Date: Tue, 12 Jul 2011 13:35:26 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Petr Salinger <Petr.Salinger@seznam.cz> Cc: freebsd-hackers@freebsd.org, Robert Millan <rmh@debian.org>, current@freebsd.org Subject: Re: [PATCH] Improve LinuxThreads compatibility in rfork() Message-ID: <20110712103526.GF43872@deviant.kiev.zoral.com.ua> In-Reply-To: <alpine.LRH.2.02.1107121108300.10573@sci.felk.cvut.cz> References: <20110711142232.GU43872@deviant.kiev.zoral.com.ua> <alpine.LRH.2.02.1107111641340.7134@sci.felk.cvut.cz> <20110711150614.GV43872@deviant.kiev.zoral.com.ua> <alpine.LRH.2.02.1107111718440.7134@sci.felk.cvut.cz> <20110711154102.GW43872@deviant.kiev.zoral.com.ua> <alpine.LRH.2.02.1107111805350.7134@sci.felk.cvut.cz> <20110711172408.GX43872@deviant.kiev.zoral.com.ua> <alpine.LRH.2.02.1107111944550.7134@sci.felk.cvut.cz> <20110711180246.GA43872@deviant.kiev.zoral.com.ua> <alpine.LRH.2.02.1107121108300.10573@sci.felk.cvut.cz>
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--qJM7dOmrnYWq+SaN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 12, 2011 at 11:16:28AM +0200, Petr Salinger wrote: > >>Seems this interface be acceptable ? > > > >Looks good to me. >=20 > The proposed code changes are in the attached patch. >=20 > Proposed wording of addition into RFORK(2): Below is the patch I intend to commit after you retest it. I added the checks for validity of the flags, and some rewording to the manual page. diff --git a/lib/libc/sys/rfork.2 b/lib/libc/sys/rfork.2 index f1ae14b..993fd1b 100644 --- a/lib/libc/sys/rfork.2 +++ b/lib/libc/sys/rfork.2 @@ -5,7 +5,7 @@ .\" .\" $FreeBSD$ .\" -.Dd March 15, 2011 +.Dd July 12, 2011 .Dt RFORK 2 .Os .Sh NAME @@ -84,6 +84,16 @@ Note that a lot of code will not run correctly in such a= n environment. .It Dv RFSIGSHARE If set, the kernel will force sharing the sigacts structure between the child and the parent. +.It Dv RFTSIGZMB +If set, the kernel will deliver a specified signal to the parent +upon the child exit, instead of default SIGCHILD. +The signal number +.Dv signum +is specified by oring the +.Dv RFTSIGFLAGS(signum) +expression into +.Fa flags . +Specifying signal number 0 disables signal delivery upon the child exit. .It Dv RFLINUXTHPN If set, the kernel will return SIGUSR1 instead of SIGCHILD upon thread exit for the child. @@ -164,6 +174,8 @@ would be exceeded (see Both the RFFDG and the RFCFDG flags were specified. .It Bq Er EINVAL Any flags not listed above were specified. +.It Bq Er EINVAL +An invalid signal number was specified. .It Bq Er ENOMEM There is insufficient swap space for the new process. .El diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index a8abd8e..9d3e22d 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -476,7 +476,10 @@ do_fork(struct thread *td, int flags, struct proc *p2,= struct thread *td2, sigacts_copy(newsigacts, p1->p_sigacts); p2->p_sigacts =3D newsigacts; } - if (flags & RFLINUXTHPN)=20 + + if (flags & RFTSIGZMB) + p2->p_sigparent =3D RFTSIGNUM(flags); + else if (flags & RFLINUXTHPN) p2->p_sigparent =3D SIGUSR1; else p2->p_sigparent =3D SIGCHLD; @@ -719,10 +722,22 @@ fork1(struct thread *td, int flags, int pages, struct= proc **procp) static int curfail; static struct timeval lastfail; =20 + /* Check for the undefined or unimplemented flags. */ + if ((flags & ~(RFFLAGS | RFTSIGFLAGS(RFTSIGMASK))) !=3D 0) + return (EINVAL); + + /* Signal value requires RFTSIGZMB. */ + if ((flags & RFTSIGFLAGS(RFTSIGMASK)) !=3D 0 && (flags & RFTSIGZMB) =3D= =3D 0) + return (EINVAL); + /* Can't copy and clear. */ if ((flags & (RFFDG|RFCFDG)) =3D=3D (RFFDG|RFCFDG)) return (EINVAL); =20 + /* Check the validity of the signal number. */ + if ((flags & RFTSIGZMB) !=3D 0 && (u_int)RFTSIGNUM(flags) > _SIG_MAXSIG) + return (EINVAL); + p1 =3D td->td_proc; =20 /* diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h index 378308d..9d56a3a 100644 --- a/sys/sys/unistd.h +++ b/sys/sys/unistd.h @@ -180,8 +180,16 @@ #define RFLINUXTHPN (1<<16) /* do linux clone exit parent notification */ #define RFSTOPPED (1<<17) /* leave child in a stopped state */ #define RFHIGHPID (1<<18) /* use a pid higher than 10 (idleproc) */ +#define RFTSIGZMB (1<<19) /* select signal for exit parent notification */ +#define RFTSIGSHIFT 20 /* selected signal number is in bits 20-27 */ +#define RFTSIGMASK 0xFF +#define RFTSIGNUM(flags) (((flags) >> RFTSIGSHIFT) & RFTSIGMASK) +#define RFTSIGFLAGS(signum) ((signum) << RFTSIGSHIFT) #define RFPPWAIT (1<<31) /* parent sleeps until child exits (vfork) */ #define RFKERNELONLY (RFSTOPPED | RFHIGHPID | RFPPWAIT) +#define RFFLAGS (RFFDG | RFPROC | RFMEM | RFNOWAIT | RFCFDG | \ + RFTHREAD | RFSIGSHARE | RFLINUXTHPN | RFSTOPPED | RFHIGHPID | RFTSIGZM= B | \ + RFPPWAIT) =20 #endif /* __BSD_VISIBLE */ =20 --qJM7dOmrnYWq+SaN Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk4cI20ACgkQC3+MBN1Mb4hM7gCeIk2P6FoqM7j24okpKp/hpnj8 ryEAoM3cL/0UcCUBjoes4UUS/nU5P8ZC =nlxa -----END PGP SIGNATURE----- --qJM7dOmrnYWq+SaN--
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