Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte aligned
addresses associated with it. These control voltage, enable state, mode,
and in legacy targets, voltage headroom. The current in-flight request
checking logic looks for exact address matches. Requests for different
addresses of the same RPMh resource as thus not detected as in-flight.
Add new cmd-db API cmd_db_match_resource_addr() to enhance the in-flight
request check for VRM requests by ignoring the address offset.
This ensures that only one request is allowed to be in-flight for a given
VRM resource. This is needed to avoid scenarios where request commands are
carried out by RPMh hardware out-of-order leading to LDO regulator
over-current protection triggering.
Fixes: 658628e7ef78 ("drivers: qcom: rpmh-rsc: add RPMH controller for QCOM SoCs")
cc: stable(a)vger.kernel.org
Reviewed-by: Konrad Dybcio <konrad.dybcio(a)linaro.org>
Tested-by: Elliot Berman <quic_eberman(a)quicinc.com> # sm8650-qrd
Signed-off-by: Maulik Shah <quic_mkshah(a)quicinc.com>
---
Changes in v4:
- Simplify cmd_db_match_resource_addr()
- Remove unrelated changes to newly added logic
- Update function description comments
- Replace Signed-off-by: with Tested-by: from Elliot
- Link to v3: https://lore.kernel.org/r/20240212-rpmh-rsc-fixes-v3-1-1be0d705dbb5@quicinc…
Changes in v3:
- Fix s-o-b chain
- Add cmd-db API to compare addresses
- Reuse already defined resource types in cmd-db
- Add Fixes tag and Cc to stable
- Retain Reviewed-by tag of v2
- Link to v2: https://lore.kernel.org/r/20240119-rpmh-rsc-fixes-v2-1-e42c0a9e36f0@quicinc…
Changes in v2:
- Use GENMASK() and FIELD_GET()
- Link to v1: https://lore.kernel.org/r/20240117-rpmh-rsc-fixes-v1-1-71ee4f8f72a4@quicinc…
---
drivers/soc/qcom/cmd-db.c | 32 +++++++++++++++++++++++++++++++-
drivers/soc/qcom/rpmh-rsc.c | 3 ++-
include/soc/qcom/cmd-db.h | 10 +++++++++-
3 files changed, 42 insertions(+), 3 deletions(-)
diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c
index a5fd68411bed..86fb2cd4f484 100644
--- a/drivers/soc/qcom/cmd-db.c
+++ b/drivers/soc/qcom/cmd-db.c
@@ -1,6 +1,10 @@
/* SPDX-License-Identifier: GPL-2.0 */
-/* Copyright (c) 2016-2018, 2020, The Linux Foundation. All rights reserved. */
+/*
+ * Copyright (c) 2016-2018, 2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -17,6 +21,8 @@
#define MAX_SLV_ID 8
#define SLAVE_ID_MASK 0x7
#define SLAVE_ID_SHIFT 16
+#define SLAVE_ID(addr) FIELD_GET(GENMASK(19, 16), addr)
+#define VRM_ADDR(addr) FIELD_GET(GENMASK(19, 4), addr)
/**
* struct entry_header: header for each entry in cmddb
@@ -220,6 +226,30 @@ const void *cmd_db_read_aux_data(const char *id, size_t *len)
}
EXPORT_SYMBOL_GPL(cmd_db_read_aux_data);
+/**
+ * cmd_db_match_resource_addr() - Compare if both Resource addresses are same
+ *
+ * @addr1: Resource address to compare
+ * @addr2: Resource address to compare
+ *
+ * Return: true if two addresses refer to the same resource, false otherwise
+ */
+bool cmd_db_match_resource_addr(u32 addr1, u32 addr2)
+{
+ /*
+ * Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte
+ * aligned addresses associated with it. Ignore the offset to check
+ * for VRM requests.
