[PATCH] powerpc/crash: Add only the onlined CPU's node to the crash FDT

[PATCH] powerpc/crash: Add only the onlined CPU's node to the crash FDT

[Vishal Chourasia]

A CPU coming online never changes the nodes that are already in the FDT,
so add only the node of that CPU. update_crash_fdt() looks up the device
node of the onlined CPU and does nothing if the FDT already has a node of
that name, which is the case when an offlined CPU comes back online. Only
when the node is missing, the crash image is invalidated while the node is
created with fdt_add_subnode() and its properties are copied from the live
device node with fdt_setprop(). All of this is done directly in
update_crash_fdt().

fdt_add_subnode() inserts the node as the first child of /cpus, which is
the same position a node attached to the live device tree takes, so the
FDT keeps the order of the live tree.

Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>
---
 arch/powerpc/kexec/crash.c | 65 +++++++++++++++++++++++++++++++-------
 arch/x86/kernel/crash.c    |  2 +-
 kernel/crash_core.c        | 11 +++++--
 3 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 775895f31037..ca37006bddea 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -18,6 +18,7 @@
 #include <linux/types.h>
 #include <linux/libfdt.h>
 #include <linux/memory.h>
+#include <linux/of.h>
 
 #include <asm/processor.h>
 #include <asm/machdep.h>
@@ -584,32 +585,71 @@ static int get_fdt_index(struct kimage *image)
 }
 
 /**
- * update_crash_fdt - updates the cpus node of the crash FDT.
+ * update_crash_fdt - add the node of the onlined CPU to the crash FDT.
  *
  * @image: a pointer to kexec_crash_image
+ * @cpu: the CPU that was onlined
+ *
+ * The node is added as the first child of /cpus, the same position a node
+ * attached to the live device tree takes. Nothing is done if the FDT already
+ * has the node, for example when an offlined CPU comes back.
  */
-static void update_crash_fdt(struct kimage *image)
+static void update_crash_fdt(struct kimage *image, unsigned int cpu)
 {
+	struct device_node *dn;
+	struct property *pp;
 	void *fdt;
-	int fdt_index;
+	int fdt_index, cpus_offset, node_offset;
+
+	dn = of_get_cpu_node(cpu, NULL);
+	if (!dn) {
+		pr_err("No device node found for CPU %u\n", cpu);
+		return;
+	}
 
 	fdt_index = get_fdt_index(image);
 	if (fdt_index < 0) {
 		pr_err("Unable to locate FDT segment.\n");
-		return;
+		goto put;
 	}
 
 	fdt = __va((void *)image->segment[fdt_index].mem);
 
-	/* Temporarily invalidate the crash image while it is replaced */
+	cpus_offset = fdt_path_offset(fdt, "/cpus");
+	if (cpus_offset < 0) {
+		pr_err("Malformed device tree: error reading /cpus node: %s\n",
+		       fdt_strerror(cpus_offset));
+		goto put;
+	}
+
+	/* Node already present, e.g. an offlined CPU came back online */
+	if (fdt_subnode_offset(fdt, cpus_offset, dn->full_name) >= 0)
+		goto put;
+
+	/* Temporarily invalidate the crash image while it is updated */
 	xchg(&kexec_crash_image, NULL);
 
-	/* update FDT to reflect changes in CPU resources */
-	if (update_cpus_node(fdt))
-		pr_err("Failed to update crash FDT");
+	node_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
+	if (node_offset < 0) {
+		pr_err("Unable to add %s subnode: %s\n", dn->full_name,
+		       fdt_strerror(node_offset));
+		goto out;
+	}
 
+	for_each_property_of_node(dn, pp) {
+		int ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
+
+		if (ret < 0) {
+			pr_err("Unable to add %s property: %s\n", pp->name,
+			       fdt_strerror(ret));
+			break;
+		}
+	}
+out:
 	/* The crash image is now valid once again */
 	xchg(&kexec_crash_image, image);
+put:
+	of_node_put(dn);
 }
 
 int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
@@ -625,10 +665,11 @@ int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
  * arch_crash_handle_hotplug_event - Handle crash CPU/Memory hotplug events to update the
  *				     necessary kexec segments based on the hotplug event.
  * @image: a pointer to kexec_crash_image
- * @arg: struct memory_notify handler for memory hotplug case and NULL for CPU hotplug case.
+ * @arg: struct memory_notify handler for memory hotplug case and pointer to the
+ *	 cpu number for CPU hotplug case.
  *
  * Update the kdump image based on the type of hotplug event, represented by image->hp_action.
- * CPU add: Update the FDT segment to include the newly added CPU.
+ * CPU add: Add the node of the newly added CPU to the FDT segment, if missing.
  * CPU remove: No action is needed, with the assumption that it's okay to have offline CPUs
  *	       part of the FDT.
  * Memory add/remove: No action is taken as this is not yet supported.
@@ -636,13 +677,15 @@ int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
 void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
 {
 	struct memory_notify *mn;
+	unsigned int cpu;
 
