Messages in this thread | | | Date | Wed, 6 Jul 2022 11:06:51 -0400 | Subject | Re: [PATCH v4 4/5] of: kexec: Refactor IMA buffer related functions to make them reusable | From | Stefan Berger <> |
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On 7/6/22 10:00, Jonathan McDowell wrote: > On Tue, Jul 05, 2022 at 06:46:54PM -0400, Mimi Zohar wrote: >> [Cc'ing Borislav Petkov <bp@suse.de>, Jonathan McDowell <noodles@fb.com >>> ] >> >> Hi Stefan, >> >> On Thu, 2022-06-30 at 22:26 -0400, Stefan Berger wrote: >>> 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> >> >> Refactoring the ima_get_kexec_buffer sounds good, but there's a merge >> conflict with Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry >> forward IMA measurement log on kexec". >> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/of/kexec.c > > None of this looks difficult to re-do on top of my changes that are in > -next; the only thing to watch out for is a couple of functions have > moved into the __init section but that looks appropriate for your TPM > log carry-over too.
Yes, I am rebasing my series now and will post v5 of this series with your patch prepended as well.
Stefan
> >>> --- >>> v4: >>> - Move debug output into setup_buffer() >>> --- >>> drivers/of/kexec.c | 131 ++++++++++++++++++++++++++------------------- >>> 1 file changed, 76 insertions(+), 55 deletions(-) >>> >>> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c >>> index c4f9b6655a2e..0710703acfb0 100644 >>> --- a/drivers/of/kexec.c >>> +++ b/drivers/of/kexec.c >>> @@ -115,48 +115,59 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, >>> 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) >>> +static int 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; >>> >>> - if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) >>> - return -ENOTSUPP; >>> - >>> - 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 ima_get_kexec_buffer(void **addr, size_t *size) >>> +{ >>> + int ret; >>> + unsigned long tmp_addr; >>> + size_t tmp_size; >>> + >>> + if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC)) >>> + return -ENOTSUPP; >>> + >>> + ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size); >>> + if (ret) >>> + return ret; >>> + >>> *addr = __va(tmp_addr); >>> *size = tmp_size; >>> >>> @@ -191,72 +202,82 @@ int ima_free_kexec_buffer(void) >>> return memblock_phys_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. >>> - */ >>> -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,
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