From: Balbir Singh bsingharora@gmail.com

The current code would fail on huge pages addresses, since the shift would be incorrect. Use the correct page shift value returned by __find_linux_pte() to get the correct physical address. The code is more generic and can handle both regular and compound pages.

Fixes: ba41e1e1ccb9 ("powerpc/mce: Hookup derror (load/store) UE errors") Signed-off-by: Balbir Singh bsingharora@gmail.com [arbab@linux.ibm.com: Fixup pseries_do_memory_failure()] Signed-off-by: Reza Arbab arbab@linux.ibm.com Co-developed-by: Santosh Sivaraj santosh@fossix.org Signed-off-by: Santosh Sivaraj santosh@fossix.org Tested-by: Mahesh Salgaonkar mahesh@linux.vnet.ibm.com Cc: stable@vger.kernel.org # v4.15+ --- arch/powerpc/include/asm/mce.h | 2 +- arch/powerpc/kernel/mce_power.c | 55 ++++++++++++++-------------- arch/powerpc/platforms/pseries/ras.c | 9 ++--- 3 files changed, 32 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h index a4c6a74ad2fb..f3a6036b6bc0 100644 --- a/arch/powerpc/include/asm/mce.h +++ b/arch/powerpc/include/asm/mce.h @@ -209,7 +209,7 @@ extern void release_mce_event(void); extern void machine_check_queue_event(void); extern void machine_check_print_event_info(struct machine_check_event *evt, bool user_mode, bool in_guest); -unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr); +unsigned long addr_to_phys(struct pt_regs *regs, unsigned long addr); #ifdef CONFIG_PPC_BOOK3S_64 void flush_and_reload_slb(void); #endif /* CONFIG_PPC_BOOK3S_64 */ diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c index a814d2dfb5b0..e74816f045f8 100644 --- a/arch/powerpc/kernel/mce_power.c +++ b/arch/powerpc/kernel/mce_power.c @@ -20,13 +20,14 @@ #include <asm/exception-64s.h>

/* - * Convert an address related to an mm to a PFN. NOTE: we are in real - * mode, we could potentially race with page table updates. + * Convert an address related to an mm to a physical address. + * NOTE: we are in real mode, we could potentially race with page table updates. */ -unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr) +unsigned long addr_to_phys(struct pt_regs *regs, unsigned long addr) { - pte_t *ptep; - unsigned long flags; + pte_t *ptep, pte; + unsigned int shift; + unsigned long flags, phys_addr; struct mm_struct *mm;

if (user_mode(regs)) @@ -35,14 +36,21 @@ unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr) mm = &init_mm;

local_irq_save(flags); - if (mm == current->mm) - ptep = find_current_mm_pte(mm->pgd, addr, NULL, NULL); - else - ptep = find_init_mm_pte(addr, NULL); + ptep = __find_linux_pte(mm->pgd, addr, NULL, &shift); local_irq_restore(flags); + if (!ptep || pte_special(*ptep)) return ULONG_MAX; - return pte_pfn(*ptep); + + pte = *ptep; + if (shift > PAGE_SHIFT) { + unsigned long rpnmask = (1ul << shift) - PAGE_SIZE; + + pte = __pte(pte_val(pte) | (addr & rpnmask)); + } + phys_addr = pte_pfn(pte) << PAGE_SHIFT; + + return phys_addr; }

/* flush SLBs and reload */ @@ -344,7 +352,7 @@ static const struct mce_derror_table mce_p9_derror_table[] = { MCE_INITIATOR_CPU, MCE_SEV_SEVERE, true }, { 0, false, 0, 0, 0, 0, 0 } };

-static int mce_find_instr_ea_and_pfn(struct pt_regs *regs, uint64_t *addr, +static int mce_find_instr_ea_and_phys(struct pt_regs *regs, uint64_t *addr, uint64_t *phys_addr) { /* @@ -354,18 +362,16 @@ static int mce_find_instr_ea_and_pfn(struct pt_regs *regs, uint64_t *addr, * faults */ int instr; - unsigned long pfn, instr_addr; + unsigned long instr_addr; struct instruction_op op; struct pt_regs tmp = *regs;

- pfn = addr_to_pfn(regs, regs->nip); - if (pfn != ULONG_MAX) { - instr_addr = (pfn << PAGE_SHIFT) + (regs->nip & ~PAGE_MASK); + instr_addr = addr_to_phys(regs, regs->nip) + (regs->nip & ~PAGE_MASK); + if (instr_addr != ULONG_MAX) { instr = *(unsigned int *)(instr_addr); if (!analyse_instr(&op, &tmp, instr)) { - pfn = addr_to_pfn(regs, op.ea); *addr = op.ea; - *phys_addr = (pfn << PAGE_SHIFT); + *phys_addr = addr_to_phys(regs, op.ea); return 0; } /* @@ -440,15 +446,9 @@ static int mce_handle_ierror(struct pt_regs *regs, *addr = regs->nip; if (mce_err->sync_error && table[i].error_type == MCE_ERROR_TYPE_UE) { - unsigned long pfn; - - if (get_paca()->in_mce < MAX_MCE_DEPTH) { - pfn = addr_to_pfn(regs, regs->nip); - if (pfn != ULONG_MAX) { - *phys_addr = - (pfn << PAGE_SHIFT); - } - } + if (get_paca()->in_mce < MAX_MCE_DEPTH) + *phys_addr = addr_to_phys(regs, + regs->nip); } } return handled; @@ -541,7 +541,8 @@ static int mce_handle_derror(struct pt_regs *regs, * kernel/exception-64s.h */ if (get_paca()->in_mce < MAX_MCE_DEPTH) - mce_find_instr_ea_and_pfn(regs, addr, phys_addr); + mce_find_instr_ea_and_phys(regs, addr, + phys_addr); } found = 1; } diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index f16fdd0f71f7..5743f6353638 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -739,13 +739,10 @@ static void pseries_do_memory_failure(struct pt_regs *regs, if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) { paddr = be64_to_cpu(mce_log->logical_address); } else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) { - unsigned long pfn; - - pfn = addr_to_pfn(regs, - be64_to_cpu(mce_log->effective_address)); - if (pfn == ULONG_MAX) + paddr = addr_to_phys(regs, + be64_to_cpu(mce_log->effective_address)); + if (paddr == ULONG_MAX) return; - paddr = pfn << PAGE_SHIFT; } else { return; }