The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e93cd35101b61e4c79149be2cfc927c4b28dc60c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 28 Nov 2019 18:22:00 +0100
Subject: [PATCH] rsi: fix use-after-free on failed probe and unbind
Make sure to stop both URBs before returning after failed probe as well
as on disconnect to avoid use-after-free in the completion handler.
Reported-by: syzbot+b563b7f8dbe8223a51e8(a)syzkaller.appspotmail.com
Fixes: a4302bff28e2 ("rsi: add bluetooth rx endpoint")
Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable <stable(a)vger.kernel.org> # 3.15
Cc: Siva Rebbagondla <siva.rebbagondla(a)redpinesignals.com>
Cc: Prameela Rani Garnepudi <prameela.j04cs(a)gmail.com>
Cc: Amitkumar Karwar <amit.karwar(a)redpinesignals.com>
Cc: Fariya Fatima <fariyaf(a)gmail.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 53f41fc2cadf..30bed719486e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -292,6 +292,15 @@ static void rsi_rx_done_handler(struct urb *urb)
dev_kfree_skb(rx_cb->rx_skb);
}
+static void rsi_rx_urb_kill(struct rsi_hw *adapter, u8 ep_num)
+{
+ struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
+ struct rx_usb_ctrl_block *rx_cb = &dev->rx_cb[ep_num - 1];
+ struct urb *urb = rx_cb->rx_urb;
+
+ usb_kill_urb(urb);
+}
+
/**
* rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
* @adapter: Pointer to the adapter structure.
@@ -823,10 +832,13 @@ static int rsi_probe(struct usb_interface *pfunction,
if (adapter->priv->coex_mode > 1) {
status = rsi_rx_urb_submit(adapter, BT_EP);
if (status)
- goto err1;
+ goto err_kill_wlan_urb;
}
return 0;
+
+err_kill_wlan_urb:
+ rsi_rx_urb_kill(adapter, WLAN_EP);
err1:
rsi_deinit_usb_interface(adapter);
err:
@@ -857,6 +869,10 @@ static void rsi_disconnect(struct usb_interface *pfunction)
adapter->priv->bt_adapter = NULL;
}
+ if (adapter->priv->coex_mode > 1)
+ rsi_rx_urb_kill(adapter, BT_EP);
+ rsi_rx_urb_kill(adapter, WLAN_EP);
+
rsi_reset_card(adapter);
rsi_deinit_usb_interface(adapter);
rsi_91x_deinit(adapter);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e93cd35101b61e4c79149be2cfc927c4b28dc60c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 28 Nov 2019 18:22:00 +0100
Subject: [PATCH] rsi: fix use-after-free on failed probe and unbind
Make sure to stop both URBs before returning after failed probe as well
as on disconnect to avoid use-after-free in the completion handler.
Reported-by: syzbot+b563b7f8dbe8223a51e8(a)syzkaller.appspotmail.com
Fixes: a4302bff28e2 ("rsi: add bluetooth rx endpoint")
Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable <stable(a)vger.kernel.org> # 3.15
Cc: Siva Rebbagondla <siva.rebbagondla(a)redpinesignals.com>
Cc: Prameela Rani Garnepudi <prameela.j04cs(a)gmail.com>
Cc: Amitkumar Karwar <amit.karwar(a)redpinesignals.com>
Cc: Fariya Fatima <fariyaf(a)gmail.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 53f41fc2cadf..30bed719486e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -292,6 +292,15 @@ static void rsi_rx_done_handler(struct urb *urb)
dev_kfree_skb(rx_cb->rx_skb);
}
+static void rsi_rx_urb_kill(struct rsi_hw *adapter, u8 ep_num)
+{
+ struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
+ struct rx_usb_ctrl_block *rx_cb = &dev->rx_cb[ep_num - 1];
+ struct urb *urb = rx_cb->rx_urb;
+
+ usb_kill_urb(urb);
+}
+
/**
* rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
* @adapter: Pointer to the adapter structure.
