[PATCH v6 13/15] selftests/nolibc: add mmap_bad test case

[Willy Tarreau]

On Fri, Jul 07, 2023 at 11:05:49PM +0800, Zhangjin Wu wrote:
> The length argument of mmap() must be greater than 0, passing a zero
> length argument expects failure with -EINVAL.

This one doesn't work for me on x86_64 kernel 5.15.112, qemu userland:

  46 mmap_bad = <0x0> EEXIST  != (<0xffffffffffffffff> EINVAL)    [FAIL]

This EEXIST actually is the errno from the previous test. If I run
the test natively it's OK:

  $ ./nolibc-test syscall:46
  Running test 'syscall'
  46 mmap_bad = <0xffffffffffffffff> EINVAL                        [OK]
  Errors during this test: 0

I'll queue it anyway for now but it would be nice that we figure what's
happening (even if we need to adjust or drop the test if it's a false
positive) so that we don't get used to "ah this is a normal error".

Willy