From b8e55a3e5c208862eacded5aad822184f89f85d9 Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Wed, 29 Jul 2020 17:10:16 +0530 Subject: [PATCH] powerpc/kexec_file: Avoid stomping memory used by special regions crashkernel region could have an overlap with special memory regions like OPAL, RTAS, TCE table & such. These regions are referred to as excluded memory ranges. Setup these ranges during image probe in order to avoid them while finding the buffer for different kdump segments. Override arch_kexec_locate_mem_hole() to locate a memory hole taking these ranges into account. Signed-off-by: Hari Bathini Reviewed-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/159602281047.575379.6636807148335160795.stgit@hbathini --- arch/powerpc/include/asm/kexec.h | 7 +- arch/powerpc/include/asm/kexec_ranges.h | 14 ++ arch/powerpc/kexec/elf_64.c | 8 + arch/powerpc/kexec/file_load_64.c | 337 +++++++++++++++++++++++++++++++- arch/powerpc/kexec/ranges.c | 177 +++++++++++++++++ 5 files changed, 539 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 9b3feef..639f31e 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -100,14 +100,16 @@ void relocate_new_kernel(unsigned long indirection_page, unsigned long reboot_co #ifdef CONFIG_KEXEC_FILE extern const struct kexec_file_ops kexec_elf64_ops; -#ifdef CONFIG_IMA_KEXEC #define ARCH_HAS_KIMAGE_ARCH struct kimage_arch { + struct crash_mem *exclude_ranges; + +#ifdef CONFIG_IMA_KEXEC phys_addr_t ima_buffer_addr; size_t ima_buffer_size; -}; #endif +}; int setup_purgatory(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, @@ -125,6 +127,7 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, unsigned long initrd_load_addr, unsigned long initrd_len, const char *cmdline); #endif /* CONFIG_PPC64 */ + #endif /* CONFIG_KEXEC_FILE */ #else /* !CONFIG_KEXEC_CORE */ diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h index 35ae31a..7a90000 100644 --- a/arch/powerpc/include/asm/kexec_ranges.h +++ b/arch/powerpc/include/asm/kexec_ranges.h @@ -7,5 +7,19 @@ void sort_memory_ranges(struct crash_mem *mrngs, bool merge); struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges); int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size); +int add_tce_mem_ranges(struct crash_mem **mem_ranges); +int add_initrd_mem_range(struct crash_mem **mem_ranges); +#ifdef CONFIG_PPC_BOOK3S_64 +int add_htab_mem_range(struct crash_mem **mem_ranges); +#else +static inline int add_htab_mem_range(struct crash_mem **mem_ranges) +{ + return 0; +} +#endif +int add_kernel_mem_range(struct crash_mem **mem_ranges); +int add_rtas_mem_range(struct crash_mem **mem_ranges); +int add_opal_mem_range(struct crash_mem **mem_ranges); +int add_reserved_mem_ranges(struct crash_mem **mem_ranges); #endif /* _ASM_POWERPC_KEXEC_RANGES_H */ diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 23ad04c..64c15a5 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -46,6 +46,14 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, if (ret) goto out; + if (image->type == KEXEC_TYPE_CRASH) { + /* min & max buffer values for kdump case */ + kbuf.buf_min = pbuf.buf_min = crashk_res.start; + kbuf.buf_max = pbuf.buf_max = + ((crashk_res.end < ppc64_rma_size) ? + crashk_res.end : (ppc64_rma_size - 1)); + } + ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr); if (ret) goto out; diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index 3e9ac5f..d09c772 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include const struct kexec_file_ops * const kexec_file_loaders[] = { &kexec_elf64_ops, @@ -24,6 +26,254 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { }; /** + * get_exclude_memory_ranges - Get exclude memory ranges. This list includes + * regions like opal/rtas, tce-table, initrd, + * kernel, htab which should be avoided while + * setting up kexec load segments. + * @mem_ranges: Range list to add the memory ranges to. + * + * Returns 0 on success, negative errno on error. + */ +static int get_exclude_memory_ranges(struct crash_mem **mem_ranges) +{ + int ret; + + ret = add_tce_mem_ranges(mem_ranges); + if (ret) + goto out; + + ret = add_initrd_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_htab_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_kernel_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_rtas_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_opal_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_reserved_mem_ranges(mem_ranges); + if (ret) + goto out; + + /* exclude memory ranges should be sorted for easy lookup */ + sort_memory_ranges(*mem_ranges, true); +out: + if (ret) + pr_err("Failed to setup exclude memory ranges\n"); + return ret; +} + +/** + * __locate_mem_hole_top_down - Looks top down for a large enough memory hole + * in the memory regions between buf_min & buf_max + * for the buffer. If found, sets kbuf->mem. