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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/of/kexec.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/of/kexec.c')
| -rw-r--r-- | drivers/of/kexec.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c new file mode 100644 index 000000000..029903b98 --- /dev/null +++ b/drivers/of/kexec.c @@ -0,0 +1,535 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Arm Limited + * + * Based on arch/arm64/kernel/machine_kexec_file.c: + * Copyright (C) 2018 Linaro Limited + * + * And arch/powerpc/kexec/file_load.c: + * Copyright (C) 2016 IBM Corporation + */ + +#include <linux/ima.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <linux/memblock.h> +#include <linux/libfdt.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define RNG_SEED_SIZE 128 + +/* + * Additional space needed for the FDT buffer so that we can add initrd, + * bootargs, kaslr-seed, rng-seed, useable-memory-range and elfcorehdr. + */ +#define FDT_EXTRA_SPACE 0x1000 + +/** + * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size + * + * @fdt: Flattened device tree for the current kernel. + * @start: Starting address of the reserved memory. + * @size: Size of the reserved memory. + * + * Return: 0 on success, or negative errno on error. + */ +static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size) +{ + int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); + + for (i = 0; i < num_rsvs; i++) { + u64 rsv_start, rsv_size; + + ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); + if (ret) { + pr_err("Malformed device tree.\n"); + return -EINVAL; + } + + if (rsv_start == start && rsv_size == size) { + ret = fdt_del_mem_rsv(fdt, i); + if (ret) { + pr_err("Error deleting device tree reservation.\n"); + return -EINVAL; + } + + return 0; + } + } + + 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; +} + +#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) +{ + 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; + + /* Do some sanity on the returned size for the ima-kexec buffer */ + if (!tmp_size) + return -ENOENT; + + ret = ima_validate_range(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 __init 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; + + memblock_phys_free(addr, size); + return 0; +} +#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) +{ + 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); + 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"); +} + +#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. + * + * Return: 0 on success, or negative errno on error. + */ +static int setup_ima_buffer(const struct kimage *image, void *fdt, + int chosen_node) +{ + int ret; + + if (!image->ima_buffer_size) + return 0; + + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,ima-kexec-buffer", + image->ima_buffer_addr, + image->ima_buffer_size); + if (ret < 0) + return -EINVAL; + + ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr, + image->ima_buffer_size); + if (ret) + return -EINVAL; + + pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n", + image->ima_buffer_addr, image->ima_buffer_size); + + return 0; +} +#else /* CONFIG_IMA_KEXEC */ +static inline int setup_ima_buffer(const struct kimage *image, void *fdt, + int chosen_node) +{ + return 0; +} +#endif /* CONFIG_IMA_KEXEC */ + +static int kho_add_chosen(const struct kimage *image, void *fdt, int chosen_node) +{ + int ret = 0; +#ifdef CONFIG_KEXEC_HANDOVER + phys_addr_t fdt_mem = 0; + phys_addr_t fdt_len = 0; + phys_addr_t scratch_mem = 0; + phys_addr_t scratch_len = 0; + + ret = fdt_delprop(fdt, chosen_node, "linux,kho-fdt"); + if (ret && ret != -FDT_ERR_NOTFOUND) + return ret; + ret = fdt_delprop(fdt, chosen_node, "linux,kho-scratch"); + if (ret && ret != -FDT_ERR_NOTFOUND) + return ret; + + if (!image->kho.fdt || !image->kho.scratch) + return 0; + + fdt_mem = image->kho.fdt; + fdt_len = PAGE_SIZE; + scratch_mem = image->kho.scratch->mem; + scratch_len = image->kho.scratch->bufsz; + + pr_debug("Adding kho metadata to DT"); + + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-fdt", + fdt_mem, fdt_len); + if (ret) + return ret; + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-scratch", + scratch_mem, scratch_len); + +#endif /* CONFIG_KEXEC_HANDOVER */ + return ret; +} + +/* + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree + * + * @image: kexec image being loaded. + * @initrd_load_addr: Address where the next initrd will be loaded. + * @initrd_len: Size of the next initrd, or 0 if there will be none. + * @cmdline: Command line for the next kernel, or NULL if there will + * be none. + * @extra_fdt_size: Additional size for the new FDT buffer. + * + * Return: fdt on success, or NULL errno on error. + */ +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image, + unsigned long initrd_load_addr, + unsigned long initrd_len, + const char *cmdline, size_t extra_fdt_size) +{ + void *fdt; + int ret, chosen_node, len; + const void *prop; + size_t fdt_size; + + fdt_size = fdt_totalsize(initial_boot_params) + + (cmdline ? strlen(cmdline) : 0) + + FDT_EXTRA_SPACE + + extra_fdt_size; + fdt = kvmalloc(fdt_size, GFP_KERNEL); + if (!fdt) + return NULL; + + ret = fdt_open_into(initial_boot_params, fdt, fdt_size); + if (ret < 0) { + pr_err("Error %d setting up the new device tree.