On x86_64:
When the second-stage kernel is booted via kexec with a limiting command
line such as "mem=<size>" we observe a pafe fault that happens.
BUG: unable to handle page fault for address: ffff97793ff47000
RIP: ima_restore_measurement_list+0xdc/0x45a
#PF: error_code(0x0000) – not-present page
This happens on x86_64 only, as this is already fixed in aarch64 in
commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer
against memory bounds")
V1: https://lore.kernel.org/all/20251112193005.3772542-1-harshit.m.mogalapalli@…
V1 attempted to do a similar sanity check in x86_64. Borislav suggested
to add a generic helper ima_validate_range() which could then be used
for both OF based and x86_64.
Testing information:
--------------------
On x86_64: With latest 6.19-rc2 based, we could reproduce the issue, and
patched kernel works fine. (with mem=8G on a 16G memory machine)
Thanks for the reviews on V1.
V1 -> V2:
- Patch 1: Add a generic helper "ima_validate_range()"
- Patch 2: Use this new helper in drivers/of/kexec.c -> No functional
change.
- Patch 3: Fix the page fault by doing sanity check with
"ima_validate_range()"
Thanks,
Harshit
Harshit Mogalapalli (3):
ima: Add ima_validate_range() for previous kernel IMA buffer
of/kexec: refactor ima_get_kexec_buffer() to use ima_validate_range()
x86/kexec: Add a sanity check on previous kernel's ima kexec buffer
arch/x86/kernel/setup.c | 6 +++++
drivers/of/kexec.c | 15 +++----------
include/linux/ima.h | 1 +
security/integrity/ima/ima_kexec.c | 35 ++++++++++++++++++++++++++++++
4 files changed, 45 insertions(+), 12 deletions(-)
--
2.50.1
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 27d17641cacfedd816789b75d342430f6b912bd2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122920-sequence-vixen-bb32@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 27d17641cacfedd816789b75d342430f6b912bd2 Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever(a)oracle.com>
Date: Mon, 17 Nov 2025 11:00:49 -0500
Subject: [PATCH] NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap
>From RFC 8881:
5.8.1.14. Attribute 75: suppattr_exclcreat
> The bit vector that would set all REQUIRED and RECOMMENDED
> attributes that are supported by the EXCLUSIVE4_1 method of file
> creation via the OPEN operation. The scope of this attribute
> applies to all objects with a matching fsid.
There's nothing in RFC 8881 that states that suppattr_exclcreat is
or is not allowed to contain bits for attributes that are clear in
the reported supported_attrs bitmask. But it doesn't make sense for
an NFS server to indicate that it /doesn't/ implement an attribute,
but then also indicate that clients /are/ allowed to set that
attribute using OPEN(create) with EXCLUSIVE4_1.
Ensure that the SECURITY_LABEL and ACL bits are not set in the
suppattr_exclcreat bitmask when they are also not set in the
supported_attrs bitmask.
Fixes: 8c18f2052e75 ("nfsd41: SUPPATTR_EXCLCREAT attribute")
Cc: stable(a)vger.kernel.org
Reviewed-by: Jeff Layton <jlayton(a)kernel.org>
Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 30ce5851fe4c..51ef97c25456 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3375,6 +3375,11 @@ static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr,
u32 supp[3];
memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp));
+ if (!IS_POSIXACL(d_inode(args->dentry)))
+ supp[0] &= ~FATTR4_WORD0_ACL;
+ if (!args->contextsupport)
+ supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
The patch below does not apply to the 6.6-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 27d17641cacfedd816789b75d342430f6b912bd2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122919-carried-livestock-9465@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 27d17641cacfedd816789b75d342430f6b912bd2 Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever(a)oracle.com>
Date: Mon, 17 Nov 2025 11:00:49 -0500
Subject: [PATCH] NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap
>From RFC 8881:
5.8.1.14. Attribute 75: suppattr_exclcreat
> The bit vector that would set all REQUIRED and RECOMMENDED
> attributes that are supported by the EXCLUSIVE4_1 method of file
> creation via the OPEN operation. The scope of this attribute
> applies to all objects with a matching fsid.
