[PATCH v4 0/2] kdump: Enable LUKS-encrypted dump target support in ARM64 and PowerPC

[PATCH v4 0/2] kdump: Enable LUKS-encrypted dump target support in ARM64 and PowerPC

[Coiby Xu]

CONFIG_CRASH_DM_CRYPT has been introduced to support LUKS-encrypted
device dump target by addressing two challenges [1],
 - Kdump kernel may not be able to decrypt the LUKS partition. For some
   machines, a system administrator may not have a chance to enter the
   password to decrypt the device in kdump initramfs after the 1st kernel
   crashes

 - LUKS2 by default use the memory-hard Argon2 key derivation function
   which is quite memory-consuming compared to the limited memory reserved
   for kdump.

To also enable this feature for ARM64 and PowerPC, we only need to add a
device tree property dmcryptkeys [2] as similar to elfcorehdr to pass the
memory address of the stored info of dm-crypt keys to the kdump kernel.

[1] https://lore.kernel.org/all/20250502011246.99238-1-coxu@redhat.com/
[2] https://github.com/devicetree-org/dt-schema/pull/181


v4
- Make arch-specific code more succinct by printing more logs in
  arch-independent code [Will Deacon]  

- Also use device tree for PowerPC to pass memory address of dm-crypt
  keys info
  - powerpc v2 patch that passes the dmcryptkeys kernel cmdline
    parameter:
    https://lore.kernel.org/all/20260106074039.564707-1-coxu@redhat.com/

v3
- Delete the property after reading it [Rob Herring]

v2
- Krzysztof
  - Use imperative mood for commit message
  - Add dt-schema ABI Documentation 
    https://github.com/devicetree-org/dt-schema/pull/181
- Don't print dm-crypt keys address via pr_debug

Coiby Xu (2):
  crash_dump/dm-crypt: Don't print in arch-specific code
  arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

 arch/arm64/kernel/machine_kexec_file.c |  4 ++++
 arch/powerpc/kexec/elf_64.c            |  4 ++++
 arch/x86/kernel/kexec-bzimage64.c      |  6 +-----
 drivers/of/fdt.c                       | 21 +++++++++++++++++++++
 drivers/of/kexec.c                     | 19 +++++++++++++++++++
 kernel/crash_dump_dm_crypt.c           |  7 +++++--
 6 files changed, 54 insertions(+), 7 deletions(-)


base-commit: 2619c62b7ef2f463bcbbb34af122689c09855c23
-- 
2.53.0

[PATCH v4 1/2] crash_dump/dm-crypt: Don't print in arch-specific code

[Coiby Xu]

When the vmcore dumping target is not a LUKS-encrypted target, it's
expected that there is no dm-crypt key thus no need to return -ENOENT.
Also print more logs in crash_load_dm_crypt_keys. The benefit is
arch-specific code can be more succinct.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/kexec-bzimage64.c | 6 +-----
 kernel/crash_dump_dm_crypt.c      | 7 +++++--
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 7508d0ccc740..d20cf976d01a 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -518,12 +518,8 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 		if (ret)
 			return ERR_PTR(ret);
 		ret = crash_load_dm_crypt_keys(image);
-		if (ret == -ENOENT) {
-			kexec_dprintk("No dm crypt key to load\n");
-		} else if (ret) {
-			pr_err("Failed to load dm crypt keys\n");
+		if (ret)
 			return ERR_PTR(ret);
-		}
 		if (image->dm_crypt_keys_addr &&
 		    cmdline_len + MAX_ELFCOREHDR_STR_LEN + MAX_DMCRYPTKEYS_STR_LEN >
 			    header->cmdline_size) {
diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c
index 401423ba477d..478dacb0625c 100644
--- a/kernel/crash_dump_dm_crypt.c
+++ b/kernel/crash_dump_dm_crypt.c
@@ -405,14 +405,16 @@ int crash_load_dm_crypt_keys(struct kimage *image)
 
 	if (key_count <= 0) {
 		kexec_dprintk("No dm-crypt keys\n");
-		return -ENOENT;
+		return 0;
 	}
 
 	if (!is_dm_key_reused) {
 		image->dm_crypt_keys_addr = 0;
 		r = build_keys_header();
-		if (r)
+		if (r) {
+			pr_err("Failed to build dm-crypt keys header, ret=%d\n", r);
 			return r;
+		}
 	}
 
 	kbuf.buffer = keys_header;
@@ -423,6 +425,7 @@ int crash_load_dm_crypt_keys(struct kimage *image)
 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 	r = kexec_add_buffer(&kbuf);
 	if (r) {
+		pr_err("Failed to call kexec_add_buffer, ret=%d\n", r);
 		kvfree((void *)kbuf.buffer);
 		return r;
 	}
-- 
2.53.0

[PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[Coiby Xu]

CONFIG_CRASH_DM_CRYPT has been introduced to support LUKS-encrypted
device dump target by addressing two challenges [1],
 - Kdump kernel may not be able to decrypt the LUKS partition. For some
   machines, a system administrator may not have a chance to enter the
   password to decrypt the device in kdump initramfs after the 1st kernel
   crashes

 - LUKS2 by default use the memory-hard Argon2 key derivation function
   which is quite memory-consuming compared to the limited memory reserved
   for kdump.

To also enable this feature for ARM64 and PowerPC, we only need to add
a device tree property dmcryptkeys [2] as similar to elfcorehdr to pass
the memory address of the stored info of dm-crypt keys to the kdump
kernel. Since this property is only needed by the kdump kernel, it won't
be exposed to user space.

[1] https://lore.kernel.org/all/20250502011246.99238-1-coxu@redhat.com/
[2] https://github.com/devicetree-org/dt-schema/pull/181

Cc: Arnaud Lefebvre <arnaud.lefebvre@clever-cloud.com>
Cc: Baoquan he <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thomas Staudt <tstaudt@de.ibm.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/arm64/kernel/machine_kexec_file.c |  4 ++++
 arch/powerpc/kexec/elf_64.c            |  4 ++++
 drivers/of/fdt.c                       | 21 +++++++++++++++++++++
 drivers/of/kexec.c                     | 19 +++++++++++++++++++
 4 files changed, 48 insertions(+)

diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 410060ebd86d..b6798bb2bb82 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -134,6 +134,10 @@ int load_other_segments(struct kimage *image,
 
 		kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 			      image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
+
+		ret = crash_load_dm_crypt_keys(image);
+		if (ret)
+			goto out_err;
 	}
 #endif
 
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 5d6d616404cf..ea50a072debf 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -79,6 +79,10 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 			goto out;
 		}
 
+		ret = crash_load_dm_crypt_keys(image);
+		if (ret)
+			goto out;
+
 		/* Setup cmdline for kdump kernel case */
 		modified_cmdline = setup_kdump_cmdline(image, cmdline,
 						       cmdline_len);
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 331646d667b9..2967e4aff807 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -866,6 +866,26 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
 		 elfcorehdr_addr, elfcorehdr_size);
 }
 
+static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node)
+{
+	const char *prop_name = "linux,dmcryptkeys";
+	const __be32 *prop;
+
+	if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT))
+		return;
+
+	pr_debug("Looking for dmcryptkeys property... ");
+
+	prop = of_get_flat_dt_prop(node, prop_name, NULL);
+	if (!prop)
+		return;
+
+	dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+
+	/* Property only accessible to crash dump kernel */
+	fdt_delprop(initial_boot_params, node, prop_name);
+}
+
 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
 
 /*
@@ -1097,6 +1117,7 @@ int __init early_init_dt_scan_chosen(char *cmdline)
 
 	early_init_dt_check_for_initrd(node);
 	early_init_dt_check_for_elfcorehdr(node);
+	early_init_dt_check_for_dmcryptkeys(node);
 
 	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
 	if (rng_seed && l > 0) {
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 1ee2d31816ae..4bfb1ea5744e 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -432,6 +432,25 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 		if (ret)
 			goto out;
 
+		if (image->dm_crypt_keys_addr != 0) {
+			ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+						       "linux,dmcryptkeys",
+						       image->dm_crypt_keys_addr,
+						       image->dm_crypt_keys_sz);
+
+			if (ret)
+				goto out;
+
+			/*
+			 * Avoid dmcryptkeys from being stomped on in kdump kernel by
+			 * setting up memory reserve map.
+			 */
+			ret = fdt_add_mem_rsv(fdt, image->dm_crypt_keys_addr,
+					      image->dm_crypt_keys_sz);
+			if (ret)
+				goto out;
+		}
+
 #ifdef CONFIG_CRASH_DUMP
 		/* add linux,usable-memory-range */
 		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
-- 
2.53.0