+ */
+ if (addr1 == addr2)
+ return true;
+ else if (SLAVE_ID(addr1) == CMD_DB_HW_VRM && VRM_ADDR(addr1) == VRM_ADDR(addr2))
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(cmd_db_match_resource_addr);
+
/**
* cmd_db_read_slave_id - Get the slave ID for a given resource address
*
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index a021dc71807b..daf64be966fe 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
*/
#define pr_fmt(fmt) "%s " fmt, KBUILD_MODNAME
@@ -557,7 +558,7 @@ static int check_for_req_inflight(struct rsc_drv *drv, struct tcs_group *tcs,
for_each_set_bit(j, &curr_enabled, MAX_CMDS_PER_TCS) {
addr = read_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_ADDR], i, j);
for (k = 0; k < msg->num_cmds; k++) {
- if (addr == msg->cmds[k].addr)
+ if (cmd_db_match_resource_addr(msg->cmds[k].addr, addr))
return -EBUSY;
}
}
diff --git a/include/soc/qcom/cmd-db.h b/include/soc/qcom/cmd-db.h
index c8bb56e6852a..47a6cab75e63 100644
--- a/include/soc/qcom/cmd-db.h
+++ b/include/soc/qcom/cmd-db.h
@@ -1,5 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
-/* Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. */
+/*
+ * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
#ifndef __QCOM_COMMAND_DB_H__
#define __QCOM_COMMAND_DB_H__
@@ -21,6 +24,8 @@ u32 cmd_db_read_addr(const char *resource_id);
const void *cmd_db_read_aux_data(const char *resource_id, size_t *len);
+bool cmd_db_match_resource_addr(u32 addr1, u32 addr2);
+
enum cmd_db_hw_type cmd_db_read_slave_id(const char *resource_id);
int cmd_db_ready(void);
@@ -31,6 +36,9 @@ static inline u32 cmd_db_read_addr(const char *resource_id)
static inline const void *cmd_db_read_aux_data(const char *resource_id, size_t *len)
{ return ERR_PTR(-ENODEV); }
+static inline bool cmd_db_match_resource_addr(u32 addr1, u32 addr2)
+{ return false; }
+
static inline enum cmd_db_hw_type cmd_db_read_slave_id(const char *resource_id)
{ return -ENODEV; }
---
base-commit: 615d300648869c774bd1fe54b4627bb0c20faed4
change-id: 20240210-rpmh-rsc-fixes-372a79ab364b
Best regards,
--
Maulik Shah <quic_mkshah(a)quicinc.com>
(struct dirty_throttle_control *)->thresh is an unsigned long, but is
passed as the u32 divisor argument to div_u64(). On architectures where
unsigned long is 64 bytes, the argument will be implicitly truncated.
Use div64_u64() instead of div_u64() so that the value used in the "is
this a safe division" check is the same as the divisor.
Also, remove redundant cast of the numerator to u64, as that should
happen implicitly.
This would be difficult to exploit in memcg domain, given the
ratio-based arithmetic domain_drity_limits() uses, but is much easier in
global writeback domain with a BDI_CAP_STRICTLIMIT-backing device, using
e.g. vm.dirty_bytes=(1<<32)*PAGE_SIZE so that dtc->thresh == (1<<32)
Fixes: f6789593d5ce ("mm/page-writeback.c: fix divide by zero in bdi_dirty_limits()")
Cc: Maxim Patlasov <MPatlasov(a)parallels.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Zach O'Keefe <zokeefe(a)google.com>
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index cd4e4ae77c40a..02147b61712bc 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1638,7 +1638,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
*/
dtc->wb_thresh = __wb_calc_thresh(dtc);
dtc->wb_bg_thresh = dtc->thresh ?
- div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
+ div64_u64(dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
/*
* In order to avoid the stacked BDI deadlock we need
--
2.43.0.429.g432eaa2c6b-goog
The patch below does not apply to the 5.15-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 64620e0a1e712a778095bd35cbb277dc2259281f Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel(a)iogearbox.net>
Date: Tue, 11 Jan 2022 14:43:41 +0000
Subject: [PATCH] bpf: Fix out of bounds access for ringbuf helpers
Both bpf_ringbuf_submit() and bpf_ringbuf_discard() have ARG_PTR_TO_ALLOC_MEM
in their bpf_func_proto definition as their first argument. They both expect
the result from a prior bpf_ringbuf_reserve() call which has a return type of
RET_PTR_TO_ALLOC_MEM_OR_NULL.