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * + * Returns 0 on success, negative errno on error. + */ +static int __locate_mem_hole_top_down(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max) +{ + int ret = -EADDRNOTAVAIL; + phys_addr_t start, end; + u64 i; + + for_each_mem_range_rev(i, &memblock.memory, NULL, NUMA_NO_NODE, + MEMBLOCK_NONE, &start, &end, NULL) { + /* + * memblock uses [start, end) convention while it is + * [start, end] here. Fix the off-by-one to have the + * same convention. + */ + end -= 1; + + if (start > buf_max) + continue; + + /* Memory hole not found */ + if (end < buf_min) + break; + + /* Adjust memory region based on the given range */ + if (start < buf_min) + start = buf_min; + if (end > buf_max) + end = buf_max; + + start = ALIGN(start, kbuf->buf_align); + if (start < end && (end - start + 1) >= kbuf->memsz) { + /* Suitable memory range found. Set kbuf->mem */ + kbuf->mem = ALIGN_DOWN(end - kbuf->memsz + 1, + kbuf->buf_align); + ret = 0; + break; + } + } + + return ret; +} + +/** + * locate_mem_hole_top_down_ppc64 - Skip special memory regions to find a + * suitable buffer with top down approach. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * @emem: Exclude memory ranges. + * + * Returns 0 on success, negative errno on error. + */ +static int locate_mem_hole_top_down_ppc64(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max, + const struct crash_mem *emem) +{ + int i, ret = 0, err = -EADDRNOTAVAIL; + u64 start, end, tmin, tmax; + + tmax = buf_max; + for (i = (emem->nr_ranges - 1); i >= 0; i--) { + start = emem->ranges[i].start; + end = emem->ranges[i].end; + + if (start > tmax) + continue; + + if (end < tmax) { + tmin = (end < buf_min ? buf_min : end + 1); + ret = __locate_mem_hole_top_down(kbuf, tmin, tmax); + if (!ret) + return 0; + } + + tmax = start - 1; + + if (tmax < buf_min) { + ret = err; + break; + } + ret = 0; + } + + if (!ret) { + tmin = buf_min; + ret = __locate_mem_hole_top_down(kbuf, tmin, tmax); + } + return ret; +} + +/** + * __locate_mem_hole_bottom_up - Looks bottom up for a large enough memory hole + * in the memory regions between buf_min & buf_max + * for the buffer. If found, sets kbuf->mem. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * + * Returns 0 on success, negative errno on error. + */ +static int __locate_mem_hole_bottom_up(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max) +{ + int ret = -EADDRNOTAVAIL; + phys_addr_t start, end; + u64 i; + + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, + MEMBLOCK_NONE, &start, &end, NULL) { + /* + * memblock uses [start, end) convention while it is + * [start, end] here. Fix the off-by-one to have the + * same convention. + */ + end -= 1; + + if (end < buf_min) + continue; + + /* Memory hole not found */ + if (start > buf_max) + break; + + /* Adjust memory region based on the given range */ + if (start < buf_min) + start = buf_min; + if (end > buf_max) + end = buf_max; + + start = ALIGN(start, kbuf->buf_align); + if (start < end && (end - start + 1) >= kbuf->memsz) { + /* Suitable memory range found. Set kbuf->mem */ + kbuf->mem = start; + ret = 0; + break; + } + } + + return ret; +} + +/** + * locate_mem_hole_bottom_up_ppc64 - Skip special memory regions to find a + * suitable buffer with bottom up approach. