[PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Stefan Berger]

The of-tree subsystem does not currently preserve the IBM vTPM 1.2 and
vTPM 2.0 measurement logs across a kexec on PowerVM and PowerKVM. This
series fixes this for the kexec_file_load() syscall using the flattened
device tree (fdt) to carry the TPM measurement log's buffer across kexec.

   Stefan

v8:
 - Added Jarkko's, Coiby's, and Rob's tags
 - Rebase on v6.0-rc3 that absorbed 2 already upstreamed patches

v7:
 - Added Nageswara's Tested-by tags
 - Added back original comment to inline function and removed Jarkko's R-b tag

v6:
 - Add __init to get_kexec_buffer as suggested by Jonathan
 - Fixed issue detected by kernel test robot

v5:
 - Rebased on 1 more patch that would otherwise create merge conflicts

v4:
 - Rebased on 2 patches that would otherwise create merge conflicts;
   posting these patches in this series with several tags removed so
   krobot can test the series already
 - Changes to individual patches documented in patch descripitons

v3:
 - Moved TPM Open Firmware related function to drivers/char/tpm/eventlog/tpm_of.c

v2:
 - rearranged patches
 - fixed compilation issues for x86

Palmer Dabbelt (1):
  drivers: of: kexec ima: Support 32-bit platforms

Stefan Berger (3):
  tpm: of: Make of-tree specific function commonly available
  of: kexec: Refactor IMA buffer related functions to make them reusable
  tpm/kexec: Duplicate TPM measurement log in of-tree for kexec

 drivers/char/tpm/eventlog/of.c |  31 +--
 drivers/of/kexec.c             | 336 ++++++++++++++++++++++++++++-----
 include/linux/kexec.h          |   6 +
 include/linux/of.h             |   9 +-
 include/linux/tpm.h            |  36 ++++
 kernel/kexec_file.c            |   6 +
 6 files changed, 346 insertions(+), 78 deletions(-)


base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
-- 
2.35.1

[PATCH v8 1/4] drivers: of: kexec ima: Support 32-bit platforms

[Stefan Berger]

From: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V recently added kexec_file() support, which uses enables kexec
IMA.  We're the first 32-bit platform to support this, so we found a
build bug.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
 drivers/of/kexec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index e6c01db393f9..548dd5b1b5c1 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -250,8 +250,8 @@ static int setup_ima_buffer(const struct kimage *image, void *fdt,
 	if (ret)
 		return -EINVAL;
 
-	pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
-		 image->ima_buffer_addr, image->ima_buffer_size);
+	pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
+		 &image->ima_buffer_addr, image->ima_buffer_size);
 
 	return 0;
 }
-- 
2.35.1

[PATCH v8 2/4] tpm: of: Make of-tree specific function commonly available

[Stefan Berger]

Simplify tpm_read_log_of() by moving reusable parts of the code into
an inline function that makes it commonly available so it can be
used also for kexec support. Call the new of_tpm_get_sml_parameters()
function from the TPM Open Firmware driver.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Coiby Xu <coxu@redhat.com>

---
v7:
 - Added original comment back into inlined function

v4:
 - converted to inline function
---
 drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
 include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
index a9ce66d09a75..f9462d19632e 100644
--- a/drivers/char/tpm/eventlog/of.c
+++ b/drivers/char/tpm/eventlog/of.c
@@ -12,6 +12,7 @@
 
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/tpm.h>
 #include <linux/tpm_eventlog.h>
 
 #include "../tpm.h"
@@ -20,11 +21,10 @@
 int tpm_read_log_of(struct tpm_chip *chip)
 {
 	struct device_node *np;
-	const u32 *sizep;
-	const u64 *basep;
 	struct tpm_bios_log *log;
 	u32 size;
 	u64 base;
+	int ret;
 
 	log = &chip->log;
 	if (chip->dev.parent && chip->dev.parent->of_node)
@@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
 	if (of_property_read_bool(np, "powered-while-suspended"))
 		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
 
-	sizep = of_get_property(np, "linux,sml-size", NULL);
-	basep = of_get_property(np, "linux,sml-base", NULL);
-	if (sizep == NULL && basep == NULL)
-		return -ENODEV;
-	if (sizep == NULL || basep == NULL)
-		return -EIO;
-
-	/*
-	 * For both vtpm/tpm, firmware has log addr and log size in big
-	 * endian format. But in case of vtpm, there is a method called
-	 * sml-handover which is run during kernel init even before
-	 * device tree is setup. This sml-handover function takes care
-	 * of endianness and writes to sml-base and sml-size in little
-	 * endian format. For this reason, vtpm doesn't need conversion
-	 * but physical tpm needs the conversion.
-	 */
-	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
-	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
-		size = be32_to_cpup((__force __be32 *)sizep);
-		base = be64_to_cpup((__force __be64 *)basep);
-	} else {
-		size = *sizep;
-		base = *basep;
-	}
+	ret = of_tpm_get_sml_parameters(np, &base, &size);
+	if (ret < 0)
+		return ret;
 