There's nothing in RFC 8881 that states that suppattr_exclcreat is
or is not allowed to contain bits for attributes that are clear in
the reported supported_attrs bitmask. But it doesn't make sense for
an NFS server to indicate that it /doesn't/ implement an attribute,
but then also indicate that clients /are/ allowed to set that
attribute using OPEN(create) with EXCLUSIVE4_1.
Ensure that the SECURITY_LABEL and ACL bits are not set in the
suppattr_exclcreat bitmask when they are also not set in the
supported_attrs bitmask.
Fixes: 8c18f2052e75 ("nfsd41: SUPPATTR_EXCLCREAT attribute")
Cc: stable(a)vger.kernel.org
Reviewed-by: Jeff Layton <jlayton(a)kernel.org>
Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 30ce5851fe4c..51ef97c25456 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3375,6 +3375,11 @@ static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr,
u32 supp[3];
memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp));
+ if (!IS_POSIXACL(d_inode(args->dentry)))
+ supp[0] &= ~FATTR4_WORD0_ACL;
+ if (!args->contextsupport)
+ supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
The patch below does not apply to the 5.10-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x fc40459de82543b565ebc839dca8f7987f16f62e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122919-catty-unrated-e504@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fc40459de82543b565ebc839dca8f7987f16f62e Mon Sep 17 00:00:00 2001
From: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn>
Date: Wed, 10 Dec 2025 17:06:01 +0800
Subject: [PATCH] xfs: fix a memory leak in xfs_buf_item_init()
xfs_buf_item_get_format() may allocate memory for bip->bli_formats,
free the memory in the error path.
Fixes: c3d5f0c2fb85 ("xfs: complain if anyone tries to create a too-large buffer log item")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn>
Reviewed-by: Christoph Hellwig <hch(a)lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino(a)redhat.com>
Signed-off-by: Carlos Maiolino <cem(a)kernel.org>
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 8d85b5eee444..f4c5be67826e 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -896,6 +896,7 @@ xfs_buf_item_init(
map_size = DIV_ROUND_UP(chunks, NBWORD);
if (map_size > XFS_BLF_DATAMAP_SIZE) {
+ xfs_buf_item_free_format(bip);
kmem_cache_free(xfs_buf_item_cache, bip);
xfs_err(mp,
"buffer item dirty bitmap (%u uints) too small to reflect %u bytes!",
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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 29763138830916f46daaa50e83e7f4f907a3236b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122927-delegate-composed-5765@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 29763138830916f46daaa50e83e7f4f907a3236b Mon Sep 17 00:00:00 2001
From: Dongli Zhang <dongli.zhang(a)oracle.com>
Date: Fri, 5 Dec 2025 15:19:05 -0800
Subject: [PATCH] KVM: nVMX: Immediately refresh APICv controls as needed on
nested VM-Exit
If an APICv status updated was pended while L2 was active, immediately
refresh vmcs01's controls instead of pending KVM_REQ_APICV_UPDATE as
kvm_vcpu_update_apicv() only calls into vendor code if a change is
necessary.
E.g. if APICv is inhibited, and then activated while L2 is running:
kvm_vcpu_update_apicv()
|
-> __kvm_vcpu_update_apicv()
|
-> apic->apicv_active = true
|
-> vmx_refresh_apicv_exec_ctrl()
|
-> vmx->nested.update_vmcs01_apicv_status = true
|
-> return
Then L2 exits to L1:
__nested_vmx_vmexit()
|
-> kvm_make_request(KVM_REQ_APICV_UPDATE)
vcpu_enter_guest(): KVM_REQ_APICV_UPDATE
-> kvm_vcpu_update_apicv()
|
-> __kvm_vcpu_update_apicv()
|
-> return // because if (apic->apicv_active == activate)
Reported-by: Chao Gao <chao.gao(a)intel.com>
Closes: https://lore.kernel.org/all/aQ2jmnN8wUYVEawF@intel.com
Fixes: 7c69661e225c ("KVM: nVMX: Defer APICv updates while L2 is active until L1 is active")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dongli Zhang <dongli.zhang(a)oracle.com>
[sean: write changelog]
Link: https://patch.msgid.link/20251205231913.441872-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc(a)google.com>
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index bcea087b642f..1725c6a94f99 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -19,6 +19,7 @@
#include "trace.h"
#include "vmx.h"
#include "smm.h"
+#include "x86_ops.h"
static bool __read_mostly enable_shadow_vmcs = 1;
module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO);
@@ -5216,7 +5217,7 @@ void __nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
if (vmx->nested.update_vmcs01_apicv_status) {
vmx->nested.update_vmcs01_apicv_status = false;
- kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
+ vmx_refresh_apicv_exec_ctrl(vcpu);
}
if (vmx->nested.update_vmcs01_hwapic_isr) {
The patch below does not apply to the 6.18-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 2f393c228cc519ddf19b8c6c05bf15723241aa96
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122907-grant-reformist-a323@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2f393c228cc519ddf19b8c6c05bf15723241aa96 Mon Sep 17 00:00:00 2001
From: Claudio Imbrenda <imbrenda(a)linux.ibm.com>
Date: Tue, 4 Nov 2025 16:40:48 +0100
Subject: [PATCH] KVM: s390: Fix gmap_helper_zap_one_page() again
A few checks were missing in gmap_helper_zap_one_page(), which can lead
to memory corruption in the guest under specific circumstances.
