From 60fe3910bb029e3671ce7ac080a7acb7e032b9e0 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Tue, 29 Nov 2016 23:45:47 +1100 Subject: kexec_file: Allow arch-specific memory walking for kexec_add_buffer Allow architectures to specify a different memory walking function for kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but PowerPC uses the memblock subsystem. Signed-off-by: Thiago Jung Bauermann Acked-by: Dave Young Acked-by: Balbir Singh Signed-off-by: Michael Ellerman --- kernel/kexec_file.c | 30 ++++++++++++++++++++++-------- kernel/kexec_internal.h | 16 ---------------- 2 files changed, 22 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 037c321c5618..f865674bff51 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -428,6 +428,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) return locate_mem_hole_bottom_up(start, end, kbuf); } +/** + * arch_kexec_walk_mem - call func(data) on free memory regions + * @kbuf: Context info for the search. Also passed to @func. + * @func: Function to call for each memory region. + * + * Return: The memory walk will stop when func returns a non-zero value + * and that value will be returned. If all free regions are visited without + * func returning non-zero, then zero will be returned. + */ +int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, + int (*func)(u64, u64, void *)) +{ + if (kbuf->image->type == KEXEC_TYPE_CRASH) + return walk_iomem_res_desc(crashk_res.desc, + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, + crashk_res.start, crashk_res.end, + kbuf, func); + else + return walk_system_ram_res(0, ULONG_MAX, kbuf, func); +} + /* * Helper function for placing a buffer in a kexec segment. This assumes * that kexec_mutex is held. @@ -474,14 +495,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, kbuf->top_down = top_down; /* Walk the RAM ranges and allocate a suitable range for the buffer */ - if (image->type == KEXEC_TYPE_CRASH) - ret = walk_iomem_res_desc(crashk_res.desc, - IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, - crashk_res.start, crashk_res.end, kbuf, - locate_mem_hole_callback); - else - ret = walk_system_ram_res(0, -1, kbuf, - locate_mem_hole_callback); + ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback); if (ret != 1) { /* A suitable memory range could not be found for buffer */ return -EADDRNOTAVAIL; diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h index 0a52315d9c62..4cef7e4706b0 100644 --- a/kernel/kexec_internal.h +++ b/kernel/kexec_internal.h @@ -20,22 +20,6 @@ struct kexec_sha_region { unsigned long len; }; -/* - * Keeps track of buffer parameters as provided by caller for requesting - * memory placement of buffer. - */ -struct kexec_buf { - struct kimage *image; - char *buffer; - unsigned long bufsz; - unsigned long mem; - unsigned long memsz; - unsigned long buf_align; - unsigned long buf_min; - unsigned long buf_max; - bool top_down; /* allocate from top of memory hole */ -}; - void kimage_file_post_load_cleanup(struct kimage *image); #else /* CONFIG_KEXEC_FILE */ static inline void kimage_file_post_load_cleanup(struct kimage *image) { } -- cgit v1.2.3-59-g8ed1b From ec2b9bfaac44ea889625a6b9473d33898b10d35f Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Tue, 29 Nov 2016 23:45:48 +1100 Subject: kexec_file: Change kexec_add_buffer to take kexec_buf as argument. This is done to simplify the kexec_add_buffer argument list. Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer. In addition, change the type of kexec_buf.buffer from char * to void *. There is no particular reason for it to be a char *, and the change allows us to get rid of 3 existing casts to char * in the code. Signed-off-by: Thiago Jung Bauermann Acked-by: Dave Young Acked-by: Balbir Singh Signed-off-by: Michael Ellerman --- arch/x86/kernel/crash.c | 37 ++++++++-------- arch/x86/kernel/kexec-bzimage64.c | 48 +++++++++++---------- include/linux/kexec.h | 8 +--- kernel/kexec_file.c | 88 ++++++++++++++++++--------------------- 4 files changed, 87 insertions(+), 94 deletions(-) (limited to 'kernel') diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 650830e39e3a..3741461c63a0 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -631,9 +631,9 @@ static int determine_backup_region(u64 start, u64 end, void *arg) int crash_load_segments(struct kimage *image) { - unsigned long src_start, src_sz, elf_sz; - void *elf_addr; int ret; + struct kexec_buf kbuf = { .image = image, .buf_min = 0, + .buf_max = ULONG_MAX, .top_down = false }; /* * Determine and load a segment for backup area. First 640K RAM @@ -647,43 +647,44 @@ int crash_load_segments(struct kimage *image) if (ret < 0) return ret; - src_start = image->arch.backup_src_start; - src_sz = image->arch.backup_src_sz; - /* Add backup segment. */ - if (src_sz) { + if (image->arch.backup_src_sz) { + kbuf.buffer = &crash_zero_bytes; + kbuf.bufsz = sizeof(crash_zero_bytes); + kbuf.memsz = image->arch.backup_src_sz; + kbuf.buf_align = PAGE_SIZE; /* * Ideally there is no source for backup segment. This is * copied in purgatory after crash. Just add a zero filled * segment for now to make sure checksum logic works fine. */ - ret = kexec_add_buffer(image, (char *)&crash_zero_bytes, - sizeof(crash_zero_bytes), src_sz, - PAGE_SIZE, 0, -1, 0, - &image->arch.backup_load_addr); + ret = kexec_add_buffer(&kbuf); if (ret) return ret; + image->arch.backup_load_addr = kbuf.mem; pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n", - image->arch.backup_load_addr, src_start, src_sz); + image->arch.backup_load_addr, + image->arch.backup_src_start, kbuf.memsz); } /* Prepare elf headers and add a segment */ - ret = prepare_elf_headers(image, &elf_addr, &elf_sz); + ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz); if (ret) return ret; - image->arch.elf_headers = elf_addr; - image->arch.elf_headers_sz = elf_sz; + image->arch.elf_headers = kbuf.buffer; + image->arch.elf_headers_sz = kbuf.bufsz; - ret = kexec_add_buffer(image, (char *)elf_addr, elf_sz, elf_sz, - ELF_CORE_HEADER_ALIGN, 0, -1, 0, - &image->arch.elf_load_addr); + kbuf.memsz = kbuf.bufsz; + kbuf.buf_align = ELF_CORE_HEADER_ALIGN; + ret = kexec_add_buffer(&kbuf); if (ret) { vfree((void *)image->arch.elf_headers); return ret; } + image->arch.elf_load_addr = kbuf.mem; pr_debug("Loaded ELF headers at 0x%lx bufsz=0x%lx memsz=0x%lx\n", - image->arch.elf_load_addr, elf_sz, elf_sz); + image->arch.elf_load_addr, kbuf.bufsz, kbuf.bufsz); return ret; } diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 3407b148c240..d0a814a9d96a 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -331,17 +331,17 @@ static void *bzImage64_load(struct kimage *image, char *kernel, struct setup_header *header; int setup_sects, kern16_size, ret = 0; - unsigned long setup_header_size, params_cmdline_sz, params_misc_sz; + unsigned long setup_header_size, params_cmdline_sz; struct boot_params *params; unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr; unsigned long purgatory_load_addr; - unsigned long kernel_bufsz, kernel_memsz, kernel_align; - char *kernel_buf; struct bzimage64_data *ldata; struct kexec_entry64_regs regs64; void *stack; unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr); unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset; + struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX, + .top_down = true }; header = (struct setup_header *)(kernel + setup_hdr_offset); setup_sects = header->setup_sects; @@ -402,11 +402,11 @@ static void *bzImage64_load(struct kimage *image, char *kernel, params_cmdline_sz = sizeof(struct boot_params) + cmdline_len + MAX_ELFCOREHDR_STR_LEN; params_cmdline_sz = ALIGN(params_cmdline_sz, 16); - params_misc_sz = params_cmdline_sz + efi_map_sz + + kbuf.bufsz = params_cmdline_sz + efi_map_sz + sizeof(struct setup_data) + sizeof(struct efi_setup_data); - params = kzalloc(params_misc_sz, GFP_KERNEL); + params = kzalloc(kbuf.bufsz, GFP_KERNEL); if (!params) return ERR_PTR(-ENOMEM); efi_map_offset = params_cmdline_sz; @@ -418,37 +418,41 @@ static void *bzImage64_load(struct kimage *image, char *kernel, /* Is there a limit on setup header size? */ memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size); - ret = kexec_add_buffer(image, (char *)params, params_misc_sz, - params_misc_sz, 16, MIN_BOOTPARAM_ADDR, - ULONG_MAX, 1, &bootparam_load_addr); + kbuf.buffer = params; + kbuf.memsz = kbuf.bufsz; + kbuf.buf_align = 16; + kbuf.buf_min = MIN_BOOTPARAM_ADDR; + ret = kexec_add_buffer(&kbuf); if (ret) goto out_free_params; + bootparam_load_addr = kbuf.mem; pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n", - bootparam_load_addr, params_misc_sz, params_misc_sz); + bootparam_load_addr, kbuf.bufsz, kbuf.bufsz); /* Load kernel */ - kernel_buf = kernel + kern16_size; - kernel_bufsz = kernel_len - kern16_size; - kernel_memsz = PAGE_ALIGN(header->init_size); - kernel_align = header->kernel_alignment; - - ret = kexec_add_buffer(image, kernel_buf, - kernel_bufsz, kernel_memsz, kernel_align, - MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1, - &kernel_load_addr); + kbuf.buffer = kernel + kern16_size; + kbuf.bufsz = kernel_len - kern16_size; + kbuf.memsz = PAGE_ALIGN(header->init_size); + kbuf.buf_align = header->kernel_alignment; + kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; + ret = kexec_add_buffer(&kbuf); if (ret) goto out_free_params; + kernel_load_addr = kbuf.mem; pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", - kernel_load_addr, kernel_memsz, kernel_memsz); + kernel_load_addr, kbuf.bufsz, kbuf.memsz); /* Load initrd high */ if (initrd) { - ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len, - PAGE_SIZE, MIN_INITRD_LOAD_ADDR, - ULONG_MAX, 1, &initrd_load_addr); + kbuf.buffer = initrd; + kbuf.bufsz = kbuf.memsz = initrd_len; + kbuf.buf_align = PAGE_SIZE; + kbuf.buf_min = MIN_INITRD_LOAD_ADDR; + ret = kexec_add_buffer(&kbuf); if (ret) goto out_free_params; + initrd_load_addr = kbuf.mem; pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", initrd_load_addr, initrd_len, initrd_len); diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 5e320ddaaa82..437ef1b47428 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -163,7 +163,7 @@ struct kexec_file_ops { */ struct kexec_buf { struct kimage *image; - char *buffer; + void *buffer; unsigned long bufsz; unsigned long mem; unsigned long memsz; @@ -175,6 +175,7 @@ struct kexec_buf { int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *)); +extern int kexec_add_buffer(struct kexec_buf *kbuf); #endif /* CONFIG_KEXEC_FILE */ struct kimage { @@ -239,11 +240,6 @@ extern asmlinkage long sys_kexec_load(unsigned long entry, struct kexec_segment __user *segments, unsigned long flags); extern int kernel_kexec(void); -extern int kexec_add_buffer(struct kimage *image, char *buffer, - unsigned long bufsz, unsigned long memsz, - unsigned long buf_align, unsigned long buf_min, - unsigned long buf_max, bool top_down, - unsigned long *load_addr); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); extern int kexec_load_purgatory(struct kimage *image, unsigned long min, diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index f865674bff51..efd2c094af7e 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -449,25 +449,27 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, return walk_system_ram_res(0, ULONG_MAX, kbuf, func); } -/* - * Helper function for placing a buffer in a kexec segment. This assumes - * that kexec_mutex is held. +/** + * kexec_add_buffer - place a buffer in a kexec segment + * @kbuf: Buffer contents and memory parameters. + * + * This function assumes that kexec_mutex is held. + * On successful return, @kbuf->mem will have the physical address of + * the buffer in memory. + * + * Return: 0 on success, negative errno on error. */ -int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, - unsigned long memsz, unsigned long buf_align, - unsigned long buf_min, unsigned long buf_max, - bool top_down, unsigned long *load_addr) +int kexec_add_buffer(struct kexec_buf *kbuf) { struct kexec_segment *ksegment; - struct kexec_buf buf, *kbuf; int ret; /* Currently adding segment this way is allowed only in file mode */ - if (!image->file_mode) + if (!kbuf->image->file_mode) return -EINVAL; - if (image->nr_segments >= KEXEC_SEGMENT_MAX) + if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX) return -EINVAL; /* @@ -477,22 +479,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, * logic goes through list of segments to make sure there are * no destination overlaps. */ - if (!list_empty(&image->control_pages)) { + if (!list_empty(&kbuf->image->control_pages)) { WARN_ON(1); return -EINVAL; } - memset(&buf, 0, sizeof(struct kexec_buf)); - kbuf = &buf; - kbuf->image = image; - kbuf->buffer = buffer; - kbuf->bufsz = bufsz; - - kbuf->memsz = ALIGN(memsz, PAGE_SIZE); - kbuf->buf_align = max(buf_align, PAGE_SIZE); - kbuf->buf_min = buf_min; - kbuf->buf_max = buf_max; - kbuf->top_down = top_down; + /* Ensure minimum alignment needed for segments. */ + kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); + kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); /* Walk the RAM ranges and allocate a suitable range for the buffer */ ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback); @@ -502,13 +496,12 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, } /* Found a suitable memory range */ - ksegment = &image->segment[image->nr_segments]; + ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; ksegment->kbuf = kbuf->buffer; ksegment->bufsz = kbuf->bufsz; ksegment->mem = kbuf->mem; ksegment->memsz = kbuf->memsz; - image->nr_segments++; - *load_addr = ksegment->mem; + kbuf->image->nr_segments++; return 0; } @@ -630,13 +623,15 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, unsigned long max, int top_down) { struct purgatory_info *pi = &image->purgatory_info; - unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad; - unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset; + unsigned long align, bss_align, bss_sz, bss_pad; + unsigned long entry, load_addr, curr_load_addr, bss_addr, offset; unsigned char *buf_addr, *src; int i, ret = 0, entry_sidx = -1; const Elf_Shdr *sechdrs_c; Elf_Shdr *sechdrs = NULL; - void *purgatory_buf = NULL; + struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1, + .buf_min = min, .buf_max = max, + .top_down = top_down }; /* * sechdrs_c points to section headers in purgatory and are read @@ -702,9 +697,7 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, } /* Determine how much memory is needed to load relocatable object. */ - buf_align = 1; bss_align = 1; - buf_sz = 0; bss_sz = 0; for (i = 0; i < pi->ehdr->e_shnum; i++) { @@ -713,10 +706,10 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, align = sechdrs[i].sh_addralign; if (sechdrs[i].sh_type != SHT_NOBITS) { - if (buf_align < align) - buf_align = align; - buf_sz = ALIGN(buf_sz, align); - buf_sz += sechdrs[i].sh_size; + if (kbuf.buf_align < align) + kbuf.buf_align = align; + kbuf.bufsz = ALIGN(kbuf.bufsz, align); + kbuf.bufsz += sechdrs[i].sh_size; } else { /* bss section */ if (bss_align < align) @@ -728,32 +721,31 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, /* Determine the bss padding required to align bss properly */ bss_pad = 0; - if (buf_sz & (bss_align - 1)) - bss_pad = bss_align - (buf_sz & (bss_align - 1)); + if (kbuf.bufsz & (bss_align - 1)) + bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1)); - memsz = buf_sz + bss_pad + bss_sz; + kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz; /* Allocate buffer for purgatory */ - purgatory_buf = vzalloc(buf_sz); - if (!purgatory_buf) { + kbuf.buffer = vzalloc(kbuf.bufsz); + if (!kbuf.buffer) { ret = -ENOMEM; goto out; } - if (buf_align < bss_align) - buf_align = bss_align; + if (kbuf.buf_align < bss_align) + kbuf.buf_align = bss_align; /* Add buffer to segment list */ - ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz, - buf_align, min, max, top_down, - &pi->purgatory_load_addr); + ret = kexec_add_buffer(&kbuf); if (ret) goto out; + pi->purgatory_load_addr = kbuf.mem; /* Load SHF_ALLOC sections */ - buf_addr = purgatory_buf; + buf_addr = kbuf.buffer; load_addr = curr_load_addr = pi->purgatory_load_addr; - bss_addr = load_addr + buf_sz + bss_pad; + bss_addr = load_addr + kbuf.bufsz + bss_pad; for (i = 0; i < pi->ehdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) @@ -799,11 +791,11 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, * Used later to identify which section is purgatory and skip it * from checksumming. */ - pi->purgatory_buf = purgatory_buf; + pi->purgatory_buf = kbuf.buffer; return ret; out: vfree(sechdrs); - vfree(purgatory_buf); + vfree(kbuf.buffer); return ret; } -- cgit v1.2.3-59-g8ed1b From e2e806f9e437b46a3fc8f3174a225c73f2e38c3d Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Tue, 29 Nov 2016 23:45:49 +1100 Subject: kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer. kexec_locate_mem_hole will be used by the PowerPC kexec_file_load implementation to find free memory for the purgatory stack. Signed-off-by: Thiago Jung Bauermann Acked-by: Dave Young Signed-off-by: Michael Ellerman --- include/linux/kexec.h | 1 + kernel/kexec_file.c | 25 ++++++++++++++++++++----- 2 files changed, 21 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 437ef1b47428..a33f63351f86 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -176,6 +176,7 @@ struct kexec_buf { int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); +int kexec_locate_mem_hole(struct kexec_buf *kbuf); #endif /* CONFIG_KEXEC_FILE */ struct kimage { diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index efd2c094af7e..0c2df7f73792 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -449,6 +449,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, return walk_system_ram_res(0, ULONG_MAX, kbuf, func); } +/** + * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel + * @kbuf: Parameters for the memory search. + * + * On success, kbuf->mem will have the start address of the memory region found. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_locate_mem_hole(struct kexec_buf *kbuf) +{ + int ret; + + ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback); + + return ret == 1 ? 0 : -EADDRNOTAVAIL; +} + /** * kexec_add_buffer - place a buffer in a kexec segment * @kbuf: Buffer contents and memory parameters. @@ -489,11 +506,9 @@ int kexec_add_buffer(struct kexec_buf *kbuf) kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); /* Walk the RAM ranges and allocate a suitable range for the buffer */ - ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback); - if (ret != 1) { - /* A suitable memory range could not be found for buffer */ - return -EADDRNOTAVAIL; - } + ret = kexec_locate_mem_hole(kbuf); + if (ret) + return ret; /* Found a suitable memory range */ ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; -- cgit v1.2.3-59-g8ed1b