From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH AUTOSEL 5.2 35/70] powerpc/64s/radix: Remove redundant pfn_pte bitop, add VM_BUG_ON
Date: Tue, 24 Sep 2019 12:45:14 -0400 [thread overview]
Message-ID: <20190924164549.27058-35-sashal@kernel.org> (raw)
In-Reply-To: <20190924164549.27058-1-sashal@kernel.org>
From: Nicholas Piggin <npiggin@gmail.com>
[ Upstream commit 6bb25170d7a44ef0ed9677814600f0785e7421d1 ]
pfn_pte is never given a pte above the addressable physical memory
limit, so the masking is redundant. In case of a software bug, it
is not obviously better to silently truncate the pfn than to corrupt
the pte (either one will result in memory corruption or crashes),
so there is no reason to add this to the fast path.
Add VM_BUG_ON to catch cases where the pfn is invalid. These would
catch the create_section_mapping bug fixed by a previous commit.
[16885.256466] ------------[ cut here ]------------
[16885.256492] kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
cpu 0x0: Vector: 700 (Program Check) at [c0000000ee0a36d0]
pc: c000000000080738: __map_kernel_page+0x248/0x6f0
lr: c000000000080ac0: __map_kernel_page+0x5d0/0x6f0
sp: c0000000ee0a3960
msr: 9000000000029033
current = 0xc0000000ec63b400
paca = 0xc0000000017f0000 irqmask: 0x03 irq_happened: 0x01
pid = 85, comm = sh
kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
Linux version 5.3.0-rc1-00001-g0fe93e5f3394
enter ? for help
[c0000000ee0a3a00] c000000000d37378 create_physical_mapping+0x260/0x360
[c0000000ee0a3b10] c000000000d370bc create_section_mapping+0x1c/0x3c
[c0000000ee0a3b30] c000000000071f54 arch_add_memory+0x74/0x130
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190724084638.24982-5-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index ccf00a8b98c6a..c470f6370dccb 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -602,8 +602,10 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
*/
static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
{
- return __pte((((pte_basic_t)(pfn) << PAGE_SHIFT) & PTE_RPN_MASK) |
- pgprot_val(pgprot));
+ VM_BUG_ON(pfn >> (64 - PAGE_SHIFT));
+ VM_BUG_ON((pfn << PAGE_SHIFT) & ~PTE_RPN_MASK);
+
+ return __pte(((pte_basic_t)pfn << PAGE_SHIFT) | pgprot_val(pgprot));
}
static inline unsigned long pte_pfn(pte_t pte)
--
2.20.1
next prev parent reply other threads:[~2019-09-24 17:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190924164549.27058-1-sashal@kernel.org>
2019-09-24 16:44 ` [PATCH AUTOSEL 5.2 17/70] PCI: rpaphp: Avoid a sometimes-uninitialized warning Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 25/70] powerpc/powernv/ioda2: Allocate TCE table levels on demand for default DMA window Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 32/70] powerpc/xmon: Check for HV mode when dumping XIVE info from OPAL Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 33/70] powerpc/rtas: use device model APIs and serialization during LPM Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 34/70] powerpc/futex: Fix warning: 'oldval' may be used uninitialized in this function Sasha Levin
2019-09-24 16:45 ` Sasha Levin [this message]
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 36/70] powerpc/64s/radix: Fix memory hotplug section page table creation Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 37/70] powerpc/pseries/mobility: use cond_resched when updating device tree Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 38/70] powerpc/perf: fix imc allocation failure handling Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 40/70] powerpc/eeh: Clear stale EEH_DEV_NO_HANDLER flag Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 48/70] selftests/powerpc: Retry on host facility unavailable Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 50/70] powerpc/64s/exception: machine check use correct cfar for late handler Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 52/70] powerpc/eeh: Clean up EEH PEs after recovery finishes Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 53/70] powerpc/imc: Dont create debugfs files for cpu-less nodes Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 55/70] powerpc/pseries: correctly track irq state in default idle Sasha Levin
2019-09-24 16:45 ` [PATCH AUTOSEL 5.2 63/70] powerpc: dump kernel log before carrying out fadump or kdump Sasha Levin
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