diff options
| -rw-r--r-- | arch/powerpc/include/asm/paca.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/mm/slb.c | 53 |
2 files changed, 53 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 97e8a57a4998..e843bc5d1a0f 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -115,6 +115,9 @@ struct paca_struct { u16 vmalloc_sllp; u8 slb_cache_ptr; u8 stab_rr; /* stab/slb round-robin counter */ +#ifdef CONFIG_DEBUG_VM + u8 in_kernel_slb_handler; +#endif u32 slb_used_bitmap; /* Bitmaps for first 32 SLB entries. */ u32 slb_kern_bitmap; u32 slb_cache[SLB_CACHE_ENTRIES]; diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index d8d9c9bd15d3..4b6e7a21a7c5 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -58,6 +58,30 @@ static inline unsigned long mk_vsid_data(unsigned long ea, int ssize, return __mk_vsid_data(get_kernel_vsid(ea, ssize), ssize, flags); } +static void assert_slb_exists(unsigned long ea) +{ +#ifdef CONFIG_DEBUG_VM + unsigned long tmp; + + WARN_ON_ONCE(mfmsr() & MSR_EE); + + asm volatile("slbfee. %0, %1" : "=r"(tmp) : "r"(ea) : "cr0"); + WARN_ON(tmp == 0); +#endif +} + +static void assert_slb_notexists(unsigned long ea) +{ +#ifdef CONFIG_DEBUG_VM + unsigned long tmp; + + WARN_ON_ONCE(mfmsr() & MSR_EE); + + asm volatile("slbfee. %0, %1" : "=r"(tmp) : "r"(ea) : "cr0"); + WARN_ON(tmp != 0); +#endif +} + static inline void slb_shadow_update(unsigned long ea, int ssize, unsigned long flags, enum slb_index index) @@ -90,6 +114,7 @@ static inline void create_shadowed_slbe(unsigned long ea, int ssize, */ slb_shadow_update(ea, ssize, flags, index); + assert_slb_notexists(ea); asm volatile("slbmte %0,%1" : : "r" (mk_vsid_data(ea, ssize, flags)), "r" (mk_esid_data(ea, ssize, index)) @@ -111,6 +136,8 @@ void __slb_restore_bolted_realmode(void) : "r" (be64_to_cpu(p->save_area[index].vsid)), "r" (be64_to_cpu(p->save_area[index].esid))); } + + assert_slb_exists(local_paca->kstack); } /* @@ -158,6 +185,7 @@ void slb_flush_and_restore_bolted(void) :: "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].vsid)), "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].esid)) : "memory"); + assert_slb_exists(get_paca()->kstack); get_paca()->slb_cache_ptr = 0; @@ -410,9 +438,17 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm) unsigned long slbie_data = 0; for (i = 0; i < offset; i++) { - /* EA */ - slbie_data = (unsigned long) + unsigned long ea; + + ea = (unsigned long) get_paca()->slb_cache[i] << SID_SHIFT; + /* + * Could assert_slb_exists here, but hypervisor + * or machine check could have come in and + * removed the entry at this point. + */ + + slbie_data = ea; slbie_data |= user_segment_size(slbie_data) << SLBIE_SSIZE_SHIFT; slbie_data |= SLBIE_C; /* user slbs have C=1 */ @@ -640,6 +676,7 @@ static long slb_insert_entry(unsigned long ea, unsigned long context, * User preloads should add isync afterwards in case the kernel * accesses user memory before it returns to userspace with rfid. */ + assert_slb_notexists(ea); asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data)); barrier(); @@ -740,7 +777,17 @@ long do_slb_fault(struct pt_regs *regs, unsigned long ea) * if they go via fast_exception_return too. */ if (id >= KERNEL_REGION_ID) { - return slb_allocate_kernel(ea, id); + long err; +#ifdef CONFIG_DEBUG_VM + /* Catch recursive kernel SLB faults. */ + BUG_ON(local_paca->in_kernel_slb_handler); + local_paca->in_kernel_slb_handler = 1; +#endif + err = slb_allocate_kernel(ea, id); +#ifdef CONFIG_DEBUG_VM + local_paca->in_kernel_slb_handler = 0; +#endif + return err; } else { struct mm_struct *mm = current->mm; long err; |