> > On Sun, Dec 21, 2008 at 10:20:16AM -0500, John David Anglin wrote: > > > Honestly, I can't decide whether to apply this. It really should never > > > happen in the kernel, since the kernel can guarantee it won't get the > > > access rights failure (highest privilege level, and can set %sr and > > > %protid to whatever it wants.) > > > > I believe this change should be applied because we enable P and the > > hardware can generate the exception. Yes, it should never happen, but > > the coding to prevent this occurring is very subtle. > > > > If we're going to paper over a bug like this, we might as well just turn > the P-bit off... I just want a segv instead of a panic as I don't think we know whether the kernel is bad or not. This bug has been around for for some time. I believe that it was reported in 2004, or earlier. Even HP has problems. Saw this today: Release Date: Nov 19 2008 Description : PHKL_39110: ( QX:QXCR1000827621 ) The system can panic with the following panic string and stack trace. Panic string : Data memory protection/access rights/alignment fault FUNC panic+0x6c report_trap_or_int_and_panic+0x94 interrupt+0x4e4 ihandler+0x940 +------------- TRAP ---------------------------- | Trap type 18 in KERNEL mode at 0x38f50 (lbcopy+0x1f0) | p struct save_state 0.0x189cc60 +------------- TRAP ---------------- Dave -- J. David Anglin dave.anglin@xxxxxxxxxxxxxx National Research Council of Canada (613) 990-0752 (FAX: 952-6602) -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
