kexec_elf: remove parsing of section headers

We're not using them, so we can drop the parsing.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>

2 files changed, 0 insertions, 138 deletions

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index da2a6b1d69e7..f0b809258ed3 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -226,7 +226,6 @@ struct kexec_elf_info {
 
         const struct elfhdr *ehdr;
         const struct elf_phdr *proghdrs;
-        struct elf_shdr *sechdrs;
 };
 
 int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
diff --git a/kernel/kexec_elf.c b/kernel/kexec_elf.c
index 34376fbc55be..137037603117 100644
--- a/kernel/kexec_elf.c
+++ b/kernel/kexec_elf.c
@@ -258,134 +258,6 @@ static int elf_read_phdrs(const char *buf, size_t len,
 }
 
 /**
- * elf_is_shdr_sane - check that it is safe to use the section header
- * @buf_len:    size of the buffer in which the ELF file is loaded.
- */
-static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len)
-{
-        bool size_ok;
-
-        /* SHT_NULL headers have undefined values, so we can't check them. */
-        if (shdr->sh_type == SHT_NULL)
-                return true;
-
-        /* Now verify sh_entsize */
-        switch (shdr->sh_type) {
-        case SHT_SYMTAB:
-                size_ok = shdr->sh_entsize == sizeof(Elf_Sym);
-                break;
-        case SHT_RELA:
-                size_ok = shdr->sh_entsize == sizeof(Elf_Rela);
-                break;
-        case SHT_DYNAMIC:
-                size_ok = shdr->sh_entsize == sizeof(Elf_Dyn);
-                break;
-        case SHT_REL:
-                size_ok = shdr->sh_entsize == sizeof(Elf_Rel);
-                break;
-        case SHT_NOTE:
-        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 = true;
-                break;
-        }
-
-        if (!size_ok) {
-                pr_debug("ELF section with wrong entry size.\n");
-                return false;
-        } else if (shdr->sh_addr + shdr->sh_size < shdr->sh_addr) {
-                pr_debug("ELF section address wraps around.\n");
-                return false;
-        }
-
-        if (shdr->sh_type != SHT_NOBITS) {
-                if (shdr->sh_offset + shdr->sh_size < shdr->sh_offset) {
-                        pr_debug("ELF section location wraps around.\n");
-                        return false;
-                } else if (shdr->sh_offset + shdr->sh_size > buf_len) {
-                        pr_debug("ELF section not in file.\n");
-                        return false;
-                }
-        }
-
-        return true;
-}
-
-static int elf_read_shdr(const char *buf, size_t len,
-                         struct kexec_elf_info *elf_info,
-                         int idx)
-{
-        struct elf_shdr *shdr = &elf_info->sechdrs[idx];
-        const struct elfhdr *ehdr = elf_info->ehdr;
-        const char *sbuf;
-        struct elf_shdr *buf_shdr;
-
-        sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr);
-        buf_shdr = (struct elf_shdr *) sbuf;
-
-        shdr->sh_name      = elf32_to_cpu(ehdr, buf_shdr->sh_name);
-        shdr->sh_type      = elf32_to_cpu(ehdr, buf_shdr->sh_type);
-        shdr->sh_addr      = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr);
-        shdr->sh_offset    = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset);
-        shdr->sh_link      = elf32_to_cpu(ehdr, buf_shdr->sh_link);
-        shdr->sh_info      = elf32_to_cpu(ehdr, buf_shdr->sh_info);
-
-        /*
-         * The following fields have a type equivalent to Elf_Addr
-         * both in 32 bit and 64 bit ELF.
-         */
-        shdr->sh_flags     = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags);
-        shdr->sh_size      = elf_addr_to_cpu(ehdr, buf_shdr->sh_size);
-        shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign);
-        shdr->sh_entsize   = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize);
-
-        return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC;
-}
-
-/**
- * elf_read_shdrs - read the section headers from the buffer
- *
- * This function assumes that the section header table was checked for sanity.
- * Use elf_is_ehdr_sane() if it wasn't.
- */
-static int elf_read_shdrs(const char *buf, size_t len,
-                          struct kexec_elf_info *elf_info)
-{
-        size_t shdr_size, i;
-
-        /*
-         * e_shnum is at most 65536 so calculating
-         * the size of the section header cannot overflow.
-         */
-        shdr_size = sizeof(struct elf_shdr) * elf_info->ehdr->e_shnum;
-
-        elf_info->sechdrs = kzalloc(shdr_size, GFP_KERNEL);
-        if (!elf_info->sechdrs)
-                return -ENOMEM;
-
-        for (i = 0; i < elf_info->ehdr->e_shnum; i++) {
-                int ret;
-
-                ret = elf_read_shdr(buf, len, elf_info, i);
-                if (ret) {
-                        kfree(elf_info->sechdrs);
-                        elf_info->sechdrs = NULL;
-                        return ret;
-                }
-        }
-
-        return 0;
-}
-
-/**
  * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info
  * @buf:        Buffer to read ELF file from.
  * @len:        Size of @buf.
@@ -417,14 +289,6 @@ static int elf_read_from_buffer(const char *buf, size_t len,
                 if (ret)
                         return ret;
         }
-        if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
-                ret = elf_read_shdrs(buf, len, elf_info);
-                if (ret) {
-                        kfree(elf_info->proghdrs);
-                        return ret;
-                }
-        }
-
         return 0;
 }
 
@@ -434,7 +298,6 @@ static int elf_read_from_buffer(const char *buf, size_t len,
 void kexec_free_elf_info(struct kexec_elf_info *elf_info)
 {
         kfree(elf_info->proghdrs);
-        kfree(elf_info->sechdrs);
         memset(elf_info, 0, sizeof(*elf_info));
 }
 /**