Re: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[Christophe Leroy (CS GROUP)]

Le 11/02/2026 à 09:24, Coiby Xu a écrit :
> CONFIG_CRASH_DM_CRYPT has been introduced to support LUKS-encrypted
> device dump target by addressing two challenges [1],
>   - Kdump kernel may not be able to decrypt the LUKS partition. For some
>     machines, a system administrator may not have a chance to enter the
>     password to decrypt the device in kdump initramfs after the 1st kernel
>     crashes
> 
>   - LUKS2 by default use the memory-hard Argon2 key derivation function
>     which is quite memory-consuming compared to the limited memory reserved
>     for kdump.
> 
> To also enable this feature for ARM64 and PowerPC, we only need to add

What do you want to say exactly with 'only' ?

> a device tree property dmcryptkeys [2] as similar to elfcorehdr to pass
> the memory address of the stored info of dm-crypt keys to the kdump
> kernel. Since this property is only needed by the kdump kernel, it won't
> be exposed to user space.
> 
> [1] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20250502011246.99238-1-coxu%40redhat.com%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0aa5f3b34d694b23b0cc08de6946f66c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639063950684962054%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=8uCc%2Bg6YNojymf8UpZhmJY19vpWXJCC9KIf3qMyQ3dI%3D&reserved=0
> [2] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fdevicetree-org%2Fdt-schema%2Fpull%2F181&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0aa5f3b34d694b23b0cc08de6946f66c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639063950684987003%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=1s5NPHgF1LsXdrDXBhawduFXOqnHPlkbohQHHvolLw4%3D&reserved=0
> 
> Cc: Arnaud Lefebvre <arnaud.lefebvre@clever-cloud.com>
> Cc: Baoquan he <bhe@redhat.com>
> Cc: Dave Young <dyoung@redhat.com>
> Cc: Kairui Song <ryncsn@gmail.com>
> Cc: Pingfan Liu <kernelfans@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Krzysztof Kozlowski <krzk@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Thomas Staudt <tstaudt@de.ibm.com>
> Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
> Cc: Will Deacon <will@kernel.org>
> Signed-off-by: Coiby Xu <coxu@redhat.com>
> ---
>   arch/arm64/kernel/machine_kexec_file.c |  4 ++++
>   arch/powerpc/kexec/elf_64.c            |  4 ++++
>   drivers/of/fdt.c                       | 21 +++++++++++++++++++++
>   drivers/of/kexec.c                     | 19 +++++++++++++++++++
>   4 files changed, 48 insertions(+)
> 
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 331646d667b9..2967e4aff807 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -866,6 +866,26 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
>   		 elfcorehdr_addr, elfcorehdr_size);
>   }
>   
> +static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node)
> +{
> +	const char *prop_name = "linux,dmcryptkeys";
> +	const __be32 *prop;
> +
> +	if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT))
> +		return;
> +
> +	pr_debug("Looking for dmcryptkeys property... ");
> +
> +	prop = of_get_flat_dt_prop(node, prop_name, NULL);
> +	if (!prop)
> +		return;
> +
> +	dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
> +
> +	/* Property only accessible to crash dump kernel */
> +	fdt_delprop(initial_boot_params, node, prop_name);

Shouldn't this property be deleted regardless of whether kernel is built 
with CONFIG_CRASH_DM_CRYPT or without ?

> +}
> +
>   static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
>   
>   /*
> @@ -1097,6 +1117,7 @@ int __init early_init_dt_scan_chosen(char *cmdline)
>   
>   	early_init_dt_check_for_initrd(node);
>   	early_init_dt_check_for_elfcorehdr(node);
> +	early_init_dt_check_for_dmcryptkeys(node);
>   
>   	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
>   	if (rng_seed && l > 0) {

Re: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[Coiby Xu]

On Wed, Feb 11, 2026 at 10:55:17AM +0100, Christophe Leroy (CS GROUP) wrote:
>
>
>Le 11/02/2026 à 09:24, Coiby Xu a écrit :
>>CONFIG_CRASH_DM_CRYPT has been introduced to support LUKS-encrypted
>>device dump target by addressing two challenges [1],
>>  - Kdump kernel may not be able to decrypt the LUKS partition. For some
>>    machines, a system administrator may not have a chance to enter the
>>    password to decrypt the device in kdump initramfs after the 1st kernel
>>    crashes
>>
>>  - LUKS2 by default use the memory-hard Argon2 key derivation function
>>    which is quite memory-consuming compared to the limited memory reserved
>>    for kdump.
>>
>>To also enable this feature for ARM64 and PowerPC, we only need to add
>
>What do you want to say exactly with 'only' ?

