Messages in this thread | | | Subject | Re: [PATCH v12 2/4] powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c | From | Lakshmi Ramasubramanian <> | Date | Thu, 17 Dec 2020 12:52:32 -0800 |
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On 12/17/20 12:05 PM, Rob Herring wrote: > On Thu, Dec 17, 2020 at 09:37:06AM -0800, Lakshmi Ramasubramanian wrote: >> The functions defined in "arch/powerpc/kexec/ima.c" handle setting up >> and freeing the resources required to carry over the IMA measurement >> list from the current kernel to the next kernel across kexec system call. >> These functions do not have architecture specific code, but are >> currently limited to powerpc. >> >> Move setup_ima_buffer() call into of_kexec_setup_new_fdt(). >> >> Move architecture independent functions from "arch/powerpc/kexec/ima.c" >> to "drivers/of/kexec.c". Delete "arch/powerpc/kexec/ima.c" and >> "arch/powerpc/include/asm/ima.h". Remove references to the deleted files >> in powerpc and in ima. >> >> delete_fdt_mem_rsv() defined in "arch/powerpc/kexec/file_load.c" >> is not used anymore. Remove this function. > > I think this patch should come first and then patch 1. Move then rework > the code.
Sure - will reorder the patches.
> >> >> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> >> --- >> arch/powerpc/include/asm/ima.h | 30 ----- >> arch/powerpc/include/asm/kexec.h | 1 - >> arch/powerpc/kexec/Makefile | 7 - >> arch/powerpc/kexec/file_load.c | 39 ------ >> arch/powerpc/kexec/ima.c | 182 -------------------------- >> drivers/of/kexec.c | 198 +++++++++++++++++++++++++++++ >> include/linux/of.h | 17 +++ >> security/integrity/ima/ima.h | 4 - >> security/integrity/ima/ima_kexec.c | 2 + >> 9 files changed, 217 insertions(+), 263 deletions(-) >> delete mode 100644 arch/powerpc/include/asm/ima.h >> delete mode 100644 arch/powerpc/kexec/ima.c >>
>> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c >> index 66787be081fe..a6ab35f16dd2 100644 >> --- a/drivers/of/kexec.c >> +++ b/drivers/of/kexec.c >> @@ -10,10 +10,12 @@ >> */ >> >> #include <linux/kernel.h> >> +#include <linux/slab.h> >> #include <linux/kexec.h> >> #include <linux/libfdt.h> >> #include <linux/of.h> >> #include <linux/of_fdt.h> >> +#include <linux/memblock.h> >> #include <linux/random.h> >> #include <linux/types.h> >> >> @@ -59,6 +61,141 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon >> return -ENOENT; >> } >> >> +/** >> + * get_addr_size_cells - Get address and size of root node >> + * >> + * @addr_cells: Return address of the root node >> + * @size_cells: Return size of the root node >> + * >> + * Return: 0 on success, or negative errno on error. >> + */ >> +static int get_addr_size_cells(int *addr_cells, int *size_cells) >> +{ >> + struct device_node *root; >> + >> + root = of_find_node_by_path("/"); >> + if (!root) >> + return -EINVAL; >> + >> + *addr_cells = of_n_addr_cells(root); >> + *size_cells = of_n_size_cells(root); >> + >> + of_node_put(root); >> + >> + return 0; >> +} >> + >> +/** >> + * do_get_kexec_buffer - Get address and size of device tree property >> + * >> + * @prop: Device tree property >> + * @len: Size of @prop >> + * @addr: Return address of the node >> + * @size: Return size of the node >> + * >> + * Return: 0 on success, or negative errno on error. >> + */ >> +static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, >> + size_t *size) >> +{ >> + int ret, addr_cells, size_cells; >> + >> + ret = get_addr_size_cells(&addr_cells, &size_cells); >> + if (ret) >> + return ret; >> + >> + if (len < 4 * (addr_cells + size_cells)) >> + return -ENOENT; >> + >> + *addr = of_read_number(prop, addr_cells); >> + *size = of_read_number(prop + 4 * addr_cells, size_cells); >> + >> + 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 ima_get_kexec_buffer(void **addr, size_t *size) >> +{ >> + int ret, len; >> + unsigned long tmp_addr; >> + size_t tmp_size; >> + const void *prop; >> + >> + prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len); >> + if (!prop) >> + return -ENOENT; >> + >> + ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size); >> + if (ret) >> + return ret; >> + >> + *addr = __va(tmp_addr); >> + *size = tmp_size; >> + >> + return 0; >> +} >> + >> +/** >> + * ima_free_kexec_buffer - free memory used by the IMA buffer >> + */ >> +int ima_free_kexec_buffer(void) >> +{ >> + int ret; >> + unsigned long addr; >> + size_t size; >> + struct property *prop; >> + >> + prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL); >> + if (!prop) >> + return -ENOENT; >> + >> + ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size); >> + if (ret) >> + return ret; >> + >> + ret = of_remove_property(of_chosen, prop); >> + if (ret) >> + return ret; >> + >> + return memblock_free(addr, size); >> +} >> + >> +/** >> + * 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. >> + */ >> +void remove_ima_buffer(void *fdt, int chosen_node) > > static
Will update.
