1 files changed, 62 insertions, 272 deletions

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 1f6680427ff0..f631a3f15587 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -38,37 +38,6 @@
 #include <asm/virtext.h>
 #include <asm/intel_pt.h>
 
-/* Alignment required for elf header segment */
-#define ELF_CORE_HEADER_ALIGN   4096
-
-/* This primarily represents number of split ranges due to exclusion */
-#define CRASH_MAX_RANGES	16
-
-struct crash_mem_range {
-	u64 start, end;
-};
-
-struct crash_mem {
-	unsigned int nr_ranges;
-	struct crash_mem_range ranges[CRASH_MAX_RANGES];
-};
-
-/* Misc data about ram ranges needed to prepare elf headers */
-struct crash_elf_data {
-	struct kimage *image;
-	/*
-	 * Total number of ram ranges we have after various adjustments for
-	 * crash reserved region, etc.
-	 */
-	unsigned int max_nr_ranges;
-
-	/* Pointer to elf header */
-	void *ehdr;
-	/* Pointer to next phdr */
-	void *bufp;
-	struct crash_mem mem;
-};
-
 /* Used while preparing memory map entries for second kernel */
 struct crash_memmap_data {
 	struct boot_params *params;
@@ -218,124 +187,49 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
 	return 0;
 }
 
-
 /* Gather all the required information to prepare elf headers for ram regions */
-static void fill_up_crash_elf_data(struct crash_elf_data *ced,
-				   struct kimage *image)
+static struct crash_mem *fill_up_crash_elf_data(void)
 {
 	unsigned int nr_ranges = 0;
-
-	ced->image = image;
+	struct crash_mem *cmem;
 
 	walk_system_ram_res(0, -1, &nr_ranges,
 				get_nr_ram_ranges_callback);
+	if (!nr_ranges)
+		return NULL;
 
-	ced->max_nr_ranges = nr_ranges;
-
-	/* Exclusion of crash region could split memory ranges */
-	ced->max_nr_ranges++;
-
-	/* If crashk_low_res is not 0, another range split possible */
-	if (crashk_low_res.end)
-		ced->max_nr_ranges++;
-}
-
-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;
-	}
+	/*
+	 * Exclusion of crash region and/or crashk_low_res may cause
+	 * another range split. So add extra two slots here.
+	 */
+	nr_ranges += 2;
+	cmem = vzalloc(sizeof(struct crash_mem) +
+			sizeof(struct crash_mem_range) * nr_ranges);
+	if (!cmem)
+		return NULL;
 
-	/* If a split happend, add the split to array */
-	if (!temp_range.end)
-		return 0;
+	cmem->max_nr_ranges = nr_ranges;
+	cmem->nr_ranges = 0;
 
-	/* Split happened */
-	if (i == CRASH_MAX_RANGES - 1) {
-		pr_err("Too many crash ranges after split\n");
-		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;
+	return cmem;
 }
 
 /*
  * Look for any unwanted ranges between mstart, mend and remove them. This
- * might lead to split and split ranges are put in ced->mem.ranges[] array
+ * might lead to split and split ranges are put in cmem->ranges[] array
  */
-static int elf_header_exclude_ranges(struct crash_elf_data *ced,
-		unsigned long long mstart, unsigned long long mend)
+static int elf_header_exclude_ranges(struct crash_mem *cmem)
 {
-	struct crash_mem *cmem = &ced->mem;
 	int ret = 0;
 
-	memset(cmem->ranges, 0, sizeof(cmem->ranges));
-
-	cmem->ranges[0].start = mstart;
-	cmem->ranges[0].end = mend;
-	cmem->nr_ranges = 1;
-
 	/* 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;
 	}
@@ -345,144 +239,12 @@ static int elf_header_exclude_ranges(struct crash_elf_data *ced,
 
