update reentrancy patches to version in upstream git

The previous version was picked from the mailing list and still had
an object_dynamic_cast call in a hot path, which is avoided with the
version that landed in git.

Also adds a few more exceptions for devices that need reentrancy.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
This commit is contained in:
Fiona Ebner 2023-06-06 10:58:50 +02:00 committed by Thomas Lamprecht
parent 0f693c2cab
commit a39364b9d1
11 changed files with 252 additions and 162 deletions

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@ -1,118 +0,0 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Sat, 4 Feb 2023 23:07:34 -0500
Subject: [PATCH] memory: prevent dma-reentracy issues
Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA.
This flag is set/checked prior to calling a device's MemoryRegion
handlers, and set when device code initiates DMA. The purpose of this
flag is to prevent two types of DMA-based reentrancy issues:
1.) mmio -> dma -> mmio case
2.) bh -> dma write -> mmio case
These issues have led to problems such as stack-exhaustion and
use-after-frees.
Summary of the problem from Peter Maydell:
https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1282
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Acked-by: Peter Xu <peterx@redhat.com>
(picked-up from https://lists.nongnu.org/archive/html/qemu-devel/2023-02/msg01142.html)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
include/hw/qdev-core.h | 7 +++++++
softmmu/memory.c | 17 +++++++++++++++++
softmmu/trace-events | 1 +
3 files changed, 25 insertions(+)
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index bd50ad5ee1..7623703943 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -162,6 +162,10 @@ struct NamedClockList {
QLIST_ENTRY(NamedClockList) node;
};
+typedef struct {
+ bool engaged_in_io;
+} MemReentrancyGuard;
+
/**
* DeviceState:
* @realized: Indicates whether the device has been fully constructed.
@@ -194,6 +198,9 @@ struct DeviceState {
int alias_required_for_version;
ResettableState reset;
GSList *unplug_blockers;
+
+ /* Is the device currently in mmio/pio/dma? Used to prevent re-entrancy */
+ MemReentrancyGuard mem_reentrancy_guard;
};
struct DeviceListener {
diff --git a/softmmu/memory.c b/softmmu/memory.c
index b1a6cae6f5..e4d2268d32 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -533,6 +533,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
uint64_t access_mask;
unsigned access_size;
unsigned i;
+ DeviceState *dev = NULL;
MemTxResult r = MEMTX_OK;
if (!access_size_min) {
@@ -542,6 +543,19 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_size_max = 4;
}
+ /* Do not allow more than one simultanous access to a device's IO Regions */
+ if (mr->owner &&
+ !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
+ dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
+ if (dev) {
+ if (dev->mem_reentrancy_guard.engaged_in_io) {
+ trace_memory_region_reentrant_io(get_cpu_index(), mr, addr, size);
+ return MEMTX_ERROR;
+ }
+ dev->mem_reentrancy_guard.engaged_in_io = true;
+ }
+ }
+
/* FIXME: support unaligned access? */
access_size = MAX(MIN(size, access_size_max), access_size_min);
access_mask = MAKE_64BIT_MASK(0, access_size * 8);
@@ -556,6 +570,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_mask, attrs);
}
}
+ if (dev) {
+ dev->mem_reentrancy_guard.engaged_in_io = false;
+ }
return r;
}
diff --git a/softmmu/trace-events b/softmmu/trace-events
index 22606dc27b..62d04ea9a7 100644
--- a/softmmu/trace-events
+++ b/softmmu/trace-events
@@ -13,6 +13,7 @@ memory_region_ops_read(int cpu_index, void *mr, uint64_t addr, uint64_t value, u
memory_region_ops_write(int cpu_index, void *mr, uint64_t addr, uint64_t value, unsigned size, const char *name) "cpu %d mr %p addr 0x%"PRIx64" value 0x%"PRIx64" size %u name '%s'"
memory_region_subpage_read(int cpu_index, void *mr, uint64_t offset, uint64_t value, unsigned size) "cpu %d mr %p offset 0x%"PRIx64" value 0x%"PRIx64" size %u"
memory_region_subpage_write(int cpu_index, void *mr, uint64_t offset, uint64_t value, unsigned size) "cpu %d mr %p offset 0x%"PRIx64" value 0x%"PRIx64" size %u"
+memory_region_reentrant_io(int cpu_index, void *mr, uint64_t offset, unsigned size) "cpu %d mr %p offset 0x%"PRIx64" size %u"
memory_region_ram_device_read(int cpu_index, void *mr, uint64_t addr, uint64_t value, unsigned size) "cpu %d mr %p addr 0x%"PRIx64" value 0x%"PRIx64" size %u"
memory_region_ram_device_write(int cpu_index, void *mr, uint64_t addr, uint64_t value, unsigned size) "cpu %d mr %p addr 0x%"PRIx64" value 0x%"PRIx64" size %u"
memory_region_sync_dirty(const char *mr, const char *listener, int global) "mr '%s' listener '%s' synced (global=%d)"

