[PATCH v3 6/7] x86/crash: pass dm crypt keys to kdump kernel

From: Coiby Xu <coxu@redhat.com>
To: kexec@lists.infradead.org
Cc: "Ondrej Kozina" <okozina@redhat.com>,
	"Milan Broz" <gmazyland@gmail.com>,
	"Thomas Staudt" <tstaudt@de.ibm.com>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	"Kairui Song" <ryncsn@gmail.com>,
	dm-devel@redhat.com, "Jan Pazdziora" <jpazdziora@redhat.com>,
	"Pingfan Liu" <kernelfans@gmail.com>,
	"Baoquan He" <bhe@redhat.com>, "Dave Young" <dyoung@redhat.com>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	"Dave Hansen" <dave.hansen@intel.com>,
	"Vitaly Kuznetsov" <vkuznets@redhat.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Borislav Petkov" <bp@alien8.de>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v3 6/7] x86/crash: pass dm crypt keys to kdump kernel
Date: Thu, 25 Apr 2024 18:04:30 +0800	[thread overview]
Message-ID: <20240425100434.198925-7-coxu@redhat.com> (raw)
In-Reply-To: <20240425100434.198925-1-coxu@redhat.com>

1st kernel will build up the kernel command parameter dmcryptkeys as
similar to elfcorehdr to pass the memory address of the stored info of
dm crypt key to kdump kernel.

Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/crash.c           | 15 ++++++++++++++-
 arch/x86/kernel/kexec-bzimage64.c |  7 +++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index e74d0c4286c1..d852f9c99f0e 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -266,6 +266,7 @@ static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem,
 				 unsigned long long mend)
 {
 	unsigned long start, end;
+	int r;
 
 	cmem->ranges[0].start = mstart;
 	cmem->ranges[0].end = mend;
@@ -274,7 +275,19 @@ static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem,
 	/* Exclude elf header region */
 	start = image->elf_load_addr;
 	end = start + image->elf_headers_sz - 1;
-	return crash_exclude_mem_range(cmem, start, end);
+	r = crash_exclude_mem_range(cmem, start, end);
+
+	if (r)
+		return r;
+
+	/* Exclude dm crypt keys region */
+	if (image->dm_crypt_keys_addr) {
+		start = image->dm_crypt_keys_addr;
+		end = start + image->dm_crypt_keys_sz - 1;
+		return crash_exclude_mem_range(cmem, start, end);
+	}
+
+	return r;
 }
 
 /* Prepare memory map for crash dump kernel */
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 68530fad05f7..9c94428927bd 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -76,6 +76,10 @@ static int setup_cmdline(struct kimage *image, struct boot_params *params,
 	if (image->type == KEXEC_TYPE_CRASH) {
 		len = sprintf(cmdline_ptr,
 			"elfcorehdr=0x%lx ", image->elf_load_addr);
+
+		if (image->dm_crypt_keys_addr != 0)
+			len += sprintf(cmdline_ptr + len,
+					"dmcryptkeys=0x%lx ", image->dm_crypt_keys_addr);
 	}
 	memcpy(cmdline_ptr + len, cmdline, cmdline_len);
 	cmdline_len += len;
@@ -441,6 +445,9 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 		ret = crash_load_segments(image);
 		if (ret)
 			return ERR_PTR(ret);
+		ret = crash_load_dm_crypt_keys(image);
+		if (ret)
+			pr_debug("Either no dm crypt key or error to retrieve the dm crypt key\n");
 	}
 #endif
 
-- 
2.44.0


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