3 files changed, 71 insertions, 61 deletions

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index c51d2cf27d93..63dea30c8e02 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -382,52 +382,36 @@ void *arch_kexec_kernel_image_load(struct kimage *image)
 /*
  * Apply purgatory relocations.
  *
- * ehdr: Pointer to elf headers
- * sechdrs: Pointer to section headers.
- * relsec: section index of SHT_RELA section.
+ * @pi:         Purgatory to be relocated.
+ * @section:    Section relocations applying to.
+ * @relsec:     Section containing RELAs.
+ * @symtabsec:  Corresponding symtab.
  *
  * TODO: Some of the code belongs to generic code. Move that in kexec.c.
  */
-int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
-                                     Elf64_Shdr *sechdrs, unsigned int relsec)
+int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+                                     Elf_Shdr *section, const Elf_Shdr *relsec,
+                                     const Elf_Shdr *symtabsec)
 {
         unsigned int i;
         Elf64_Rela *rel;
         Elf64_Sym *sym;
         void *location;
-        Elf64_Shdr *section, *symtabsec;
         unsigned long address, sec_base, value;
         const char *strtab, *name, *shstrtab;
+        const Elf_Shdr *sechdrs;
 
-        /*
-         * ->sh_offset has been modified to keep the pointer to section
-         * contents in memory
-         */
-        rel = (void *)sechdrs[relsec].sh_offset;
-
-        /* Section to which relocations apply */
-        section = &sechdrs[sechdrs[relsec].sh_info];
-
-        pr_debug("Applying relocate section %u to %u\n", relsec,
-                 sechdrs[relsec].sh_info);
-
-        /* Associated symbol table */
-        symtabsec = &sechdrs[sechdrs[relsec].sh_link];
-
-        /* String table */
-        if (symtabsec->sh_link >= ehdr->e_shnum) {
-                /* Invalid strtab section number */
-                pr_err("Invalid string table section index %d\n",
-                       symtabsec->sh_link);
-                return -ENOEXEC;
-        }
+        /* String & section header string table */
+        sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
+        strtab = (char *)pi->ehdr + sechdrs[symtabsec->sh_link].sh_offset;
+        shstrtab = (char *)pi->ehdr + sechdrs[pi->ehdr->e_shstrndx].sh_offset;
 
-        strtab = (char *)sechdrs[symtabsec->sh_link].sh_offset;
+        rel = (void *)pi->ehdr + relsec->sh_offset;
 
-        /* section header string table */
-        shstrtab = (char *)sechdrs[ehdr->e_shstrndx].sh_offset;
+        pr_debug("Applying relocate section %s to %u\n",
+                 shstrtab + relsec->sh_name, relsec->sh_info);
 
-        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+        for (i = 0; i < relsec->sh_size / sizeof(*rel); i++) {
 
                 /*
                  * rel[i].r_offset contains byte offset from beginning
@@ -450,8 +434,8 @@ int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
                  * to apply. ELF64_R_SYM() and ELF64_R_TYPE() macros get
                  * these respectively.
                  */
-                sym = (Elf64_Sym *)symtabsec->sh_offset +
-                                ELF64_R_SYM(rel[i].r_info);
+                sym = (void *)pi->ehdr + symtabsec->sh_offset;
+                sym += ELF64_R_SYM(rel[i].r_info);
 
                 if (sym->st_name)
                         name = strtab + sym->st_name;
@@ -474,12 +458,12 @@ int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
 
                 if (sym->st_shndx == SHN_ABS)
                         sec_base = 0;
-                else if (sym->st_shndx >= ehdr->e_shnum) {
+                else if (sym->st_shndx >= pi->ehdr->e_shnum) {
                         pr_err("Invalid section %d for symbol %s\n",
                                sym->st_shndx, name);
                         return -ENOEXEC;
                 } else
-                        sec_base = sechdrs[sym->st_shndx].sh_addr;
+                        sec_base = pi->sechdrs[sym->st_shndx].sh_addr;
 
                 value = sym->st_value;
                 value += sec_base;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 8c5819d1a808..0e389b9b7722 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -171,6 +171,15 @@ struct kexec_buf {
         bool top_down;
 };
 
