On Sat, 23 Feb 2008, Ingo Molnar wrote: > > * Ingo Molnar <[EMAIL PROTECTED]> wrote: > > > could you try the fix below ontop of x86.git#testing, does it solve > > your boot hang? > > find below another fix that is somewhat better as it does not affect the > native kernel and !PARAVIRT.
This works. > > btw., this also explains why this bug wasnt reported sooner against > x86.git#testing: people done normally use PARAVIRT on 64-bit yet. > (there is no 64-bit host support) > > Ingo > > ----------------> > Subject: x86: stackprotector & PARAVIRT fix > From: Ingo Molnar <[EMAIL PROTECTED]> > Date: Sat Feb 23 07:06:55 CET 2008 > > on paravirt enabled 64-bit kernels the paravirt ops do function > calls themselves - which is bad with the stackprotector - for > example pda_init() loads 0 into %gs and then does MSR_GS_BASE > write (which modifies gs.base) - but that MSR write is a function > call on paravirt, which with stackprotector tries to read the > stack canary from the PDA ... crashing the bootup. > > the solution was suggested by Arjan van de Ven: to exclude paravirt.c > from stackprotector, too many lowlevel functionality is in it. It's > not like we'll have paravirt functions with character arrays on > their stack anyway... > > Signed-off-by: Arjan van de Ven <[EMAIL PROTECTED]> > Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> > --- > arch/x86/kernel/Makefile | 1 + > 1 file changed, 1 insertion(+) > > Index: linux-x86.q/arch/x86/kernel/Makefile > =================================================================== > --- linux-x86.q.orig/arch/x86/kernel/Makefile > +++ linux-x86.q/arch/x86/kernel/Makefile > @@ -15,6 +15,7 @@ nostackp := $(call cc-option, -fno-stack > CFLAGS_vsyscall_64.o := $(PROFILING) -g0 $(nostackp) > CFLAGS_hpet.o := $(nostackp) > CFLAGS_tsc_64.o := $(nostackp) > +CFLAGS_paravirt.o := $(nostackp) > > obj-y := process_$(BITS).o signal_$(BITS).o > entry_$(BITS).o > obj-y += traps_$(BITS).o irq_$(BITS).o > -- James Morris <[EMAIL PROTECTED]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
