Adding upstream version 1:2.0.27.upstream/1%2.0.27upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 787 insertions, 0 deletions

diff --git a/kexec/kexec-elf.c b/kexec/kexec-elf.c
new file mode 100644
index 0000000..be60bbd
--- /dev/null
+++ b/kexec/kexec-elf.c
@@ -0,0 +1,787 @@
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include "elf.h"
+#include <boot/elf_boot.h>
+#include "kexec.h"
+#include "kexec-elf.h"
+#include "crashdump.h"
+
+static const int probe_debug = 0;
+
+uint16_t elf16_to_cpu(const struct mem_ehdr *ehdr, uint16_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = le16_to_cpu(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = be16_to_cpu(value);
+	}
+	return value;
+}
+
+uint32_t elf32_to_cpu(const struct mem_ehdr *ehdr, uint32_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = le32_to_cpu(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = be32_to_cpu(value);
+	}
+	return value;
+}
+
+uint64_t elf64_to_cpu(const struct mem_ehdr *ehdr, uint64_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = le64_to_cpu(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = be64_to_cpu(value);
+	}
+	return value;
+}
+
+uint16_t cpu_to_elf16(const struct mem_ehdr *ehdr, uint16_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = cpu_to_le16(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = cpu_to_be16(value);
+	}
+	return value;
+}
+
+uint32_t cpu_to_elf32(const struct mem_ehdr *ehdr, uint32_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = cpu_to_le32(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = cpu_to_be32(value);
+	}
+	return value;
+}
+
+uint64_t cpu_to_elf64(const struct mem_ehdr *ehdr, uint64_t value)
+{
+	if (ehdr->ei_data == ELFDATA2LSB) {
+		value = cpu_to_le64(value);
+	}
+	else if (ehdr->ei_data == ELFDATA2MSB) {
+		value = cpu_to_be64(value);
+	}
+	return value;
+}
+
+#define ELF32_MAX 0xffffffff
+#define ELF64_MAX 0xffffffffffffffff
+#if ELF64_MAX > ULONG_MAX
+#undef ELF64_MAX
+#define ELF64_MAX ULONG_MAX
+#endif
+
+unsigned long elf_max_addr(const struct mem_ehdr *ehdr)
+{
+	unsigned long max_addr = 0;
+	if (ehdr->ei_class == ELFCLASS32) {
+		max_addr = ELF32_MAX;
+	}
+	else if (ehdr->ei_class == ELFCLASS64) {
+		max_addr = ELF64_MAX;
+	}
+	return max_addr;
+}
+static int build_mem_elf32_ehdr(const char *buf, off_t len, struct mem_ehdr *ehdr)
+{
+	Elf32_Ehdr lehdr;
+	if ((uintmax_t)len < (uintmax_t)sizeof(lehdr)) {
+		/* Buffer is to small to be an elf executable */
+		if (probe_debug) {
+			fprintf(stderr, "Buffer is to small to hold ELF header\n");
+		}
+		return -1;
+	}
+	memcpy(&lehdr, buf, sizeof(lehdr));
+	if (elf16_to_cpu(ehdr, lehdr.e_ehsize) != sizeof(Elf32_Ehdr)) {
+		/* Invalid Elf header size */
+		if (probe_debug) {
+			fprintf(stderr, "Bad ELF header size\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_entry) > UINT32_MAX) {
+		/* entry is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_entry to large\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_phoff) > UINT32_MAX) {