Hi Christophe,

Thanks for raising the question! To clarify, CONFIG_CRASH_DM_CRYPT
provides the framework to address these challenges for LUKS-encrypted
dump target. Since the heavy lifting is handled in the arch-independent
code, we only need to...

If it looks good to you, I'll rephrase it as "To also enable this
feature for ARM64 and PowerPC, the missing piece is to let the kdump
kernel know where to find the dm-crypt keys which are randomly stored in
memory reserved for kdump. I'll introduce a new device tree property
dmcryptkeys ...".

>
>>a device tree property dmcryptkeys [2] as similar to elfcorehdr to pass
>>the memory address of the stored info of dm-crypt keys to the kdump
>>kernel. Since this property is only needed by the kdump kernel, it won't
>>be exposed to user space.
>>
>>[1] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20250502011246.99238-1-coxu%40redhat.com%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0aa5f3b34d694b23b0cc08de6946f66c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639063950684962054%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=8uCc%2Bg6YNojymf8UpZhmJY19vpWXJCC9KIf3qMyQ3dI%3D&reserved=0
>>[2] https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fdevicetree-org%2Fdt-schema%2Fpull%2F181&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0aa5f3b34d694b23b0cc08de6946f66c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639063950684987003%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=1s5NPHgF1LsXdrDXBhawduFXOqnHPlkbohQHHvolLw4%3D&reserved=0
>>
>>Cc: Arnaud Lefebvre <arnaud.lefebvre@clever-cloud.com>
>>Cc: Baoquan he <bhe@redhat.com>
>>Cc: Dave Young <dyoung@redhat.com>
>>Cc: Kairui Song <ryncsn@gmail.com>
>>Cc: Pingfan Liu <kernelfans@gmail.com>
>>Cc: Andrew Morton <akpm@linux-foundation.org>
>>Cc: Krzysztof Kozlowski <krzk@kernel.org>
>>Cc: Rob Herring <robh@kernel.org>
>>Cc: Thomas Staudt <tstaudt@de.ibm.com>
>>Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
>>Cc: Will Deacon <will@kernel.org>
>>Signed-off-by: Coiby Xu <coxu@redhat.com>
>>---
>>  arch/arm64/kernel/machine_kexec_file.c |  4 ++++
>>  arch/powerpc/kexec/elf_64.c            |  4 ++++
>>  drivers/of/fdt.c                       | 21 +++++++++++++++++++++
>>  drivers/of/kexec.c                     | 19 +++++++++++++++++++
>>  4 files changed, 48 insertions(+)
>>
>>diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
>>index 331646d667b9..2967e4aff807 100644
>>--- a/drivers/of/fdt.c
>>+++ b/drivers/of/fdt.c
>>@@ -866,6 +866,26 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
>>  		 elfcorehdr_addr, elfcorehdr_size);
>>  }
>>+static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node)
>>+{
>>+	const char *prop_name = "linux,dmcryptkeys";
>>+	const __be32 *prop;
>>+
>>+	if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT))
>>+		return;
>>+
>>+	pr_debug("Looking for dmcryptkeys property... ");
>>+
>>+	prop = of_get_flat_dt_prop(node, prop_name, NULL);
>>+	if (!prop)
>>+		return;
>>+
>>+	dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
>>+
>>+	/* Property only accessible to crash dump kernel */
>>+	fdt_delprop(initial_boot_params, node, prop_name);
>
>Shouldn't this property be deleted regardless of whether kernel is 
>built with CONFIG_CRASH_DM_CRYPT or without ?

This property will be created only if 1) CONFIG_CRASH_DM_CRYPT is
enabled and 2) the dump target is LUKS-encrypted. So there is no need to
delete it if it doesn't exist at all.

