Date: Thu, 23 Nov 2017 14:29:08 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r326134 - head/sys/cddl/contrib/opensolaris/uts/common/dtrace Message-ID: <201711231429.vANET8R2038484@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: markj Date: Thu Nov 23 14:29:07 2017 New Revision: 326134 URL: https://svnweb.freebsd.org/changeset/base/326134 Log: Duplicate helpers after disabling inherited tracepoints during a fork. We may create probes in the nascent child process, so we first need to ensure that any inherited tracepoints are first removed. Otherwise the probe sites will not be in the state expected by fasttrap, and it won't be able to enable the probes. MFC after: 2 weeks Modified: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Thu Nov 23 14:28:14 2017 (r326133) +++ head/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c Thu Nov 23 14:29:07 2017 (r326134) @@ -601,8 +601,8 @@ fasttrap_fork(proc_t *p, proc_t *cp) pid_t ppid = p->p_pid; int i; -#ifdef illumos ASSERT(curproc == p); +#ifdef illumos ASSERT(p->p_proc_flag & P_PR_LOCK); #else PROC_LOCK_ASSERT(p, MA_OWNED); @@ -610,26 +610,15 @@ fasttrap_fork(proc_t *p, proc_t *cp) #ifdef illumos ASSERT(p->p_dtrace_count > 0); #else - if (p->p_dtrace_helpers) { - /* - * dtrace_helpers_duplicate() allocates memory. - */ - _PHOLD(cp); - PROC_UNLOCK(p); - PROC_UNLOCK(cp); - dtrace_helpers_duplicate(p, cp); - PROC_LOCK(cp); - PROC_LOCK(p); - _PRELE(cp); - } /* * This check is purposely here instead of in kern_fork.c because, * for legal resons, we cannot include the dtrace_cddl.h header * inside kern_fork.c and insert if-clause there. */ - if (p->p_dtrace_count == 0) + if (p->p_dtrace_count == 0 && p->p_dtrace_helpers == NULL) return; #endif + ASSERT(cp->p_dtrace_count == 0); /* @@ -658,6 +647,8 @@ fasttrap_fork(proc_t *p, proc_t *cp) _PHOLD(cp); PROC_UNLOCK(cp); PROC_UNLOCK(p); + if (p->p_dtrace_count == 0) + goto dup_helpers; #endif /* @@ -711,6 +702,9 @@ fasttrap_fork(proc_t *p, proc_t *cp) mutex_enter(&cp->p_lock); sprunlock(cp); #else +dup_helpers: + if (p->p_dtrace_helpers != NULL) + dtrace_helpers_duplicate(p, cp); PROC_LOCK(p); PROC_LOCK(cp); _PRELE(cp);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201711231429.vANET8R2038484>