 static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
 {
-	struct crash_elf_data *ced = arg;
-	Elf64_Ehdr *ehdr;
-	Elf64_Phdr *phdr;
-	unsigned long mstart, mend;
-	struct kimage *image = ced->image;
-	struct crash_mem *cmem;
-	int ret, i;
-
-	ehdr = ced->ehdr;
-
-	/* Exclude unwanted mem ranges */
-	ret = elf_header_exclude_ranges(ced, res->start, res->end);
-	if (ret)
-		return ret;
-
-	/* Go through all the ranges in ced->mem.ranges[] and prepare phdr */
-	cmem = &ced->mem;
-
-	for (i = 0; i < cmem->nr_ranges; i++) {
-		mstart = cmem->ranges[i].start;
-		mend = cmem->ranges[i].end;
-
-		phdr = ced->bufp;
-		ced->bufp += sizeof(Elf64_Phdr);
-
-		phdr->p_type = PT_LOAD;
-		phdr->p_flags = PF_R|PF_W|PF_X;
-		phdr->p_offset  = mstart;
-
-		/*
-		 * If a range matches backup region, adjust offset to backup
-		 * segment.
-		 */
-		if (mstart == image->arch.backup_src_start &&
-		    (mend - mstart + 1) == image->arch.backup_src_sz)
-			phdr->p_offset = image->arch.backup_load_addr;
-
-		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++;
-		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);
-	}
-
-	return ret;
-}
-
-static int prepare_elf64_headers(struct crash_elf_data *ced,
-		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, *bufp;
-	unsigned int cpu;
-	unsigned long long notes_addr;
-	int ret;
+	struct crash_mem *cmem = arg;
 
-	/* extra phdr for vmcoreinfo elf note */
-	nr_phdr = nr_cpus + 1;
-	nr_phdr += ced->max_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.
-	 */
+	cmem->ranges[cmem->nr_ranges].start = res->start;
+	cmem->ranges[cmem->nr_ranges].end = res->end;
+	cmem->nr_ranges++;
 
-	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;
-
-	bufp = buf;
-	ehdr = (Elf64_Ehdr *)bufp;
-	bufp += sizeof(Elf64_Ehdr);
-	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 = (Elf64_Phdr *)bufp;
-		bufp += sizeof(Elf64_Phdr);
-		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)++;
-	}
-
-	/* Prepare one PT_NOTE header for vmcoreinfo */
-	phdr = (Elf64_Phdr *)bufp;
-	bufp += sizeof(Elf64_Phdr);
-	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)++;
-
-#ifdef CONFIG_X86_64
-	/* Prepare PT_LOAD type program header for kernel text region */
-	phdr = (Elf64_Phdr *)bufp;
-	bufp += sizeof(Elf64_Phdr);
-	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)++;
-#endif
-
-	/* Prepare PT_LOAD headers for system ram chunks. */
-	ced->ehdr = ehdr;
-	ced->bufp = bufp;
-	ret = walk_system_ram_res(0, -1, ced,
-			prepare_elf64_ram_headers_callback);
-	if (ret < 0)
-		return ret;
-
-	*addr = buf;
-	*sz = elf_sz;
 	return 0;
 }
 
@@ -490,18 +252,46 @@ static int prepare_elf64_headers(struct crash_elf_data *ced,
 static int prepare_elf_headers(struct kimage *image, void **addr,
 					unsigned long *sz)
 {
-	struct crash_elf_data *ced;
-	int ret;
+	struct crash_mem *cmem;
+	Elf64_Ehdr *ehdr;
+	Elf64_Phdr *phdr;
+	int ret, i;
 
-	ced = kzalloc(sizeof(*ced), GFP_KERNEL);
-	if (!ced)
+	cmem = fill_up_crash_elf_data();
+	if (!cmem)
 		return -ENOMEM;
 
-	fill_up_crash_elf_data(ced, image);
+	ret = walk_system_ram_res(0, -1, cmem,
+				prepare_elf64_ram_headers_callback);
+	if (ret)
+		goto out;
+
+	/* Exclude unwanted mem ranges */
+	ret = elf_header_exclude_ranges(cmem);
+	if (ret)
+		goto out;
 
 	/* By default prepare 64bit headers */
-	ret =  prepare_elf64_headers(ced, addr, sz);
-	kfree(ced);
+	ret =  crash_prepare_elf64_headers(cmem,
+				IS_ENABLED(CONFIG_X86_64), addr, sz);
+	if (ret)
+		goto out;
+
+	/*
+	 * If a range matches backup region, adjust offset to backup
+	 * segment.
+	 */
+	ehdr = (Elf64_Ehdr *)*addr;
+	phdr = (Elf64_Phdr *)(ehdr + 1);
+	for (i = 0; i < ehdr->e_phnum; phdr++, i++)
+		if (phdr->p_type == PT_LOAD &&
+				phdr->p_paddr == image->arch.backup_src_start &&
+				phdr->p_memsz == image->arch.backup_src_sz) {
+			phdr->p_offset = image->arch.backup_load_addr;
+			break;
+		}
+out:
+	vfree(cmem);
 	return ret;
 }
 
@@ -547,14 +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 */