> >> +{ >> + int ret, len; >> + unsigned long addr; >> + size_t size; >> + const void *prop; >> + >> + prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len); >> + if (!prop) >> + return; >> + >> + ret = do_get_kexec_buffer(prop, len, &addr, &size); >> + fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer"); >> + if (ret) >> + return; >> + >> + ret = fdt_find_and_del_mem_rsv(fdt, addr, size); >> + if (!ret) >> + pr_debug("Removed old IMA buffer reservation.\n"); >> +} > > All the above needs to be in an '#ifdef CONFIG_IMA_KEXEC'.
remove_ima_buffer() needs to be defined when CONFIG_HAVE_IMA_KEXEC is enabled. CONFIG_HAVE_IMA_KEXEC can be enabled even if CONFIG_IMA_KEXEC is not.
I'll move remove_ima_buffer() under "#ifdef CONFIG_HAVE_IMA_KEXEC" in this file.
> >> + >> /* >> * of_kexec_setup_new_fdt - modify /chosen and memory reservation for the next kernel >> * >> @@ -219,6 +356,10 @@ int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt, >> } >> >> ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0); >> + if (ret) >> + goto out; >> + >> + ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen")); >> >> out: >> if (ret) >> @@ -226,3 +367,60 @@ int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt, >> >> return 0; >> } >> + >> +#ifdef CONFIG_IMA_KEXEC >> +/** >> + * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer >> + * >> + * @image: kimage struct to set IMA buffer data >> + * @load_addr: Starting address where IMA buffer is loaded at >> + * @size: Number of bytes in the IMA buffer >> + * >> + * Architectures should use this function to pass on the IMA buffer >> + * information to the next kernel. >> + * >> + * Return: 0 on success, negative errno on error. >> + */ >> +int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr, >> + size_t size) > > This should be a static inline in asm/kexec.h.
arch_ima_add_kexec_buffer() is identical for powerpc and arm64. Would it be better to "static inline" this function in "of.h" instead of duplicating it in "asm/kexec.h" for powerpc and arm64?
> >> +{ >> + image->arch.ima_buffer_addr = load_addr; >> + image->arch.ima_buffer_size = 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. >> + */ >> +int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node) > > static Will update.
> >> +{ >> + int ret; >> + >> + remove_ima_buffer(fdt, chosen_node); >> + if (!image->arch.ima_buffer_size) >> + return 0; >> + >> + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, >> + "linux,ima-kexec-buffer", >> + image->arch.ima_buffer_addr, >> + image->arch.ima_buffer_size); >> + if (ret) >> + return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL); >> + >> + ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr, >> + image->arch.ima_buffer_size); >> + if (ret) >> + return -EINVAL; >> + >> + pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n", >> + image->arch.ima_buffer_addr, image->arch.ima_buffer_size); >> + >> + return 0; >> +} >> +#endif /* CONFIG_IMA_KEXEC */ >> diff --git a/include/linux/of.h b/include/linux/of.h >> index 3375f5295875..7477f2266d8f 100644 >> --- a/include/linux/of.h >> +++ b/include/linux/of.h >> @@ -562,6 +562,23 @@ struct kimage; >> int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt, >> unsigned long initrd_load_addr, unsigned long initrd_len, >> const char *cmdline); >> +int ima_get_kexec_buffer(void **addr, size_t *size); >> +int ima_free_kexec_buffer(void); >> +void remove_ima_buffer(void *fdt, int chosen_node); >> + >> +#ifdef CONFIG_IMA_KEXEC >> +int arch_ima_add_kexec_buffer(struct kimage *image, >> + unsigned long load_addr, >> + size_t size); >> +int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node); > > This doesn't need to be public.
Will update.
thanks, -lakshmi
> >> +#else >> +static inline int setup_ima_buffer(const struct kimage *image, void *fdt, >> + int chosen_node) >> +{ >> + remove_ima_buffer(fdt, chosen_node); >> + return 0; >> +} >> +#endif /* CONFIG_IMA_KEXEC */ >> >> #else /* CONFIG_OF */ >> >> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h >> index 6ebefec616e4..7c3947ad3773 100644 >> --- a/security/integrity/ima/ima.h >> +++ b/security/integrity/ima/ima.h >> @@ -24,10 +24,6 @@ >> >> #include "../integrity.h" >> >> -#ifdef CONFIG_HAVE_IMA_KEXEC >> -#include <asm/ima.h> >> -#endif >> - >> enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, >> IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; >> enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 }; >> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c >> index 121de3e04af2..3d6a8820e2a5 100644 >> --- a/security/integrity/ima/ima_kexec.c >> +++ b/security/integrity/ima/ima_kexec.c >> @@ -9,7 +9,9 @@ >> >> #include <linux/seq_file.h> >> #include <linux/vmalloc.h> >> +#include <linux/of.h> >> #include <linux/kexec.h> >> +#include <linux/ima.h> >> #include "ima.h" >> >> #ifdef CONFIG_IMA_KEXEC >> -- >> 2.29.2 >>
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