+		/* phoff is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_phoff to large\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_shoff) > UINT32_MAX) {
+		/* shoff is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_shoff to large\n");
+		}
+		return -1;
+	}
+	ehdr->e_type      = elf16_to_cpu(ehdr, lehdr.e_type);
+	ehdr->e_machine   = elf16_to_cpu(ehdr, lehdr.e_machine);
+	ehdr->e_version   = elf32_to_cpu(ehdr, lehdr.e_version);
+	ehdr->e_entry     = elf32_to_cpu(ehdr, lehdr.e_entry);
+	ehdr->e_phoff     = elf32_to_cpu(ehdr, lehdr.e_phoff);
+	ehdr->e_shoff     = elf32_to_cpu(ehdr, lehdr.e_shoff);
+	ehdr->e_flags     = elf32_to_cpu(ehdr, lehdr.e_flags);
+	ehdr->e_phnum     = elf16_to_cpu(ehdr, lehdr.e_phnum);
+	ehdr->e_shnum     = elf16_to_cpu(ehdr, lehdr.e_shnum);
+	ehdr->e_shstrndx  = elf16_to_cpu(ehdr, lehdr.e_shstrndx);
+
+	if ((ehdr->e_phnum > 0) &&
+		(elf16_to_cpu(ehdr, lehdr.e_phentsize) != sizeof(Elf32_Phdr)))
+	{
+		/* Invalid program header size */
+		if (probe_debug) {
+			fprintf(stderr, "ELF bad program header size\n");
+		}
+		return -1;
+	}
+	if ((ehdr->e_shnum > 0) &&
+		(elf16_to_cpu(ehdr, lehdr.e_shentsize) != sizeof(Elf32_Shdr)))
+	{
+		/* Invalid section header size */
+		if (probe_debug) {
+			fprintf(stderr, "ELF bad section header size\n");
+		}
+		return -1;
+	}
+
+	return 0;
+}
+
+static int build_mem_elf64_ehdr(const char *buf, off_t len, struct mem_ehdr *ehdr)
+{
+	Elf64_Ehdr lehdr;
+	if ((uintmax_t)len < (uintmax_t)sizeof(lehdr)) {
+		/* Buffer is to small to be an elf executable */
+		if (probe_debug) {
+			fprintf(stderr, "Buffer is to small to hold ELF header\n");
+		}
+		return -1;
+	}
+	memcpy(&lehdr, buf, sizeof(lehdr));
+	if (elf16_to_cpu(ehdr, lehdr.e_ehsize) != sizeof(Elf64_Ehdr)) {
+		/* Invalid Elf header size */
+		if (probe_debug) {
+			fprintf(stderr, "Bad ELF header size\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_entry) > UINT32_MAX) {
+		/* entry is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_entry to large\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_phoff) > UINT32_MAX) {
+		/* phoff is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_phoff to large\n");
+		}
+		return -1;
+	}
+	if (elf32_to_cpu(ehdr, lehdr.e_shoff) > UINT32_MAX) {
+		/* shoff is to large */
+		if (probe_debug) {
+			fprintf(stderr, "ELF e_shoff to large\n");
+		}
+		return -1;
+	}
+	ehdr->e_type      = elf16_to_cpu(ehdr, lehdr.e_type);
+	ehdr->e_machine   = elf16_to_cpu(ehdr, lehdr.e_machine);
+	ehdr->e_version   = elf32_to_cpu(ehdr, lehdr.e_version);
+	ehdr->e_entry     = elf64_to_cpu(ehdr, lehdr.e_entry);
+	ehdr->e_phoff     = elf64_to_cpu(ehdr, lehdr.e_phoff);
+	ehdr->e_shoff     = elf64_to_cpu(ehdr, lehdr.e_shoff);
+	ehdr->e_flags     = elf32_to_cpu(ehdr, lehdr.e_flags);
+	ehdr->e_phnum     = elf16_to_cpu(ehdr, lehdr.e_phnum);
+	ehdr->e_shnum     = elf16_to_cpu(ehdr, lehdr.e_shnum);
+	ehdr->e_shstrndx  = elf16_to_cpu(ehdr, lehdr.e_shstrndx);
+