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@ -1,38 +0,0 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Mon, 13 Mar 2023 04:24:16 -0400
Subject: [PATCH] memory: Allow disabling re-entrancy checking per-MR
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
include/exec/memory.h | 3 +++
softmmu/memory.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 15ade918ba..e6819e3c39 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -791,6 +791,9 @@ struct MemoryRegion {
unsigned ioeventfd_nb;
MemoryRegionIoeventfd *ioeventfds;
RamDiscardManager *rdm; /* Only for RAM */
+
+ /* For devices designed to perform re-entrant IO into their own IO MRs */
+ bool disable_reentrancy_guard;
};
struct IOMMUMemoryRegion {
diff --git a/softmmu/memory.c b/softmmu/memory.c
index e4d2268d32..d88acb204b 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -544,7 +544,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
}
/* Do not allow more than one simultanous access to a device's IO Regions */
- if (mr->owner &&
+ if (mr->owner && !mr->disable_reentrancy_guard &&
!mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
if (dev) {

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@ -0,0 +1,130 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Thu, 27 Apr 2023 17:10:06 -0400
Subject: [PATCH] memory: prevent dma-reentracy issues
Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA.
This flag is set/checked prior to calling a device's MemoryRegion
handlers, and set when device code initiates DMA. The purpose of this
flag is to prevent two types of DMA-based reentrancy issues:
1.) mmio -> dma -> mmio case
2.) bh -> dma write -> mmio case
These issues have led to problems such as stack-exhaustion and
use-after-frees.
Summary of the problem from Peter Maydell:
https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1282
Resolves: CVE-2023-0330
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230427211013.2994127-2-alxndr@bu.edu>
[thuth: Replace warn_report() with warn_report_once()]
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry-picked from commit a2e1753b8054344f32cf94f31c6399a58794a380)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
include/exec/memory.h | 5 +++++
include/hw/qdev-core.h | 7 +++++++
softmmu/memory.c | 16 ++++++++++++++++
3 files changed, 28 insertions(+)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 15ade918ba..e45ce6061f 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -767,6 +767,8 @@ struct MemoryRegion {
bool is_iommu;
RAMBlock *ram_block;
Object *owner;
+ /* owner as TYPE_DEVICE. Used for re-entrancy checks in MR access hotpath */
+ DeviceState *dev;
const MemoryRegionOps *ops;
void *opaque;
@@ -791,6 +793,9 @@ struct MemoryRegion {
unsigned ioeventfd_nb;
MemoryRegionIoeventfd *ioeventfds;
RamDiscardManager *rdm; /* Only for RAM */
+
+ /* For devices designed to perform re-entrant IO into their own IO MRs */
+ bool disable_reentrancy_guard;
};
struct IOMMUMemoryRegion {
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index bd50ad5ee1..7623703943 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -162,6 +162,10 @@ struct NamedClockList {
QLIST_ENTRY(NamedClockList) node;
};
+typedef struct {
+ bool engaged_in_io;
+} MemReentrancyGuard;
+
/**
* DeviceState:
* @realized: Indicates whether the device has been fully constructed.
@@ -194,6 +198,9 @@ struct DeviceState {
int alias_required_for_version;
ResettableState reset;
GSList *unplug_blockers;
+
+ /* Is the device currently in mmio/pio/dma? Used to prevent re-entrancy */
+ MemReentrancyGuard mem_reentrancy_guard;
};
struct DeviceListener {
diff --git a/softmmu/memory.c b/softmmu/memory.c
index b1a6cae6f5..b7b3386e9d 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -542,6 +542,18 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_size_max = 4;
}
+ /* Do not allow more than one simultaneous access to a device's IO Regions */
+ if (mr->dev && !mr->disable_reentrancy_guard &&
+ !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
+ if (mr->dev->mem_reentrancy_guard.engaged_in_io) {
+ warn_report_once("Blocked re-entrant IO on MemoryRegion: "
+ "%s at addr: 0x%" HWADDR_PRIX,
+ memory_region_name(mr), addr);
+ return MEMTX_ACCESS_ERROR;
+ }
+ mr->dev->mem_reentrancy_guard.engaged_in_io = true;
+ }
+
/* FIXME: support unaligned access? */
access_size = MAX(MIN(size, access_size_max), access_size_min);
access_mask = MAKE_64BIT_MASK(0, access_size * 8);
@@ -556,6 +568,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_mask, attrs);
}
}
+ if (mr->dev) {
+ mr->dev->mem_reentrancy_guard.engaged_in_io = false;
+ }
return r;
}
@@ -1170,6 +1185,7 @@ static void memory_region_do_init(MemoryRegion *mr,
}
mr->name = g_strdup(name);
mr->owner = owner;
+ mr->dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
mr->ram_block = NULL;
if (name) {

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@ -1,6 +1,6 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Mon, 13 Mar 2023 04:24:17 -0400
Date: Thu, 27 Apr 2023 17:10:10 -0400
Subject: [PATCH] lsi53c895a: disable reentrancy detection for script RAM
As the code is designed to use the memory APIs to access the script ram,
@ -10,6 +10,12 @@ In the future, ram_io may be converted from an IO to a proper RAM MemoryRegion.
Reported-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-6-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry-picked from commit bfd6e7ae6a72b84e2eb9574f56e6ec037f05182c)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
hw/scsi/lsi53c895a.c | 6 ++++++
1 file changed, 6 insertions(+)

