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From: Alexandru Elisei <alexandru.elisei@arm.com>
To: kvm@vger.kernel.org
Cc: pbonzini@redhat.com, drjones@redhat.com, maz@kernel.org,
	andre.przywara@arm.com, vladimir.murzin@arm.com,
	mark.rutland@arm.com
Subject: [kvm-unit-tests PATCH v3 14/18] lib: arm/arm64: Refuse to disable the MMU with non-identity stack pointer
Date: Tue, 31 Dec 2019 16:09:45 +0000	[thread overview]
Message-ID: <1577808589-31892-15-git-send-email-alexandru.elisei@arm.com> (raw)
In-Reply-To: <1577808589-31892-1-git-send-email-alexandru.elisei@arm.com>

When the MMU is off, all addresses are physical addresses. If the stack
pointer is not an identity mapped address (the virtual address is not the
same as the physical address), then we end up trying to access an invalid
memory region. This can happen if we call mmu_disable from a secondary CPU,
which has its stack allocated from the vmalloc region.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 lib/arm/mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
index 928a3702c563..111e3a52591a 100644
--- a/lib/arm/mmu.c
+++ b/lib/arm/mmu.c
@@ -68,8 +68,12 @@ void mmu_enable(pgd_t *pgtable)
 extern void asm_mmu_disable(void);
 void mmu_disable(void)
 {
+	unsigned long sp = current_stack_pointer;
 	int cpu = current_thread_info()->cpu;
 
+	assert_msg(__virt_to_phys(sp) == sp,
+			"Attempting to disable MMU with non-identity mapped stack");
+
 	mmu_mark_disabled(cpu);
 
 	asm_mmu_disable();
-- 
2.7.4


  parent reply	other threads:[~2019-12-31 16:10 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-31 16:09 [kvm-unit-tests PATCH v3 00/18] arm/arm64: Various fixes Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 01/18] lib: arm/arm64: Remove unnecessary dcache maintenance operations Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 02/18] lib: arm: Add proper data synchronization barriers for TLBIs Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 03/18] lib: Add WRITE_ONCE and READ_ONCE implementations in compiler.h Alexandru Elisei
2020-01-02 18:03   ` Andre Przywara
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 04/18] lib: arm/arm64: Use WRITE_ONCE to update the translation tables Alexandru Elisei
2020-01-02 18:06   ` Andre Przywara
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 05/18] lib: arm/arm64: Remove unused CPU_OFF parameter Alexandru Elisei
2020-01-02 18:11   ` Andre Przywara
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 06/18] arm/arm64: psci: Don't run C code without stack or vectors Alexandru Elisei
2020-01-02 18:11   ` Andre Przywara
2020-01-03 15:31     ` Andrew Jones
2020-01-06 11:02       ` Alexandru Elisei
2020-01-06 13:03         ` Andrew Jones
2020-01-06 14:03           ` Alexandru Elisei
2020-01-06 10:41     ` Alexandru Elisei
2020-01-06 11:17       ` Andre Przywara
2020-01-06 11:28         ` Alexandru Elisei
2020-01-06 11:36         ` Mark Rutland
2020-01-06 11:41       ` Mark Rutland
2020-01-06 13:17         ` Andrew Jones
2020-01-06 14:12           ` Alexandru Elisei
2020-01-06 15:20             ` Andrew Jones
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 07/18] lib: arm/arm64: Add missing include for alloc_page.h in pgtable.h Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 08/18] lib: arm: Implement flush_tlb_all Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 09/18] lib: arm/arm64: Teach mmu_clear_user about block mappings Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 10/18] arm/arm64: selftest: Add prefetch abort test Alexandru Elisei
2020-01-06  9:24   ` Andrew Jones
2020-01-06 11:03     ` Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 11/18] arm64: timer: Write to ICENABLER to disable timer IRQ Alexandru Elisei
2020-01-03 13:36   ` Andre Przywara
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 12/18] arm64: timer: EOIR the interrupt after masking the timer Alexandru Elisei
2020-01-03 13:36   ` Andre Przywara
2020-01-06 11:35     ` Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 13/18] arm64: timer: Test behavior when timer disabled or masked Alexandru Elisei
2020-01-03 13:37   ` Andre Przywara
2020-01-06 13:22     ` Alexandru Elisei
2019-12-31 16:09 ` Alexandru Elisei [this message]
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 15/18] arm/arm64: Perform dcache clean + invalidate after turning MMU off Alexandru Elisei
2020-01-03 16:49   ` Andre Przywara
2020-01-06 14:27     ` Alexandru Elisei
2020-01-06 16:28       ` Andrew Jones
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 16/18] arm: cstart64.S: Downgrade TLBI to non-shareable in asm_mmu_enable Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 17/18] arm/arm64: Invalidate TLB before enabling MMU Alexandru Elisei
2019-12-31 16:09 ` [kvm-unit-tests PATCH v3 18/18] arm: cstart64.S: Remove icache invalidation from asm_mmu_enable Alexandru Elisei
2020-01-06  9:28 ` [kvm-unit-tests PATCH v3 00/18] arm/arm64: Various fixes Andrew Jones
2020-01-09 10:01   ` Alexandru Elisei

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