Add the missing checks.
Fixes: 5deafa27d9ae ("KVM: s390: Fix to clear PTE when discarding a swapped page")
Cc: stable(a)vger.kernel.org
Reported-by: Marc Hartmayer <mhartmay(a)linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay(a)linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger(a)linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda(a)linux.ibm.com>
Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com>
diff --git a/arch/s390/mm/gmap_helpers.c b/arch/s390/mm/gmap_helpers.c
index 549f14ad08af..d41b19925a5a 100644
--- a/arch/s390/mm/gmap_helpers.c
+++ b/arch/s390/mm/gmap_helpers.c
@@ -47,6 +47,7 @@ static void ptep_zap_softleaf_entry(struct mm_struct *mm, softleaf_t entry)
void gmap_helper_zap_one_page(struct mm_struct *mm, unsigned long vmaddr)
{
struct vm_area_struct *vma;
+ unsigned long pgstev;
spinlock_t *ptl;
pgste_t pgste;
pte_t *ptep;
@@ -65,9 +66,13 @@ void gmap_helper_zap_one_page(struct mm_struct *mm, unsigned long vmaddr)
if (pte_swap(*ptep)) {
preempt_disable();
pgste = pgste_get_lock(ptep);
+ pgstev = pgste_val(pgste);
- ptep_zap_softleaf_entry(mm, softleaf_from_pte(*ptep));
- pte_clear(mm, vmaddr, ptep);
+ if ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
+ (pgstev & _PGSTE_GPS_ZERO)) {
+ ptep_zap_softleaf_entry(mm, softleaf_from_pte(*ptep));
+ pte_clear(mm, vmaddr, ptep);
+ }
pgste_set_unlock(ptep, pgste);
preempt_enable();
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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x fc40459de82543b565ebc839dca8f7987f16f62e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122919-balancing-colony-41ee@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fc40459de82543b565ebc839dca8f7987f16f62e Mon Sep 17 00:00:00 2001
From: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn>
Date: Wed, 10 Dec 2025 17:06:01 +0800
Subject: [PATCH] xfs: fix a memory leak in xfs_buf_item_init()
xfs_buf_item_get_format() may allocate memory for bip->bli_formats,
free the memory in the error path.
Fixes: c3d5f0c2fb85 ("xfs: complain if anyone tries to create a too-large buffer log item")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn>
Reviewed-by: Christoph Hellwig <hch(a)lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino(a)redhat.com>
Signed-off-by: Carlos Maiolino <cem(a)kernel.org>
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 8d85b5eee444..f4c5be67826e 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -896,6 +896,7 @@ xfs_buf_item_init(
map_size = DIV_ROUND_UP(chunks, NBWORD);
if (map_size > XFS_BLF_DATAMAP_SIZE) {
+ xfs_buf_item_free_format(bip);
kmem_cache_free(xfs_buf_item_cache, bip);
xfs_err(mp,
"buffer item dirty bitmap (%u uints) too small to reflect %u bytes!",
If damon_call() is executed against a DAMON context that is not running,
the function returns error while keeping the damon_call_control object
linked to the context's call_controls list. Let's suppose the object is
deallocated after the damon_call(), and yet another damon_call() is
executed against the same context. The function tries to add the new
damon_call_control object to the call_controls list, which still has the
pointer to the previous damon_call_control object, which is deallocated.