\n", ret); + goto out; + } + + /* Remove memory reservation for the current device tree. */ + ret = fdt_find_and_del_mem_rsv(fdt, initial_boot_params_pa, + fdt_totalsize(initial_boot_params)); + if (ret == -EINVAL) { + pr_err("Error removing memory reservation.\n"); + goto out; + } + + chosen_node = fdt_path_offset(fdt, "/chosen"); + if (chosen_node == -FDT_ERR_NOTFOUND) + chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), + "chosen"); + if (chosen_node < 0) { + ret = chosen_node; + goto out; + } + + ret = fdt_delprop(fdt, chosen_node, "linux,elfcorehdr"); + if (ret && ret != -FDT_ERR_NOTFOUND) + goto out; + ret = fdt_delprop(fdt, chosen_node, "linux,usable-memory-range"); + if (ret && ret != -FDT_ERR_NOTFOUND) + goto out; + + /* Did we boot using an initrd? */ + prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", &len); + if (prop) { + u64 tmp_start, tmp_end, tmp_size; + + tmp_start = of_read_number(prop, len / 4); + + prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", &len); + if (!prop) { + ret = -EINVAL; + goto out; + } + + tmp_end = of_read_number(prop, len / 4); + + /* + * kexec reserves exact initrd size, while firmware may + * reserve a multiple of PAGE_SIZE, so check for both. + */ + tmp_size = tmp_end - tmp_start; + ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size); + if (ret == -ENOENT) + ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, + round_up(tmp_size, PAGE_SIZE)); + if (ret == -EINVAL) + goto out; + } + + /* add initrd-* */ + if (initrd_load_addr) { + ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-start", + initrd_load_addr); + if (ret) + goto out; + + ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end", + initrd_load_addr + initrd_len); + if (ret) + goto out; + + ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len); + if (ret) + goto out; + + } else { + ret = fdt_delprop(fdt, chosen_node, "linux,initrd-start"); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + + ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end"); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + if (image->type == KEXEC_TYPE_CRASH) { + /* add linux,elfcorehdr */ + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,elfcorehdr", image->elf_load_addr, + image->elf_headers_sz); + if (ret) + goto out; + + /* + * Avoid elfcorehdr from being stomped on in kdump kernel by + * setting up memory reserve map. + */ + ret = fdt_add_mem_rsv(fdt, image->elf_load_addr, + image->elf_headers_sz); + if (ret) + goto out; + + if (image->dm_crypt_keys_addr != 0) { + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,dmcryptkeys", + image->dm_crypt_keys_addr, + image->dm_crypt_keys_sz); + + if (ret) + goto out; + + /* + * Avoid dmcryptkeys from being stomped on in kdump kernel by + * setting up memory reserve map. + */ + ret = fdt_add_mem_rsv(fdt, image->dm_crypt_keys_addr, + image->dm_crypt_keys_sz); + if (ret) + goto out; + } + +#ifdef CONFIG_CRASH_DUMP + /* add linux,usable-memory-range */ + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,usable-memory-range", crashk_res.start, + crashk_res.end - crashk_res.start + 1); + if (ret) + goto out; + + if (crashk_low_res.end) { + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,usable-memory-range", + crashk_low_res.start, + crashk_low_res.end - crashk_low_res.start + 1); + if (ret) + goto out; + } + + for (int i = 0; i < crashk_cma_cnt; i++) { + ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, + "linux,usable-memory-range", + crashk_cma_ranges[i].start, + crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1); + if (ret) + goto out; + } +#endif + } + + /* Add kho metadata if this is a KHO image */ + ret = kho_add_chosen(image, fdt, chosen_node); + if (ret) + goto out; + + /* add bootargs */ + if (cmdline) { + ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline); + if (ret) + goto out; + } else { + ret = fdt_delprop(fdt, chosen_node, "bootargs"); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + /* add kaslr-seed */ + ret = fdt_delprop(fdt, chosen_node, "kaslr-seed"); + if (ret == -FDT_ERR_NOTFOUND) + ret = 0; + else if (ret) + goto out; + + if (rng_is_initialized()) { + u64 seed = get_random_u64(); + + ret = fdt_setprop_u64(fdt, chosen_node, "kaslr-seed", seed); + if (ret) + goto out; + } else { + pr_notice("RNG is not initialised: omitting \"%s\" property\n", + "kaslr-seed"); + } + + /* add rng-seed */ + if (rng_is_initialized()) { + void *rng_seed; + + ret = fdt_setprop_placeholder(fdt, chosen_node, "rng-seed", + RNG_SEED_SIZE, &rng_seed); + if (ret) + goto out; + get_random_bytes(rng_seed, RNG_SEED_SIZE); + } else { + pr_notice("RNG is not initialised: omitting \"%s\" property\n", + "rng-seed"); + } + + ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0); + if (ret) + goto out; + + remove_ima_buffer(fdt, chosen_node); + ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen")); + +out: + if (ret) { + kvfree(fdt); + fdt = NULL; + } + + return fdt; +} |