 	switch (image->hp_action) {
 	case KEXEC_CRASH_HP_REMOVE_CPU:
 		return;
 
 	case KEXEC_CRASH_HP_ADD_CPU:
-		update_crash_fdt(image);
+		cpu = *(unsigned int *)arg;
+		update_crash_fdt(image, cpu);
 		break;
 
 	case KEXEC_CRASH_HP_REMOVE_MEMORY:
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index e6f23933a6df..1660f26f3a44 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -441,7 +441,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
  * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
  * @image: a pointer to kexec_crash_image
  * @arg: struct memory_notify handler for memory hotplug case and
- *       NULL for CPU hotplug case.
+ *       pointer to the cpu number (unused here) for CPU hotplug case.
  *
  * Prepare the new elfcorehdr and replace the existing elfcorehdr.
  */
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index d0bd2d0cf899..53d4f2c1760c 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -651,6 +651,9 @@ int crash_check_hotplug_support(void)
  * NR_CPUS and CRASH_MAX_MEMORY_RANGES. The elfcorehdr is
  * excluded from SHA verification by default if the architecture
  * supports crash hotplug.
+ *
+ * @arg is a struct memory_notify pointer for memory hotplug events and a
+ * pointer to the unsigned int cpu number for CPU hotplug events.
  */
 static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu, void *arg)
 {
@@ -676,10 +679,14 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu,
 		goto out;
 
 	if (hp_action == KEXEC_CRASH_HP_ADD_CPU ||
-		hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
+		hp_action == KEXEC_CRASH_HP_REMOVE_CPU) {
 		pr_debug("hp_action %u, cpu %u\n", hp_action, cpu);
-	else
+		/* CPU events are raised with no argument, the CPU number is passed instead */
+		WARN_ON(arg);
+		arg = &cpu;
+	} else {
 		pr_debug("hp_action %u\n", hp_action);
+	}
 
 	/*
 	 * The elfcorehdr_index is set to -1 when the struct kimage
-- 
2.54.0

Re: [PATCH] powerpc/crash: Add only the onlined CPU's node to the crash FDT

[Mukesh Pilaniya]

