The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=a6144f713cee8f522150b1398b225eedbf4cfef1
commit a6144f713cee8f522150b1398b225eedbf4cfef1 Author: Konstantin Belousov <[email protected]> AuthorDate: 2021-05-15 00:10:05 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2021-05-22 12:16:08 +0000 ktrace: do not stop tracing other processes if our cannot write to this vnode Other processes might still be able to write, make the decision to stop based on the per-process situation. Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D30257 --- sys/kern/kern_ktrace.c | 53 ++++++++++++++++++-------------------------------- 1 file changed, 19 insertions(+), 34 deletions(-) diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c index 8728801acdf7..9916022961e9 100644 --- a/sys/kern/kern_ktrace.c +++ b/sys/kern/kern_ktrace.c @@ -1190,7 +1190,7 @@ ktr_writerequest(struct thread *td, struct ktr_request *req) struct uio auio; struct iovec aiov[3]; struct mount *mp; - int datalen, buflen, vrele_count; + int datalen, buflen; int error; /* @@ -1264,44 +1264,29 @@ ktr_writerequest(struct thread *td, struct ktr_request *req) } /* - * If error encountered, give up tracing on this vnode. We defer - * all the vrele()'s on the vnode until after we are finished walking - * the various lists to avoid needlessly holding locks. - * NB: at this point we still hold the vnode reference that must - * not go away as we need the valid vnode to compare with. Thus let - * vrele_count start at 1 and the reference will be freed - * by the loop at the end after our last use of vp. - */ - log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n", - error); - vrele_count = 1; - /* - * First, clear this vnode from being used by any processes in the - * system. - * XXX - If one process gets an EPERM writing to the vnode, should - * we really do this? Other processes might have suitable - * credentials for the operation. + * If error encountered, give up tracing on this vnode on this + * process. Other processes might still be suitable for + * writes to this vnode. */ + p = td->td_proc; + log(LOG_NOTICE, + "ktrace write failed, errno %d, tracing stopped for pid %d\n", + error, p->p_pid); cred = NULL; sx_slock(&allproc_lock); - FOREACH_PROC_IN_SYSTEM(p) { - PROC_LOCK(p); - if (p->p_tracevp == vp) { - mtx_lock(&ktrace_mtx); - ktr_freeproc(p, &cred, NULL); - mtx_unlock(&ktrace_mtx); - vrele_count++; - } - PROC_UNLOCK(p); - if (cred != NULL) { - crfree(cred); - cred = NULL; - } + PROC_LOCK(p); + mtx_lock(&ktrace_mtx); + if (p->p_tracevp == vp) + ktr_freeproc(p, &cred, NULL); + mtx_unlock(&ktrace_mtx); + PROC_UNLOCK(p); + if (cred != NULL) { + crfree(cred); + cred = NULL; } sx_sunlock(&allproc_lock); - - while (vrele_count-- > 0) - vrele(vp); + vrele(vp); + vrele(vp); } /* _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-main To unsubscribe, send any mail to "[email protected]"