 	if (size == 0) {
 		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index dfeb25a0362d..6356baaa1393 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
 	return NULL;
 }
 #endif
+
+#ifdef CONFIG_OF
+static inline int of_tpm_get_sml_parameters(struct device_node *np,
+					    u64 *base, u32 *size)
+{
+	const u32 *sizep;
+	const u64 *basep;
+
+	sizep = of_get_property(np, "linux,sml-size", NULL);
+	basep = of_get_property(np, "linux,sml-base", NULL);
+	if (sizep == NULL && basep == NULL)
+		return -ENODEV;
+	if (sizep == NULL || basep == NULL)
+		return -EIO;
+
+	/*
+	 * For both vtpm/tpm, firmware has log addr and log size in big
+	 * endian format. But in case of vtpm, there is a method called
+	 * sml-handover which is run during kernel init even before
+	 * device tree is setup. This sml-handover function takes care
+	 * of endianness and writes to sml-base and sml-size in little
+	 * endian format. For this reason, vtpm doesn't need conversion
+	 * but physical tpm needs the conversion.
+	 */
+	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
+	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
+		*size = be32_to_cpup((__force __be32 *)sizep);
+		*base = be64_to_cpup((__force __be64 *)basep);
+	} else {
+		*size = *sizep;
+		*base = *basep;
+	}
+	return 0;
+}
+#endif
+
 #endif
-- 
2.35.1

Re: [PATCH v8 2/4] tpm: of: Make of-tree specific function commonly available

[Jarkko Sakkinen]

On Thu, Sep 01, 2022 at 05:46:08PM -0400, Stefan Berger wrote:
> Simplify tpm_read_log_of() by moving reusable parts of the code into
> an inline function that makes it commonly available so it can be
> used also for kexec support. Call the new of_tpm_get_sml_parameters()
> function from the TPM Open Firmware driver.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Cc: Jarkko Sakkinen <jarkko@kernel.org>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Tested-by: Coiby Xu <coxu@redhat.com>
> 
> ---
> v7:
>  - Added original comment back into inlined function
> 
> v4:
>  - converted to inline function
> ---
>  drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
>  include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> index a9ce66d09a75..f9462d19632e 100644
> --- a/drivers/char/tpm/eventlog/of.c
> +++ b/drivers/char/tpm/eventlog/of.c
> @@ -12,6 +12,7 @@
>  
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/tpm.h>
>  #include <linux/tpm_eventlog.h>
>  
>  #include "../tpm.h"
> @@ -20,11 +21,10 @@
>  int tpm_read_log_of(struct tpm_chip *chip)
>  {
>  	struct device_node *np;
> -	const u32 *sizep;
> -	const u64 *basep;
>  	struct tpm_bios_log *log;
>  	u32 size;
>  	u64 base;
> +	int ret;
>  
>  	log = &chip->log;
>  	if (chip->dev.parent && chip->dev.parent->of_node)
> @@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
>  	if (of_property_read_bool(np, "powered-while-suspended"))
>  		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
>  
> -	sizep = of_get_property(np, "linux,sml-size", NULL);
> -	basep = of_get_property(np, "linux,sml-base", NULL);
> -	if (sizep == NULL && basep == NULL)
> -		return -ENODEV;
> -	if (sizep == NULL || basep == NULL)
> -		return -EIO;
> -
> -	/*
> -	 * For both vtpm/tpm, firmware has log addr and log size in big
> -	 * endian format. But in case of vtpm, there is a method called
> -	 * sml-handover which is run during kernel init even before
> -	 * device tree is setup. This sml-handover function takes care
> -	 * of endianness and writes to sml-base and sml-size in little
> -	 * endian format. For this reason, vtpm doesn't need conversion
> -	 * but physical tpm needs the conversion.
> -	 */
> -	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> -	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> -		size = be32_to_cpup((__force __be32 *)sizep);
> -		base = be64_to_cpup((__force __be64 *)basep);
> -	} else {
> -		size = *sizep;
> -		base = *basep;
> -	}
> +	ret = of_tpm_get_sml_parameters(np, &base, &size);
> +	if (ret < 0)
> +		return ret;
>  
>  	if (size == 0) {
>  		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index dfeb25a0362d..6356baaa1393 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
>  	return NULL;
>  }
>  #endif
> +
> +#ifdef CONFIG_OF
> +static inline int of_tpm_get_sml_parameters(struct device_node *np,
> +					    u64 *base, u32 *size)
> +{
> +	const u32 *sizep;
> +	const u64 *basep;
> +
> +	sizep = of_get_property(np, "linux,sml-size", NULL);
> +	basep = of_get_property(np, "linux,sml-base", NULL);
> +	if (sizep == NULL && basep == NULL)
> +		return -ENODEV;
> +	if (sizep == NULL || basep == NULL)
> +		return -EIO;
> +
> +	/*
> +	 * For both vtpm/tpm, firmware has log addr and log size in big
> +	 * endian format. But in case of vtpm, there is a method called
> +	 * sml-handover which is run during kernel init even before
> +	 * device tree is setup. This sml-handover function takes care
> +	 * of endianness and writes to sml-base and sml-size in little
> +	 * endian format. For this reason, vtpm doesn't need conversion
> +	 * but physical tpm needs the conversion.
> +	 */
> +	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> +	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> +		*size = be32_to_cpup((__force __be32 *)sizep);
> +		*base = be64_to_cpup((__force __be64 *)basep);
> +	} else {
> +		*size = *sizep;
> +		*base = *basep;
> +	}
> +	return 0;
> +}
> +#endif
> +
>  #endif
> -- 
> 2.35.1
> 

