Re: [PATCH v8 3/7] powerpc/mce: Fix MCE handling for huge pages
Mahesh Jagannath Salgaonkar writes:
> On 8/7/19 8:26 PM, Santosh Sivaraj wrote:
>> From: Balbir Singh
>>
>> 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
>> [ar...@linux.ibm.com: Fixup pseries_do_memory_failure()]
>> Signed-off-by: Reza Arbab
>> Co-developed-by: Santosh Sivaraj
>> Signed-off-by: Santosh Sivaraj
>> ---
>> arch/powerpc/include/asm/mce.h | 2 +-
>> arch/powerpc/kernel/mce_power.c | 50 ++--
>> arch/powerpc/platforms/pseries/ras.c | 9 ++---
>> 3 files changed, 29 insertions(+), 32 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..bed38a8e2e50 100644
>> --- a/arch/powerpc/kernel/mce_power.c
>> +++ b/arch/powerpc/kernel/mce_power.c
>> @@ -20,13 +20,14 @@
>> #include
>>
>> /*
>> - * 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 = _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, );
>> 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 */
>> @@ -354,18 +362,16 @@ static int mce_find_instr_ea_and_pfn(struct pt_regs
>> *regs, uint64_t *addr,
>
> Now that we have addr_to_phys() can we change this function name as well
> to mce_find_instr_ea_and_phys() ?
Makes sense, will avoid confusions.
>
> Tested-by: Mahesh Salgaonkar
>
> This should go to stable tree. Can you move this patch to 2nd position ?
Thanks for testing. Sure. Will reorder and mark stable as well.
Thanks,
Santosh
>
> Thanks,
> -Mahesh.
>
Re: [PATCH v8 3/7] powerpc/mce: Fix MCE handling for huge pages
On 8/7/19 8:26 PM, Santosh Sivaraj wrote:
> From: Balbir Singh
>
> 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
> [ar...@linux.ibm.com: Fixup pseries_do_memory_failure()]
> Signed-off-by: Reza Arbab
> Co-developed-by: Santosh Sivaraj
> Signed-off-by: Santosh Sivaraj
> ---
> arch/powerpc/include/asm/mce.h | 2 +-
> arch/powerpc/kernel/mce_power.c | 50 ++--
> arch/powerpc/platforms/pseries/ras.c | 9 ++---
> 3 files changed, 29 insertions(+), 32 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..bed38a8e2e50 100644
> --- a/arch/powerpc/kernel/mce_power.c
> +++ b/arch/powerpc/kernel/mce_power.c
> @@ -20,13 +20,14 @@
> #include
>
> /*
> - * 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 = _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, );
> 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 */
> @@ -354,18 +362,16 @@ static int mce_find_instr_ea_and_pfn(struct pt_regs
> *regs, uint64_t *addr,
Now that we have addr_to_phys() can we change this function name as well
to mce_find_instr_ea_and_phys() ?
Tested-by: Mahesh Salgaonkar
This should go to stable tree. Can you move this patch to 2nd position ?
Thanks,
-Mahesh.
[PATCH v8 3/7] powerpc/mce: Fix MCE handling for huge pages
From: Balbir Singh
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
[ar...@linux.ibm.com: Fixup pseries_do_memory_failure()]
Signed-off-by: Reza Arbab
Co-developed-by: Santosh Sivaraj
Signed-off-by: Santosh Sivaraj
---
arch/powerpc/include/asm/mce.h | 2 +-
arch/powerpc/kernel/mce_power.c | 50 ++--
arch/powerpc/platforms/pseries/ras.c | 9 ++---
3 files changed, 29 insertions(+), 32 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..bed38a8e2e50 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -20,13 +20,14 @@
#include
/*
- * 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 = _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, );
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 */
@@ -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(, , 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,
+
