Paul Mackerras wrote: > Kamalesh Babulal writes: > >> After applying the patch above and the patch posted on >> http://lkml.org/lkml/2008/4/8/42 >> the bug had the following information, > > Thanks. The patch below, against Linus' current git tree, fixes one > bug that might be the cause of the problem, and also attempts to > detect the erroneous situation earlier and fix it up, and also print > some debug information. Please try to reproduce the problem with this > patch applied, and if there are any console log messages starting with > SLB: or FWNMI:, please send me the console log. > > Paul. > > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S > index c0db5b7..f7f0962 100644 > --- a/arch/powerpc/kernel/entry_64.S > +++ b/arch/powerpc/kernel/entry_64.S > @@ -439,6 +439,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT) > mr r1,r8 /* start using new stack pointer */ > std r7,PACAKSAVE(r13) > > + /* check that SLB entry 2 contains the right thing */ > + clrrdi r6,r1,28 > + clrldi. r0,r6,2 > + beq 3f > + li r0,2 > + slbmfee r7,r0 > + oris r6,r6,[EMAIL PROTECTED] > + cmpd r6,r7 > + beq 3f > + bl bad_slb_switch > + ld r3,PACACURRENT(r13) > + addi r3,r3,THREAD > +3: > ld r6,_CCR(r1) > mtcrf 0xFF,r6 > > @@ -540,6 +553,19 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) > ld r4,_XER(r1) > mtspr SPRN_XER,r4 > > + /* check that SLB entry 2 contains the right thing */ > + clrrdi r6,r1,28 /* stack ESID */ > + clrldi. r0,r6,2 > + beq 57f > + li r0,2 > + slbmfee r7,r0 > + oris r6,r6,[EMAIL PROTECTED] > + cmpd r6,r7 > + beq 57f > + addi r3,r1,STACK_FRAME_OVERHEAD > + bl bad_slb_exc > + ld r3,_MSR(r1) > +57: > REST_8GPRS(5, r1) > > andi. r0,r3,MSR_RI > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c > index be35ffa..c938134 100644 > --- a/arch/powerpc/kernel/smp.c > +++ b/arch/powerpc/kernel/smp.c > @@ -45,6 +45,7 @@ > #include <asm/system.h> > #include <asm/mpic.h> > #include <asm/vdso_datapage.h> > +#include <asm/mmu.h> > #ifdef CONFIG_PPC64 > #include <asm/paca.h> > #endif > @@ -580,6 +581,10 @@ int __devinit start_secondary(void *unused) > atomic_inc(&init_mm.mm_count); > current->active_mm = &init_mm; > > + /* Bolt in the entry for the kernel stack now */ > + if (cpu_has_feature(CPU_FTR_SLB)) > + slb_flush_and_rebolt(); > + > smp_store_cpu_info(cpu); > set_dec(tb_ticks_per_jiffy); > preempt_disable(); > diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c > index 906daed..bb7765b 100644 > --- a/arch/powerpc/mm/slb.c > +++ b/arch/powerpc/mm/slb.c > @@ -309,3 +309,34 @@ void slb_initialize(void) > * one. */ > asm volatile("isync":::"memory"); > } > + > +static void dump_slb(void) > +{ > + long entry; > + unsigned long esid, vsid; > + > + printk(KERN_EMERG "SLB contents now:\n"); > + for (entry = 0; entry < 64; ++entry) { > + asm volatile("slbmfee %0,%1" : "=r" (esid) : "r" (entry)); > + if (esid == 0) > + /* valid bit is clear along with everything else */ > + continue; > + asm volatile("slbmfev %0,%1" : "=r" (vsid) : "r" (entry)); > + printk(KERN_EMERG "%d: %.16lx %.16lx\n", entry, esid, vsid); > + } > +} > + > +void bad_slb_exc(struct pt_regs *regs) > +{ > + printk(KERN_EMERG "SLB: stack not bolted on exception return\n"); > + dump_slb(); > + slb_flush_and_rebolt(); > + show_regs(regs); > +} > + > +void bad_slb_switch(void) > +{ > + printk(KERN_EMERG "SLB: stack not bolted on context switch\n"); > + dump_slb(); > + slb_flush_and_rebolt(); > +} > diff --git a/arch/powerpc/platforms/pseries/ras.c > b/arch/powerpc/platforms/pseries/ras.c > index a1ab25c..ed68083 100644 > --- a/arch/powerpc/platforms/pseries/ras.c > +++ b/arch/powerpc/platforms/pseries/ras.c > @@ -325,6 +325,8 @@ static int recover_mce(struct pt_regs *regs, struct > rtas_error_log * err) > > if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { > /* Platform corrected itself */ > + printk(KERN_ALERT "FWNMI: platform corrected error %.16lx\n", > + *(unsigned long *)err); > nonfatal = 1; > } else if ((regs->msr & MSR_RI) && > user_mode(regs) &&
Hi Paul, Thanks, after applying the patch the oops is not reproducible on the machine. The console log had no message starting with SLB: or FWNMI:. I have updated the bugzilla also. Tested-by: Kamalesh Babulal <[EMAIL PROTECTED]> -- Thanks & Regards, Kamalesh Babulal, Linux Technology Center, IBM, ISTL. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