@@ -823,10 +832,13 @@ static int rsi_probe(struct usb_interface *pfunction,
if (adapter->priv->coex_mode > 1) {
status = rsi_rx_urb_submit(adapter, BT_EP);
if (status)
- goto err1;
+ goto err_kill_wlan_urb;
}
return 0;
+
+err_kill_wlan_urb:
+ rsi_rx_urb_kill(adapter, WLAN_EP);
err1:
rsi_deinit_usb_interface(adapter);
err:
@@ -857,6 +869,10 @@ static void rsi_disconnect(struct usb_interface *pfunction)
adapter->priv->bt_adapter = NULL;
}
+ if (adapter->priv->coex_mode > 1)
+ rsi_rx_urb_kill(adapter, BT_EP);
+ rsi_rx_urb_kill(adapter, WLAN_EP);
+
rsi_reset_card(adapter);
rsi_deinit_usb_interface(adapter);
rsi_91x_deinit(adapter);
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e93cd35101b61e4c79149be2cfc927c4b28dc60c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 28 Nov 2019 18:22:00 +0100
Subject: [PATCH] rsi: fix use-after-free on failed probe and unbind
Make sure to stop both URBs before returning after failed probe as well
as on disconnect to avoid use-after-free in the completion handler.
Reported-by: syzbot+b563b7f8dbe8223a51e8(a)syzkaller.appspotmail.com
Fixes: a4302bff28e2 ("rsi: add bluetooth rx endpoint")
Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable <stable(a)vger.kernel.org> # 3.15
Cc: Siva Rebbagondla <siva.rebbagondla(a)redpinesignals.com>
Cc: Prameela Rani Garnepudi <prameela.j04cs(a)gmail.com>
Cc: Amitkumar Karwar <amit.karwar(a)redpinesignals.com>
Cc: Fariya Fatima <fariyaf(a)gmail.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 53f41fc2cadf..30bed719486e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -292,6 +292,15 @@ static void rsi_rx_done_handler(struct urb *urb)
dev_kfree_skb(rx_cb->rx_skb);
}
+static void rsi_rx_urb_kill(struct rsi_hw *adapter, u8 ep_num)
+{
+ struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
+ struct rx_usb_ctrl_block *rx_cb = &dev->rx_cb[ep_num - 1];
+ struct urb *urb = rx_cb->rx_urb;
+
+ usb_kill_urb(urb);
+}
+
/**
* rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
* @adapter: Pointer to the adapter structure.
@@ -823,10 +832,13 @@ static int rsi_probe(struct usb_interface *pfunction,
if (adapter->priv->coex_mode > 1) {
status = rsi_rx_urb_submit(adapter, BT_EP);
if (status)
- goto err1;
+ goto err_kill_wlan_urb;
}
return 0;
+
+err_kill_wlan_urb:
+ rsi_rx_urb_kill(adapter, WLAN_EP);
err1:
rsi_deinit_usb_interface(adapter);
err:
@@ -857,6 +869,10 @@ static void rsi_disconnect(struct usb_interface *pfunction)
adapter->priv->bt_adapter = NULL;
}
+ if (adapter->priv->coex_mode > 1)
+ rsi_rx_urb_kill(adapter, BT_EP);
+ rsi_rx_urb_kill(adapter, WLAN_EP);
+
rsi_reset_card(adapter);
rsi_deinit_usb_interface(adapter);
rsi_91x_deinit(adapter);
The f6783319737f appears to fix a reproducible crash that we have
been experiencing while stress-testing creation and deletion of
containers.
The fix seems to apply to 4.19.y more easily if you first apply
also 5d299eabea5a ('sched/fair: Add tmp_alone_branch assertion').
