Hi, Thank you for the patch. This patch cleanly applies on next-20230627. Unrelated to this patch: I'm not sure if this patch was written against linux next. Always try to send patches against latest next tag from following repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git On 6/26/23 11:36 PM, Osama Muhammad wrote: > Hi Shuah, > > Any feedback on this patch?. > > Thanks, > Osama > > > On Sat, 17 Jun 2023 at 18:01, Osama Muhammad <osmtendev@xxxxxxxxx> wrote: >> >> Hi, >> >> Yes, I did install the latest kernel headers and TASK_COMM_LEN is not >> accessible in userspace. >> >> I looked into the test which uses TASK_COMM_LEN but the test defines >> it in its own header file. >> >> Example: https://elixir.bootlin.com/linux/latest/source/tools/testing/selftests/bpf/progs/pyperf.h#L13 >> >> TASK_COMM_LEN is defined in include/linux/sched.h, but this header >> file is not exposed to userspace. >> >> TASK_COMM_LEN is not defined in /include/uapi/linux/sched.h which is >> exposed to userspace kernel headers. >> Please find the link to the header file exposed to user space :- >> -https://elixir.bootlin.com/linux/v5.15.116/source/include/uapi/linux/sched.h >> >> As for arm64/abi/tpidr2.c It includes linux/sched.h which will be >> /include/uapi/linux/sched.h because the user space program is >> including it. >> So it also cannot use TASK_COMM_LEN directly. >> >> Regards, >> Osama >> >> On Tue, 13 Jun 2023 at 02:56, Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> wrote: >>> >>> On 6/10/23 07:01, Osama Muhammad wrote: >>>> Hi all, >>>> >>>> I looked into it and tried to use TASK_COMM_LEN in the test. Even >>>> though I included "linux/sched.h '', I was not able to compile the >>>> test because it couldn't find it in the header file. >>>> I dived deep into the issue and turns out header file mapped in >>>> /usr/include/linux/sched.h is actually mapped to >>>> /include/uapi/linux/sched.h[1] in linux source, >>>> where TASK_COMM_LEN is not even defined. Instead TASK_COMM_LEN is >>>> defined in /include/linux/sched.h which is not mapped to any header >>>> files in >>>> userspace(/(/usr/include/linux). >>>> I also tried to find the TASK_COM_LEN in /usr/include/linux/ but I >>>> couldn't find it. Following are the search results. >>>> grep -rnw '/usr/include/linux/' -e 'TASK_COMM_LEN" >>>> RESULTS OF COMMAND :- /usr/include/linux/taskstats.h:38:#define >>>> TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN >>>> Based on this information, I have two questions: >>>> 1. Would this require a fix to move 'TASK_COMM_LEN' macro from >>>> /include/linux/sched.h to UAPI headers /include/uapi/linux/sched.h. >>>> 2. Is there any other way to access TASK_COMM_LEN in the selftest that >>>> I'm not aware of? >>>> >>>> [1]:-https://elixir.bootlin.com/linux/v5.15.116/source/include/uapi/linux/sched.h >>>> >>> >>> The best source is Linux mainline. >>> >>> Take a look at test files that include linux/sched.h >>> >>> arm64/abi/tpidr2.c is one of them. >>> >>> Did you install headers before compiling the test? >>> make headers_install >>> >>> thanks, >>> -- Shuah >>> >>> -- BR, Muhammad Usama Anjum