Acked-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v8 3/4] of: kexec: Refactor IMA buffer related functions to make them reusable

[Stefan Berger]

Refactor IMA buffer related functions to make them reusable for carrying
TPM logs across kexec.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Tested-by: Coiby Xu <coxu@redhat.com>

---
v6:
 - Add __init to get_kexec_buffer as suggested by Jonathan

v5:
 - Rebased on Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry
   forward IMA measurement log on kexec"
v4:
 - Move debug output into setup_buffer()
---
 drivers/of/kexec.c | 126 ++++++++++++++++++++++++++-------------------
 1 file changed, 74 insertions(+), 52 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 548dd5b1b5c1..15a82b574f36 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -117,45 +117,57 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
 }
 
 #ifdef CONFIG_HAVE_IMA_KEXEC
-/**
- * ima_get_kexec_buffer - get IMA buffer from the previous kernel
- * @addr:	On successful return, set to point to the buffer contents.
- * @size:	On successful return, set to the buffer size.
- *
- * Return: 0 on success, negative errno on error.
- */
-int __init ima_get_kexec_buffer(void **addr, size_t *size)
+static int __init get_kexec_buffer(const char *name, unsigned long *addr,
+				   size_t *size)
 {
 	int ret, len;
-	unsigned long tmp_addr;
 	unsigned long start_pfn, end_pfn;
-	size_t tmp_size;
 	const void *prop;
 
-	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
+	prop = of_get_property(of_chosen, name, &len);
 	if (!prop)
 		return -ENOENT;
 
-	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+	ret = do_get_kexec_buffer(prop, len, addr, size);
 	if (ret)
 		return ret;
 
-	/* Do some sanity on the returned size for the ima-kexec buffer */
-	if (!tmp_size)
+	/* Do some sanity on the returned size for the kexec buffer */
+	if (!*size)
 		return -ENOENT;
 
 	/*
 	 * Calculate the PFNs for the buffer and ensure
 	 * they are with in addressable memory.
 	 */
-	start_pfn = PHYS_PFN(tmp_addr);
-	end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
+	start_pfn = PHYS_PFN(*addr);
+	end_pfn = PHYS_PFN(*addr + *size - 1);
 	if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
-		pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
-			tmp_addr, tmp_size);
+		pr_warn("%s buffer at 0x%lx, size = 0x%zx beyond memory\n",
+			name, *addr, *size);
 		return -EINVAL;
 	}
 
+	return 0;
+}
+
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr:	On successful return, set to point to the buffer contents.
+ * @size:	On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __init ima_get_kexec_buffer(void **addr, size_t *size)
+{
+	int ret;
+	unsigned long tmp_addr;
+	size_t tmp_size;
+
+	ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
+	if (ret)
+		return ret;
+
 	*addr = __va(tmp_addr);
 	*size = tmp_size;
 
@@ -188,72 +200,82 @@ int __init ima_free_kexec_buffer(void)
 }
 #endif
 
-/**
- * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
- *
- * @fdt: Flattened Device Tree to update
- * @chosen_node: Offset to the chosen node in the device tree
- *
- * The IMA measurement buffer is of no use to a subsequent kernel, so we always
- * remove it from the device tree.
- */
-static void remove_ima_buffer(void *fdt, int chosen_node)
+static int remove_buffer(void *fdt, int chosen_node, const char *name)
 {
 	int ret, len;
 	unsigned long addr;
 	size_t size;
 	const void *prop;
 
-	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
-		return;
-
-	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
+	prop = fdt_getprop(fdt, chosen_node, name, &len);
 	if (!prop)
-		return;
+		return -ENOENT;
 
 	ret = do_get_kexec_buffer(prop, len, &addr, &size);
-	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+	fdt_delprop(fdt, chosen_node, name);
 	if (ret)
-		return;
+		return ret;
 
 	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
 	if (!ret)
-		pr_debug("Removed old IMA buffer reservation.\n");
+		pr_debug("Remove old %s buffer reserveration", name);
+	return ret;
 }
 