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * @emem: Exclude memory ranges. + * + * Returns 0 on success, negative errno on error. + */ +static int locate_mem_hole_bottom_up_ppc64(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max, + const struct crash_mem *emem) +{ + int i, ret = 0, err = -EADDRNOTAVAIL; + u64 start, end, tmin, tmax; + + tmin = buf_min; + for (i = 0; i < emem->nr_ranges; i++) { + start = emem->ranges[i].start; + end = emem->ranges[i].end; + + if (end < tmin) + continue; + + if (start > tmin) { + tmax = (start > buf_max ? buf_max : start - 1); + ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax); + if (!ret) + return 0; + } + + tmin = end + 1; + + if (tmin > buf_max) { + ret = err; + break; + } + ret = 0; + } + + if (!ret) { + tmax = buf_max; + ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax); + } + return ret; +} + +/** * setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global * variables and call setup_purgatory() to initialize * common global variable. @@ -68,6 +318,67 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, } /** + * arch_kexec_locate_mem_hole - Skip special memory regions like rtas, opal, + * tce-table, reserved-ranges & such (exclude + * memory ranges) as they can't be used for kexec + * segment buffer. Sets kbuf->mem when a suitable + * memory hole is found. + * @kbuf: Buffer contents and memory parameters. + * + * Assumes minimum of PAGE_SIZE alignment for kbuf->memsz & kbuf->buf_align. + * + * Returns 0 on success, negative errno on error. + */ +int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) +{ + struct crash_mem **emem; + u64 buf_min, buf_max; + int ret; + + /* + * Use the generic kexec_locate_mem_hole for regular + * kexec_file_load syscall + */ + if (kbuf->image->type != KEXEC_TYPE_CRASH) + return kexec_locate_mem_hole(kbuf); + + /* Look up the exclude ranges list while locating the memory hole */ + emem = &(kbuf->image->arch.exclude_ranges); + if (!(*emem) || ((*emem)->nr_ranges == 0)) { + pr_warn("No exclude range list. Using the default locate mem hole method\n"); + return kexec_locate_mem_hole(kbuf); + } + + /* Segments for kdump kernel should be within crashkernel region */ + buf_min = (kbuf->buf_min < crashk_res.start ? + crashk_res.start : kbuf->buf_min); + buf_max = (kbuf->buf_max > crashk_res.end ? + crashk_res.end : kbuf->buf_max); + + if (buf_min > buf_max) { + pr_err("Invalid buffer min and/or max values\n"); + return -EINVAL; + } + + if (kbuf->top_down) + ret = locate_mem_hole_top_down_ppc64(kbuf, buf_min, buf_max, + *emem); + else + ret = locate_mem_hole_bottom_up_ppc64(kbuf, buf_min, buf_max, + *emem); + + /* Add the buffer allocated to the exclude list for the next lookup */ + if (!ret) { + add_mem_range(emem, kbuf->mem, kbuf->memsz); + sort_memory_ranges(*emem, true); + } else { + pr_err("Failed to locate memory buffer of size %lu\n", + kbuf->memsz); + } + return ret; +} + +/** * arch_kexec_kernel_image_probe - Does additional handling needed to setup * kexec segments. * @image: kexec image being loaded. @@ -79,9 +390,31 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) { - /* We don't support crash kernels yet. */ - if (image->type == KEXEC_TYPE_CRASH) + if (image->type == KEXEC_TYPE_CRASH) { + int ret; + + /* Get exclude memory ranges needed for setting up kdump segments */ + ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges)); + if (ret) + pr_err("Failed to setup exclude memory ranges for buffer lookup\n"); + /* Return this until all changes for panic kernel are in */ return -EOPNOTSUPP; + } return kexec_image_probe_default(image, buf, buf_len); } + +/** + * arch_kimage_file_post_load_cleanup - Frees up all the allocations done + * while loading the image. + * @image: kexec image being loaded. + * + * Returns 0 on success, negative errno on error. + */ +int arch_kimage_file_post_load_cleanup(struct kimage *image) +{ + kfree(image->arch.exclude_ranges); + image->arch.exclude_ranges = NULL; + + return kexec_image_post_load_cleanup_default(image); +} diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c index dc3ce03..6b81c85 100644 --- a/arch/powerpc/kexec/ranges.c +++ b/arch/powerpc/kexec/ranges.c @@ -233,3 +233,180 @@ int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size) return __add_mem_range(mem_ranges, base, size); } + +/** + * add_tce_mem_ranges - Adds tce-table range to the given memory ranges list. + * @mem_ranges: Range list to add the memory range(s) to. + * + * Returns 0 on success, negative