Anything that avoids complicating the kernel exit path is worth doing! The exit path is complicated enough as it is. --david On 9/7/07, Petr Tesarik <ptesarik@xxxxxxx> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Shaohua Li wrote: > > On Thu, 2007-09-06 at 15:59 +0200, Petr Tesarik wrote: > >>[...] > >> So, what happens if upon syscall entry notification the debugger > >> modifies the part of the RBS (in user-space) which corresponds to the > >> arguments of that syscall? Currently, the syscall takes the modified > >> arguments, but with your change it would still take the stale data > >> from > >> the kernel RBS. > > The patch does sync from user RBS to kernel RBS just after syscall trace > > enter. this is an exception I said doing sync just before syscall > > return. I thought this covers your case, no? > > Ah, I'm sorry, I missed that part of the patch. Well, if we have to do a > sync on every syscall_trace_enter() and syscall_trace_leave(), then the > only cases where introducing TIF_RESTORE_RSE saves us a duplicate sync > seems to be in the clone/fork and exit paths. In other words, it's > probably not worth the added complexity. But since you have written the > whole complex thing already, I have no objections against it. > > Regards, > Petr Tesarik > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQFG4QtOjpY2ODFi2ogRArB1AJ0bcewvu+VQvpoQ7NMeloJDK9GDLACgnmVW > qw0ovAkl8PztYwpsru96eXc= > =eZUo > -----END PGP SIGNATURE----- > - > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Mosberger Consulting LLC, http://www.mosberger-consulting.com/ - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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