On Thu, 30 May 2013, Will Deacon wrote: > On Thu, May 30, 2013 at 10:09:49AM +0100, Will Deacon wrote: > > On Thu, May 30, 2013 at 02:41:42AM +0100, Wang, Yalin wrote: > > > If you have some patch for this issue, > > > I can do the test for it . > > > > I'll have a look at cooking something which uses an exception table entry > > to rewind the PC and retry the system call. That's simpler than directly > > injecting a user page fault from the system call path. > > Ok, please can you try the following? > > Will > > --->8 > > diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S > index bc5bc0a..855926e 100644 > --- a/arch/arm/kernel/entry-common.S > +++ b/arch/arm/kernel/entry-common.S > @@ -361,6 +361,15 @@ ENTRY(vector_swi) > str r8, [sp, #S_PSR] @ Save CPSR > str r0, [sp, #S_OLD_R0] @ Save OLD_R0 > zero_fp > + enable_irq > + ct_user_exit > + > +#ifdef CONFIG_ALIGNMENT_TRAP > + ldr ip, __cr_alignment > + ldr ip, [ip] > + mcr p15, 0, ip, c1, c0 @ update control register > +#endif This is wrong. you must set up the align bit in the control register _before_ enabling IRQs or an IRQ handler might run without alignment fixup. Otherwise the patch looks good to me. Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