Please consider including into 4.19 upstream commits
ba5d73851e71847ba7f7f4c27a1a6e1f5ab91c79
("block: cleanup __blkdev_issue_discard()")
and
4800bf7bc8c725e955fcbc6191cc872f43f506d3
("block: fix 32 bit overflow in __blkdev_issue_discard()")
Overflow of unsigned long "req_sects" (fixed in second patch)
actually exist here much longer.
And 4.19 commit 744889b7cbb56a64f957e65ade7cb65fe3f35714
("block: don't deal with discard limit in blkdev_issue_discard()")
make it worse by replacing
req_sects = min_t(sector_t, nr_sects, q->limits.max_discard_sectors);
with
unsigned int req_sects = nr_sects;
because now discard length isn't cut by max_discard_sectors it easily overflows.
As a result BLKDISCARD fails unexpectedly:
ioctl(3, BLKDISCARD, [0, 0x20000000000]) = -1 EOPNOTSUPP (Operation not supported)
From: Mark Rutland <mark.rutland(a)arm.com>
Confusingly, there are three SPSR layouts that a kernel may need to deal
with:
(1) An AArch64 SPSR_ELx view of an AArch64 pstate
(2) An AArch64 SPSR_ELx view of an AArch32 pstate
(3) An AArch32 SPSR_* view of an AArch32 pstate
When the KVM AArch32 support code deals with SPSR_{EL2,HYP}, it's either
dealing with #2 or #3 consistently. On arm64 the PSR_AA32_* definitions
match the AArch64 SPSR_ELx view, and on arm the PSR_AA32_* definitions
match the AArch32 SPSR_* view.
However, when we inject an exception into an AArch32 guest, we have to
synthesize the AArch32 SPSR_* that the guest will see. Thus, an AArch64
host needs to synthesize layout #3 from layout #2.
This patch adds a new host_spsr_to_spsr32() helper for this, and makes
use of it in the KVM AArch32 support code. For arm64 we need to shuffle
the DIT bit around, and remove the SS bit, while for arm we can use the
value as-is.
I've open-coded the bit manipulation for now to avoid having to rework
the existing PSR_* definitions into PSR64_AA32_* and PSR32_AA32_*
definitions. I hope to perform a more thorough refactoring in future so
that we can handle pstate view manipulation more consistently across the
kernel tree.
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei(a)arm.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20200108134324.46500-4-mark.rutland@arm.com
---
arch/arm/include/asm/kvm_emulate.h | 5 +++++
arch/arm64/include/asm/kvm_emulate.h | 32 ++++++++++++++++++++++++++++
virt/kvm/arm/aarch32.c | 6 +++---
3 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index c488c629e6c8..08d9805f613b 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -53,6 +53,11 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
*__vcpu_spsr(vcpu) = v;
}
+static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
+{
+ return spsr;
+}
+
static inline unsigned long vcpu_get_reg(struct kvm_vcpu *vcpu,
u8 reg_num)
{
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index f407b6bdad2e..53ea7637b7b2 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -219,6 +219,38 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1] = v;
}
+/*
+ * The layout of SPSR for an AArch32 state is different when observed from an
+ * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
+ * view given an AArch64 view.
+ *
+ * In ARM DDI 0487E.a see:
+ *
+ * - The AArch64 view (SPSR_EL2) in section C5.2.18, page C5-426
+ * - The AArch32 view (SPSR_abt) in section G8.2.126, page G8-6256
+ * - The AArch32 view (SPSR_und) in section G8.2.132, page G8-6280
+ *
+ * Which show the following differences:
+ *
+ * | Bit | AA64 | AA32 | Notes |
+ * +-----+------+------+-----------------------------|
+ * | 24 | DIT | J | J is RES0 in ARMv8 |
+ * | 21 | SS | DIT | SS doesn't exist in AArch32 |
+ *
+ * ... and all other bits are (currently) common.