+	if ((ehdr->e_phnum > 0) &&
+		(elf16_to_cpu(ehdr, lehdr.e_phentsize) != sizeof(Elf64_Phdr)))
+	{
+		/* Invalid program header size */
+		if (probe_debug) {
+			fprintf(stderr, "ELF bad program header size\n");
+		}
+		return -1;
+	}
+	if ((ehdr->e_shnum > 0) &&
+		(elf16_to_cpu(ehdr, lehdr.e_shentsize) != sizeof(Elf64_Shdr)))
+	{
+		/* Invalid section header size */
+		if (probe_debug) {
+			fprintf(stderr, "ELF bad section header size\n");
+		}
+		return -1;
+	}
+
+	return 0;
+}
+
+static int build_mem_ehdr(const char *buf, off_t len, struct mem_ehdr *ehdr)
+{
+	unsigned char e_ident[EI_NIDENT];
+	int result;
+	memset(ehdr, 0, sizeof(*ehdr));
+	if ((uintmax_t)len < (uintmax_t)sizeof(e_ident)) {
+		/* Buffer is to small to be an elf executable */
+		if (probe_debug) {
+			fprintf(stderr, "Buffer is to small to hold ELF e_ident\n");
+		}
+		return -1;
+	}
+	memcpy(e_ident, buf, sizeof(e_ident));
+	if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
+		/* No ELF header magic */
+		if (probe_debug) {
+			fprintf(stderr, "NO ELF header magic\n");
+		}
+		return -1;
+	}
+	ehdr->ei_class   = e_ident[EI_CLASS];
+	ehdr->ei_data    = e_ident[EI_DATA];
+	if (	(ehdr->ei_class != ELFCLASS32) &&
+		(ehdr->ei_class != ELFCLASS64))
+	{
+		/* Not a supported elf class */
+		if (probe_debug) {
+			fprintf(stderr, "Not a supported ELF class\n");
+		}
+		return -1;
+	}
+	if (	(ehdr->ei_data != ELFDATA2LSB) &&
+		(ehdr->ei_data != ELFDATA2MSB))
+	{
+		/* Not a supported elf data type */
+		if (probe_debug) {
+			fprintf(stderr, "Not a supported ELF data format\n");
+		}
+		return -1;
+	}
+
+	result = -1;
+	if (ehdr->ei_class == ELFCLASS32) {
+		result = build_mem_elf32_ehdr(buf, len, ehdr);
+	}
+	else if (ehdr->ei_class == ELFCLASS64) {
+		result = build_mem_elf64_ehdr(buf, len, ehdr);
+	}
+	if (result < 0) {
+		return result;
+	}
+	if ((e_ident[EI_VERSION] != EV_CURRENT) ||
+		(ehdr->e_version != EV_CURRENT))
+	{
+		if (probe_debug) {
+			fprintf(stderr, "Unknown ELF version\n");
+		}
+		/* Unknwon elf version */
+		return -1;
+	}
+	return 0;
+}
+
+static int build_mem_elf32_phdr(const char *buf, struct mem_ehdr *ehdr, int idx)
+{
+	struct mem_phdr *phdr;
+	const char *pbuf;
+	Elf32_Phdr lphdr;
+	pbuf = buf + ehdr->e_phoff + (idx * sizeof(lphdr));
+	phdr = &ehdr->e_phdr[idx];
+	memcpy(&lphdr, pbuf, sizeof(lphdr));
+
+	if (	(elf32_to_cpu(ehdr, lphdr.p_filesz) > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lphdr.p_memsz)  > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lphdr.p_offset) > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lphdr.p_paddr)  > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lphdr.p_vaddr)  > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lphdr.p_align)  > UINT32_MAX))
+	{
+		fprintf(stderr, "Program segment size out of range\n");
+		return -1;
+	}
+
+	phdr->p_type   = elf32_to_cpu(ehdr, lphdr.p_type);
+	phdr->p_paddr  = elf32_to_cpu(ehdr, lphdr.p_paddr);
+	phdr->p_vaddr  = elf32_to_cpu(ehdr, lphdr.p_vaddr);
