Author: kib Date: Wed Nov 1 11:32:52 2017 New Revision: 325275 URL: https://svnweb.freebsd.org/changeset/base/325275
Log: In hwpmc, do not double-close the logging file. hwpmc(4) must not voluntarily call fo_close(), doing this causes double-close of the file. It seems to almost avoid bad consequences for pipes, but other types of files demonstrate random memory access. To fix, remove fo_close() calls, which also do not provide the declared wake-up of waiters consistently. Instead, send a signal to the logger and configure the logger process to not block it. Since logger never returns to userspace, the signal only causes termination of the interruptible sleeps in fo_write(). Reported and tested by: pho Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week X-Differential revision: https://reviews.freebsd.org/D12882 Modified: head/sys/dev/hwpmc/hwpmc_logging.c Modified: head/sys/dev/hwpmc/hwpmc_logging.c ============================================================================== --- head/sys/dev/hwpmc/hwpmc_logging.c Wed Nov 1 11:16:18 2017 (r325274) +++ head/sys/dev/hwpmc/hwpmc_logging.c Wed Nov 1 11:32:52 2017 (r325275) @@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$"); #include <sys/pmclog.h> #include <sys/proc.h> #include <sys/signalvar.h> +#include <sys/syscallsubr.h> #include <sys/sysctl.h> #include <sys/systm.h> #include <sys/uio.h> @@ -250,6 +251,7 @@ pmclog_loop(void *arg) struct ucred *ownercred; struct ucred *mycred; struct thread *td; + sigset_t unb; struct uio auio; struct iovec aiov; size_t nbytes; @@ -257,6 +259,11 @@ pmclog_loop(void *arg) po = (struct pmc_owner *) arg; p = po->po_owner; td = curthread; + + SIGEMPTYSET(unb); + SIGADDSET(unb, SIGHUP); + (void)kern_sigprocmask(td, SIG_UNBLOCK, &unb, NULL, 0); + mycred = td->td_ucred; PROC_LOCK(p); @@ -291,16 +298,8 @@ pmclog_loop(void *arg) mtx_unlock_spin(&po->po_mtx); /* No more buffers and shutdown required. */ - if (po->po_flags & PMC_PO_SHUTDOWN) { - mtx_unlock(&pmc_kthread_mtx); - /* - * Close the file to get PMCLOG_EOF - * error in pmclog(3). - */ - fo_close(po->po_file, curthread); - mtx_lock(&pmc_kthread_mtx); + if (po->po_flags & PMC_PO_SHUTDOWN) break; - } (void) msleep(po, &pmc_kthread_mtx, PWAIT, "pmcloop", 0); @@ -541,19 +540,16 @@ pmclog_schedule_io(struct pmc_owner *po) static void pmclog_stop_kthread(struct pmc_owner *po) { - /* - * Close the file to force the thread out of fo_write, - * unset flag, wakeup the helper thread, - * wait for it to exit - */ - if (po->po_file != NULL) - fo_close(po->po_file, curthread); - mtx_lock(&pmc_kthread_mtx); po->po_flags &= ~PMC_PO_OWNS_LOGFILE; + if (po->po_kthread != NULL) { + PROC_LOCK(po->po_kthread); + kern_psignal(po->po_kthread, SIGHUP); + PROC_UNLOCK(po->po_kthread); + } wakeup_one(po); - if (po->po_kthread) + while (po->po_kthread) msleep(po->po_kthread, &pmc_kthread_mtx, PPAUSE, "pmckstp", 0); mtx_unlock(&pmc_kthread_mtx); } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