+ */
+static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
+{
+ const unsigned long overlap = BIT(24) | BIT(21);
+ unsigned long dit = !!(spsr & PSR_AA32_DIT_BIT);
+
+ spsr &= ~overlap;
+
+ spsr |= dit << 21;
+
+ return spsr;
+}
+
static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
{
u32 mode;
diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c
index 773cf1439081..631d397ac81b 100644
--- a/virt/kvm/arm/aarch32.c
+++ b/virt/kvm/arm/aarch32.c
@@ -129,15 +129,15 @@ static unsigned long get_except32_cpsr(struct kvm_vcpu *vcpu, u32 mode)
static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
{
- unsigned long new_spsr_value = *vcpu_cpsr(vcpu);
- bool is_thumb = (new_spsr_value & PSR_AA32_T_BIT);
+ unsigned long spsr = *vcpu_cpsr(vcpu);
+ bool is_thumb = (spsr & PSR_AA32_T_BIT);
u32 return_offset = return_offsets[vect_offset >> 2][is_thumb];
u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
*vcpu_cpsr(vcpu) = get_except32_cpsr(vcpu, mode);
/* Note: These now point to the banked copies */
- vcpu_write_spsr(vcpu, new_spsr_value);
+ vcpu_write_spsr(vcpu, host_spsr_to_spsr32(spsr));
*vcpu_reg32(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
/* Branch to exception vector */
--
2.20.1
From: Mark Rutland <mark.rutland(a)arm.com>
When KVM injects an exception into a guest, it generates the CPSR value
from scratch, configuring CPSR.{M,A,I,T,E}, and setting all other
bits to zero.
This isn't correct, as the architecture specifies that some CPSR bits
are (conditionally) cleared or set upon an exception, and others are
unchanged from the original context.
This patch adds logic to match the architectural behaviour. To make this
simple to follow/audit/extend, documentation references are provided,
and bits are configured in order of their layout in SPSR_EL2. This
layout can be seen in the diagram on ARM DDI 0487E.a page C5-426.
Note that this code is used by both arm and arm64, and is intended to
fuction with the SPSR_EL2 and SPSR_HYP layouts.
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei(a)arm.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20200108134324.46500-3-mark.rutland@arm.com
---
arch/arm/include/asm/kvm_emulate.h | 12 ++++
arch/arm64/include/asm/ptrace.h | 1 +
virt/kvm/arm/aarch32.c | 111 ++++++++++++++++++++++++++---
3 files changed, 114 insertions(+), 10 deletions(-)
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index fe55d8737a11..c488c629e6c8 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -14,13 +14,25 @@
#include <asm/cputype.h>
/* arm64 compatibility macros */
+#define PSR_AA32_MODE_FIQ FIQ_MODE
+#define PSR_AA32_MODE_SVC SVC_MODE
#define PSR_AA32_MODE_ABT ABT_MODE
#define PSR_AA32_MODE_UND UND_MODE
#define PSR_AA32_T_BIT PSR_T_BIT
+#define PSR_AA32_F_BIT PSR_F_BIT
#define PSR_AA32_I_BIT PSR_I_BIT
#define PSR_AA32_A_BIT PSR_A_BIT
#define PSR_AA32_E_BIT PSR_E_BIT
#define PSR_AA32_IT_MASK PSR_IT_MASK
+#define PSR_AA32_GE_MASK 0x000f0000
+#define PSR_AA32_DIT_BIT 0x00200000
+#define PSR_AA32_PAN_BIT 0x00400000
+#define PSR_AA32_SSBS_BIT 0x00800000
+#define PSR_AA32_Q_BIT PSR_Q_BIT
+#define PSR_AA32_V_BIT PSR_V_BIT
+#define PSR_AA32_C_BIT PSR_C_BIT
+#define PSR_AA32_Z_BIT PSR_Z_BIT
+#define PSR_AA32_N_BIT PSR_N_BIT
unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index fbebb411ae20..bf57308fcd63 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -62,6 +62,7 @@
#define PSR_AA32_I_BIT 0x00000080
#define PSR_AA32_A_BIT 0x00000100
#define PSR_AA32_E_BIT 0x00000200
+#define PSR_AA32_PAN_BIT 0x00400000
#define PSR_AA32_SSBS_BIT 0x00800000
#define PSR_AA32_DIT_BIT 0x01000000
#define PSR_AA32_Q_BIT 0x08000000
diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c
index c4c57ba99e90..773cf1439081 100644
--- a/virt/kvm/arm/aarch32.c
+++ b/virt/kvm/arm/aarch32.c
@@ -10,6 +10,7 @@
* Author: Christoffer Dall <c.dall(a)virtualopensystems.com>
*/
+#include <linux/bits.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
@@ -28,22 +29,112 @@ static const u8 return_offsets[8][2] = {
[7] = { 4, 4 }, /* FIQ, unused */
};
+/*
+ * When an exception is taken, most CPSR fields are left unchanged in the
+ * handler. However, some are explicitly overridden (e.g. M[4:0]).