+	phdr->p_filesz = elf32_to_cpu(ehdr, lphdr.p_filesz);
+	phdr->p_memsz  = elf32_to_cpu(ehdr, lphdr.p_memsz);
+	phdr->p_offset = elf32_to_cpu(ehdr, lphdr.p_offset);
+	phdr->p_flags  = elf32_to_cpu(ehdr, lphdr.p_flags);
+	phdr->p_align  = elf32_to_cpu(ehdr, lphdr.p_align);
+
+	return 0;
+}
+
+static int build_mem_elf64_phdr(const char *buf, struct mem_ehdr *ehdr, int idx)
+{
+	struct mem_phdr *phdr;
+	const char *pbuf;
+	Elf64_Phdr lphdr;
+	pbuf = buf + ehdr->e_phoff + (idx * sizeof(lphdr));
+	phdr = &ehdr->e_phdr[idx];
+	memcpy(&lphdr, pbuf, sizeof(lphdr));
+
+	if (	(elf64_to_cpu(ehdr, lphdr.p_filesz) > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lphdr.p_memsz)  > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lphdr.p_offset) > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lphdr.p_paddr)  > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lphdr.p_vaddr)  > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lphdr.p_align)  > UINT64_MAX))
+	{
+		fprintf(stderr, "Program segment size out of range\n");
+		return -1;
+	}
+
+	phdr->p_type   = elf32_to_cpu(ehdr, lphdr.p_type);
+	phdr->p_paddr  = elf64_to_cpu(ehdr, lphdr.p_paddr);
+	phdr->p_vaddr  = elf64_to_cpu(ehdr, lphdr.p_vaddr);
+	phdr->p_filesz = elf64_to_cpu(ehdr, lphdr.p_filesz);
+	phdr->p_memsz  = elf64_to_cpu(ehdr, lphdr.p_memsz);
+	phdr->p_offset = elf64_to_cpu(ehdr, lphdr.p_offset);
+	phdr->p_flags  = elf32_to_cpu(ehdr, lphdr.p_flags);
+	phdr->p_align  = elf64_to_cpu(ehdr, lphdr.p_align);
+
+	return 0;
+}
+
+static int build_mem_phdrs(const char *buf, off_t len, struct mem_ehdr *ehdr,
+				uint32_t flags)
+{
+	size_t phdr_size, mem_phdr_size, i;
+
+	/* e_phnum is at most 65535 so calculating
+	 * the size of the program header cannot overflow.
+	 */
+	/* Is the program header in the file buffer? */
+	phdr_size = 0;
+	if (ehdr->ei_class == ELFCLASS32) {
+		phdr_size = sizeof(Elf32_Phdr);
+	}
+	else if (ehdr->ei_class == ELFCLASS64) {
+		phdr_size = sizeof(Elf64_Phdr);
+	}
+	else {
+		fprintf(stderr, "Invalid ei_class?\n");
+		return -1;
+	}
+	phdr_size *= ehdr->e_phnum;
+	if ((uintmax_t)(ehdr->e_phoff + phdr_size) > (uintmax_t)len) {
+		/* The program header did not fit in the file buffer */
+		if (probe_debug || (flags & ELF_SKIP_FILESZ_CHECK)) {
+			fprintf(stderr, "ELF program headers truncated"
+				" have %ju bytes need %ju bytes\n",
+				(uintmax_t)len,
+				(uintmax_t)(ehdr->e_phoff + phdr_size));
+		}
+		return -1;
+	}
+
+	/* Allocate the e_phdr array */
+	mem_phdr_size = sizeof(ehdr->e_phdr[0]) * ehdr->e_phnum;
+	ehdr->e_phdr = xmalloc(mem_phdr_size);
+
+	for(i = 0; i < ehdr->e_phnum; i++) {
+		struct mem_phdr *phdr;
+		int result;
+		result = -1;
+		if (ehdr->ei_class == ELFCLASS32) {
+			result = build_mem_elf32_phdr(buf, ehdr, i);
+
+		}
+		else if (ehdr->ei_class == ELFCLASS64) {
+			result = build_mem_elf64_phdr(buf, ehdr, i);
+		}
+		if (result < 0) {
+			return result;
+		}
+
+		/* Check the program headers to be certain
+		 * they are safe to use.