Hi Vishal,
On 04/11/26 11:08 am, Vishal Chourasia wrote:
> A CPU coming online never changes the nodes that are already in the FDT,
> so add only the node of that CPU. update_crash_fdt() looks up the device
> node of the onlined CPU and does nothing if the FDT already has a node of
> that name, which is the case when an offlined CPU comes back online. Only
> when the node is missing, the crash image is invalidated while the node is
> created with fdt_add_subnode() and its properties are copied from the live
> device node with fdt_setprop(). All of this is done directly in
> update_crash_fdt().
> 
> fdt_add_subnode() inserts the node as the first child of /cpus, which is
> the same position a node attached to the live device tree takes, so the
> FDT keeps the order of the live tree.
> 
> Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>
> ---
>  arch/powerpc/kexec/crash.c | 65 +++++++++++++++++++++++++++++++-------
>  arch/x86/kernel/crash.c    |  2 +-
>  kernel/crash_core.c        | 11 +++++--
>  3 files changed, 64 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
> index 775895f31037..ca37006bddea 100644
> --- a/arch/powerpc/kexec/crash.c
> +++ b/arch/powerpc/kexec/crash.c
> @@ -18,6 +18,7 @@
>  #include <linux/types.h>
>  #include <linux/libfdt.h>
>  #include <linux/memory.h>
> +#include <linux/of.h>
>  
>  #include <asm/processor.h>
>  #include <asm/machdep.h>
> @@ -584,32 +585,71 @@ static int get_fdt_index(struct kimage *image)
>  }
>  
>  /**
> - * update_crash_fdt - updates the cpus node of the crash FDT.
> + * update_crash_fdt - add the node of the onlined CPU to the crash FDT.
>   *
>   * @image: a pointer to kexec_crash_image
> + * @cpu: the CPU that was onlined
> + *
> + * The node is added as the first child of /cpus, the same position a node
> + * attached to the live device tree takes. Nothing is done if the FDT already
> + * has the node, for example when an offlined CPU comes back.
>   */
> -static void update_crash_fdt(struct kimage *image)
> +static void update_crash_fdt(struct kimage *image, unsigned int cpu)
>  {
> +	struct device_node *dn;
> +	struct property *pp;
>  	void *fdt;
> -	int fdt_index;
> +	int fdt_index, cpus_offset, node_offset;
> +
> +	dn = of_get_cpu_node(cpu, NULL);
> +	if (!dn) {
> +		pr_err("No device node found for CPU %u\n", cpu);
> +		return;
> +	}
>  
>  	fdt_index = get_fdt_index(image);
>  	if (fdt_index < 0) {
>  		pr_err("Unable to locate FDT segment.\n");
> -		return;
> +		goto put;
>  	}
>  
>  	fdt = __va((void *)image->segment[fdt_index].mem);
>  
> -	/* Temporarily invalidate the crash image while it is replaced */
> +	cpus_offset = fdt_path_offset(fdt, "/cpus");
> +	if (cpus_offset < 0) {
> +		pr_err("Malformed device tree: error reading /cpus node: %s\n",
> +		       fdt_strerror(cpus_offset));
> +		goto put;
> +	}
> +
> +	/* Node already present, e.g. an offlined CPU came back online */
> +	if (fdt_subnode_offset(fdt, cpus_offset, dn->full_name) >= 0)
> +		goto put;
> +
> +	/* Temporarily invalidate the crash image while it is updated */
>  	xchg(&kexec_crash_image, NULL);
>  
> -	/* update FDT to reflect changes in CPU resources */
> -	if (update_cpus_node(fdt))
> -		pr_err("Failed to update crash FDT");
> +	node_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
> +	if (node_offset < 0) {
> +		pr_err("Unable to add %s subnode: %s\n", dn->full_name,
> +		       fdt_strerror(node_offset));
> +		goto out;
> +	}
>  
> +	for_each_property_of_node(dn, pp) {
> +		int ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
> +
> +		if (ret < 0) {
> +			pr_err("Unable to add %s property: %s\n", pp->name,
> +			       fdt_strerror(ret));
> +			break;
> +		}
If a property copy fails the loop just breaks and the image is
re-validated leaving a partially populated CPU node in the FDT. The
next hotplug event then sees the node as already present and never
repairs it so either drop or roll back the node on failure instead.

> +	}
> +out:
>  	/* The crash image is now valid once again */
>  	xchg(&kexec_crash_image, image);
> +put:
> +	of_node_put(dn);
>  }
>  
>  int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
> @@ -625,10 +665,11 @@ int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
>   * arch_crash_handle_hotplug_event - Handle crash CPU/Memory hotplug events to update the
>   *				     necessary kexec segments based on the hotplug event.
>   * @image: a pointer to kexec_crash_image
> - * @arg: struct memory_notify handler for memory hotplug case and NULL for CPU hotplug case.
> + * @arg: struct memory_notify handler for memory hotplug case and pointer to the
> + *	 cpu number for CPU hotplug case.
>   *
>   * Update the kdump image based on the type of hotplug event, represented by image->hp_action.
> - * CPU add: Update the FDT segment to include the newly added CPU.
> + * CPU add: Add the node of the newly added CPU to the FDT segment, if missing.
>   * CPU remove: No action is needed, with the assumption that it's okay to have offline CPUs
>   *	       part of the FDT.
>   * Memory add/remove: No action is taken as this is not yet supported.
> @@ -636,13 +677,15 @@ int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
>  void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
>  {
>  	struct memory_notify *mn;
> +	unsigned int cpu;
>  
>  	switch (image->hp_action) {
>  	case KEXEC_CRASH_HP_REMOVE_CPU:
>  		return;
>  
>  	case KEXEC_CRASH_HP_ADD_CPU:
> -		update_crash_fdt(image);
> +		cpu = *(unsigned int *)arg;
> +		update_crash_fdt(image, cpu);
>  		break;
>  
>  	case KEXEC_CRASH_HP_REMOVE_MEMORY:
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index e6f23933a6df..1660f26f3a44 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -441,7 +441,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
>   * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
>   * @image: a pointer to kexec_crash_image
>   * @arg: struct memory_notify handler for memory hotplug case and
> - *       NULL for CPU hotplug case.
> + *       pointer to the cpu number (unused here) for CPU hotplug case.
>   *
>   * Prepare the new elfcorehdr and replace the existing elfcorehdr.
>   */
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index d0bd2d0cf899..53d4f2c1760c 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -651,6 +651,9 @@ int crash_check_hotplug_support(void)
>   * NR_CPUS and CRASH_MAX_MEMORY_RANGES. The elfcorehdr is
>   * excluded from SHA verification by default if the architecture
>   * supports crash hotplug.
> + *
> + * @arg is a struct memory_notify pointer for memory hotplug events and a
> + * pointer to the unsigned int cpu number for CPU hotplug events.
>   */
>  static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu, void *arg)
>  {
> @@ -676,10 +679,14 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu,
>  		goto out;
>  
>  	if (hp_action == KEXEC_CRASH_HP_ADD_CPU ||
> -		hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
> +		hp_action == KEXEC_CRASH_HP_REMOVE_CPU) {
>  		pr_debug("hp_action %u, cpu %u\n", hp_action, cpu);
> -	else
> +		/* CPU events are raised with no argument, the CPU number is passed instead */
> +		WARN_ON(arg);
> +		arg = &cpu;
> +	} else {
>  		pr_debug("hp_action %u\n", hp_action);
> +	}
>  
>  	/*
>  	 * The elfcorehdr_index is set to -1 when the struct kimage

