selftests/kselftest/runner/run_one(): allow running non-executable files

stable inclusion
from stable-v5.10.195
commit d94aac13a10229c43c7c3578e653c003f89f398a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I95JOC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d94aac13a10229c43c7c3578e653c003f89f398a

--------------------------------

[ Upstream commit 303f8e2d ]

When running a test program, 'run_one()' checks if the program has the
execution permission and fails if it doesn't.  However, it's easy to
mistakenly lose the permissions, as some common tools like 'diff' don't
support the permission change well[1].  Compared to that, making mistakes
in the test program's path would only rare, as those are explicitly listed
in 'TEST_PROGS'.  Therefore, it might make more sense to resolve the
situation on our own and run the program.

For this reason, this commit makes the test program runner function still
print the warning message but to try parsing the interpreter of the
program and to explicitly run it with the interpreter, in this case.

[1] https://lore.kernel.org/mm-commits/YRJisBs9AunccCD4@kroah.com/

Link: https://lkml.kernel.org/r/20210810164534.25902-1-sj38.park@gmail.com


Signed-off-by: SeongJae Park <sjpark@amazon.de>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 9616cb34 ("kselftest/runner.sh: Propagate SIGTERM to runner child")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>