-#ifdef CONFIG_IMA_KEXEC
 /**
- * setup_ima_buffer - add IMA buffer information to the fdt
- * @image:		kexec image being loaded.
- * @fdt:		Flattened device tree for the next kernel.
- * @chosen_node:	Offset to the chosen node.
+ * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
  *
- * Return: 0 on success, or negative errno on error.
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
  */
-static int setup_ima_buffer(const struct kimage *image, void *fdt,
-			    int chosen_node)
+static void remove_ima_buffer(void *fdt, int chosen_node)
+{
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return;
+
+	remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
+}
+
+#ifdef CONFIG_IMA_KEXEC
+static int setup_buffer(void *fdt, int chosen_node, const char *name,
+			phys_addr_t addr, size_t size)
 {
 	int ret;
 
-	if (!image->ima_buffer_size)
+	if (!size)
 		return 0;
 
 	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
-				       "linux,ima-kexec-buffer",
-				       image->ima_buffer_addr,
-				       image->ima_buffer_size);
+				       name, addr, size);
 	if (ret < 0)
 		return -EINVAL;
 
-	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
-			      image->ima_buffer_size);
+	ret = fdt_add_mem_rsv(fdt, addr, size);
 	if (ret)
 		return -EINVAL;
 
-	pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
-		 &image->ima_buffer_addr, image->ima_buffer_size);
+	pr_debug("%s at 0x%pa, size = 0x%zx\n", name, &addr, size);
 
 	return 0;
+
+}
+
+/**
+ * setup_ima_buffer - add IMA buffer information to the fdt
+ * @image:		kexec image being loaded.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @chosen_node:	Offset to the chosen node.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int setup_ima_buffer(const struct kimage *image, void *fdt,
+			    int chosen_node)
+{
+	return setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
+			    image->ima_buffer_addr, image->ima_buffer_size);
 }
 #else /* CONFIG_IMA_KEXEC */
 static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
-- 
2.35.1

[PATCH v8 4/4] tpm/kexec: Duplicate TPM measurement log in of-tree for kexec

[Stefan Berger]

The memory area of the TPM measurement log is currently not properly
duplicated for carrying it across kexec when an Open Firmware
Devicetree is used. Therefore, the contents of the log get corrupted.
Fix this for the kexec_file_load() syscall by allocating a buffer and
copying the contents of the existing log into it. The new buffer is
preserved across the kexec and a pointer to it is available when the new
kernel is started. To achieve this, store the allocated buffer's address
in the flattened device tree (fdt) under the name linux,tpm-kexec-buffer
and search for this entry early in the kernel startup before the TPM
subsystem starts up. Adjust the pointer in the of-tree stored under
linux,sml-base to point to this buffer holding the preserved log. The TPM
driver can then read the base address from this entry when making the log
available. Invalidate the log by removing 'linux,sml-base' from the
devicetree if anything goes wrong with updating the buffer.

Use subsys_initcall() to call the function to restore the buffer even if
the TPM subsystem or driver are not used. This allows the buffer to be
carried across the next kexec without involvement of the TPM subsystem
and ensures a valid buffer pointed to by the of-tree.

Use the subsys_initcall(), rather than an ealier initcall, since
page_is_ram() in get_kexec_buffer() only starts working at this stage.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Tested-by: Coiby Xu <coxu@redhat.com>
Reviewed-by: Rob Herring <robh@kernel.org>

---
v6:
 - Define prototype for tpm_add_kexec_buffer under same config options
   as drivers/of/kexec.c is compiled, provide inline function otherwise.
   (kernel test robot)

v4:
 - Added #include <linux/vmalloc.h> due to parisc
 - Use phys_addr_t for physical address rather than void *
 - Remove linux,sml-base if the buffer cannot be updated after a kexec
 - Added __init to functions where possible
---
 drivers/of/kexec.c    | 216 +++++++++++++++++++++++++++++++++++++++++-
 include/linux/kexec.h |   6 ++
 include/linux/of.h    |   9 +-
 kernel/kexec_file.c   |   6 ++
 4 files changed, 234 insertions(+), 3 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 15a82b574f36..dd926e057215 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -19,6 +19,8 @@
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/tpm.h>
+#include <linux/vmalloc.h>
 
 #define RNG_SEED_SIZE		128
 
@@ -116,7 +118,6 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
 	return 0;
 }
 
-#ifdef CONFIG_HAVE_IMA_KEXEC
 static int __init get_kexec_buffer(const char *name, unsigned long *addr,
 				   size_t *size)
 {
@@ -151,6 +152,7 @@ static int __init get_kexec_buffer(const char *name, unsigned long *addr,
 	return 0;
 }
 
+#ifdef CONFIG_HAVE_IMA_KEXEC
 /**
  * ima_get_kexec_buffer - get IMA buffer from the previous kernel
  * @addr:	On successful return, set to point to the buffer contents.
@@ -239,7 +241,6 @@ static void remove_ima_buffer(void *fdt, int chosen_node)
 	remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
 }
 
