Date: Thu, 19 Oct 2017 00:38:14 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r324734 - head/sys/kern Message-ID: <201710190038.v9J0cEQ1033510@repo.freebsd.org>
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Author: mjg Date: Thu Oct 19 00:38:14 2017 New Revision: 324734 URL: https://svnweb.freebsd.org/changeset/base/324734 Log: Tidy up pmc support at execve. The proc-specific check is inherently racy, so the code can just unlock beforehand. MFC after: 1 week Modified: head/sys/kern/kern_exec.c Modified: head/sys/kern/kern_exec.c ============================================================================== --- head/sys/kern/kern_exec.c Thu Oct 19 00:31:00 2017 (r324733) +++ head/sys/kern/kern_exec.c Thu Oct 19 00:38:14 2017 (r324734) @@ -849,28 +849,23 @@ interpret: p->p_args = newargs; newargs = NULL; + PROC_UNLOCK(p); + #ifdef HWPMC_HOOKS /* * Check if system-wide sampling is in effect or if the * current process is using PMCs. If so, do exec() time * processing. This processing needs to happen AFTER the * P_INEXEC flag is cleared. - * - * The proc lock needs to be released before taking the PMC - * SX. */ if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { - PROC_UNLOCK(p); VOP_UNLOCK(imgp->vp, 0); pe.pm_credentialschanged = credential_changing; pe.pm_entryaddr = imgp->entry_addr; PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); vn_lock(imgp->vp, LK_SHARED | LK_RETRY); - } else - PROC_UNLOCK(p); -#else /* !HWPMC_HOOKS */ - PROC_UNLOCK(p); + } #endif /* Set values passed into the program in registers. */
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