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From: Santosh Sivaraj <santosh@fossix.org>
To: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Mahesh Salgaonkar <mahesh@linux.ibm.com>,
	Reza Arbab <arbab@linux.ibm.com>,
	Chandan Rajendra <chandan@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Balbir Singh <bsingharora@gmail.com>,
	Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
	stable@vger.kernel.org
Subject: [PATCH v11 2/7] powerpc/mce: Fix MCE handling for huge pages
Date: Tue, 20 Aug 2019 13:43:47 +0530	[thread overview]
Message-ID: <20190820081352.8641-3-santosh@fossix.org> (raw)
In-Reply-To: <20190820081352.8641-1-santosh@fossix.org>

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>
Tested-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_power.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index a814d2dfb5b0..714a98e0927f 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -26,6 +26,7 @@
 unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr)
 {
 	pte_t *ptep;
+	unsigned int shift;
 	unsigned long flags;
 	struct mm_struct *mm;
 
@@ -35,13 +36,18 @@ 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;
+
+	if (shift > PAGE_SHIFT) {
+		unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
+
+		return pte_pfn(__pte(pte_val(*ptep) | (addr & rpnmask)));
+	}
+
 	return pte_pfn(*ptep);
 }
 
@@ -344,7 +350,7 @@ 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)
 {
 	/*
@@ -541,7 +547,8 @@ 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;
 	}
-- 
2.21.0


  parent reply	other threads:[~2019-08-20  8:14 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-20  8:13 [PATCH v11 0/7] powerpc: implement machine check safe memcpy Santosh Sivaraj
2019-08-20  8:13 ` [PATCH v11 1/7] powerpc/mce: Schedule work from irq_work Santosh Sivaraj
2019-08-22 13:09   ` Michael Ellerman
2019-08-20  8:13 ` Santosh Sivaraj [this message]
2019-08-20  8:13 ` [PATCH v11 3/7] powerpc/mce: Make machine_check_ue_event() static Santosh Sivaraj
2019-08-20  8:13 ` [PATCH v11 4/7] extable: Add function to search only kernel exception table Santosh Sivaraj
2019-08-20  8:13 ` [PATCH v11 5/7] powerpc/mce: Handle UE event for memcpy_mcsafe Santosh Sivaraj
2019-08-20  8:13 ` [PATCH v11 6/7] powerpc/memcpy: Add memcpy_mcsafe for pmem Santosh Sivaraj
2019-08-20  8:13 ` [PATCH v11 7/7] powerpc: add machine check safe copy_to_user Santosh Sivaraj

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