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@ -0,0 +1,37 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Thu, 27 Apr 2023 17:10:11 -0400
Subject: [PATCH] bcm2835_property: disable reentrancy detection for iomem
As the code is designed for re-entrant calls from bcm2835_property to
bcm2835_mbox and back into bcm2835_property, mark iomem as
reentrancy-safe.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230427211013.2994127-7-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry-picked from commit 985c4a4e547afb9573b6bd6843d20eb2c3d1d1cd)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
hw/misc/bcm2835_property.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/misc/bcm2835_property.c b/hw/misc/bcm2835_property.c
index 890ae7bae5..de056ea2df 100644
--- a/hw/misc/bcm2835_property.c
+++ b/hw/misc/bcm2835_property.c
@@ -382,6 +382,13 @@ static void bcm2835_property_init(Object *obj)
memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_property_ops, s,
TYPE_BCM2835_PROPERTY, 0x10);
+
+ /*
+ * bcm2835_property_ops call into bcm2835_mbox, which in-turn reads from
+ * iomem. As such, mark iomem as re-entracy safe.
+ */
+ s->iomem.disable_reentrancy_guard = true;
+
sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
}

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@ -0,0 +1,35 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Thu, 27 Apr 2023 17:10:12 -0400
Subject: [PATCH] raven: disable reentrancy detection for iomem
As the code is designed for re-entrant calls from raven_io_ops to
pci-conf, mark raven_io_ops as reentrancy-safe.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20230427211013.2994127-8-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry-picked from commit 6dad5a6810d9c60ca320d01276f6133bbcfa1fc7)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
hw/pci-host/raven.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/pci-host/raven.c b/hw/pci-host/raven.c
index 072ffe3c5e..9a11ac4b2b 100644
--- a/hw/pci-host/raven.c
+++ b/hw/pci-host/raven.c
@@ -294,6 +294,13 @@ static void raven_pcihost_initfn(Object *obj)
memory_region_init(&s->pci_memory, obj, "pci-memory", 0x3f000000);
address_space_init(&s->pci_io_as, &s->pci_io, "raven-io");
+ /*
+ * Raven's raven_io_ops use the address-space API to access pci-conf-idx
+ * (which is also owned by the raven device). As such, mark the
+ * pci_io_non_contiguous as re-entrancy safe.
+ */
+ s->pci_io_non_contiguous.disable_reentrancy_guard = true;
+
/* CPU address space */
memory_region_add_subregion(address_space_mem, PCI_IO_BASE_ADDR,
&s->pci_io);

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@ -0,0 +1,36 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Thu, 27 Apr 2023 17:10:13 -0400
Subject: [PATCH] apic: disable reentrancy detection for apic-msi
As the code is designed for re-entrant calls to apic-msi, mark apic-msi
as reentrancy-safe.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-9-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry-picked from commit 50795ee051a342c681a9b45671c552fbd6274db8)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
hw/intc/apic.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 20b5a94073..ac3d47d231 100644
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -885,6 +885,13 @@ static void apic_realize(DeviceState *dev, Error **errp)
memory_region_init_io(&s->io_memory, OBJECT(s), &apic_io_ops, s, "apic-msi",
APIC_SPACE_SIZE);
+ /*
+ * apic-msi's apic_mem_write can call into ioapic_eoi_broadcast, which can
+ * write back to apic-msi. As such mark the apic-msi region re-entrancy
+ * safe.
+ */
+ s->io_memory.disable_reentrancy_guard = true;
+
s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, apic_timer, s);
local_apics[s->id] = s;

12
debian/patches/series vendored
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@ -1,10 +1,12 @@
extra/0001-monitor-qmp-fix-race-with-clients-disconnecting-earl.patch
extra/0002-memory-prevent-dma-reentracy-issues.patch
extra/0003-scsi-megasas-Internal-cdbs-have-16-byte-length.patch
extra/0004-ide-avoid-potential-deadlock-when-draining-during-tr.patch
extra/0005-memory-Allow-disabling-re-entrancy-checking-per-MR.patch
extra/0002-scsi-megasas-Internal-cdbs-have-16-byte-length.patch
extra/0003-ide-avoid-potential-deadlock-when-draining-during-tr.patch
extra/0004-ui-return-NULL-when-getting-cursor-without-a-console.patch
extra/0005-memory-prevent-dma-reentracy-issues.patch
extra/0006-lsi53c895a-disable-reentrancy-detection-for-script-R.patch
extra/0007-ui-return-NULL-when-getting-cursor-without-a-console.patch
extra/0007-bcm2835_property-disable-reentrancy-detection-for-io.patch
extra/0008-raven-disable-reentrancy-detection-for-iomem.patch
extra/0009-apic-disable-reentrancy-detection-for-apic-msi.patch
bitmap-mirror/0001-drive-mirror-add-support-for-sync-bitmap-mode-never.patch
bitmap-mirror/0002-drive-mirror-add-support-for-conditional-and-always-.patch
bitmap-mirror/0003-mirror-add-check-for-bitmap-mode-without-bitmap.patch