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Date:   Sat, 20 May 2023 16:09:49 +0200
From:   Willy Tarreau <w@1wt.eu>
To:     Thomas =?iso-8859-1?Q?Wei=DFschuh?= <thomas@t-8ch.de>
Cc:     Zhangjin Wu <falcon@tinylab.org>, aou@eecs.berkeley.edu,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        linux-riscv@lists.infradead.org, palmer@dabbelt.com,
        paul.walmsley@sifive.com, shuah@kernel.org
Subject: Re: [PATCH] selftests/nolibc: Fix up compile error for rv32
Message-ID: <20230520140949.GA27611@1wt.eu>
References: <20230520-nolibc-stackprotector-riscv-v1-1-d8912012a034@weissschuh.net>
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On Sat, May 20, 2023 at 04:00:54PM +0200, Thomas Wei?schuh wrote:
> > diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
> > index 063f9959ac44..d8b59c8f6c03 100644
> > --- a/tools/testing/selftests/nolibc/nolibc-test.c
> > +++ b/tools/testing/selftests/nolibc/nolibc-test.c
> > @@ -596,7 +596,7 @@ int run_syscall(int min, int max)
> >  		CASE_TEST(write_badf);        EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break;
> >  		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 0)); break;
> >  		CASE_TEST(syscall_noargs);    EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break;
> > -		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_fstat, 0, NULL), -1, EFAULT); break;
> > +		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_read, -1, &tmp, 1), -1, EBADF); break;
> 
> The goal of this second test was to make sure that arguments are passed
> in the correct order. For this I tried to have a syscall were the
> checked error is generated from a non-first argument.
> (The NULL generating the EFAULT).
> So the new check does not fullfil this goal anymore.

Ah OK good to know.

> Maybe we can find a new syscall to test with?

Maybe it would be worth considering pselect() or equivalent which
involve many arguments. I don't know if rv32 has fstatat() or
lstat() for example, that could be used as alternatives ?

> The code should have had a comment I guess.

Indeed ;-)

With that said, if rv32 is missing some essential syscalls, my question
regarding its relevance here still holds!

Willy