As a result, use-after-free happens.
This can actually be triggered using the DAMON sysfs interface. It is not
easily exploitable since it requires the sysfs write permission and making
a definitely weird file writes, though. Please refer to the report for
more details about the issue reproduction steps.
Fix the issue by making two changes. Firstly, move the final
kdamond_call() for cancelling all existing damon_call() requests from
terminating DAMON context to be done before the ctx->kdamond reset.
This makes any code that sees NULL ctx->kdamond can safely assume the
context may not access damon_call() requests anymore. Secondly, let
damon_call() to cleanup the damon_call_control objects that were added
to the already-terminated DAMON context, before returning the error.
Fixes: 004ded6bee11 ("mm/damon: accept parallel damon_call() requests")
Reported-by: JaeJoon Jung <rgbi3307(a)gmail.com>
Closes: https://lore.kernel.org/20251224094401.20384-1-rgbi3307@gmail.com
Cc: <stable(a)vger.kernel.org> # 6.17.x
Signed-off-by: SeongJae Park <sj(a)kernel.org>
---
Changes from v1
(https://lkml.kernel.org/r/20251228183105.289441-1-sj@kernel.org):
- Do final kdamond_call() before ctx->kdamond reset.
- Fix Fixes: tag.
mm/damon/core.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 2d3e8006db50..199529dd7c66 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1442,6 +1442,35 @@ bool damon_is_running(struct damon_ctx *ctx)
return running;
}
+/*
+ * damon_call_handle_inactive_ctx() - handle DAMON call request that added to
+ * an inactive context.
+ * @ctx: The inactive DAMON context.
+ * @control: Control variable of the call request.
+ *
+ * This function is called in a case that @control is added to @ctx but @ctx is
+ * not running (inactive). See if @ctx handled @control or not, and cleanup
+ * @control if it was not handled.
+ *
+ * Returns 0 if @control was handled by @ctx, negative error code otherwise.
+ */
+static int damon_call_handle_inactive_ctx(
+ struct damon_ctx *ctx, struct damon_call_control *control)
+{
+ struct damon_call_control *c;
+
+ mutex_lock(&ctx->call_controls_lock);
+ list_for_each_entry(c, &ctx->call_controls, list) {
+ if (c == control) {
+ list_del(&control->list);
+ mutex_unlock(&ctx->call_controls_lock);
+ return -EINVAL;
+ }
+ }
+ mutex_unlock(&ctx->call_controls_lock);
+ return 0;
+}
+
/**
* damon_call() - Invoke a given function on DAMON worker thread (kdamond).
* @ctx: DAMON context to call the function for.
@@ -1472,7 +1501,7 @@ int damon_call(struct damon_ctx *ctx, struct damon_call_control *control)
list_add_tail(&control->list, &ctx->call_controls);
mutex_unlock(&ctx->call_controls_lock);
if (!damon_is_running(ctx))
- return -EINVAL;
+ return damon_call_handle_inactive_ctx(ctx, control);
if (control->repeat)
return 0;
wait_for_completion(&control->completion);
@@ -2797,13 +2826,13 @@ static int kdamond_fn(void *data)
if (ctx->ops.cleanup)
ctx->ops.cleanup(ctx);
kfree(ctx->regions_score_histogram);
+ kdamond_call(ctx, true);
pr_debug("kdamond (%d) finishes\n", current->pid);
mutex_lock(&ctx->kdamond_lock);
ctx->kdamond = NULL;
mutex_unlock(&ctx->kdamond_lock);
- kdamond_call(ctx, true);
damos_walk_cancel(ctx);
mutex_lock(&damon_lock);
base-commit: 40fd05d807b3a7678e3284b8a9a6cb89a32fa8ce
--
2.47.3
When starting multi-core loongarch virtualization on loongarch physical
machine, loading livepatch on the physical machine will cause an error
similar to the following:
[ 411.686289] livepatch: klp_try_switch_task: CPU 31/KVM:3116 has an
unreliable stack
The specific test steps are as follows:
1.Start a multi-core virtual machine on a physical machine
2.Enter the following command on the physical machine to turn on the debug
switch:
echo "file kernel/livepatch/transition.c +p" > /sys/kernel/debug/\
dynamic_debug/control
3.Load livepatch:
modprobe livepatch-sample
Through the above steps, similar prints can be viewed in dmesg.
