> >>> So as soon as you have a proper kernel + the proper headers installed >>> and try to build, it would pick up MADV_POPULATE_READ and >>> MADV_POPULATE_WRITE from the updated headers. That makes sense: you >>> annot run any MADV_POPULATE_READ/MADV_POPULATE_WRITE tests on a kernel >>> that doesn't support it. >>> >>> See vm/userfaultfd.c where we do something similar. >>> >> >> Kselftest is for testing the kernel with kernel headers. That is the >> reason why there is the dependency on header install. >> >>> >>> As soon as we have a proper environment, it seems to work just fine: >>> >>> Linux vm-0 5.15.0-0.rc1.20210915git3ca706c189db.13.fc36.x86_64 #1 SMP Thu Sep 16 11:32:54 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux >>> [root@vm-0 linux]# cat /etc/redhat-release >>> Fedora release 36 (Rawhide) >> >> This is a distro release. We don't want to have dependency on headers >> from the distro to run selftests. Hope this makes sense. >> >> I still see this on my test system running Linux 5.15-rc5. > > Did you also install Linux headers? I assume no, correct? > What happens in your environment when compiling and running the memfd_secret test? If assume you'll see a "skip" when executing, because it might also refer to the local version of linux headers and although it builds, it really cannot build something "functional". It just doesn't add a "#warning" to make that obvious. -- Thanks, David / dhildenb