+		 * Skip the check if ELF_SKIP_FILESZ_CHECK is set.
+		 */
+		phdr = &ehdr->e_phdr[i];
+		if (!(flags & ELF_SKIP_FILESZ_CHECK)
+			&& (uintmax_t)(phdr->p_offset + phdr->p_filesz) >
+			   (uintmax_t)len) {
+			/* The segment does not fit in the buffer */
+			if (probe_debug) {
+				fprintf(stderr, "ELF segment not in file\n");
+			}
+			return -1;
+		}
+		if (phdr->p_paddr != (unsigned long long)-1 &&
+			(phdr->p_paddr + phdr->p_memsz) < phdr->p_paddr) {
+			/* The memory address wraps */
+			if (probe_debug) {
+				fprintf(stderr, "ELF address wrap around\n");
+			}
+			return -1;
+		}
+		/* Remember where the segment lives in the buffer */
+		phdr->p_data = buf + phdr->p_offset;
+	}
+	return 0;
+}
+
+static int build_mem_elf32_shdr(const char *buf, struct mem_ehdr *ehdr, int idx)
+{
+	struct mem_shdr *shdr;
+	const char *sbuf;
+	int size_ok;
+	Elf32_Shdr lshdr;
+	sbuf = buf + ehdr->e_shoff + (idx * sizeof(lshdr));
+	shdr = &ehdr->e_shdr[idx];
+	memcpy(&lshdr, sbuf, sizeof(lshdr));
+
+	if (	(elf32_to_cpu(ehdr, lshdr.sh_flags)     > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lshdr.sh_addr)      > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lshdr.sh_offset)    > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lshdr.sh_size)      > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lshdr.sh_addralign) > UINT32_MAX) ||
+		(elf32_to_cpu(ehdr, lshdr.sh_entsize)   > UINT32_MAX))
+	{
+		fprintf(stderr, "Program section size out of range\n");
+		return -1;
+	}
+
+	shdr->sh_name      = elf32_to_cpu(ehdr, lshdr.sh_name);
+	shdr->sh_type      = elf32_to_cpu(ehdr, lshdr.sh_type);
+	shdr->sh_flags     = elf32_to_cpu(ehdr, lshdr.sh_flags);
+	shdr->sh_addr      = elf32_to_cpu(ehdr, lshdr.sh_addr);
+	shdr->sh_offset    = elf32_to_cpu(ehdr, lshdr.sh_offset);
+	shdr->sh_size      = elf32_to_cpu(ehdr, lshdr.sh_size);
+	shdr->sh_link      = elf32_to_cpu(ehdr, lshdr.sh_link);
+	shdr->sh_info      = elf32_to_cpu(ehdr, lshdr.sh_info);
+	shdr->sh_addralign = elf32_to_cpu(ehdr, lshdr.sh_addralign);
+	shdr->sh_entsize   = elf32_to_cpu(ehdr, lshdr.sh_entsize);
+
+	/* Now verify sh_entsize */
+	size_ok = 0;
+	switch(shdr->sh_type) {
+	case SHT_SYMTAB:
+		size_ok = shdr->sh_entsize == sizeof(Elf32_Sym);
+		break;
+	case SHT_RELA:
+		size_ok = shdr->sh_entsize == sizeof(Elf32_Rela);
+		break;
+	case SHT_DYNAMIC:
+		size_ok = shdr->sh_entsize == sizeof(Elf32_Dyn);
+		break;
+	case SHT_REL:
+		size_ok = shdr->sh_entsize == sizeof(Elf32_Rel);
+		break;
+	case SHT_NOTE:
+	case SHT_NULL:
+	case SHT_PROGBITS:
+	case SHT_HASH:
+	case SHT_NOBITS:
+	default:
+		/* This is a section whose entsize requirements
+		 * I don't care about.  If I don't know about
+		 * the section I can't care about it's entsize
+		 * requirements.