+ *
+ * The SPSR/SPSR_ELx layouts differ, and the below is intended to work with
+ * either format. Note: SPSR.J bit doesn't exist in SPSR_ELx, but this bit was
+ * obsoleted by the ARMv7 virtualization extensions and is RES0.
+ *
+ * For the SPSR layout seen from AArch32, see:
+ * - ARM DDI 0406C.d, page B1-1148
+ * - ARM DDI 0487E.a, page G8-6264
+ *
+ * For the SPSR_ELx layout for AArch32 seen from AArch64, see:
+ * - ARM DDI 0487E.a, page C5-426
+ *
+ * Here we manipulate the fields in order of the AArch32 SPSR_ELx layout, from
+ * MSB to LSB.
+ */
+static unsigned long get_except32_cpsr(struct kvm_vcpu *vcpu, u32 mode)
+{
+ u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
+ unsigned long old, new;
+
+ old = *vcpu_cpsr(vcpu);
+ new = 0;
+
+ new |= (old & PSR_AA32_N_BIT);
+ new |= (old & PSR_AA32_Z_BIT);
+ new |= (old & PSR_AA32_C_BIT);
+ new |= (old & PSR_AA32_V_BIT);
+ new |= (old & PSR_AA32_Q_BIT);
+
+ // CPSR.IT[7:0] are set to zero upon any exception
+ // See ARM DDI 0487E.a, section G1.12.3
+ // See ARM DDI 0406C.d, section B1.8.3
+
+ new |= (old & PSR_AA32_DIT_BIT);
+
+ // CPSR.SSBS is set to SCTLR.DSSBS upon any exception
+ // See ARM DDI 0487E.a, page G8-6244
+ if (sctlr & BIT(31))
+ new |= PSR_AA32_SSBS_BIT;
+
+ // CPSR.PAN is unchanged unless SCTLR.SPAN == 0b0
+ // SCTLR.SPAN is RES1 when ARMv8.1-PAN is not implemented
+ // See ARM DDI 0487E.a, page G8-6246
+ new |= (old & PSR_AA32_PAN_BIT);
+ if (!(sctlr & BIT(23)))
+ new |= PSR_AA32_PAN_BIT;
+
+ // SS does not exist in AArch32, so ignore
+
+ // CPSR.IL is set to zero upon any exception
+ // See ARM DDI 0487E.a, page G1-5527
+
+ new |= (old & PSR_AA32_GE_MASK);
+
+ // CPSR.IT[7:0] are set to zero upon any exception
+ // See prior comment above
+
+ // CPSR.E is set to SCTLR.EE upon any exception
+ // See ARM DDI 0487E.a, page G8-6245
+ // See ARM DDI 0406C.d, page B4-1701
+ if (sctlr & BIT(25))
+ new |= PSR_AA32_E_BIT;
+
+ // CPSR.A is unchanged upon an exception to Undefined, Supervisor
+ // CPSR.A is set upon an exception to other modes
+ // See ARM DDI 0487E.a, pages G1-5515 to G1-5516
+ // See ARM DDI 0406C.d, page B1-1182
+ new |= (old & PSR_AA32_A_BIT);
+ if (mode != PSR_AA32_MODE_UND && mode != PSR_AA32_MODE_SVC)
