* Re: [PATCH] Re: export of sys_call_table @ 2002-10-09 12:20 Petr Vandrovec 2002-10-09 19:54 ` Brian F. G. Bidulock 0 siblings, 1 reply; 3+ messages in thread From: Petr Vandrovec @ 2002-10-09 12:20 UTC (permalink / raw) To: Brian F. G. Bidulock; +Cc: linux-kernel, LiS, davem On 8 Oct 02 at 18:21, Brian F. G. Bidulock wrote: > --- kernel/sys.c.orig 2002-08-02 19:39:46.000000000 -0500 > +++ kernel/sys.c 2002-10-08 16:46:55.000000000 -0500 ... I believe that you should check that nobody else has registered its own streams module. You can also allow for multiple streams modules in parallel (and fall through when module returns on -ENOIOCTLCMD or -ENOTTY), but I believe that usually only one module will be registered. And I believe that export symbols should NOT be _GPL_ONLY: before (non-GPL) export of syscall_table was available, non-GPL modules were able to hook syscalls, and when _GPL_ONLY was introduced into kernel it was promised that we'll never make currently provided functionality GPL-only (as far as I remember). Best regards, Petr Vandrovec int register_streams_calls(...) > +void register_streams_calls(int (*putpmsg) (int, void *, void *, int, int), > + int (*getpmsg) (int, void *, void *, int, int)) > +{ int err; if (!putpmsg || !getpmsg) return -EINVAL; > + down_write(&streams_call_sem); err = -EBUSY; if (!do_putpmsg) { err = 0; > + do_putpmsg = putpmsg; > + do_getpmsg = getpmsg; } > + up_write(&streams_call_sem); return err; > +} > + > +void unregister_streams_calls(void) > +{ down_write(&streams_call_sem); do_putpmsg = NULL; do_getpmsg = NULL; up_write(&streams_call_sem); } ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Re: export of sys_call_table 2002-10-09 12:20 [PATCH] Re: export of sys_call_table Petr Vandrovec @ 2002-10-09 19:54 ` Brian F. G. Bidulock 2002-10-10 16:01 ` [Linux-streams] " David Grothe 0 siblings, 1 reply; 3+ messages in thread From: Brian F. G. Bidulock @ 2002-10-09 19:54 UTC (permalink / raw) To: Petr Vandrovec; +Cc: linux-kernel, LiS, davem Petr, Thanks you for the constructive suggestions. I'll see if we can add those in an test it up. --brian On Wed, 09 Oct 2002, Petr Vandrovec wrote: > On 8 Oct 02 at 18:21, Brian F. G. Bidulock wrote: > > --- kernel/sys.c.orig 2002-08-02 19:39:46.000000000 -0500 > > +++ kernel/sys.c 2002-10-08 16:46:55.000000000 -0500 > ... > > I believe that you should check that nobody else has registered its > own streams module. You can also allow for multiple streams modules > in parallel (and fall through when module returns on -ENOIOCTLCMD or -ENOTTY), > but I believe that usually only one module will be registered. > > And I believe that export symbols should NOT be _GPL_ONLY: before > (non-GPL) export of syscall_table was available, non-GPL modules were > able to hook syscalls, and when _GPL_ONLY was introduced into kernel > it was promised that we'll never make currently provided functionality > GPL-only (as far as I remember). > Best regards, > Petr Vandrovec > > int register_streams_calls(...) > > +void register_streams_calls(int (*putpmsg) (int, void *, void *, int, int), > > + int (*getpmsg) (int, void *, void *, int, int)) > > +{ > > int err; > if (!putpmsg || !getpmsg) return -EINVAL; > > > + down_write(&streams_call_sem); > > err = -EBUSY; > if (!do_putpmsg) { > err = 0; > > > + do_putpmsg = putpmsg; > > + do_getpmsg = getpmsg; > > } > > > + up_write(&streams_call_sem); > > return err; > > > +} > > + > > +void unregister_streams_calls(void) > > +{ > > down_write(&streams_call_sem); > do_putpmsg = NULL; > do_getpmsg = NULL; > up_write(&streams_call_sem); > } > -- Brian F. G. Bidulock ¦ The reasonable man adapts himself to the ¦ bidulock@openss7.org ¦ world; the unreasonable one persists in ¦ http://www.openss7.org/ ¦ trying to adapt the world to himself. ¦ ¦ Therefore all progress depends on the ¦ ¦ unreasonable man. -- George Bernard Shaw ¦ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Linux-streams] Re: [PATCH] Re: export of sys_call_table 2002-10-09 19:54 ` Brian F. G. Bidulock @ 2002-10-10 16:01 ` David Grothe 0 siblings, 0 replies; 3+ messages in thread From: David Grothe @ 2002-10-10 16:01 UTC (permalink / raw) To: bidulock, Petr Vandrovec; +Cc: linux-kernel, LiS, davem [-- Attachment #1: Type: text/plain, Size: 287 bytes --] Brian, Petr, et al: Does this patch address your suggestions? This has been tested on 2.4.19. Thanks, Dave At 01:54 PM 10/9/2002 Wednesday, Brian F. G. Bidulock wrote: >Petr, > >Thanks you for the constructive suggestions. I'll see if we >can add those in an test it up. > >--brian [-- Attachment #2: stock-i386-2.4.19.txt --] [-- Type: text/plain, Size: 2699 bytes --] --- arch/i386/kernel/entry.S.orig 2002-08-02 19:39:42.000000000 -0500 +++ arch/i386/kernel/entry.S 2002-10-08 15:43:08.000000000 -0500 @@ -584,8 +584,8 @@ .long SYMBOL_NAME(sys_capset) /* 185 */ .long SYMBOL_NAME(sys_sigaltstack) .long SYMBOL_NAME(sys_sendfile) - .long SYMBOL_NAME(sys_ni_syscall) /* streams1 */ - .long SYMBOL_NAME(sys_ni_syscall) /* streams2 */ + .long SYMBOL_NAME(sys_getpmsg) /* streams1 */ + .long SYMBOL_NAME(sys_putpmsg) /* streams2 */ .long SYMBOL_NAME(sys_vfork) /* 190 */ .long SYMBOL_NAME(sys_getrlimit) .long SYMBOL_NAME(sys_mmap2) --- kernel/ksyms.c.orig 2002-08-02 19:39:46.000000000 -0500 +++ kernel/ksyms.c 2002-10-10 10:46:43.000000000 -0500 @@ -497,6 +497,11 @@ EXPORT_SYMBOL(seq_release); EXPORT_SYMBOL(seq_read); EXPORT_SYMBOL(seq_lseek); +extern int register_streams_calls(int (*putpmsg) (int,void *,void *,int,int), + int (*getpmsg) (int,void *,void *,int,int)); +extern void unregister_streams_calls(void); +EXPORT_SYMBOL(register_streams_calls); +EXPORT_SYMBOL(unregister_streams_calls); /* Program loader interfaces */ EXPORT_SYMBOL(setup_arg_pages); --- kernel/sys.c.orig 2002-08-02 19:39:46.000000000 -0500 +++ kernel/sys.c 2002-10-10 10:51:27.000000000 -0500 @@ -167,6 +167,50 @@ return notifier_chain_unregister(&reboot_notifier_list, nb); } +static int (*do_putpmsg) (int, void *, void *, int, int) = NULL; +static int (*do_getpmsg) (int, void *, void *, int, int) = NULL; + +static DECLARE_RWSEM(streams_call_sem) ; + +long asmlinkage sys_putpmsg(int fd, void *ctlptr, void *datptr, int band, int flags) +{ + int ret = -ENOSYS; + down_read(&streams_call_sem) ; /* should return int, but doesn't */ + if (do_putpmsg) + ret = (*do_putpmsg) (fd, ctlptr, datptr, band, flags); + up_read(&streams_call_sem); + return ret; +} + +long asmlinkage sys_getpmsg(int fd, void *ctlptr, void *datptr, int band, int flags) +{ + int ret = -ENOSYS; + down_read(&streams_call_sem) ; /* should return int, but doesn't */ + if (do_getpmsg) + ret = (*do_getpmsg) (fd, ctlptr, datptr, band, flags); + up_read(&streams_call_sem); + return ret; +} + +int register_streams_calls(int (*putpmsg) (int, void *, void *, int, int), + int (*getpmsg) (int, void *, void *, int, int)) +{ + down_write(&streams_call_sem) ; /* should return int, but doesn't */ + if ( (putpmsg != NULL && do_putpmsg != NULL) + || (getpmsg != NULL && do_getpmsg != NULL) + ) + return -EBUSY; + do_putpmsg = putpmsg; + do_getpmsg = getpmsg; + up_write(&streams_call_sem); + return 0 ; +} + +void unregister_streams_calls(void) +{ + register_streams_calls(NULL, NULL); +} + asmlinkage long sys_ni_syscall(void) { return -ENOSYS; ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-10-10 15:55 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2002-10-09 12:20 [PATCH] Re: export of sys_call_table Petr Vandrovec 2002-10-09 19:54 ` Brian F. G. Bidulock 2002-10-10 16:01 ` [Linux-streams] " David Grothe
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