>
>>+}
>>+
>>  static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
>>  /*
>>@@ -1097,6 +1117,7 @@ int __init early_init_dt_scan_chosen(char *cmdline)
>>  	early_init_dt_check_for_initrd(node);
>>  	early_init_dt_check_for_elfcorehdr(node);
>>+	early_init_dt_check_for_dmcryptkeys(node);
>>  	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
>>  	if (rng_seed && l > 0) {
>

-- 
Best regards,
Coiby

Re: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[kernel test robot]

Hi Coiby,

kernel test robot noticed the following build errors:

[auto build test ERROR on 2619c62b7ef2f463bcbbb34af122689c09855c23]

url:    https://github.com/intel-lab-lkp/linux/commits/Coiby-Xu/crash_dump-dm-crypt-Don-t-print-in-arch-specific-code/20260211-162729
base:   2619c62b7ef2f463bcbbb34af122689c09855c23
patch link:    https://lore.kernel.org/r/20260211082401.2407853-3-coxu%40redhat.com
patch subject: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel
config: powerpc64-randconfig-r111-20260212 (https://download.01.org/0day-ci/archive/20260212/202602120648.RgQALnnI-lkp@intel.com/config)
compiler: powerpc64-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260212/202602120648.RgQALnnI-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602120648.RgQALnnI-lkp@intel.com/

All errors (new ones prefixed by >>):

   arch/powerpc/kexec/elf_64.c: In function 'elf64_load':
>> arch/powerpc/kexec/elf_64.c:82:23: error: implicit declaration of function 'crash_load_dm_crypt_keys' [-Werror=implicit-function-declaration]
      82 |                 ret = crash_load_dm_crypt_keys(image);
         |                       ^~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/crash_load_dm_crypt_keys +82 arch/powerpc/kexec/elf_64.c

    27	
    28	static void *elf64_load(struct kimage *image, char *kernel_buf,
    29				unsigned long kernel_len, char *initrd,
    30				unsigned long initrd_len, char *cmdline,
    31				unsigned long cmdline_len)
    32	{
    33		int ret;
    34		unsigned long kernel_load_addr;
    35		unsigned long initrd_load_addr = 0, fdt_load_addr;
    36		void *fdt;
    37		const void *slave_code;
    38		struct elfhdr ehdr;
    39		char *modified_cmdline = NULL;
    40		struct crash_mem *rmem = NULL;
    41		struct kexec_elf_info elf_info;
    42		struct kexec_buf kbuf = { .image = image, .buf_min = 0,
    43					  .buf_max = ppc64_rma_size };
    44		struct kexec_buf pbuf = { .image = image, .buf_min = 0,
    45					  .buf_max = ppc64_rma_size, .top_down = true,
    46					  .mem = KEXEC_BUF_MEM_UNKNOWN };
    47	
    48		ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
    49		if (ret)
    50			return ERR_PTR(ret);
    51	
    52		if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
    53			/* min & max buffer values for kdump case */
    54			kbuf.buf_min = pbuf.buf_min = crashk_res.start;
    55			kbuf.buf_max = pbuf.buf_max =
    56					((crashk_res.end < ppc64_rma_size) ?
    57					 crashk_res.end : (ppc64_rma_size - 1));
    58		}
    59	
    60		ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
    61		if (ret)
    62			goto out;
    63	
    64		kexec_dprintk("Loaded the kernel at 0x%lx\n", kernel_load_addr);
    65	
    66		ret = kexec_load_purgatory(image, &pbuf);
    67		if (ret) {
    68			pr_err("Loading purgatory failed.\n");
    69			goto out;
    70		}
    71	
    72		kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
    73	
    74		/* Load additional segments needed for panic kernel */
    75		if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
    76			ret = load_crashdump_segments_ppc64(image, &kbuf);
    77			if (ret) {
    78				pr_err("Failed to load kdump kernel segments\n");
    79				goto out;
    80			}
    81	
  > 82			ret = crash_load_dm_crypt_keys(image);
    83			if (ret)
    84				goto out;
    85	
    86			/* Setup cmdline for kdump kernel case */
    87			modified_cmdline = setup_kdump_cmdline(image, cmdline,
    88							       cmdline_len);
    89			if (!modified_cmdline) {
    90				pr_err("Setting up cmdline for kdump kernel failed\n");
    91				ret = -EINVAL;
    92				goto out;
    93			}
    94			cmdline = modified_cmdline;
    95		}
    96	
    97		if (initrd != NULL) {
    98			kbuf.buffer = initrd;
    99			kbuf.bufsz = kbuf.memsz = initrd_len;
   100			kbuf.buf_align = PAGE_SIZE;
   101			kbuf.top_down = false;
   102			kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
   103			ret = kexec_add_buffer(&kbuf);
   104			if (ret)
   105				goto out;
   106			initrd_load_addr = kbuf.mem;
   107	
   108			kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_load_addr);
   109		}
   110	
   111		ret = get_reserved_memory_ranges(&rmem);
   112		if (ret)
   113			goto out;
   114	
   115		fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
   116						   initrd_len, cmdline,
   117						   kexec_extra_fdt_size_ppc64(image, rmem));
   118		if (!fdt) {
   119			pr_err("Error setting up the new device tree.\n");
   120			ret = -EINVAL;
   121			goto out;
   122		}
   123	
   124		ret = setup_new_fdt_ppc64(image, fdt, rmem);
   125		if (ret)
   126			goto out_free_fdt;
   127	
   128		if (!IS_ENABLED(CONFIG_CRASH_HOTPLUG) || image->type != KEXEC_TYPE_CRASH)
   129			fdt_pack(fdt);
   130	
   131		kbuf.buffer = fdt;
   132		kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
   133		kbuf.buf_align = PAGE_SIZE;
   134		kbuf.top_down = true;
   135		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
   136		ret = kexec_add_buffer(&kbuf);
   137		if (ret)
   138			goto out_free_fdt;
   139	
   140		/* FDT will be freed in arch_kimage_file_post_load_cleanup */
   141		image->arch.fdt = fdt;
   142	
   143		fdt_load_addr = kbuf.mem;
   144	
   145		kexec_dprintk("Loaded device tree at 0x%lx\n", fdt_load_addr);
   146	
   147		slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
   148		ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
   149					    fdt_load_addr);
   150		if (ret)
   151			pr_err("Error setting up the purgatory.\n");
   152	
   153		goto out;
   154	
   155	out_free_fdt:
   156		kvfree(fdt);
   157	out:
   158		kfree(rmem);
   159		kfree(modified_cmdline);
   160		kexec_free_elf_info(&elf_info);
   161	
   162		return ret ? ERR_PTR(ret) : NULL;
   163	}
   164	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

