| Message ID | 20230418134409.177485-5-stefanb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Preserve TPM measurement log across kexec (ppc64) | expand |
Hi Stefan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 6a8f57ae2eb07ab39a6f0ccad60c760743051026]
url: https://github.com/intel-lab-lkp/linux/commits/Stefan-Berger/drivers-of-kexec-ima-Support-32-bit-platforms/20230418-214600
base: 6a8f57ae2eb07ab39a6f0ccad60c760743051026
patch link: https://lore.kernel.org/r/20230418134409.177485-5-stefanb%40linux.ibm.com
patch subject: [PATCH v9 4/4] tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20230419/202304190146.FrlhoboB-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/16a833d47b9aca53a1b099dea4066b76b7f14ee1
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Berger/drivers-of-kexec-ima-Support-32-bit-platforms/20230418-214600
git checkout 16a833d47b9aca53a1b099dea4066b76b7f14ee1
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=um SUBARCH=i386 olddefconfig
make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash drivers/input/mouse/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304190146.FrlhoboB-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/linux/irqdomain.h:36,
from include/linux/acpi.h:13,
from include/linux/i2c.h:13,
from drivers/input/mouse/synaptics.c:30:
>> include/linux/of.h:1664:48: warning: 'struct kimage' declared inside parameter list will not be visible outside of this definition or declaration
1664 | static inline void tpm_add_kexec_buffer(struct kimage *image) { }
| ^~~~~~
drivers/input/mouse/synaptics.c:164:27: warning: 'smbus_pnp_ids' defined but not used [-Wunused-const-variable=]
164 | static const char * const smbus_pnp_ids[] = {
| ^~~~~~~~~~~~~
vim +1664 include/linux/of.h
1660
1661 #if defined(CONFIG_KEXEC_FILE) && defined(CONFIG_OF_FLATTREE)
1662 void tpm_add_kexec_buffer(struct kimage *image);
1663 #else
> 1664 static inline void tpm_add_kexec_buffer(struct kimage *image) { }
1665 #endif
1666
On Tue, Apr 18, 2023 at 09:44:09AM -0400, Stefan Berger wrote: > 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. Hi Stefan, some minor feedback from my side. > Use the subsys_initcall(), rather than an ealier initcall, since nit via checkpatch.pl --codespell: s/ealier/earlier/ > 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> ... > +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); Does buffer need to be freed here? > + return; > + } > + > + image->tpm_buffer = buffer; > + image->tpm_buffer_addr = kbuf.mem; > + image->tpm_buffer_size = size; > +}
Hi Stefan,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 6a8f57ae2eb07ab39a6f0ccad60c760743051026]
url: https://github.com/intel-lab-lkp/linux/commits/Stefan-Berger/drivers-of-kexec-ima-Support-32-bit-platforms/20230418-214600
base: 6a8f57ae2eb07ab39a6f0ccad60c760743051026
patch link: https://lore.kernel.org/r/20230418134409.177485-5-stefanb%40linux.ibm.com
patch subject: [PATCH v9 4/4] tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
config: x86_64-randconfig-a013-20230417 (https://download.01.org/0day-ci/archive/20230419/202304190215.d0zwo1ni-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/16a833d47b9aca53a1b099dea4066b76b7f14ee1
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Berger/drivers-of-kexec-ima-Support-32-bit-platforms/20230418-214600
git checkout 16a833d47b9aca53a1b099dea4066b76b7f14ee1
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/mailbox/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304190215.d0zwo1ni-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from drivers/mailbox/mailbox.c:18:
In file included from include/linux/mailbox_client.h:10:
>> include/linux/of.h:1664:48: warning: declaration of 'struct kimage' will not be visible outside of this function [-Wvisibility]
static inline void tpm_add_kexec_buffer(struct kimage *image) { }
^
1 warning generated.
vim +1664 include/linux/of.h
1660
1661 #if defined(CONFIG_KEXEC_FILE) && defined(CONFIG_OF_FLATTREE)
1662 void tpm_add_kexec_buffer(struct kimage *image);
1663 #else
> 1664 static inline void tpm_add_kexec_buffer(struct kimage *image) { }
1665 #endif
1666
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index fa8c0c75adf9..9831d25dd83e 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 6883c5922701..6116abdda590 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -380,6 +380,12 @@ 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 0af611307db2..9afa99950310 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1658,4 +1658,10 @@ 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 f1a0e4e3fb5c..58c7aaf11883 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);