kexec_file, x86: move re-factored code to generic side
authorAKASHI Takahiro <takahiro.akashi@linaro.org>
Fri, 13 Apr 2018 22:36:06 +0000 (15:36 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 14 Apr 2018 00:10:27 +0000 (17:10 -0700)
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@linaro.org
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Dave Young <dyoung@redhat.com>
Tested-by: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/kernel/crash.c
include/linux/kexec.h
kernel/kexec_file.c

index 229b8ecf8428a1c611a815b0401a5813bf339222..f631a3f155875bfad8b8e709364a1e5c38706e24 100644 (file)
 #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_elf_data(void)
        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(struct crash_mem *cmem)
        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_callback(struct resource *res, void *arg)
        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 kimage *image, void **addr,
                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 kimage *image, struct crash_mem *cmem,
        /* 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 */
index 102c725421a1d243a2ed40dd634e6d36eb337152..68865fd51aadf643eb673fa3cbd1f484babe5c61 100644 (file)
@@ -168,6 +168,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
                               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 {
index 332c4fd12cb1460774498ba030846f819ebe23c5..b06b1fac5252c95dbcf4aba0cb842868a55b9f86 100644 (file)
 #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(struct kimage *image, const char *name,
        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;
+}