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* [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work
       [not found] <20190812092236.16648-1-santosh@fossix.org>
@ 2019-08-12  9:22 ` Santosh Sivaraj
  2019-08-13  4:46   ` Mahesh Jagannath Salgaonkar
  2019-08-14  9:02   ` Balbir Singh
  2019-08-12  9:22 ` [PATCH v9 2/7] powerpc/mce: Fix MCE handling for huge pages Santosh Sivaraj
  1 sibling, 2 replies; 5+ messages in thread
From: Santosh Sivaraj @ 2019-08-12  9:22 UTC (permalink / raw)
  To: linuxppc-dev, Linux Kernel
  Cc: Aneesh Kumar K.V, Mahesh Salgaonkar, Reza Arbab, Balbir Singh,
	Chandan Rajendra, Michael Ellerman, Nicholas Piggin,
	christophe leroy, Mahesh Salgaonkar, stable

schedule_work() cannot be called from MCE exception context as MCE can
interrupt even in interrupt disabled context.

fixes: 733e4a4c ("powerpc/mce: hookup memory_failure for UE errors")
Suggested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Cc: stable@vger.kernel.org # v4.15+
---
 arch/powerpc/kernel/mce.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index b18df633eae9..cff31d4a501f 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -33,6 +33,7 @@ static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
 					mce_ue_event_queue);
 
 static void machine_check_process_queued_event(struct irq_work *work);
+static void machine_check_ue_irq_work(struct irq_work *work);
 void machine_check_ue_event(struct machine_check_event *evt);
 static void machine_process_ue_event(struct work_struct *work);
 
@@ -40,6 +41,10 @@ static struct irq_work mce_event_process_work = {
         .func = machine_check_process_queued_event,
 };
 
+static struct irq_work mce_ue_event_irq_work = {
+	.func = machine_check_ue_irq_work,
+};
+
 DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 
 static void mce_set_error_info(struct machine_check_event *mce,
@@ -199,6 +204,10 @@ void release_mce_event(void)
 	get_mce_event(NULL, true);
 }
 
+static void machine_check_ue_irq_work(struct irq_work *work)
+{
+	schedule_work(&mce_ue_event_work);
+}
 
 /*
  * Queue up the MCE event which then can be handled later.
@@ -216,7 +225,7 @@ void machine_check_ue_event(struct machine_check_event *evt)
 	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
 
 	/* Queue work to process this event later. */
-	schedule_work(&mce_ue_event_work);
+	irq_work_queue(&mce_ue_event_irq_work);
 }
 
 /*
-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v9 2/7] powerpc/mce: Fix MCE handling for huge pages
       [not found] <20190812092236.16648-1-santosh@fossix.org>
  2019-08-12  9:22 ` [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
@ 2019-08-12  9:22 ` Santosh Sivaraj
       [not found]   ` <20190812135532.66AC120684@mail.kernel.org>
  1 sibling, 1 reply; 5+ messages in thread
From: Santosh Sivaraj @ 2019-08-12  9:22 UTC (permalink / raw)
  To: linuxppc-dev, Linux Kernel
  Cc: Aneesh Kumar K.V, Mahesh Salgaonkar, Reza Arbab, Balbir Singh,
	Chandan Rajendra, Michael Ellerman, Nicholas Piggin,
	christophe leroy, Mahesh Salgaonkar, stable

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;
 	}
-- 
2.21.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v9 2/7] powerpc/mce: Fix MCE handling for huge pages
       [not found]   ` <20190812135532.66AC120684@mail.kernel.org>
@ 2019-08-13  0:40     ` Santosh Sivaraj
  0 siblings, 0 replies; 5+ messages in thread
From: Santosh Sivaraj @ 2019-08-13  0:40 UTC (permalink / raw)
  To: Sasha Levin, Sasha Levin, Balbir Singh, linuxppc-dev
  Cc: Aneesh Kumar K.V, stable

Sasha Levin <sashal@kernel.org> writes:

> Hi,
>
> [This is an automated email]
>
> This commit has been processed because it contains a "Fixes:" tag,
> fixing commit: ba41e1e1ccb9 powerpc/mce: Hookup derror (load/store) UE errors.
>
> The bot has tested the following trees: v5.2.8, v4.19.66.
>
> v5.2.8: Build OK!
> v4.19.66: Failed to apply! Possible dependencies:
>     360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
>     41f4e631daf8 ("KVM: PPC: Book3S HV: Extract PMU save/restore operations as C-callable functions")
>     884dfb722db8 ("KVM: PPC: Book3S HV: Simplify machine check handling")
>     89329c0be8bd ("KVM: PPC: Book3S HV: Clear partition table entry on vm teardown")
>     8e3f5fc1045d ("KVM: PPC: Book3S HV: Framework and hcall stubs for nested virtualization")
>     95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
>     a43c1590426c ("powerpc/pseries: Flush SLB contents on SLB MCE errors.")
>     c05772018491 ("powerpc/64s: Better printing of machine check info for guest MCEs")
>     d24ea8a7336a ("KVM: PPC: Book3S: Simplify external interrupt handling")
>     df709a296ef7 ("KVM: PPC: Book3S HV: Simplify real-mode interrupt handling")
>     f7035ce9f1df ("KVM: PPC: Book3S HV: Move interrupt delivery on guest entry to C code")
>
>
> NOTE: The patch will not be queued to stable trees until it is upstream.
>
> How should we proceed with this patch?