+int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+                                            Elf_Shdr *section,
+                                            const Elf_Shdr *relsec,
+                                            const Elf_Shdr *symtab);
+int __weak arch_kexec_apply_relocations(struct purgatory_info *pi,
+                                        Elf_Shdr *section,
+                                        const Elf_Shdr *relsec,
+                                        const Elf_Shdr *symtab);
+
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
                                int (*func)(struct resource *, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
@@ -304,10 +313,6 @@ int crash_shrink_memory(unsigned long new_size);
 size_t crash_get_memory_size(void);
 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 
-int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
-                                        Elf_Shdr *sechdrs, unsigned int relsec);
-int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
-                                        unsigned int relsec);
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 9bd1ec1dd875..5c70f7f2bae3 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -110,19 +110,35 @@ int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 }
 #endif
 
-/* Apply relocations of type RELA */
+/*
+ * arch_kexec_apply_relocations_add - apply relocations of type RELA
+ * @pi:         Purgatory to be relocated.
+ * @section:    Section relocations applying to.
+ * @relsec:     Section containing RELAs.
+ * @symtab:     Corresponding symtab.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
 int __weak
-arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
-                                 unsigned int relsec)
+arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
+                                 const Elf_Shdr *relsec, const Elf_Shdr *symtab)
 {
         pr_err("RELA relocation unsupported.\n");
         return -ENOEXEC;
 }
 
-/* Apply relocations of type REL */
+/*
+ * arch_kexec_apply_relocations - apply relocations of type REL
+ * @pi:         Purgatory to be relocated.
+ * @section:    Section relocations applying to.
+ * @relsec:     Section containing RELs.
+ * @symtab:     Corresponding symtab.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
 int __weak
-arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
-                             unsigned int relsec)
+arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
+                             const Elf_Shdr *relsec, const Elf_Shdr *symtab)
 {
         pr_err("REL relocation unsupported.\n");
         return -ENOEXEC;
@@ -879,14 +895,19 @@ static int kexec_apply_relocations(struct kimage *image)
 {
         int i, ret;
         struct purgatory_info *pi = &image->purgatory_info;
-        Elf_Shdr *sechdrs = pi->sechdrs;
+        const Elf_Shdr *sechdrs;
+
+        sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
 
-        /* Apply relocations */
         for (i = 0; i < pi->ehdr->e_shnum; i++) {
-                Elf_Shdr *section, *symtab;
+                const Elf_Shdr *relsec;
+                const Elf_Shdr *symtab;
+                Elf_Shdr *section;
+
+                relsec = sechdrs + i;
 
-                if (sechdrs[i].sh_type != SHT_RELA &&
-                    sechdrs[i].sh_type != SHT_REL)
+                if (relsec->sh_type != SHT_RELA &&
+                    relsec->sh_type != SHT_REL)
                         continue;
 
                 /*
@@ -895,12 +916,12 @@ static int kexec_apply_relocations(struct kimage *image)
                  * symbol table. And ->sh_info contains section header
                  * index of section to which relocations apply.
                  */
-                if (sechdrs[i].sh_info >= pi->ehdr->e_shnum ||
-                    sechdrs[i].sh_link >= pi->ehdr->e_shnum)
+                if (relsec->sh_info >= pi->ehdr->e_shnum ||
+                    relsec->sh_link >= pi->ehdr->e_shnum)
                         return -ENOEXEC;
 
-                section = &sechdrs[sechdrs[i].sh_info];
-                symtab = &sechdrs[sechdrs[i].sh_link];
+                section = pi->sechdrs + relsec->sh_info;
+                symtab = sechdrs + relsec->sh_link;
 
                 if (!(section->sh_flags & SHF_ALLOC))
                         continue;
@@ -917,12 +938,12 @@ static int kexec_apply_relocations(struct kimage *image)
                  * Respective architecture needs to provide support for applying
                  * relocations of type SHT_RELA/SHT_REL.
                  */
-                if (sechdrs[i].sh_type == SHT_RELA)
-                        ret = arch_kexec_apply_relocations_add(pi->ehdr,
-                                                               sechdrs, i);
-                else if (sechdrs[i].sh_type == SHT_REL)
-                        ret = arch_kexec_apply_relocations(pi->ehdr,
-                                                           sechdrs, i);
+                if (relsec->sh_type == SHT_RELA)
+                        ret = arch_kexec_apply_relocations_add(pi, section,
+                                                               relsec, symtab);
+                else if (relsec->sh_type == SHT_REL)
+                        ret = arch_kexec_apply_relocations(pi, section,
+                                                           relsec, symtab);
                 if (ret)
                         return ret;
         }