errno on error. + */ +int add_tce_mem_ranges(struct crash_mem **mem_ranges) +{ + struct device_node *dn = NULL; + int ret = 0; + + for_each_node_by_type(dn, "pci") { + u64 base; + u32 size; + + ret = of_property_read_u64(dn, "linux,tce-base", &base); + ret |= of_property_read_u32(dn, "linux,tce-size", &size); + if (ret) { + /* + * It is ok to have pci nodes without tce. So, ignore + * property does not exist error. + */ + if (ret == -EINVAL) { + ret = 0; + continue; + } + break; + } + + ret = add_mem_range(mem_ranges, base, size); + if (ret) + break; + } + + of_node_put(dn); + return ret; +} + +/** + * add_initrd_mem_range - Adds initrd range to the given memory ranges list, + * if the initrd was retained. + * @mem_ranges: Range list to add the memory range to. + * + * Returns 0 on success, negative errno on error. + */ +int add_initrd_mem_range(struct crash_mem **mem_ranges) +{ + u64 base, end; + int ret; + + /* This range means something, only if initrd was retained */ + if (!strstr(saved_command_line, "retain_initrd")) + return 0; + + ret = of_property_read_u64(of_chosen, "linux,initrd-start", &base); + ret |= of_property_read_u64(of_chosen, "linux,initrd-end", &end); + if (!ret) + ret = add_mem_range(mem_ranges, base, end - base + 1); + + return ret; +} + +#ifdef CONFIG_PPC_BOOK3S_64 +/** + * add_htab_mem_range - Adds htab range to the given memory ranges list, + * if it exists + * @mem_ranges: Range list to add the memory range to. + * + * Returns 0 on success, negative errno on error. + */ +int add_htab_mem_range(struct crash_mem **mem_ranges) +{ + if (!htab_address) + return 0; + + return add_mem_range(mem_ranges, __pa(htab_address), htab_size_bytes); +} +#endif + +/** + * add_kernel_mem_range - Adds kernel text region to the given + * memory ranges list. + * @mem_ranges: Range list to add the memory range to. + * + * Returns 0 on success, negative errno on error. + */ +int add_kernel_mem_range(struct crash_mem **mem_ranges) +{ + return add_mem_range(mem_ranges, 0, __pa(_end)); +} + +/** + * add_rtas_mem_range - Adds RTAS region to the given memory ranges list. + * @mem_ranges: Range list to add the memory range to. + * + * Returns 0 on success, negative errno on error. + */ +int add_rtas_mem_range(struct crash_mem **mem_ranges) +{ + struct device_node *dn; + u32 base, size; + int ret = 0; + + dn = of_find_node_by_path("/rtas"); + if (!dn) + return 0; + + ret = of_property_read_u32(dn, "linux,rtas-base", &base); + ret |= of_property_read_u32(dn, "rtas-size", &size); + if (!ret) + ret = add_mem_range(mem_ranges, base, size); + + of_node_put(dn); + return ret; +} + +/** + * add_opal_mem_range - Adds OPAL region to the given memory ranges list. + * @mem_ranges: Range list to add the memory range to. + * + * Returns 0 on success, negative errno on error. + */ +int add_opal_mem_range(struct crash_mem **mem_ranges) +{ + struct device_node *dn; + u64 base, size; + int ret; + + dn = of_find_node_by_path("/ibm,opal"); + if (!dn) + return 0; + + ret = of_property_read_u64(dn, "opal-base-address", &base); + ret |= of_property_read_u64(dn, "opal-runtime-size", &size); + if (!ret) + ret = add_mem_range(mem_ranges, base, size); + + of_node_put(dn); + return ret; +} + +/** + * add_reserved_mem_ranges - Adds "/reserved-ranges" regions exported by f/w + * to the given memory ranges list. + * @mem_ranges: Range list to add the memory ranges to. + * + * Returns 0 on success, negative errno on error. + */ +int add_reserved_mem_ranges(struct crash_mem **mem_ranges) +{ + int n_mem_addr_cells, n_mem_size_cells, i, len, cells, ret = 0; + const __be32 *prop; + + prop = of_get_property(of_root, "reserved-ranges", &len); + if (!prop) + return 0; + + n_mem_addr_cells = of_n_addr_cells(of_root); + n_mem_size_cells = of_n_size_cells(of_root); + cells = n_mem_addr_cells + n_mem_size_cells; + + /* Each reserved range is an (address,size) pair */ + for (i = 0; i < (len / (sizeof(u32) * cells)); i++) { + u64 base, size; + + base = of_read_number(prop + (i * cells), n_mem_addr_cells); + size = of_read_number(prop + (i * cells) + n_mem_addr_cells, + n_mem_size_cells); + + ret = add_mem_range(mem_ranges, base, size); + if (ret) + break; + } + + return ret; +} -- 2.7.4