From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=ALL_TRUSTED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NO_DNS_FOR_FROM autolearn=no autolearn_force=no version=3.4.6 Received: from biznet-home.integral.gnuweeb.org (unknown [182.253.183.184]) by gnuweeb.org (Postfix) with ESMTPSA id 8BBAF7E375; Sun, 8 Jan 2023 18:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1673202684; bh=9umJdbd5KJp+UAquobmdtoTrKKFWq86YVx9C36KKXTM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y7NWNwnRsbgY/ky7Pr0tGgXFs9PhWyZ7zoHECB+EhKwbBt+dhqloDjPfoaP5niaUW 96fqfpIMvsASqaE8lCwVaOVhEh+Fd/fgIDgt4/YychEgZiPABIFatwbl+YEkEGwP8S 04KzDsYS4rGpvVISxChA7vjerSQxjXd4FxJkC0ruAZXXx33qPfsgkncN0or3oXl5Z7 C7EHWCESCTlPOHQLq+XyFvRdqZAoNOCu5SM/ZEDy4z2XhzjAKEXMm0BX7VtLhkDRpD 41/cXCqsUAeyj8vKDGOJZsIft4owS6YNUvoazObcyXK+h4FCXIHtUZ/7BQ1TmGAIel +qDcepXBz8V6g== Date: Mon, 9 Jan 2023 01:31:17 +0700 From: Ammar Faizi To: Willy Tarreau Cc: Shuah Khan , "Paul E. McKenney" , Gilang Fachrezy , Alviro Iskandar Setiawan , GNU/Weeb Mailing List , Linux Kernel Mailing List , Linux Kselftest Mailing List Subject: Re: [PATCH v3 0/5] nolibc signal handling support Message-ID: References: <20230108135904.851762-1-ammar.faizi@intel.com> <20230108175842.GB18859@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230108175842.GB18859@1wt.eu> List-Id: On Sun, Jan 08, 2023 at 06:58:42PM +0100, Willy Tarreau wrote: > I'm currently testing it on various archs. For now: > > - x86_64 and arm64 pass the test Thanks for testing. > - i386 and arm fail: > 59 sigactiontest_sigaction_sig(2): Failed to set a signal handler > = -1 EINVAL [FAIL] > 60 signaltest_signal_sig(2): Failed to set a signal handler > = -1 EINVAL [FAIL] I'll take a look at i386 for now. > - riscv and mips build are now broken: > sysroot/riscv/include/sys.h:1110:18: error: 'struct sigaction' has no member named 'sa_restorer' > 1110 | if (!act2.sa_restorer) { > | ^ > sysroot/riscv/include/sys.h:1111:34: error: 'SA_RESTORER' undeclared (first use in this function); did you mean 'SA_RESTART'? > 1111 | act2.sa_flags |= SA_RESTORER; > | ^~~~~~~~~~~ > | SA_RESTART Just a speculation: This is probably because not all architectures have a SA_RESTORER. I'll need to figure out how Linux handles signal on those architectures. > - s390 segfaults: > 58 select_fault = -1 EFAULT [OK] > 59 sigactionqemu: uncaught target signal 11 (Segmentation fault) - core dumped > Segmentation fault > > It dies in __restore_rt at 1006ba4 while performing the syscall, > I don't know why, maybe this arch requires an alt stack or whatever : > > 0000000001006ba0 <__restore_rt>: > 1006ba0: a7 19 00 ad lghi %r1,173 > 1006ba4: 0a 00 svc 0 > 1006ba6: 07 07 nopr %r7 Bah, no clue on this. I'll CC s390 people in the next version and ask them to shed some light. > At the very least we need to make sure we don't degrade existing tests, > which means making sure that it builds everywhere and that all those > which build do work. Understand. > It would be nice to figure what's failing on i386. Given that both it > and arm fail on EINVAL while both x86_64 and arm64 work, I suspect that > once you figure what breaks i386 it'll fix the problem on arm at the > same time. I had a quick look but didn't spot anything suspicious. > Once we've figured this, we could decide to tag archs supporting > sig_action() and condition the functions definition and the tests to > these. I'll be pondering this code this week (to follow what actually the rt_sigaction wants on i386 and arm): https://github.com/torvalds/linux/blob/v6.2-rc3/kernel/signal.c#L4404-L4434 Hopefully, I can get it sorted before the weekend. > The advantage of trying with i386 is that your regular tools and the > debugger you used for x86_64 will work. I'm proceeding like this with > the toolchains from https://mirrors.edge.kernel.org/pub/tools/crosstool/ : > > $ make nolibc-test LDFLAGS=-g CFLAGS=-g ARCH=i386 CC=/path/to/gcc-11.3.0-nolibc/i386-linux/bin/i386-linux-gcc > $ gdb ./nolibc-test > > b sigaction > > run > > s > ... Nice tip! I'll be playing with that. > Note that the code looks correct at first glance: > > 0804b4a0 <__restore_rt>: > 804b4a0: b8 ad 00 00 00 mov $0xad,%eax > 804b4a5: cd 80 int $0x80 > > I also think that the printf() in test_sigaction_sig() are not welcome > as they corrupt the output. Maybe one thing you could do to preserve the > info would be to prepend a space in front of the message and remove the > LF. For example the simple patch below: [...] > Which is way more readable and still grep-friendly. Yeah, that looks much better. Applied to my local git tree with attribution. -- Ammar Faizi