Meaning, after a NULL check in the code, the verifier will promote the register
type in the non-NULL branch to a PTR_TO_MEM and in the NULL branch to a known
zero scalar. Generally, pointer arithmetic on PTR_TO_MEM is allowed, so the
latter could have an offset.
The ARG_PTR_TO_ALLOC_MEM expects a PTR_TO_MEM register type. However, the non-
zero result from bpf_ringbuf_reserve() must be fed into either bpf_ringbuf_submit()
or bpf_ringbuf_discard() but with the original offset given it will then read
out the struct bpf_ringbuf_hdr mapping.
The verifier missed to enforce a zero offset, so that out of bounds access
can be triggered which could be used to escalate privileges if unprivileged
BPF was enabled (disabled by default in kernel).
Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: <tr3e.wang(a)gmail.com> (SecCoder Security Lab)
Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net>
Acked-by: John Fastabend <john.fastabend(a)gmail.com>
Acked-by: Alexei Starovoitov <ast(a)kernel.org>
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e0b3f4d683eb..c72c57a6684f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5318,9 +5318,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
case PTR_TO_BUF:
case PTR_TO_BUF | MEM_RDONLY:
case PTR_TO_STACK:
+ /* Some of the argument types nevertheless require a
+ * zero register offset.
+ */
+ if (arg_type == ARG_PTR_TO_ALLOC_MEM)
+ goto force_off_check;
break;
/* All the rest must be rejected: */
default:
+force_off_check:
err = __check_ptr_off_reg(env, reg, regno,
type == PTR_TO_BTF_ID);
if (err < 0)
smp_call_function_single disables IRQs when executing the callback. To
prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere.
This is already done by qman_update_cgr and qman_delete_cgr; fix the
other lockers.
Fixes: 96f413f47677 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()")
CC: stable(a)vger.kernel.org
Signed-off-by: Sean Anderson <sean.anderson(a)seco.com>
Reviewed-by: Camelia Groza <camelia.groza(a)nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com>
---
I got no response the first time I sent this, so I am resending to net.
This issue was introduced in a series which went through net, so I hope
it makes sense to take it via net.
[1] https://lore.kernel.org/linux-arm-kernel/20240108161904.2865093-1-sean.ande…
(no changes since v3)
Changes in v3:
- Change blamed commit to something more appropriate
Changes in v2:
- Fix one additional call to spin_unlock
drivers/soc/fsl/qbman/qman.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/soc/fsl/qbman/qman.c b/drivers/soc/fsl/qbman/qman.c
index 739e4eee6b75..1bf1f1ea67f0 100644
--- a/drivers/soc/fsl/qbman/qman.c
+++ b/drivers/soc/fsl/qbman/qman.c
@@ -1456,11 +1456,11 @@ static void qm_congestion_task(struct work_struct *work)
union qm_mc_result *mcr;
struct qman_cgr *cgr;
- spin_lock(&p->cgr_lock);
+ spin_lock_irq(&p->cgr_lock);
qm_mc_start(&p->p);
qm_mc_commit(&p->p, QM_MCC_VERB_QUERYCONGESTION);
if (!qm_mc_result_timeout(&p->p, &mcr)) {
- spin_unlock(&p->cgr_lock);
+ spin_unlock_irq(&p->cgr_lock);
dev_crit(p->config->dev, "QUERYCONGESTION timeout\n");
qman_p_irqsource_add(p, QM_PIRQ_CSCI);
return;
@@ -1476,7 +1476,7 @@ static void qm_congestion_task(struct work_struct *work)
list_for_each_entry(cgr, &p->cgr_cbs, node)
if (cgr->cb && qman_cgrs_get(&c, cgr->cgrid))
cgr->cb(p, cgr, qman_cgrs_get(&rr, cgr->cgrid));
- spin_unlock(&p->cgr_lock);
+ spin_unlock_irq(&p->cgr_lock);
qman_p_irqsource_add(p, QM_PIRQ_CSCI);
}
@@ -2440,7 +2440,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags,
preempt_enable();
cgr->chan = p->config->channel;
- spin_lock(&p->cgr_lock);
+ spin_lock_irq(&p->cgr_lock);
if (opts) {
struct qm_mcc_initcgr local_opts = *opts;
@@ -2477,7 +2477,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags,
qman_cgrs_get(&p->cgrs[1], cgr->cgrid))
cgr->cb(p, cgr, 1);
out:
- spin_unlock(&p->cgr_lock);
+ spin_unlock_irq(&p->cgr_lock);
put_affine_portal();
return ret;
}
--
2.35.1.1320.gc452695387.dirty
[Embedded World 2024, SECO SpA]<https://www.messe-ticket.de/Nuernberg/embeddedworld2024/Register/ew24517689>
Since commit 1a50d9403fb9 ("treewide: Fix probing of devices in DT
overlays"), when using device-tree overlays, the FWNODE_FLAG_NOT_DEVICE
is set on each overlay nodes. This flag is cleared when a struct device
is actually created for the DT node.