+		 */
+		size_ok = 1;
+		break;
+	}
+	if (!size_ok) {
+		fprintf(stderr, "Bad section header(%x) entsize: %lld\n",
+			shdr->sh_type, shdr->sh_entsize);
+		return -1;
+	}
+	return 0;
+}
+
+static int build_mem_elf64_shdr(const char *buf, struct mem_ehdr *ehdr, int idx)
+{
+	struct mem_shdr *shdr;
+	const char *sbuf;
+	int size_ok;
+	Elf64_Shdr lshdr;
+	sbuf = buf + ehdr->e_shoff + (idx * sizeof(lshdr));
+	shdr = &ehdr->e_shdr[idx];
+	memcpy(&lshdr, sbuf, sizeof(lshdr));
+
+	if (	(elf64_to_cpu(ehdr, lshdr.sh_flags)     > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lshdr.sh_addr)      > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lshdr.sh_offset)    > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lshdr.sh_size)      > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lshdr.sh_addralign) > UINT64_MAX) ||
+		(elf64_to_cpu(ehdr, lshdr.sh_entsize)   > UINT64_MAX))
+	{
+		fprintf(stderr, "Program section size out of range\n");
+		return -1;
+	}
+
+	shdr->sh_name      = elf32_to_cpu(ehdr, lshdr.sh_name);
+	shdr->sh_type      = elf32_to_cpu(ehdr, lshdr.sh_type);
+	shdr->sh_flags     = elf64_to_cpu(ehdr, lshdr.sh_flags);
+	shdr->sh_addr      = elf64_to_cpu(ehdr, lshdr.sh_addr);
+	shdr->sh_offset    = elf64_to_cpu(ehdr, lshdr.sh_offset);
+	shdr->sh_size      = elf64_to_cpu(ehdr, lshdr.sh_size);
+	shdr->sh_link      = elf32_to_cpu(ehdr, lshdr.sh_link);
+	shdr->sh_info      = elf32_to_cpu(ehdr, lshdr.sh_info);
+	shdr->sh_addralign = elf64_to_cpu(ehdr, lshdr.sh_addralign);
+	shdr->sh_entsize   = elf64_to_cpu(ehdr, lshdr.sh_entsize);
+
+	/* Now verify sh_entsize */
+	size_ok = 0;
+	switch(shdr->sh_type) {
+	case SHT_SYMTAB:
+		size_ok = shdr->sh_entsize == sizeof(Elf64_Sym);
+		break;
+	case SHT_RELA:
+		size_ok = shdr->sh_entsize == sizeof(Elf64_Rela);
+		break;
+	case SHT_DYNAMIC:
+		size_ok = shdr->sh_entsize == sizeof(Elf64_Dyn);
+		break;
+	case SHT_REL:
+		size_ok = shdr->sh_entsize == sizeof(Elf64_Rel);
+		break;
+	case SHT_NOTE:
+	case SHT_NULL:
+	case SHT_PROGBITS:
+	case SHT_HASH:
+	case SHT_NOBITS:
+	default:
+		/* This is a section whose entsize requirements
+		 * I don't care about.  If I don't know about
+		 * the section I can't care about it's entsize
+		 * requirements.
+		 */
+		size_ok = 1;
+		break;
+	}
+	if (!size_ok) {
+		fprintf(stderr, "Bad section header(%x) entsize: %lld\n",
+			shdr->sh_type, shdr->sh_entsize);
+		return -1;
+	}
+	return 0;
+}
+
+static int build_mem_shdrs(const char *buf, off_t len, struct mem_ehdr *ehdr,
+				uint32_t flags)
+{
+	size_t shdr_size, mem_shdr_size, i;
+
+	/* e_shnum is at most 65536 so calculating
+	 * the size of the section header cannot overflow.