I will send a backport once this has been merged upstream.

Thanks,
Santosh

>
> --
> Thanks,
> Sasha

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work
  2019-08-12  9:22 ` [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
@ 2019-08-13  4:46   ` Mahesh Jagannath Salgaonkar
  2019-08-14  9:02   ` Balbir Singh
  1 sibling, 0 replies; 5+ messages in thread
From: Mahesh Jagannath Salgaonkar @ 2019-08-13  4:46 UTC (permalink / raw)
  To: Santosh Sivaraj, linuxppc-dev, Linux Kernel
  Cc: Aneesh Kumar K.V, Mahesh Salgaonkar, Reza Arbab, Balbir Singh,
	Chandan Rajendra, Michael Ellerman, Nicholas Piggin,
	christophe leroy, stable

On 8/12/19 2:52 PM, Santosh Sivaraj wrote:
> schedule_work() cannot be called from MCE exception context as MCE can
> interrupt even in interrupt disabled context.
> 
> fixes: 733e4a4c ("powerpc/mce: hookup memory_failure for UE errors")
> Suggested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
> Cc: stable@vger.kernel.org # v4.15+
> ---
>  arch/powerpc/kernel/mce.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

Thanks,
-Mahesh.

> 
> diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
> index b18df633eae9..cff31d4a501f 100644
> --- a/arch/powerpc/kernel/mce.c
> +++ b/arch/powerpc/kernel/mce.c
> @@ -33,6 +33,7 @@ static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
>  					mce_ue_event_queue);
>  
>  static void machine_check_process_queued_event(struct irq_work *work);
> +static void machine_check_ue_irq_work(struct irq_work *work);
>  void machine_check_ue_event(struct machine_check_event *evt);
>  static void machine_process_ue_event(struct work_struct *work);
>  
> @@ -40,6 +41,10 @@ static struct irq_work mce_event_process_work = {
>          .func = machine_check_process_queued_event,
>  };
>  
> +static struct irq_work mce_ue_event_irq_work = {
> +	.func = machine_check_ue_irq_work,
> +};
> +
>  DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
>  
>  static void mce_set_error_info(struct machine_check_event *mce,
> @@ -199,6 +204,10 @@ void release_mce_event(void)
>  	get_mce_event(NULL, true);
>  }
>  
> +static void machine_check_ue_irq_work(struct irq_work *work)
> +{
> +	schedule_work(&mce_ue_event_work);
> +}
>  
>  /*
>   * Queue up the MCE event which then can be handled later.
> @@ -216,7 +225,7 @@ void machine_check_ue_event(struct machine_check_event *evt)
>  	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
>  
>  	/* Queue work to process this event later. */
> -	schedule_work(&mce_ue_event_work);
> +	irq_work_queue(&mce_ue_event_irq_work);
>  }
>  
>  /*
> 


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work
  2019-08-12  9:22 ` [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
  2019-08-13  4:46   ` Mahesh Jagannath Salgaonkar
@ 2019-08-14  9:02   ` Balbir Singh
  1 sibling, 0 replies; 5+ messages in thread
From: Balbir Singh @ 2019-08-14  9:02 UTC (permalink / raw)
  To: Santosh Sivaraj, linuxppc-dev, Linux Kernel
  Cc: Aneesh Kumar K.V, Mahesh Salgaonkar, Reza Arbab,
	Chandan Rajendra, Michael Ellerman, Nicholas Piggin,
	christophe leroy, Mahesh Salgaonkar, stable



On 12/8/19 7:22 pm, Santosh Sivaraj wrote:
> schedule_work() cannot be called from MCE exception context as MCE can
> interrupt even in interrupt disabled context.
> 
> fixes: 733e4a4c ("powerpc/mce: hookup memory_failure for UE errors")
> Suggested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
> Cc: stable@vger.kernel.org # v4.15+
> ---

Acked-by: Balbir Singh <bsingharora@gmail.com>

^ permalink raw reply	[flat|nested] 5+ messages in thread

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Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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     [not found] <20190812092236.16648-1-santosh@fossix.org>
2019-08-12  9:22 ` [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
2019-08-13  4:46   ` Mahesh Jagannath Salgaonkar
2019-08-14  9:02   ` Balbir Singh
2019-08-12  9:22 ` [PATCH v9 2/7] powerpc/mce: Fix MCE handling for huge pages Santosh Sivaraj
     [not found]   ` <20190812135532.66AC120684@mail.kernel.org>
2019-08-13  0:40     ` Santosh Sivaraj

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