From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx> Subject: kexec_file, x86: move re-factored code to generic side In the previous patches, commonly-used routines, exclude_mem_range() and prepare_elf64_headers(), were carved out. Now place them in kexec common code. A prefix "crash_" is given to each of their names to avoid possible name collisions. Link: http://lkml.kernel.org/r/20180306102303.9063-8-takahiro.akashi@xxxxxxxxxx Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx> Acked-by: Dave Young <dyoung@xxxxxxxxxx> Tested-by: Dave Young <dyoung@xxxxxxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/crash.c | 195 +------------------------------------- include/linux/kexec.h | 19 +++ kernel/kexec_file.c | 175 ++++++++++++++++++++++++++++++++++ 3 files changed, 201 insertions(+), 188 deletions(-) diff -puN arch/x86/kernel/crash.c~kexec_file-x86-move-re-factored-code-to-generic-side arch/x86/kernel/crash.c --- a/arch/x86/kernel/crash.c~kexec_file-x86-move-re-factored-code-to-generic-side +++ a/arch/x86/kernel/crash.c @@ -38,19 +38,6 @@ #include <asm/virtext.h> #include <asm/intel_pt.h> -/* Alignment required for elf header segment */ -#define ELF_CORE_HEADER_ALIGN 4096 - -struct crash_mem_range { - u64 start, end; -}; - -struct crash_mem { - unsigned int max_nr_ranges; - unsigned int nr_ranges; - struct crash_mem_range ranges[0]; -}; - /* Used while preparing memory map entries for second kernel */ struct crash_memmap_data { struct boot_params *params; @@ -227,77 +214,6 @@ static struct crash_mem *fill_up_crash_e return cmem; } -static int exclude_mem_range(struct crash_mem *mem, - unsigned long long mstart, unsigned long long mend) -{ - int i, j; - unsigned long long start, end; - struct crash_mem_range temp_range = {0, 0}; - - for (i = 0; i < mem->nr_ranges; i++) { - start = mem->ranges[i].start; - end = mem->ranges[i].end; - - if (mstart > end || mend < start) - continue; - - /* Truncate any area outside of range */ - if (mstart < start) - mstart = start; - if (mend > end) - mend = end; - - /* Found completely overlapping range */ - if (mstart == start && mend == end) { - mem->ranges[i].start = 0; - mem->ranges[i].end = 0; - if (i < mem->nr_ranges - 1) { - /* Shift rest of the ranges to left */ - for (j = i; j < mem->nr_ranges - 1; j++) { - mem->ranges[j].start = - mem->ranges[j+1].start; - mem->ranges[j].end = - mem->ranges[j+1].end; - } - } - mem->nr_ranges--; - return 0; - } - - if (mstart > start && mend < end) { - /* Split original range */ - mem->ranges[i].end = mstart - 1; - temp_range.start = mend + 1; - temp_range.end = end; - } else if (mstart != start) - mem->ranges[i].end = mstart - 1; - else - mem->ranges[i].start = mend + 1; - break; - } - - /* If a split happend, add the split to array */ - if (!temp_range.end) - return 0; - - /* Split happened */ - if (i == mem->max_nr_ranges - 1) - return -ENOMEM; - - /* Location where new range should go */ - j = i + 1; - if (j < mem->nr_ranges) { - /* Move over all ranges one slot towards the end */ - for (i = mem->nr_ranges - 1; i >= j; i--) - mem->ranges[i + 1] = mem->ranges[i]; - } - - mem->ranges[j].start = temp_range.start; - mem->ranges[j].end = temp_range.end; - mem->nr_ranges++; - return 0; -} - /* * Look for any unwanted ranges between mstart, mend and remove them. This * might lead to split and split ranges are put in cmem->ranges[] array @@ -307,12 +223,13 @@ static int elf_header_exclude_ranges(str int ret = 0; /* Exclude crashkernel region */ - ret = exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); if (ret) return ret; if (crashk_low_res.end) { - ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); + ret = crash_exclude_mem_range(cmem, crashk_low_res.start, + crashk_low_res.end); if (ret) return ret; } @@ -331,105 +248,6 @@ static int prepare_elf64_ram_headers_cal return 0; } -static int prepare_elf64_headers(struct crash_mem *cmem, bool kernel_map, - void **addr, unsigned long *sz) -{ - Elf64_Ehdr *ehdr; - Elf64_Phdr *phdr; - unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz; - unsigned char *buf; - unsigned int cpu, i; - unsigned long long notes_addr; - unsigned long mstart, mend; - - /* extra phdr for vmcoreinfo elf note */ - nr_phdr = nr_cpus + 1; - nr_phdr += cmem->nr_ranges; - - /* - * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping - * area on x86_64 (ffffffff80000000 - ffffffffa0000000). - * I think this is required by tools like gdb. So same physical - * memory will be mapped in two elf headers. One will contain kernel - * text virtual addresses and other will have __va(physical) addresses. - */ - - nr_phdr++; - elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr); - elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN); - - buf = vzalloc(elf_sz); - if (!buf) - return -ENOMEM; - - ehdr = (Elf64_Ehdr *)buf; - phdr = (Elf64_Phdr *)(ehdr + 1); - memcpy(ehdr->e_ident, ELFMAG, SELFMAG); - ehdr->e_ident[EI_CLASS] = ELFCLASS64; - ehdr->e_ident[EI_DATA] = ELFDATA2LSB; - ehdr->e_ident[EI_VERSION] = EV_CURRENT; - ehdr->e_ident[EI_OSABI] = ELF_OSABI; - memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); - ehdr->e_type = ET_CORE; - ehdr->e_machine = ELF_ARCH; - ehdr->e_version = EV_CURRENT; - ehdr->e_phoff = sizeof(Elf64_Ehdr); - ehdr->e_ehsize = sizeof(Elf64_Ehdr); - ehdr->e_phentsize = sizeof(Elf64_Phdr); - - /* Prepare one phdr of type PT_NOTE for each present cpu */ - for_each_present_cpu(cpu) { - phdr->p_type = PT_NOTE; - notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); - phdr->p_offset = phdr->p_paddr = notes_addr; - phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t); - (ehdr->e_phnum)++; - phdr++; - } - - /* Prepare one PT_NOTE header for vmcoreinfo */ - phdr->p_type = PT_NOTE; - phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); - phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; - (ehdr->e_phnum)++; - phdr++; - - /* Prepare PT_LOAD type program header for kernel text region */ - if (kernel_map) { - phdr->p_type = PT_LOAD; - phdr->p_flags = PF_R|PF_W|PF_X; - phdr->p_vaddr = (Elf64_Addr)_text; - phdr->p_filesz = phdr->p_memsz = _end - _text; - phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); - ehdr->e_phnum++; - phdr++; - } - - /* Go through all the ranges in cmem->ranges[] and prepare phdr */ - for (i = 0; i < cmem->nr_ranges; i++) { - mstart = cmem->ranges[i].start; - mend = cmem->ranges[i].end; - - phdr->p_type = PT_LOAD; - phdr->p_flags = PF_R|PF_W|PF_X; - phdr->p_offset = mstart; - - phdr->p_paddr = mstart; - phdr->p_vaddr = (unsigned long long) __va(mstart); - phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; - phdr->p_align = 0; - ehdr->e_phnum++; - phdr++; - pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", - phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz, - ehdr->e_phnum, phdr->p_offset); - } - - *addr = buf; - *sz = elf_sz; - return 0; -} - /* Prepare elf headers. Return addr and size */ static int prepare_elf_headers(struct kimage *image, void **addr, unsigned long *sz) @@ -454,7 +272,8 @@ static int prepare_elf_headers(struct ki goto out; /* By default prepare 64bit headers */ - ret = prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz); + ret = crash_prepare_elf64_headers(cmem, + IS_ENABLED(CONFIG_X86_64), addr, sz); if (ret) goto out; @@ -518,14 +337,14 @@ static int memmap_exclude_ranges(struct /* Exclude Backup region */ start = image->arch.backup_load_addr; end = start + image->arch.backup_src_sz - 1; - ret = exclude_mem_range(cmem, start, end); + ret = crash_exclude_mem_range(cmem, start, end); if (ret) return ret; /* Exclude elf header region */ start = image->arch.elf_load_addr; end = start + image->arch.elf_headers_sz - 1; - return exclude_mem_range(cmem, start, end); + return crash_exclude_mem_range(cmem, start, end); } /* Prepare memory map for crash dump kernel */ diff -puN include/linux/kexec.h~kexec_file-x86-move-re-factored-code-to-generic-side include/linux/kexec.h --- a/include/linux/kexec.h~kexec_file-x86-move-re-factored-code-to-generic-side +++ a/include/linux/kexec.h @@ -168,6 +168,25 @@ int __weak arch_kexec_walk_mem(struct ke int (*func)(struct resource *, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); + +/* Alignment required for elf header segment */ +#define ELF_CORE_HEADER_ALIGN 4096 + +struct crash_mem_range { + u64 start, end; +}; + +struct crash_mem { + unsigned int max_nr_ranges; + unsigned int nr_ranges; + struct crash_mem_range ranges[0]; +}; + +extern int crash_exclude_mem_range(struct crash_mem *mem, + unsigned long long mstart, + unsigned long long mend); +extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, + void **addr, unsigned long *sz); #endif /* CONFIG_KEXEC_FILE */ struct kimage { diff -puN kernel/kexec_file.c~kexec_file-x86-move-re-factored-code-to-generic-side kernel/kexec_file.c --- a/kernel/kexec_file.c~kexec_file-x86-move-re-factored-code-to-generic-side +++ a/kernel/kexec_file.c @@ -22,6 +22,11 @@ #include <linux/ima.h> #include <crypto/hash.h> #include <crypto/sha.h> +#include <linux/elf.h> +#include <linux/elfcore.