+ new |= PSR_AA32_A_BIT;
+
+ // CPSR.I is set upon any exception
+ // See ARM DDI 0487E.a, pages G1-5515 to G1-5516
+ // See ARM DDI 0406C.d, page B1-1182
+ new |= PSR_AA32_I_BIT;
+
+ // CPSR.F is set upon an exception to FIQ
+ // CPSR.F is unchanged upon an exception to other modes
+ // See ARM DDI 0487E.a, pages G1-5515 to G1-5516
+ // See ARM DDI 0406C.d, page B1-1182
+ new |= (old & PSR_AA32_F_BIT);
+ if (mode == PSR_AA32_MODE_FIQ)
+ new |= PSR_AA32_F_BIT;
+
+ // CPSR.T is set to SCTLR.TE upon any exception
+ // See ARM DDI 0487E.a, page G8-5514
+ // See ARM DDI 0406C.d, page B1-1181
+ if (sctlr & BIT(30))
+ new |= PSR_AA32_T_BIT;
+
+ new |= mode;
+
+ return new;
+}
+
static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
{
- unsigned long cpsr;
unsigned long new_spsr_value = *vcpu_cpsr(vcpu);
bool is_thumb = (new_spsr_value & PSR_AA32_T_BIT);
u32 return_offset = return_offsets[vect_offset >> 2][is_thumb];
u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
- cpsr = mode | PSR_AA32_I_BIT;
-
- if (sctlr & (1 << 30))
- cpsr |= PSR_AA32_T_BIT;
- if (sctlr & (1 << 25))
- cpsr |= PSR_AA32_E_BIT;
-
- *vcpu_cpsr(vcpu) = cpsr;
+ *vcpu_cpsr(vcpu) = get_except32_cpsr(vcpu, mode);
/* Note: These now point to the banked copies */
vcpu_write_spsr(vcpu, new_spsr_value);
@@ -84,7 +175,7 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt,
fsr = &vcpu_cp15(vcpu, c5_DFSR);
}
- prepare_fault32(vcpu, PSR_AA32_MODE_ABT | PSR_AA32_A_BIT, vect_offset);
+ prepare_fault32(vcpu, PSR_AA32_MODE_ABT, vect_offset);
*far = addr;
--
2.20.1
From: Mark Rutland <mark.rutland(a)arm.com>
When KVM injects an exception into a guest, it generates the PSTATE
value from scratch, configuring PSTATE.{M[4:0],DAIF}, and setting all
other bits to zero.
This isn't correct, as the architecture specifies that some PSTATE bits
are (conditionally) cleared or set upon an exception, and others are
unchanged from the original context.
This patch adds logic to match the architectural behaviour. To make this
simple to follow/audit/extend, documentation references are provided,
and bits are configured in order of their layout in SPSR_EL2. This
layout can be seen in the diagram on ARM DDI 0487E.a page C5-429.