[Coiby Xu]

On Thu, Feb 12, 2026 at 06:35:52AM +0800, kernel test robot wrote:
>Hi Coiby,
>
>kernel test robot noticed the following build errors:
>
>[auto build test ERROR on 2619c62b7ef2f463bcbbb34af122689c09855c23]
>
>url:    https://github.com/intel-lab-lkp/linux/commits/Coiby-Xu/crash_dump-dm-crypt-Don-t-print-in-arch-specific-code/20260211-162729
>base:   2619c62b7ef2f463bcbbb34af122689c09855c23
>patch link:    https://lore.kernel.org/r/20260211082401.2407853-3-coxu%40redhat.com
>patch subject: [PATCH v4 2/2] arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel
>config: powerpc64-randconfig-r111-20260212 (https://download.01.org/0day-ci/archive/20260212/202602120648.RgQALnnI-lkp@intel.com/config)
>compiler: powerpc64-linux-gcc (GCC) 11.5.0
>reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260212/202602120648.RgQALnnI-lkp@intel.com/reproduce)
>
>If you fix the issue in a separate patch/commit (i.e. not just a new version of
>the same patch/commit), kindly add following tags
>| Reported-by: kernel test robot <lkp@intel.com>
>| Closes: https://lore.kernel.org/oe-kbuild-all/202602120648.RgQALnnI-lkp@intel.com/
>
>All errors (new ones prefixed by >>):
>
>   arch/powerpc/kexec/elf_64.c: In function 'elf64_load':
>>> arch/powerpc/kexec/elf_64.c:82:23: error: implicit declaration of function 'crash_load_dm_crypt_keys' [-Werror=implicit-function-declaration]
>      82 |                 ret = crash_load_dm_crypt_keys(image);
>         |                       ^~~~~~~~~~~~~~~~~~~~~~~~
>   cc1: some warnings being treated as errors

Thanks for reporting this issue. I'll fix this issue in new patch set.

-- 
Best regards,
Coiby