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <linux/slab.h> #include <linux/syscalls.h> #include <linux/vmalloc.h> #include "kexec_internal.h" @@ -1079,3 +1084,173 @@ int kexec_purgatory_get_set_symbol(struc return 0; } #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */ + +int crash_exclude_mem_range(struct crash_mem *mem, + unsigned long long mstart, unsigned long long mend) +{ + int i, j; + unsigned long long start, end; + struct crash_mem_range temp_range = {0, 0}; + + for (i = 0; i < mem->nr_ranges; i++) { + start = mem->ranges[i].start; + end = mem->ranges[i].end; + + if (mstart > end || mend < start) + continue; + + /* Truncate any area outside of range */ + if (mstart < start) + mstart = start; + if (mend > end) + mend = end; + + /* Found completely overlapping range */ + if (mstart == start && mend == end) { + mem->ranges[i].start = 0; + mem->ranges[i].end = 0; + if (i < mem->nr_ranges - 1) { + /* Shift rest of the ranges to left */ + for (j = i; j < mem->nr_ranges - 1; j++) { + mem->ranges[j].start = + mem->ranges[j+1].start; + mem->ranges[j].end = + mem->ranges[j+1].end; + } + } + mem->nr_ranges--; + return 0; + } + + if (mstart > start && mend < end) { + /* Split original range */ + mem->ranges[i].end = mstart - 1; + temp_range.start = mend + 1; + temp_range.end = end; + } else if (mstart != start) + mem->ranges[i].end = mstart - 1; + else + mem->ranges[i].start = mend + 1; + break; + } + + /* If a split happened, add the split to array */ + if (!temp_range.end) + return 0; + + /* Split happened */ + if (i == mem->max_nr_ranges - 1) + return -ENOMEM; + + /* Location where new range should go */ + j = i + 1; + if (j < mem->nr_ranges) { + /* Move over all ranges one slot towards the end */ + for (i = mem->nr_ranges - 1; i >= j; i--) + mem->ranges[i + 1] = mem->ranges[i]; + } + + mem->ranges[j].start = temp_range.start; + mem->ranges[j].end = temp_range.end; + mem->nr_ranges++; + return 0; +} + +int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, + void **addr, unsigned long *sz) +{ + Elf64_Ehdr *ehdr; + Elf64_Phdr *phdr; + unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz; + unsigned char *buf; + unsigned int cpu, i; + unsigned long long notes_addr; + unsigned long mstart, mend; + + /* extra phdr for vmcoreinfo elf note */ + nr_phdr = nr_cpus + 1; + nr_phdr += mem->nr_ranges; + + /* + * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping + * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64). + * I think this is required by tools like gdb. So same physical + * memory will be mapped in two elf headers. One will contain kernel + * text virtual addresses and other will have __va(physical) addresses. + */ + + nr_phdr++; + elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr); + elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN); + + buf = vzalloc(elf_sz); + if (!buf) + return -ENOMEM; + + ehdr = (Elf64_Ehdr *)buf; + phdr = (Elf64_Phdr *)(ehdr + 1); + memcpy(ehdr->e_ident, ELFMAG, SELFMAG); + ehdr->e_ident[EI_CLASS] = ELFCLASS64; + ehdr->e_ident[EI_DATA] = ELFDATA2LSB; + ehdr->e_ident[EI_VERSION] = EV_CURRENT; + ehdr->e_ident[EI_OSABI] = ELF_OSABI; + memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); + ehdr->e_type = ET_CORE; + ehdr->e_machine = ELF_ARCH; + ehdr->e_version = EV_CURRENT; + ehdr->e_phoff = sizeof(Elf64_Ehdr); + ehdr->e_ehsize = sizeof(Elf64_Ehdr); + ehdr->e_phentsize = sizeof(Elf64_Phdr); + + /* Prepare one phdr of type PT_NOTE for each present cpu */ + for_each_present_cpu(cpu) { + phdr->p_type = PT_NOTE; + notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); + phdr->p_offset = phdr->p_paddr = notes_addr; + phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t); + (ehdr->e_phnum)++; + phdr++; + } + + /* Prepare one PT_NOTE header for vmcoreinfo */ + phdr->p_type = PT_NOTE; + phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); + phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; + (ehdr->e_phnum)++; + phdr++; + + /* Prepare PT_LOAD type program header for kernel text region */ + if (kernel_map) { + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_vaddr = (Elf64_Addr)_text; + phdr->p_filesz = phdr->p_memsz = _end - _text; + phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); + ehdr->e_phnum++; + phdr++; + } + + /* Go through all the ranges in mem->ranges[] and prepare phdr */ + for (i = 0; i < mem->nr_ranges; i++) { + mstart = mem->ranges[i].start; + mend = mem->ranges[i].end; + + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_offset = mstart; + + phdr->p_paddr = mstart; + phdr->p_vaddr = (unsigned long long) __va(mstart); + phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; + phdr->p_align = 0; + ehdr->e_phnum++; + phdr++; + pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", + phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz, + ehdr->e_phnum, phdr->p_offset); + } + + *addr = buf; + *sz = elf_sz; + return 0; +} _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