Also, when a device is created, the device DT node is parsed for known
phandle and devlinks consumer/supplier links are created between the
device (consumer) and the devices referenced by phandles (suppliers).
As these supplier device can have a struct device not already created,
the FWNODE_FLAG_NOT_DEVICE can be set for suppliers and leads the
devlink supplier point to the device's parent instead of the device
itself.
Avoid this situation clearing the supplier FWNODE_FLAG_NOT_DEVICE just
before the devlink creation if a device is supposed to be created and
handled later in the process.
Fixes: 1a50d9403fb9 ("treewide: Fix probing of devices in DT overlays")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Herve Codina <herve.codina(a)bootlin.com>
---
drivers/of/property.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index 641a40cf5cf3..ff5cac477dbe 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1097,6 +1097,7 @@ static void of_link_to_phandle(struct device_node *con_np,
struct device_node *sup_np)
{
struct device_node *tmp_np = of_node_get(sup_np);
+ struct fwnode_handle *sup_fwnode;
/* Check that sup_np and its ancestors are available. */
while (tmp_np) {
@@ -1113,7 +1114,20 @@ static void of_link_to_phandle(struct device_node *con_np,
tmp_np = of_get_next_parent(tmp_np);
}
- fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np));
+ /*
+ * In case of overlays, the fwnode are added with FWNODE_FLAG_NOT_DEVICE
+ * flag set. A node can have a phandle that references an other node
+ * added by the overlay.
+ * Clear the supplier's FWNODE_FLAG_NOT_DEVICE so that fw_devlink links
+ * to this supplier instead of linking to its parent.
+ */
+ sup_fwnode = of_fwnode_handle(sup_np);
+ if (sup_fwnode->flags & FWNODE_FLAG_NOT_DEVICE) {
+ if (of_property_present(sup_np, "compatible") &&
+ of_device_is_available(sup_np))
+ sup_fwnode->flags &= ~FWNODE_FLAG_NOT_DEVICE;
+ }
+ fwnode_link_add(of_fwnode_handle(con_np), sup_fwnode);
}
/**
--
2.43.0
The patchset fixes some warnings reported by the kernel during boot.
The cache size info is from Processor_Datasheet_v2XX.pdf [1], Section
2.2.1 Master Processor.
The cache line size and the set-associative info are from Cortex-A53
Documentation [2].
From the doc, it can be concluded that L1 i-cache is 4-way assoc, L1
d-cache is 2-way assoc and L2 cache is 16-way assoc. Calculate the dts
props accordingly.
Also, to use KVM's VGIC code, GICH, GICV registers spaces and maintenance
IRQ are added to the dts with verification.
