On Fri, 12 Mar 2010, John David Anglin wrote: > The other issue is r16. I'm thinking we may need to reload r16 as the > context may change if we schedule, etc. If this checking is broken, it > would break the LWS assumptions. This theory is shotdown. The patch below possibly helps a bit but it doesn't resolve the minifail bug. The intention of the last couple of hunks is to return to the right place if cr30 changes as a result of scheduling. With more debugging, it seems that this is a clone mmap copy issue. Normally, the forked child doesn't see any non-zero data in the stack region allocated by pthread_create. However, if it does, the thread invariably dies and the stack region is corrupt after the fork. I guess I said this before ;( Dave -- J. David Anglin dave.anglin@xxxxxxxxxxxxxx National Research Council of Canada (613) 990-0752 (FAX: 952-6602) diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 3a44f7f..820d6ca 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -758,6 +758,10 @@ ENTRY(__kernel_thread) STREG %r22, PT_GR22(%r1) /* save r22 (arg5) */ copy %r0, %r22 /* user_tid */ + copy %r0, %r21 /* child_tid */ +#else + stw %r0, -52(%r30) /* user_tid */ + stw %r0, -56(%r30) /* child_tid */ #endif STREG %r26, PT_GR26(%r1) /* Store function & argument for child */ STREG %r25, PT_GR25(%r1) @@ -765,7 +769,7 @@ ENTRY(__kernel_thread) ldo CLONE_VM(%r26), %r26 /* Force CLONE_VM since only init_mm */ or %r26, %r24, %r26 /* will have kernel mappings. */ ldi 1, %r25 /* stack_start, signals kernel thread */ - stw %r0, -52(%r30) /* user_tid */ + ldi 0, %r23 /* child_stack_size */ #ifdef CONFIG_64BIT ldo -16(%r30),%r29 /* Reference param save area */ #endif @@ -972,7 +976,10 @@ intr_check_sig: BL do_notify_resume,%r2 copy %r16, %r26 /* struct pt_regs *regs */ - b,n intr_check_sig + mfctl %cr30,%r16 /* Reload */ + LDREG TI_TASK(%r16), %r16 /* thread_info -> task_struct */ + b intr_check_sig + ldo TASK_REGS(%r16),%r16 intr_restore: copy %r16,%r29 @@ -1026,14 +1033,12 @@ intr_do_resched: ldo -16(%r30),%r29 /* Reference param save area */ #endif - ldil L%intr_check_sig, %r2 -#ifndef CONFIG_64BIT - b schedule -#else - load32 schedule, %r20 - bv %r0(%r20) -#endif - ldo R%intr_check_sig(%r2), %r2 + BL schedule,%r2 + nop + mfctl %cr30,%r16 /* Reload */ + LDREG TI_TASK(%r16), %r16 /* thread_info -> task_struct */ + b intr_check_sig + ldo TASK_REGS(%r16),%r16 /* preempt the current task on returning to kernel * mode from an interrupt, iff need_resched is set, -- 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