-#ifdef CONFIG_IMA_KEXEC
 static int setup_buffer(void *fdt, int chosen_node, const char *name,
 			phys_addr_t addr, size_t size)
 {
@@ -263,6 +264,7 @@ static int setup_buffer(void *fdt, int chosen_node, const char *name,
 
 }
 
+#ifdef CONFIG_IMA_KEXEC
 /**
  * setup_ima_buffer - add IMA buffer information to the fdt
  * @image:		kexec image being loaded.
@@ -285,6 +287,213 @@ static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
 }
 #endif /* CONFIG_IMA_KEXEC */
 
+/**
+ * tpm_get_kexec_buffer - get TPM log buffer from the previous kernel
+ * @phyaddr:	On successful return, set to physical address of buffer
+ * @size:	On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int __init tpm_get_kexec_buffer(phys_addr_t *phyaddr, size_t *size)
+{
+	unsigned long tmp_addr;
+	size_t tmp_size;
+	int ret;
+
+	ret = get_kexec_buffer("linux,tpm-kexec-buffer", &tmp_addr, &tmp_size);
+	if (ret)
+		return ret;
+
+	*phyaddr = (phys_addr_t)tmp_addr;
+	*size = tmp_size;
+
+	return 0;
+}
+
+/**
+ * tpm_of_remove_kexec_buffer - remove the linux,tpm-kexec-buffer node
+ */
+static int __init tpm_of_remove_kexec_buffer(void)
+{
+	struct property *prop;
+
+	prop = of_find_property(of_chosen, "linux,tpm-kexec-buffer", NULL);
+	if (!prop)
+		return -ENOENT;
+
+	return of_remove_property(of_chosen, prop);
+}
+
+/**
+ * remove_tpm_buffer - remove the TPM log buffer property and reservation from @fdt
+ *
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The TPM log measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
+ */
+static void remove_tpm_buffer(void *fdt, int chosen_node)
+{
+	if (!IS_ENABLED(CONFIG_PPC64))
+		return;
+
+	remove_buffer(fdt, chosen_node, "linux,tpm-kexec-buffer");
+}
+
+/**
+ * setup_tpm_buffer - add TPM measurement log buffer information to the fdt
+ * @image:		kexec image being loaded.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @chosen_node:	Offset to the chosen node.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int setup_tpm_buffer(const struct kimage *image, void *fdt,
+			    int chosen_node)
+{
+	if (!IS_ENABLED(CONFIG_PPC64))
+		return 0;
+
+	return setup_buffer(fdt, chosen_node, "linux,tpm-kexec-buffer",
+			    image->tpm_buffer_addr, image->tpm_buffer_size);
+}
+
+void tpm_add_kexec_buffer(struct kimage *image)
+{
+	struct kexec_buf kbuf = { .image = image, .buf_align = 1,
+				  .buf_min = 0, .buf_max = ULONG_MAX,
+				  .top_down = true };
+	struct device_node *np;
+	void *buffer;
+	u32 size;
+	u64 base;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_PPC64))
+		return;
+
+	np = of_find_node_by_name(NULL, "vtpm");
+	if (!np)
+		return;
+
+	if (of_tpm_get_sml_parameters(np, &base, &size) < 0)
+		return;
+
+	buffer = vmalloc(size);
+	if (!buffer)
+		return;
+	memcpy(buffer, __va(base), size);
+
+	kbuf.buffer = buffer;
+	kbuf.bufsz = size;
+	kbuf.memsz = size;
+	ret = kexec_add_buffer(&kbuf);
+	if (ret) {
+		pr_err("Error passing over kexec TPM measurement log buffer: %d\n",
+		       ret);
+		return;
+	}
+
+	image->tpm_buffer = buffer;
+	image->tpm_buffer_addr = kbuf.mem;
+	image->tpm_buffer_size = size;
+}
+
+/**
+ * tpm_post_kexec - Make stored TPM log buffer available in of-tree
+ */
+static int __init tpm_post_kexec(void)
+{
+	struct property *newprop, *p;
+	struct device_node *np;
+	phys_addr_t phyaddr;
+	u32 oflogsize;
+	size_t size;
+	u64 unused;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_PPC64))
+		return 0;
+
+	np = of_find_node_by_name(NULL, "vtpm");
+	if (!np)
+		return 0;
+
+	if (!of_get_property(of_chosen, "linux,tpm-kexec-buffer", NULL)) {
+		/*
+		 * linux,tpm-kexec-buffer may be missing on initial boot
+		 * or if previous kernel didn't pass a buffer.
+		 */
+		if (of_get_property(of_chosen, "linux,booted-from-kexec", NULL)) {
+			/* no buffer but kexec'd: remove 'linux,sml-base' */
+			ret = -EINVAL;
+			goto err_remove_sml_base;
+		}
+		return 0;
+	}
+
+	/*
+	 * If any one of the following steps fails we remove linux,sml-base
+	 * to invalidate the TPM log.
+	 */
+	ret = tpm_get_kexec_buffer(&phyaddr, &size);
+	if (ret)
+		goto err_remove_kexec_buffer;
+
+	/* logsize must not have changed */
+	ret = of_tpm_get_sml_parameters(np, &unused, &oflogsize);
+	if (ret < 0)
+		goto err_free_memblock;
+	ret = -EINVAL;
+	if (oflogsize != size)
+		goto err_free_memblock;
+
+	/* replace linux,sml-base with new physical address of buffer */
+	ret = -ENOMEM;
+	newprop = kzalloc(sizeof(*newprop), GFP_KERNEL);
+	if (!newprop)
+		goto err_free_memblock;
+
+	newprop->name = kstrdup("linux,sml-base", GFP_KERNEL);
+	newprop->length = sizeof(phyaddr);
+	newprop->value = kmalloc(sizeof(phyaddr), GFP_KERNEL);
+	if (!newprop->name || !newprop->value)
+		goto err_free_newprop_struct;
+
+	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
+	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
+		ret = -ENODEV;
+		goto err_free_newprop_struct;
+	} else {
+		*(phys_addr_t *)newprop->value = phyaddr;
+	}
+
+	ret = of_update_property(np, newprop);
+	if (ret) {
+		pr_err("Could not update linux,sml-base with new address");
+		goto err_free_newprop_struct;
+	}
+
+	return 0;
+
+err_free_newprop_struct:
+	kfree(newprop->value);
+	kfree(newprop->name);
+	kfree(newprop);
+err_free_memblock:
+	memblock_phys_free((phys_addr_t)phyaddr, size);
+err_remove_kexec_buffer:
+	tpm_of_remove_kexec_buffer();
+err_remove_sml_base:
+	p = of_find_property(np, "linux,sml-base", NULL);
+	if (p)
+		of_remove_property(np, p);
+
+	return ret;
+}
+subsys_initcall(tpm_post_kexec);
+
 /*
  * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
  *
@@ -483,6 +692,9 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 	remove_ima_buffer(fdt, chosen_node);
 	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
 