+	 */
+	/* Is the program header in the file buffer? */
+	shdr_size = 0;
+	if (ehdr->ei_class == ELFCLASS32) {
+		shdr_size = sizeof(Elf32_Shdr);
+	}
+	else if (ehdr->ei_class == ELFCLASS64) {
+		shdr_size = sizeof(Elf64_Shdr);
+	}
+	else {
+		fprintf(stderr, "Invalid ei_class?\n");
+		return -1;
+	}
+	shdr_size *= ehdr->e_shnum;
+	if ((uintmax_t)(ehdr->e_shoff + shdr_size) > (uintmax_t)len) {
+		/* The section header did not fit in the file buffer */
+		if (probe_debug) {
+			fprintf(stderr, "ELF section header does not fit in file\n");
+		}
+		return -1;
+	}
+
+	/* Allocate the e_shdr array */
+	mem_shdr_size = sizeof(ehdr->e_shdr[0]) * ehdr->e_shnum;
+	ehdr->e_shdr = xmalloc(mem_shdr_size);
+
+	for(i = 0; i < ehdr->e_shnum; i++) {
+		struct mem_shdr *shdr;
+		int result;
+		result = -1;
+		if (ehdr->ei_class == ELFCLASS32) {
+			result = build_mem_elf32_shdr(buf, ehdr, i);
+		}
+		else if (ehdr->ei_class == ELFCLASS64) {
+			result = build_mem_elf64_shdr(buf, ehdr, i);
+		}
+		if (result < 0) {
+			return result;
+		}
+		/* Check the section headers to be certain
+		 * they are safe to use.
+		 * Skip the check if ELF_SKIP_FILESZ_CHECK is set.
+		 */
+		shdr = &ehdr->e_shdr[i];
+		if (!(flags & ELF_SKIP_FILESZ_CHECK)
+			&& (shdr->sh_type != SHT_NOBITS)
+			&& (uintmax_t)(shdr->sh_offset + shdr->sh_size) >
+			   (uintmax_t)len) {
+			/* The section does not fit in the buffer */
+			if (probe_debug) {
+				fprintf(stderr, "ELF section %zd not in file\n",
+					i);
+			}
+			return -1;
+		}
+		if ((shdr->sh_addr + shdr->sh_size) < shdr->sh_addr) {
+			/* The memory address wraps */
+			if (probe_debug) {
+				fprintf(stderr, "ELF address wrap around\n");
+			}
+			return -1;
+		}
+		/* Remember where the section lives in the buffer */
+		shdr->sh_data = (unsigned char *)(buf + shdr->sh_offset);
+	}
+	return 0;
+}
+
+static void read_nhdr(const struct mem_ehdr *ehdr,
+	ElfNN_Nhdr *hdr, const unsigned char *note)
+{
+	memcpy(hdr, note, sizeof(*hdr));
+	hdr->n_namesz = elf32_to_cpu(ehdr, hdr->n_namesz);
+	hdr->n_descsz = elf32_to_cpu(ehdr, hdr->n_descsz);
+	hdr->n_type   = elf32_to_cpu(ehdr, hdr->n_type);
+
+}
+static int build_mem_notes(struct mem_ehdr *ehdr)
+{
+	const unsigned char *note_start, *note_end, *note;
+	size_t note_size, i;
+	/* First find the note segment or section */
+	note_start = note_end = NULL;
+	for(i = 0; !note_start && (i < ehdr->e_phnum); i++) {
+		struct mem_phdr *phdr = &ehdr->e_phdr[i];
+		/*
+		 * binutils <= 2.17 has a bug where it can create the
+		 * PT_NOTE segment with an offset of 0. Therefore
+		 * check p_offset > 0.