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei(a)arm.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20200108134324.46500-2-mark.rutland@arm.com
---
arch/arm64/include/uapi/asm/ptrace.h | 1 +
arch/arm64/kvm/inject_fault.c | 70 ++++++++++++++++++++++++++--
2 files changed, 66 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
index 7ed9294e2004..d1bb5b69f1ce 100644
--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -49,6 +49,7 @@
#define PSR_SSBS_BIT 0x00001000
#define PSR_PAN_BIT 0x00400000
#define PSR_UAO_BIT 0x00800000
+#define PSR_DIT_BIT 0x01000000
#define PSR_V_BIT 0x10000000
#define PSR_C_BIT 0x20000000
#define PSR_Z_BIT 0x40000000
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index ccdb6a051ab2..6aafc2825c1c 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -14,9 +14,6 @@
#include <asm/kvm_emulate.h>
#include <asm/esr.h>
-#define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \
- PSR_I_BIT | PSR_D_BIT)
-
#define CURRENT_EL_SP_EL0_VECTOR 0x0
#define CURRENT_EL_SP_ELx_VECTOR 0x200
#define LOWER_EL_AArch64_VECTOR 0x400
@@ -50,6 +47,69 @@ static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type)
return vcpu_read_sys_reg(vcpu, VBAR_EL1) + exc_offset + type;
}
+/*
+ * When an exception is taken, most PSTATE fields are left unchanged in the
+ * handler. However, some are explicitly overridden (e.g. M[4:0]). Luckily all
+ * of the inherited bits have the same position in the AArch64/AArch32 SPSR_ELx
+ * layouts, so we don't need to shuffle these for exceptions from AArch32 EL0.
+ *
+ * For the SPSR_ELx layout for AArch64, see ARM DDI 0487E.a page C5-429.
+ * For the SPSR_ELx layout for AArch32, see ARM DDI 0487E.a page C5-426.
+ *
+ * Here we manipulate the fields in order of the AArch64 SPSR_ELx layout, from
+ * MSB to LSB.
+ */
+static unsigned long get_except64_pstate(struct kvm_vcpu *vcpu)
+{
+ unsigned long sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
+ unsigned long old, new;
+
+ old = *vcpu_cpsr(vcpu);
+ new = 0;
+
+ new |= (old & PSR_N_BIT);
+ new |= (old & PSR_Z_BIT);
+ new |= (old & PSR_C_BIT);
+ new |= (old & PSR_V_BIT);
+
+ // TODO: TCO (if/when ARMv8.5-MemTag is exposed to guests)
+
+ new |= (old & PSR_DIT_BIT);
+
+ // PSTATE.UAO is set to zero upon any exception to AArch64
+ // See ARM DDI 0487E.a, page D5-2579.
+
+ // PSTATE.PAN is unchanged unless SCTLR_ELx.SPAN == 0b0
+ // SCTLR_ELx.SPAN is RES1 when ARMv8.1-PAN is not implemented
+ // See ARM DDI 0487E.a, page D5-2578.
+ new |= (old & PSR_PAN_BIT);
+ if (!(sctlr & SCTLR_EL1_SPAN))
+ new |= PSR_PAN_BIT;
+
+ // PSTATE.SS is set to zero upon any exception to AArch64
+ // See ARM DDI 0487E.a, page D2-2452.
+
+ // PSTATE.IL is set to zero upon any exception to AArch64
+ // See ARM DDI 0487E.a, page D1-2306.
+
+ // PSTATE.SSBS is set to SCTLR_ELx.DSSBS upon any exception to AArch64
+ // See ARM DDI 0487E.a, page D13-3258
+ if (sctlr & SCTLR_ELx_DSSBS)
+ new |= PSR_SSBS_BIT;
+
+ // PSTATE.BTYPE is set to zero upon any exception to AArch64
+ // See ARM DDI 0487E.a, pages D1-2293 to D1-2294.
+
+ new |= PSR_D_BIT;
+ new |= PSR_A_BIT;
+ new |= PSR_I_BIT;
+ new |= PSR_F_BIT;
+
+ new |= PSR_MODE_EL1h;
+
+ return new;
+}
+
static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
{
unsigned long cpsr = *vcpu_cpsr(vcpu);
@@ -59,7 +119,7 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr
vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu));
*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
- *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
+ *vcpu_cpsr(vcpu) = get_except64_pstate(vcpu);
vcpu_write_spsr(vcpu, cpsr);
vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
@@ -94,7 +154,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu));
*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
- *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
+ *vcpu_cpsr(vcpu) = get_except64_pstate(vcpu);
vcpu_write_spsr(vcpu, cpsr);
/*
--
2.20.1