+	remove_tpm_buffer(fdt, chosen_node);
+	ret = setup_tpm_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
+
 out:
 	if (ret) {
 		kvfree(fdt);
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 13e6c4b58f07..744eab28bfb7 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -383,6 +383,12 @@ struct kimage {
 	void *elf_headers;
 	unsigned long elf_headers_sz;
 	unsigned long elf_load_addr;
+
+	/* Virtual address of TPM log buffer for kexec syscall */
+	void *tpm_buffer;
+
+	phys_addr_t tpm_buffer_addr;
+	size_t tpm_buffer_size;
 };
 
 /* kexec interface functions */
diff --git a/include/linux/of.h b/include/linux/of.h
index 766d002bddb9..538490e224d3 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -100,6 +100,8 @@ struct of_reconfig_data {
 	struct property		*old_prop;
 };
 
+struct kimage;
+
 /* initialize a node */
 extern struct kobj_type of_node_ktype;
 extern const struct fwnode_operations of_fwnode_ops;
@@ -436,7 +438,6 @@ int of_map_id(struct device_node *np, u32 id,
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
-struct kimage;
 void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 				   unsigned long initrd_load_addr,
 				   unsigned long initrd_len,
@@ -1607,4 +1608,10 @@ static inline int of_overlay_notifier_unregister(struct notifier_block *nb)
 
 #endif
 
+#if defined(CONFIG_KEXEC_FILE) && defined(CONFIG_OF_FLATTREE)
+void tpm_add_kexec_buffer(struct kimage *image);
+#else
+static inline void tpm_add_kexec_buffer(struct kimage *image) { }
+#endif
+
 #endif /* _LINUX_OF_H */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 1d546dc97c50..fa79ffa6f828 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -27,6 +27,7 @@
 #include <linux/kernel_read_file.h>
 #include <linux/syscalls.h>
 #include <linux/vmalloc.h>
+#include <linux/of.h>
 #include "kexec_internal.h"
 
 #ifdef CONFIG_KEXEC_SIG
@@ -113,6 +114,9 @@ void kimage_file_post_load_cleanup(struct kimage *image)
 	image->ima_buffer = NULL;
 #endif /* CONFIG_IMA_KEXEC */
 
+	vfree(image->tpm_buffer);
+	image->tpm_buffer = NULL;
+
 	/* See if architecture has anything to cleanup post load */
 	arch_kimage_file_post_load_cleanup(image);
 
@@ -248,6 +252,8 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 
 	/* IMA needs to pass the measurement list to the next kernel. */
 	ima_add_kexec_buffer(image);
+	/* Pass the TPM measurement log to next kernel */
+	tpm_add_kexec_buffer(image);
 
 	/* Call arch image load handlers */
 	ldata = arch_kexec_kernel_image_load(image);
-- 
2.35.1

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Stefan Berger]

Hi Rob,

   can you take this series in your tree?

