On 03/07/2018 06:07 AM, Anders Roxell wrote: > In a -ffreestanding environment without glibc, we shouldn't be able to > call either getenv or printf. It seems that printf() happens to work > fine, but it ends up using the glibc getenv(), which doesn't work unless > we call the glibc _start() function first. > Using _start() was originally meant as an optimization to reduce the > memory consumption of the test program itself, in order to get a more > accurate representation of the available RAM at system boot time. > However, it causes more problems than it helps, especially when run from > a shell script that also consumes some memory. > > get_size[2838]: segfault at ffffffffffffffd0 ip 000000000040538b > sp 00007ffc41980668 error 5 in get_size[400000+b0000] > audit: type=1701 audit(1521532923.838:4): auid=0 uid=0 gid=0 ses=2 > subj=kernel pid=2838 comm=\"get_size\" > exe=\"/opt/kselftests/next/size/get_size\" sig=11 res=1 > get_size[2840]: segfault at ffffffffffffffd0 ip 000000000040538b > sp 00007ffdace9b378 error 5 in get_size[400000+b0000] > audit: type=1701 audit(1521532932.057:5): auid=0 uid=0 gid=0 ses=2 > subj=kernel pid=2840 comm=\"get_size\" > exe=\"/opt/kselftests/next/size/get_size\" sig=11 res=1 > > Rework to get_size test to use main (and printf) instead of _start. All > other seftest tests uses main and not _start. > > Fixes: 0081901af95f ("selftests: size call ksft_print_header() to print TAP header") > Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx> Andres, Thanks for finding and reporting the problem. This patch is in linux-kselftest next for 4.17-rc1. I would rather revert the patch than fix it a this time. I knew there was a reason why Tim didn't use printf() in the first, I couldn't remember. I won't be sending 0081901af95f ("selftests: size call ksft_print_header() to print TAP header") for inclusion into 4.17-rc1 thanks, -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html