Date: Mon, 13 May 2002 12:15:59 -0700 From: Marcel Moolenaar <marcel@cup.hp.com> To: Andrew Atrens <andrew_atrens@yahoo.ca> Cc: java@freebsd.org Subject: Re: linux-ibm-jdk-1.3.1[x] broken for non-root users on -stable Message-ID: <20020513191559.GA42806@gauss.cup.hp.com> In-Reply-To: <20020513181818.16354.qmail@web11305.mail.yahoo.com> References: <20020513181818.16354.qmail@web11305.mail.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, May 13, 2002 at 02:18:18PM -0400, Andrew Atrens wrote: > linux ibm jdk1.3.1_1 run as joe user - > > 26966 java CALL linux_modify_ldt(0x11,0xbfbff8ac,0x10) > 26966 java RET linux_modify_ldt 8190/0x1ffe > 26966 java CALL linux_sigaltstack(0xbfbff8ac,0x806ccf0) > 26966 java RET linux_sigaltstack 0 > 26966 java PSIG SIGBUS SIG_DFL > 26966 java NAMI "java.core" > > linux ibm jdk1.3.1_1 run as root - > > 27019 java CALL linux_modify_ldt(0x11,0xbfbff8ac,0x10) > 27019 java RET linux_modify_ldt 8190/0x1ffe > 27019 java CALL linux_sigaltstack(0xbfbff8ac,0x806ccf0) > 27019 java RET linux_sigaltstack 0 > 27019 java CALL mprotect(0xbfbc8000,0x1000,0) > 27019 java RET mprotect 0 Hi Andrew, The kernel trace does not indicate there's a problem with emulation per se. The SIGBUS is caused within java and unfortunately, there's no way a kernel trace can tell us if the SIGBUS is caused by how emulation works. I suspect it does, but it doesn't tell me where I need to look. The best thing to do now is to disassemble the code between the call to sigaltstack and the call to mprotect and figure out where exactly the SIGBUS is coming from. You can backtrace from there. I suspect the root of the problem to be prior to the sigaltstack though... Another approach would be to look at high risk syscalls (such as modify_ldt) and see if they behave differently for joe and root. I'm not surprised to see silent "adjustments" to parameters and/or results based on privileges. This is a more random approach, but if you have 1 or 2 strong suspects then it's the quickest way to remove any wandering doubts from your brain that may block real progress.. HTH, -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-java" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020513191559.GA42806>