[1]: https://github.com/96boards/documentation/blob/master/enterprise/poplar/har…
[2]: https://developer.arm.com/documentation/ddi0500/j/Level-1-Memory-System
Signed-off-by: Yang Xiwen <forbidden405(a)outlook.com>
---
Changes in v3:
- send patches to stable (Andrew Lunn)
- rewrite the commit logs more formally (Andrew Lunn)
- rename l2-cache0 to l2-cache (Krzysztof Kozlowski)
- Link to v2: https://lore.kernel.org/r/20240218-cache-v2-0-1fd919e2bd3e@outlook.com
Changes in v2:
- arm64: dts: hi3798cv200: add GICH, GICV register spces and
maintainance IRQ.
- Link to v1: https://lore.kernel.org/r/20240218-cache-v1-0-2c0a8a4472e7@outlook.com
---
Yang Xiwen (3):
arm64: dts: hi3798cv200: fix the size of GICR
arm64: dts: hi3798cv200: add GICH, GICV register space and irq
arm64: dts: hi3798cv200: add cache info
arch/arm64/boot/dts/hisilicon/hi3798cv200.dtsi | 43 +++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)
---
base-commit: 8d3dea210042f54b952b481838c1e7dfc4ec751d
change-id: 20240218-cache-11c8bf7566c2
Best regards,
--
Yang Xiwen <forbidden405(a)outlook.com>
'nr' member of struct spmi_controller, which serves as an identifier
for the controller/bus. This value is a dynamic ID assigned in
spmi_controller_alloc, and overriding it from the driver results in an
ida_free error "ida_free called for id=xx which is not allocated".
Signed-off-by: Vamshi Gajjela <vamshigajjela(a)google.com>
Fixes: 70f59c90c819 ("staging: spmi: add Hikey 970 SPMI controller driver")
Cc: stable(a)vger.kernel.org
---
drivers/spmi/hisi-spmi-controller.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/spmi/hisi-spmi-controller.c b/drivers/spmi/hisi-spmi-controller.c
index 674a350cc676..fa068b34b040 100644
--- a/drivers/spmi/hisi-spmi-controller.c
+++ b/drivers/spmi/hisi-spmi-controller.c
@@ -300,7 +300,6 @@ static int spmi_controller_probe(struct platform_device *pdev)
spin_lock_init(&spmi_controller->lock);
- ctrl->nr = spmi_controller->channel;
ctrl->dev.parent = pdev->dev.parent;
ctrl->dev.of_node = of_node_get(pdev->dev.of_node);
--
2.44.0.rc1.240.g4c46232300-goog
There are few uses of CoCo that don't rely on working cryptography and
hence a working RNG. Unfortunately, the CoCo threat model means that the
VM host cannot be trusted and may actively work against guests to
extract secrets or manipulate computation. Since a malicious host can
modify or observe nearly all inputs to guests, the only remaining source
of entropy for CoCo guests is RDRAND.
If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole
is meant to gracefully continue on gathering entropy from other sources,
but since there aren't other sources on CoCo, this is catastrophic.
This is mostly a concern at boot time when initially seeding the RNG, as
after that the consequences of a broken RDRAND are much more
theoretical.
So, try at boot to seed the RNG using 256 bits of RDRAND output. If this
fails, panic(). This will also trigger if the system is booted without
RDRAND, as RDRAND is essential for a safe CoCo boot.
This patch is deliberately written to be "just a CoCo x86 driver
feature" and not part of the RNG itself. Many device drivers and
platforms have some desire to contribute something to the RNG, and
add_device_randomness() is specifically meant for this purpose. Any
driver can call this with seed data of any quality, or even garbage
quality, and it can only possibly make the quality of the RNG better or
have no effect, but can never make it worse. Rather than trying to
build something into the core of the RNG, this patch interprets the
particular CoCo issue as just a CoCo issue, and therefore separates this
all out into driver (well, arch/platform) code.
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: Daniel P. Berrangé <berrange(a)redhat.com>
Cc: Dave Hansen <dave.hansen(a)linux.intel.com>
Cc: H. Peter Anvin <hpa(a)zytor.com>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Reviewed-by: Elena Reshetova <elena.reshetova(a)intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Reviewed-by: Theodore Ts'o <tytso(a)mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com>
---
Changes v3->v4:
- Add stable@ tag and reviewed-by lines.
