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-rw-r--r--kexec/kexec-elf.c787
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;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 16:43:20 +0000