From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: edk2-devel@lists.01.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Leif Lindholm <leif.lindholm@linaro.org>,
Laszlo Ersek <lersek@redhat.com>,
Eric Auger <eric.auger@redhat.com>,
Andrew Jones <drjones@redhat.com>,
Philippe Mathieu-Daude <philmd@redhat.com>
Subject: [PATCH v2 2/4] ArmPkg/ArmMmuLib ARM: handle unmapped sections when updating permissions
Date: Fri, 30 Nov 2018 12:28:27 +0100 [thread overview]
Message-ID: <20181130112829.12173-3-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20181130112829.12173-1-ard.biesheuvel@linaro.org>
The ARM ArmMmuLib code currently does not take into account that
setting permissions on a region should take into account that a
region may not be mapped yet to begin with.
So when updating a section descriptor whose old value is zero,
pass in the address explicitly.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
index ec51e072ab43..889b22867dc7 100644
--- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
+++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibCore.c
@@ -695,8 +695,12 @@ UpdateSectionEntries (
} else {
// still a section entry
- // mask off appropriate fields
- Descriptor = CurrentDescriptor & ~EntryMask;
+ if (CurrentDescriptor != 0) {
+ // mask off appropriate fields
+ Descriptor = CurrentDescriptor & ~EntryMask;
+ } else {
+ Descriptor = ((UINTN)FirstLevelIdx + i) << TT_DESCRIPTOR_SECTION_BASE_SHIFT;
+ }
// mask in new attributes and/or permissions
Descriptor |= EntryValue;
--
2.19.1
next prev parent reply other threads:[~2018-11-30 11:28 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 11:28 [PATCH v2 0/4] ArmVirtQemu: unmap page #0 to catch NULL pointer dereferences Ard Biesheuvel
2018-11-30 11:28 ` [PATCH v2 1/4] ArmPkg/ArmMmuLib ARM: handle unmapped section in GetMemoryRegion() Ard Biesheuvel
2018-11-30 11:38 ` Leif Lindholm
2018-12-03 10:33 ` Philippe Mathieu-Daudé
2018-11-30 11:28 ` Ard Biesheuvel [this message]
2018-11-30 11:39 ` [PATCH v2 2/4] ArmPkg/ArmMmuLib ARM: handle unmapped sections when updating permissions Leif Lindholm
2018-11-30 11:28 ` [PATCH v2 3/4] ArmVirtPkg/NorFlashQemuLib: disregard our primary FV Ard Biesheuvel
2018-12-03 13:32 ` Laszlo Ersek
2018-11-30 11:28 ` [PATCH v2 4/4] ArmVirtPkg/QemuVirtMemInfoLib: trim the MMIO region mapping Ard Biesheuvel
2018-12-03 13:32 ` Laszlo Ersek
2018-12-03 15:25 ` [PATCH v2 0/4] ArmVirtQemu: unmap page #0 to catch NULL pointer dereferences Ard Biesheuvel
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