-- 
Regards,
Mukesh Pilaniya

Re: [PATCH] powerpc/crash: Add only the onlined CPU's node to the crash FDT

[Vishal Chourasia]

On 04/11/26 11:22, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> - [High] powerpc/crash: detached DLPAR CPU nodes accumulate in crash FDT in update_crash_fdt()
> - [High] powerpc/crash: incomplete CPU subnode left in FDT on fdt_setprop() failure in update_crash_fdt()
> --
>
> commit f91f7035e04400925af984e21ed910579118bae0
> Author: Vishal Chourasia <vishalc@linux.ibm.com>
>
> powerpc/crash: Add only the onlined CPU's node to the crash FDT
>
> This patch updates crash FDT handling on CPU online events to pass the onlined
> CPU number to arch_crash_handle_hotplug_event() and insert only that CPU's
> device node into the crash FDT if it is not already present, rather than
> rebuilding all CPU nodes via update_cpus_node().
>
>> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
>> index 775895f310379..ca37006bddeae 100644
>> --- a/arch/powerpc/kexec/crash.c
>> +++ b/arch/powerpc/kexec/crash.c
> [ ... ]
>> @@ -584,32 +585,71 @@ static int get_fdt_index(struct kimage *image)
>>   }
>>   
>>   /**
>> - * update_crash_fdt - updates the cpus node of the crash FDT.
>> + * update_crash_fdt - add the node of the onlined CPU to the crash FDT.
>>    *
>>    * @image: a pointer to kexec_crash_image
>> + * @cpu: the CPU that was onlined
>> + *
>> + * The node is added as the first child of /cpus, the same position a node
>> + * attached to the live device tree takes. Nothing is done if the FDT already
>> + * has the node, for example when an offlined CPU comes back.
>>    */
>> -static void update_crash_fdt(struct kimage *image)
>> +static void update_crash_fdt(struct kimage *image, unsigned int cpu)
>>   {
>> +	struct device_node *dn;
>> +	struct property *pp;
>>   	void *fdt;
>> -	int fdt_index;
>> +	int fdt_index, cpus_offset, node_offset;
>> +
>> +	dn = of_get_cpu_node(cpu, NULL);
>> +	if (!dn) {
>> +		pr_err("No device node found for CPU %u\n", cpu);
>> +		return;
>> +	}
>>   
>>   	fdt_index = get_fdt_index(image);
>>   	if (fdt_index < 0) {
>>   		pr_err("Unable to locate FDT segment.\n");
>> -		return;
>> +		goto put;
>>   	}
>>   
>>   	fdt = __va((void *)image->segment[fdt_index].mem);
>>   
>> -	/* Temporarily invalidate the crash image while it is replaced */
>> +	cpus_offset = fdt_path_offset(fdt, "/cpus");
>> +	if (cpus_offset < 0) {
>> +		pr_err("Malformed device tree: error reading /cpus node: %s\n",
>> +		       fdt_strerror(cpus_offset));
>> +		goto put;
>> +	}
>> +
>> +	/* Node already present, e.g. an offlined CPU came back online */
>> +	if (fdt_subnode_offset(fdt, cpus_offset, dn->full_name) >= 0)
>> +		goto put;
>> +
>> +	/* Temporarily invalidate the crash image while it is updated */
>>   	xchg(&kexec_crash_image, NULL);
>>   
>> -	/* update FDT to reflect changes in CPU resources */
>> -	if (update_cpus_node(fdt))
>> -		pr_err("Failed to update crash FDT");
>> +	node_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
> [Severity: High]
> What happens across DLPAR CPU removal and addition when update_crash_fdt()
> only appends missing CPU nodes and never removes detached ones?
>
> On pSeries, dlpar_cpu_remove() offlines the CPU threads (where
> KEXEC_CRASH_HP_REMOVE_CPU is a no-op in arch_crash_handle_hotplug_event()),
> pseries_cpuhp_detach_nodes() detaches the CPU device_node from /cpus in the
> live device tree, and pseries_remove_processor() clears its bits in
> cpu_present_mask so those logical CPU IDs can be reused.
>
> Previously, update_cpus_node() deleted all existing cpu subnodes under /cpus
> in the crash FDT and rebuilt them from the live /cpus tree, purging any
> detached DLPAR CPU nodes. With this change, detached CPU subnodes remain in
> the crash FDT indefinitely:

