From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <musl-return-20616-ml=inbox.vuxu.org@lists.openwall.com>
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-3.1 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H4,
	RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham
	autolearn_force=no version=3.4.4
Received: from second.openwall.net (second.openwall.net [193.110.157.125])
	by inbox.vuxu.org (Postfix) with SMTP id 0B6EB24DA7
	for <ml@inbox.vuxu.org>; Tue, 12 Mar 2024 01:51:44 +0100 (CET)
Received: (qmail 23990 invoked by uid 550); 12 Mar 2024 00:47:33 -0000
Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm
Precedence: bulk
List-Post: <mailto:musl@lists.openwall.com>
List-Help: <mailto:musl-help@lists.openwall.com>
List-Unsubscribe: <mailto:musl-unsubscribe@lists.openwall.com>
List-Subscribe: <mailto:musl-subscribe@lists.openwall.com>
List-ID: <musl.lists.openwall.com>
Reply-To: musl@lists.openwall.com
Received: (qmail 23955 invoked from network); 12 Mar 2024 00:47:33 -0000
Date: Mon, 11 Mar 2024 20:51:50 -0400
From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Cc: Hongliang Wang <wanghongliang@loongson.cn>
Message-ID: <20240312005150.GB4163@brightrain.aerifal.cx>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.5.21 (2010-09-15)
Subject: [musl] loongarch64 atomics not working?

There's been a report of mksh hanging on loongarch64, at least under
qemu, apparently hanging in a_cas_p:

(gdb) run
Starting program: /mksh 
^C
Program received signal SIGINT, Interrupt.
a_cas_p (p=0x120054288 <vdso_func>, t=0x12003b970 <cgt_init>, s=0x7fffffffc34c)
    at ./src/internal/atomic.h:94
warning: 94     ./src/internal/atomic.h: No such file or directory
(gdb) bt
#0  a_cas_p (p=0x120054288 <vdso_func>, t=0x12003b970 <cgt_init>, 
    s=0x7fffffffc34c) at ./src/internal/atomic.h:94
#1  cgt_init (clk=0, ts=0x7ffffffefb60) at src/time/clock_gettime.c:51
#2  0x000000012003ba4c in __clock_gettime (clk=clk@entry=0, 
    ts=ts@entry=0x7ffffffefb60) at src/time/clock_gettime.c:67
#3  0x000000012003830c in gettimeofday (tv=tv@entry=0x7ffffffefba0, 
    tz=tz@entry=0x0) at src/time/gettimeofday.c:9
#4  0x000000012002f098 in change_winsz () at var.c:1718
#5  0x0000000120000348 in main_init (lp=<synthetic pointer>, 
    sp=<synthetic pointer>, argv=0x7ffffffefd18, argc=1) at main.c:369
#6  main (argc=<optimized out>, argv=<optimized out>) at main.c:738

This is very basic usage, just the vdso clock_gettime init code trying
to replace a pointer atomically. Is it working on real hardware? I'm
trying to figure out if this is a qemu bug, or if the asm or the asm
argument constraints are wrong in musl's
arch/loongarch64/atomic_arch.h.

Rich