+		 *
+		 * See: http://sourceware.org/bugzilla/show_bug.cgi?id=594
+		 */
+		if (phdr->p_type == PT_NOTE && phdr->p_offset) {
+			note_start = (unsigned char *)phdr->p_data;
+			note_end = note_start + phdr->p_filesz;
+		}
+	}
+	for(i = 0; !note_start && (i < ehdr->e_shnum); i++) {
+		struct mem_shdr *shdr = &ehdr->e_shdr[i];
+		if (shdr->sh_type == SHT_NOTE) {
+			note_start = shdr->sh_data;
+			note_end = note_start + shdr->sh_size;
+		}
+	}
+	if (!note_start) {
+		return 0;
+	}
+
+	/* Walk through and count the notes */
+	ehdr->e_notenum = 0;
+	for(note = note_start; note < note_end; note+= note_size) {
+		ElfNN_Nhdr hdr;
+		read_nhdr(ehdr, &hdr, note);
+		note_size  = sizeof(hdr);
+		note_size += _ALIGN(hdr.n_namesz, 4);
+		note_size += _ALIGN(hdr.n_descsz, 4);
+		ehdr->e_notenum += 1;
+	}
+	/* Now walk and normalize the notes */
+	ehdr->e_note = xmalloc(sizeof(*ehdr->e_note) * ehdr->e_notenum);
+	for(i = 0, note = note_start; note < note_end; note+= note_size, i++) {
+		const unsigned char *name, *desc;
+		ElfNN_Nhdr hdr;
+		read_nhdr(ehdr, &hdr, note);
+		note_size  = sizeof(hdr);
+		name       = note + note_size;
+		note_size += _ALIGN(hdr.n_namesz, 4);
+		desc       = note + note_size;
+		note_size += _ALIGN(hdr.n_descsz, 4);
+
+		if (((note+note_size) > note_end) ||
+		    ((note+note_size) < note_start)) {
+			/* Something is very wrong here ! Most likely the note
+			 * header is invalid */
+			fprintf(stderr, "ELF Note corrupted !\n");
+			return -1;
+		}
+
+		if ((hdr.n_namesz != 0) && (name[hdr.n_namesz -1] != '\0')) {
+			/* If note name string is not null terminated, just
+			 * warn user about it and continue processing. This
+			 * allows us to parse /proc/kcore on older kernels
+			 * where /proc/kcore elf notes were not null
+			 * terminated. It has been fixed in 2.6.19.
+			 */
+			fprintf(stderr, "Warning: Elf Note name is not null "
+					"terminated\n");
+		}
+		ehdr->e_note[i].n_type = hdr.n_type;
+		ehdr->e_note[i].n_name = (char *)name;
+		ehdr->e_note[i].n_desc = desc;
+		ehdr->e_note[i].n_descsz = hdr.n_descsz;
+
+	}
+	return 0;
+}
+
+void free_elf_info(struct mem_ehdr *ehdr)
+{
+	free(ehdr->e_phdr);
+	free(ehdr->e_shdr);
+	memset(ehdr, 0, sizeof(*ehdr));
+}
+
+int build_elf_info(const char *buf, off_t len, struct mem_ehdr *ehdr,
+			uint32_t flags)
+{
+	int result;
+	result = build_mem_ehdr(buf, len, ehdr);
+	if (result < 0) {
+		return result;
+	}
+	if ((ehdr->e_phoff > 0) && (ehdr->e_phnum > 0)) {
+		result = build_mem_phdrs(buf, len, ehdr, flags);
+		if (result < 0) {
+			free_elf_info(ehdr);
+			return result;
+		}
+	}
+	if ((ehdr->e_shoff > 0) && (ehdr->e_shnum > 0)) {
+		result = build_mem_shdrs(buf, len, ehdr, flags);
+		if (result < 0) {
+			free_elf_info(ehdr);
+			return result;
+		}
+	}
+	result = build_mem_notes(ehdr);
+	if (result < 0) {
+		free_elf_info(ehdr);
+		return result;
+	}
+	return 0;
+}
+