As mentioned in the previous paragraph, during the CPU offline path,
crash handler doesn't update the crash image and returns early.
update_cpus_node() is not invoked.

>
> 1. kdump_extra_fdt_size_ppc64() in arch/powerpc/kexec/file_load_64.c only
>     budgets extra FDT space for possible_cpu_nodes concurrent CPU nodes:
>
> 	if (image->type == KEXEC_TYPE_CRASH) {
> 		possible_cpu_nodes = num_possible_cpus() / threads_per_core;
> 		if (possible_cpu_nodes > cpu_nodes)
> 			extra_size += (possible_cpu_nodes - cpu_nodes) * cpu_node_size();
> 	}
>
>     When a CPU is DLPAR-removed and a CPU with a different DRC index is
>     DLPAR-added, retaining the detached node alongside the newly added node
>     exceeds possible_cpu_nodes and causes fdt_add_subnode() or fdt_setprop() to
>     fail with -FDT_ERR_NOSPACE.
Behaviour is same as before.
>
> 2. Because detached nodes remain under /cpus in the crash FDT,
>     smp_setup_cpu_maps() in the kdump kernel still iterates over them and
>     assigns logical CPU IDs up to nr_cpu_ids, which can push valid present
>     CPUs past nr_cpu_ids.
>
> 3. If the same DRC index is later DLPAR-added again via
>     dlpar_configure_connector() with updated properties (such as
>     ibm,associativity), fdt_subnode_offset(fdt, cpus_offset, dn->full_name) >= 0
>     matches the stale node and skips updating its properties.
>
>> +	if (node_offset < 0) {
>> +		pr_err("Unable to add %s subnode: %s\n", dn->full_name,
>> +		       fdt_strerror(node_offset));
>> +		goto out;
>> +	}
>>   
>> +	for_each_property_of_node(dn, pp) {
>> +		int ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
>> +
>> +		if (ret < 0) {
>> +			pr_err("Unable to add %s property: %s\n", pp->name,
>> +			       fdt_strerror(ret));
>> +			break;
>> +		}
>> +	}
> [Severity: High]
> If fdt_setprop() fails partway through copying the properties in
> update_crash_fdt(), should node_offset be removed with fdt_del_node(fdt,
> node_offset) before breaking out?
>
> Leaving the partially populated subnode under /cpus has two consequences:
>
> 1. Any subsequent update_crash_fdt() call for sibling SMT threads of the same
>     core (or a later re-online of the CPU) sees
>     fdt_subnode_offset(fdt, cpus_offset, dn->full_name) >= 0 and returns early
>     without populating the missing properties.
>
> 2. If the device_type = "cpu" property was written before fdt_setprop() failed
>     on ibm,ppc-interrupt-server#s and reg, early_init_dt_scan_cpus() in
>     arch/powerpc/kernel/prom.c will match the partial CPU node during kdump
>     boot, get NULL for intserv with len left uninitialized, and dereference
>     intserv[i]:
>
> 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
> 	if (!intserv)
> 		intserv = of_get_flat_dt_prop(node, "reg", &len);
>
> 	nthreads = len / sizeof(int);
>
> 	for (i = 0; i < nthreads; i++) {
> 		if (be32_to_cpu(intserv[i]) ==
> 			fdt_boot_cpuid_phys(initial_boot_params)) {

Similar errors on update_cpus_node() can live the crash fdt
inconsistent and result in crash kernel boot hangs.

>