- Add comment for Dave explaining where the "32" comes from.
arch/x86/coco/core.c | 40 +++++++++++++++++++++++++++++++++++++
arch/x86/include/asm/coco.h | 2 ++
arch/x86/kernel/setup.c | 2 ++
3 files changed, 44 insertions(+)
diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c
index eeec9986570e..0e988bff4aec 100644
--- a/arch/x86/coco/core.c
+++ b/arch/x86/coco/core.c
@@ -3,13 +3,16 @@
* Confidential Computing Platform Capability checks
*
* Copyright (C) 2021 Advanced Micro Devices, Inc.
+ * Copyright (C) 2024 Jason A. Donenfeld <Jason(a)zx2c4.com>. All Rights Reserved.
*
* Author: Tom Lendacky <thomas.lendacky(a)amd.com>
*/
#include <linux/export.h>
#include <linux/cc_platform.h>
+#include <linux/random.h>
+#include <asm/archrandom.h>
#include <asm/coco.h>
#include <asm/processor.h>
@@ -153,3 +156,40 @@ __init void cc_set_mask(u64 mask)
{
cc_mask = mask;
}
+
+__init void cc_random_init(void)
+{
+ /*
+ * The seed is 32 bytes (in units of longs), which is 256 bits, which
+ * is the security level that the RNG is targeting.
+ */
+ unsigned long rng_seed[32 / sizeof(long)];
+ size_t i, longs;
+
+ if (cc_vendor == CC_VENDOR_NONE)
+ return;
+
+ /*
+ * Since the CoCo threat model includes the host, the only reliable
+ * source of entropy that can be neither observed nor manipulated is
+ * RDRAND. Usually, RDRAND failure is considered tolerable, but since
+ * CoCo guests have no other unobservable source of entropy, it's
+ * important to at least ensure the RNG gets some initial random seeds.
+ */
+ for (i = 0; i < ARRAY_SIZE(rng_seed); i += longs) {
+ longs = arch_get_random_longs(&rng_seed[i], ARRAY_SIZE(rng_seed) - i);
+
+ /*
+ * A zero return value means that the guest doesn't have RDRAND
+ * or the CPU is physically broken, and in both cases that
+ * means most crypto inside of the CoCo instance will be
+ * broken, defeating the purpose of CoCo in the first place. So
+ * just panic here because it's absolutely unsafe to continue
+ * executing.
+ */
+ if (longs == 0)
+ panic("RDRAND is defective.");
+ }
+ add_device_randomness(rng_seed, sizeof(rng_seed));
+ memzero_explicit(rng_seed, sizeof(rng_seed));
+}
diff --git a/arch/x86/include/asm/coco.h b/arch/x86/include/asm/coco.h
index 76c310b19b11..e9d059449885 100644
--- a/arch/x86/include/asm/coco.h
+++ b/arch/x86/include/asm/coco.h
@@ -15,6 +15,7 @@ extern enum cc_vendor cc_vendor;
void cc_set_mask(u64 mask);
u64 cc_mkenc(u64 val);
u64 cc_mkdec(u64 val);
+void cc_random_init(void);
#else
#define cc_vendor (CC_VENDOR_NONE)
@@ -27,6 +28,7 @@ static inline u64 cc_mkdec(u64 val)
{
return val;
}
+static inline void cc_random_init(void) { }
#endif
#endif /* _ASM_X86_COCO_H */
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 84201071dfac..30a653cfc7d2 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -36,6 +36,7 @@
#include <asm/bios_ebda.h>
#include <asm/bugs.h>
#include <asm/cacheinfo.h>
+#include <asm/coco.h>
#include <asm/cpu.h>
#include <asm/efi.h>
#include <asm/gart.h>
@@ -994,6 +995,7 @@ void __init setup_arch(char **cmdline_p)
* memory size.
*/
mem_encrypt_setup_arch();
+ cc_random_init();
efi_fake_memmap();
efi_find_mirror();
--
2.43.2