The reason for this issue is that the code of the kvm_exc_entry function
was copied in the function kvm_loongarch_env_init. When the cpu needs to
execute kvm_exc_entry, it will switch to the copied address for execution.
The new address of the kvm_exc_entry function cannot be recognized in ORC,
which eventually leads to the arch_stack_walk_reliable function returning
an error and printing an exception message.
To solve the above problems, we directly compile the switch.S file into
the kernel instead of the module. In this way, the function kvm_exc_entry
will no longer need to be copied.
changlog:
V3<-V2:
1.Replace the EXPORT_SYMBOL macro declaration symbol with the
EXPORT_SYMBOL_FOR_KVM macro
2.Add some comments in kvm_enter_guest
3.Place the correct pc address in era
4.Move .p2align after .text
V2<-V1:
1.Rollback the modification of function parameter types such as
kvm_save_fpu. In the asm-prototypes.h header file, only the parameter types
it depends on are included
Cc: Huacai Chen <chenhuacai(a)kernel.org>
Cc: WANG Xuerui <kernel(a)xen0n.name>
Cc: Tianrui Zhao <zhaotianrui(a)loongson.cn>
Cc: Bibo Mao <maobibo(a)loongson.cn>
Cc: Charlie Jenkins <charlie(a)rivosinc.com>
Cc: Xianglai Li <lixianglai(a)loongson.cn>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Cc: Tiezhu Yang <yangtiezhu(a)loongson.cn>
Xianglai Li (2):
LoongArch: KVM: Compile the switch.S file directly into the kernel
LoongArch: KVM: fix "unreliable stack" issue
arch/loongarch/Kbuild | 2 +-
arch/loongarch/include/asm/asm-prototypes.h | 21 +++++++++++++
arch/loongarch/include/asm/kvm_host.h | 3 --
arch/loongarch/kvm/Makefile | 2 +-
arch/loongarch/kvm/main.c | 35 ++-------------------
arch/loongarch/kvm/switch.S | 32 ++++++++++++++++---
6 files changed, 53 insertions(+), 42 deletions(-)
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
--
2.39.1
Since commit 4b47a3aefb29 ("kbuild: Restore pattern to avoid stripping
.rela.dyn from vmlinux") vmlinux has .rel*.dyn preserved. Therefore, use
vmlinux to produce Image, not vmlinux.unstripped.
Doing so fixes booting a RELOCATABLE=y Image with kexec. The problem is
caused by this chain of events:
- Since commit 3e86e4d74c04 ("kbuild: keep .modinfo section in
vmlinux.unstripped"), vmlinux.unstripped gets a .modinfo section.
- The .modinfo section has SHF_ALLOC, so it ends up in Image, at the end
of it.
- The Image header's image_size field does not expect to include
.modinfo and does not account for it, since it should not be in Image.
- If .modinfo is large enough, the file size of Image ends up larger
than image_size, which eventually leads to it failing
sanity_check_segment_list().
Using vmlinux instead of vmlinux.unstripped means that the unexpected
.modinfo section is gone from Image, fixing the file size problem.
Cc: stable(a)vger.kernel.org
Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped")
Signed-off-by: Vivian Wang <wangruikang(a)iscas.ac.cn>
---
arch/riscv/boot/Makefile | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/riscv/boot/Makefile b/arch/riscv/boot/Makefile
index bfc3d0b75b9b..5301adf5f3f5 100644
--- a/arch/riscv/boot/Makefile
+++ b/arch/riscv/boot/Makefile
@@ -31,11 +31,7 @@ $(obj)/xipImage: vmlinux FORCE
endif
-ifdef CONFIG_RELOCATABLE
-$(obj)/Image: vmlinux.unstripped FORCE
-else
$(obj)/Image: vmlinux FORCE
-endif
$(call if_changed,objcopy)
$(obj)/Image.gz: $(obj)/Image FORCE
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251230-riscv-vmlinux-not-unstripped-30ec0c930fd2
Best regards,
--
Vivian "dramforever" Wang