Date: Fri, 04 Aug 2017 16:19:32 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 219399] System panics after several hours of 14-threads-compilation orgies using poudriere on AMD Ryzen... Message-ID: <bug-219399-8-e7jvLQ80AM@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-219399-8@https.bugs.freebsd.org/bugzilla/> References: <bug-219399-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219399 --- Comment #204 from Don Lewis <truckman@FreeBSD.org> --- Created attachment 185022 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=185022&action=edit program to cause Ryzen hang/reboot on tweaked FreeBSD by executing code in high memory If you modify the FreeBSD kernel to lower the shared page, but leave sv_maxuser at its original value so that a user program can mmap the page at 0x7ffffffff000, the attached program will fill that page with RET instructions and perform calls to those in a loop. I have not observed any issues with calls to the RET instructions at 0x7fffffffff3f or below. When the RET instruction at 0x7fffffffff40 is executed, my machine will typically silently reboot without a panic message, or it will sometimes hang with the screen blanked. This test is the most sensitive on core 0, which handles most interrupts, so run under "cpuset -l 0" for best results. The problem appears to be triggered when the RET instruction is interrupted. It is possible to load and execute arbitrary code for other experiments. -- You are receiving this mail because: You are the assignee for the bug.
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