Regards,
    Stefan

On 9/1/22 17:46, Stefan Berger wrote:
> The of-tree subsystem does not currently preserve the IBM vTPM 1.2 and
> vTPM 2.0 measurement logs across a kexec on PowerVM and PowerKVM. This
> series fixes this for the kexec_file_load() syscall using the flattened
> device tree (fdt) to carry the TPM measurement log's buffer across kexec.
> 
>     Stefan
> 
> v8:
>   - Added Jarkko's, Coiby's, and Rob's tags
>   - Rebase on v6.0-rc3 that absorbed 2 already upstreamed patches
> 
> v7:
>   - Added Nageswara's Tested-by tags
>   - Added back original comment to inline function and removed Jarkko's R-b tag
> 
> v6:
>   - Add __init to get_kexec_buffer as suggested by Jonathan
>   - Fixed issue detected by kernel test robot
> 
> v5:
>   - Rebased on 1 more patch that would otherwise create merge conflicts
> 
> v4:
>   - Rebased on 2 patches that would otherwise create merge conflicts;
>     posting these patches in this series with several tags removed so
>     krobot can test the series already
>   - Changes to individual patches documented in patch descripitons
> 
> v3:
>   - Moved TPM Open Firmware related function to drivers/char/tpm/eventlog/tpm_of.c
> 
> v2:
>   - rearranged patches
>   - fixed compilation issues for x86
> 
> Palmer Dabbelt (1):
>    drivers: of: kexec ima: Support 32-bit platforms
> 
> Stefan Berger (3):
>    tpm: of: Make of-tree specific function commonly available
>    of: kexec: Refactor IMA buffer related functions to make them reusable
>    tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
> 
>   drivers/char/tpm/eventlog/of.c |  31 +--
>   drivers/of/kexec.c             | 336 ++++++++++++++++++++++++++++-----
>   include/linux/kexec.h          |   6 +
>   include/linux/of.h             |   9 +-
>   include/linux/tpm.h            |  36 ++++
>   kernel/kexec_file.c            |   6 +
>   6 files changed, 346 insertions(+), 78 deletions(-)
> 
> 
> base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Rob Herring]

On Mon, Sep 12, 2022 at 8:01 AM Stefan Berger <stefanb@linux.ibm.com> wrote:
>
>
> Hi Rob,
>
>    can you take this series in your tree?

IMO, it should be someone that cares about TPM, kexec, or powerpc.
Yes, there's code in drivers/of/, but that is purely to avoid
duplication of code across powerpc and arm64.

Rob

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Stefan Berger]

On 9/14/22 14:01, Rob Herring wrote:
> On Mon, Sep 12, 2022 at 8:01 AM Stefan Berger <stefanb@linux.ibm.com> wrote:
>>
>>
>> Hi Rob,
>>
>>     can you take this series in your tree?
> 
> IMO, it should be someone that cares about TPM, kexec, or powerpc.
> Yes, there's code in drivers/of/, but that is purely to avoid
> duplication of code across powerpc and arm64.

What about 1/4? Can someone else take it into their tree?

    Stefan
> 
> Rob

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Rob Herring]

On Wed, Sep 14, 2022 at 2:46 PM Stefan Berger <stefanb@linux.ibm.com> wrote:
>
>
>
> On 9/14/22 14:01, Rob Herring wrote:
> > On Mon, Sep 12, 2022 at 8:01 AM Stefan Berger <stefanb@linux.ibm.com> wrote:
> >>
> >>
> >> Hi Rob,
> >>
> >>     can you take this series in your tree?
> >
> > IMO, it should be someone that cares about TPM, kexec, or powerpc.
> > Yes, there's code in drivers/of/, but that is purely to avoid
> > duplication of code across powerpc and arm64.
>
> What about 1/4? Can someone else take it into their tree?

I thought that was taken long ago now by Palmer in the riscv tree, but
it seems not.

In any case, it has my Ack, so yes, someone else can take it. It *can*
go in via 2 different trees (as git won't care), but we generally try
to avoid that.

Rob

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Baoquan He]

On 09/14/22 at 01:01pm, Rob Herring wrote:
> On Mon, Sep 12, 2022 at 8:01 AM Stefan Berger <stefanb@linux.ibm.com> wrote:
> >
> >
> > Hi Rob,
> >
> >    can you take this series in your tree?
> 
> IMO, it should be someone that cares about TPM, kexec, or powerpc.
> Yes, there's code in drivers/of/, but that is purely to avoid
> duplication of code across powerpc and arm64.

Looks like a PPC specific improvement, is it possible to have TPM on
other ARCHes? For generic code patch, Andrew kindly help pick them
into his tree if cooked. If it's an arch or component specific code,
we usually ask arch or component maintainer to take it.

For this patchset, it should be merged into ppc tree?

