Date: Tue, 24 May 2016 12:06:57 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r300604 - head/sys/kern Message-ID: <201605241206.u4OC6vxt066392@repo.freebsd.org>
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Author: andrew Date: Tue May 24 12:06:56 2016 New Revision: 300604 URL: https://svnweb.freebsd.org/changeset/base/300604 Log: Limit calling pmc_hook to when the interrupt comes while running userspace. We may enable interrupts from within the callback, e.g. in a data abort during copyin. If we receive an interrupt at that time pmc_hook will be called again and, as it is handling userspace stack tracing, will hit a KASSERT as it checks if the trapframe is from userland. With this I can run hwpmc with intrng on a ThunderX and have it trace all CPUs. Obtained from: ABT Systems Ltd Sponsored by: The FreeBSD Foundation Modified: head/sys/kern/subr_intr.c Modified: head/sys/kern/subr_intr.c ============================================================================== --- head/sys/kern/subr_intr.c Tue May 24 11:47:14 2016 (r300603) +++ head/sys/kern/subr_intr.c Tue May 24 12:06:56 2016 (r300604) @@ -317,7 +317,8 @@ intr_irq_handler(struct trapframe *tf) td->td_intr_frame = oldframe; critical_exit(); #ifdef HWPMC_HOOKS - if (pmc_hook && (PCPU_GET(curthread)->td_pflags & TDP_CALLCHAIN)) + if (pmc_hook && TRAPF_USERMODE(tf) && + (PCPU_GET(curthread)->td_pflags & TDP_CALLCHAIN)) pmc_hook(PCPU_GET(curthread), PMC_FN_USER_CALLCHAIN, tf); #endif }
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