From eba0cfa6b0bef4f2e73c8630a7efa3944df8b0f8 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 04:56:35 +0200 Subject: Adding upstream version 1:2.0.27. Signed-off-by: Daniel Baumann --- kexec/kexec-elf.c | 787 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 787 insertions(+) create mode 100644 kexec/kexec-elf.c (limited to 'kexec/kexec-elf.c') 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 +#include +#include +#include +#include +#include +#include "elf.h" +#include +#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; +} + -- cgit v1.2.3