Author: trasz Date: Thu Apr 11 11:21:45 2019 New Revision: 346120 URL: https://svnweb.freebsd.org/changeset/base/346120
Log: Use shared vnode locks for the ELF interpreter. Reviewed by: kib MFC after: 2 weeks Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D19874 Modified: head/sys/kern/imgact_elf.c Modified: head/sys/kern/imgact_elf.c ============================================================================== --- head/sys/kern/imgact_elf.c Thu Apr 11 08:06:45 2019 (r346119) +++ head/sys/kern/imgact_elf.c Thu Apr 11 11:21:45 2019 (r346120) @@ -716,7 +716,7 @@ __elfN(load_file)(struct proc *p, const char *file, u_ struct nameidata *nd; struct vattr *attr; struct image_params *imgp; - u_long rbase; + u_long flags, rbase; u_long base_addr = 0; int error; @@ -744,7 +744,10 @@ __elfN(load_file)(struct proc *p, const char *file, u_ imgp->object = NULL; imgp->execlabel = NULL; - NDINIT(nd, LOOKUP, LOCKLEAF | FOLLOW, UIO_SYSSPACE, file, curthread); + flags = FOLLOW | LOCKSHARED | LOCKLEAF; + +again: + NDINIT(nd, LOOKUP, flags, UIO_SYSSPACE, file, curthread); if ((error = namei(nd)) != 0) { nd->ni_vp = NULL; goto fail; @@ -759,15 +762,30 @@ __elfN(load_file)(struct proc *p, const char *file, u_ if (error) goto fail; + /* + * Also make certain that the interpreter stays the same, + * so set its VV_TEXT flag, too. Since this function is only + * used to load the interpreter, the VV_TEXT is almost always + * already set. + */ + if (VOP_IS_TEXT(nd->ni_vp) == 0) { + if (VOP_ISLOCKED(nd->ni_vp) != LK_EXCLUSIVE) { + /* + * LK_UPGRADE could have resulted in dropping + * the lock. Just try again from the start, + * this time with exclusive vnode lock. + */ + vput(nd->ni_vp); + flags &= ~LOCKSHARED; + goto again; + } + + VOP_SET_TEXT(nd->ni_vp); + } + error = exec_map_first_page(imgp); if (error) goto fail; - - /* - * Also make certain that the interpreter stays the same, so set - * its VV_TEXT flag, too. - */ - VOP_SET_TEXT(nd->ni_vp); imgp->object = nd->ni_vp->v_object; _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