Thanks
Baoquan

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Coiby Xu]

Hi Michael,

Could the PowerPC tree take this patch set which resolves a
PowerVM/KVM-specific issue?

On Thu, Sep 01, 2022 at 05:46:06PM -0400, Stefan Berger wrote:
>The of-tree subsystem does not currently preserve the IBM vTPM 1.2 and
>vTPM 2.0 measurement logs across a kexec on PowerVM and PowerKVM. This
>series fixes this for the kexec_file_load() syscall using the flattened
>device tree (fdt) to carry the TPM measurement log's buffer across kexec.
>
>   Stefan
>
>v8:
> - Added Jarkko's, Coiby's, and Rob's tags
> - Rebase on v6.0-rc3 that absorbed 2 already upstreamed patches
>
>v7:
> - Added Nageswara's Tested-by tags
> - Added back original comment to inline function and removed Jarkko's R-b tag
>
>v6:
> - Add __init to get_kexec_buffer as suggested by Jonathan
> - Fixed issue detected by kernel test robot
>
>v5:
> - Rebased on 1 more patch that would otherwise create merge conflicts
>
>v4:
> - Rebased on 2 patches that would otherwise create merge conflicts;
>   posting these patches in this series with several tags removed so
>   krobot can test the series already
> - Changes to individual patches documented in patch descripitons
>
>v3:
> - Moved TPM Open Firmware related function to drivers/char/tpm/eventlog/tpm_of.c
>
>v2:
> - rearranged patches
> - fixed compilation issues for x86
>
>Palmer Dabbelt (1):
>  drivers: of: kexec ima: Support 32-bit platforms
>
>Stefan Berger (3):
>  tpm: of: Make of-tree specific function commonly available
>  of: kexec: Refactor IMA buffer related functions to make them reusable
>  tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
>
> drivers/char/tpm/eventlog/of.c |  31 +--
> drivers/of/kexec.c             | 336 ++++++++++++++++++++++++++++-----
> include/linux/kexec.h          |   6 +
> include/linux/of.h             |   9 +-
> include/linux/tpm.h            |  36 ++++
> kernel/kexec_file.c            |   6 +
> 6 files changed, 346 insertions(+), 78 deletions(-)
>
>
>base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
>-- 
>2.35.1
>

-- 
Best regards,
Coiby

Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Stefan Berger]

On 11/10/22 21:21, Coiby Xu wrote:
> Hi Michael,
> 
> Could the PowerPC tree take this patch set which resolves a
> PowerVM/KVM-specific issue?

Michael has (shown me) an alternative approach that protects the already allocated memory to carry it across the kexec. This seems like a good and potentially better alternative, also from the perspective of the changes need, which is a lot less , and it's already used for other stuff as well.

    Stefan

> 
> On Thu, Sep 01, 2022 at 05:46:06PM -0400, Stefan Berger wrote:
>> The of-tree subsystem does not currently preserve the IBM vTPM 1.2 and
>> vTPM 2.0 measurement logs across a kexec on PowerVM and PowerKVM. This
>> series fixes this for the kexec_file_load() syscall using the flattened
>> device tree (fdt) to carry the TPM measurement log's buffer across kexec.
>>
>>   Stefan
>>
>> v8:
>> - Added Jarkko's, Coiby's, and Rob's tags
>> - Rebase on v6.0-rc3 that absorbed 2 already upstreamed patches
>>
>> v7:
>> - Added Nageswara's Tested-by tags
>> - Added back original comment to inline function and removed Jarkko's R-b tag
>>
>> v6:
>> - Add __init to get_kexec_buffer as suggested by Jonathan
>> - Fixed issue detected by kernel test robot
>>
>> v5:
>> - Rebased on 1 more patch that would otherwise create merge conflicts
>>
>> v4:
>> - Rebased on 2 patches that would otherwise create merge conflicts;
>>   posting these patches in this series with several tags removed so
>>   krobot can test the series already
>> - Changes to individual patches documented in patch descripitons
>>
>> v3:
>> - Moved TPM Open Firmware related function to drivers/char/tpm/eventlog/tpm_of.c
>>
>> v2:
>> - rearranged patches
>> - fixed compilation issues for x86
>>
>> Palmer Dabbelt (1):
>>  drivers: of: kexec ima: Support 32-bit platforms
>>
>> Stefan Berger (3):
>>  tpm: of: Make of-tree specific function commonly available
>>  of: kexec: Refactor IMA buffer related functions to make them reusable
>>  tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
>>
>> drivers/char/tpm/eventlog/of.c |  31 +--
>> drivers/of/kexec.c             | 336 ++++++++++++++++++++++++++++-----
>> include/linux/kexec.h          |   6 +
>> include/linux/of.h             |   9 +-
>> include/linux/tpm.h            |  36 ++++
>> kernel/kexec_file.c            |   6 +
>> 6 files changed, 346 insertions(+), 78 deletions(-)
>>
>>
>> base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
>> -- 
>> 2.35.1
>>
>