From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
This 'relocs' tool is copied from the x86 version, ported for s390, and
greatly simplified to remove unnecessary features.
It reads vmlinux and outputs assembly to create a .vmlinux.relocs_64
section which contains the offsets of all R_390_64 relocations which
apply to allocatable sections.
Acked-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/s390/tools/.gitignore | 1 +
arch/s390/tools/Makefile | 5 +
arch/s390/tools/relocs.c | 390 +++++++++++++++++++++++++++++++++++++
3 files changed, 396 insertions(+)
create mode 100644 arch/s390/tools/relocs.c
diff --git a/arch/s390/tools/.gitignore b/arch/s390/tools/.gitignore
index ea62f37b79ef..e6af51d9d183 100644
--- a/arch/s390/tools/.gitignore
+++ b/arch/s390/tools/.gitignore
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
gen_facilities
gen_opcode_table
+relocs
diff --git a/arch/s390/tools/Makefile b/arch/s390/tools/Makefile
index f9dd47ff9ac4..f2862364fb42 100644
--- a/arch/s390/tools/Makefile
+++ b/arch/s390/tools/Makefile
@@ -25,3 +25,8 @@ $(kapi)/facility-defs.h: $(obj)/gen_facilities FORCE
$(kapi)/dis-defs.h: $(obj)/gen_opcode_table FORCE
$(call filechk,dis-defs.h)
+
+hostprogs += relocs
+PHONY += relocs
+relocs: $(obj)/relocs
+ @:
diff --git a/arch/s390/tools/relocs.c b/arch/s390/tools/relocs.c
new file mode 100644
index 000000000000..d3ae25e3c3a4
--- /dev/null
+++ b/arch/s390/tools/relocs.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <elf.h>
+#include <byteswap.h>
+#define USE_BSD
+#include <endian.h>
+
+#define ELF_BITS 64
+
+#define ELF_MACHINE EM_S390
+#define ELF_MACHINE_NAME "IBM S/390"
+#define SHT_REL_TYPE SHT_RELA
+#define Elf_Rel Elf64_Rela
+
+#define ELF_CLASS ELFCLASS64
+#define ELF_ENDIAN ELFDATA2MSB
+#define ELF_R_SYM(val) ELF64_R_SYM(val)
+#define ELF_R_TYPE(val) ELF64_R_TYPE(val)
+#define ELF_ST_TYPE(o) ELF64_ST_TYPE(o)
+#define ELF_ST_BIND(o) ELF64_ST_BIND(o)
+#define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o)
+
+#define ElfW(type) _ElfW(ELF_BITS, type)
+#define _ElfW(bits, type) __ElfW(bits, type)
+#define __ElfW(bits, type) Elf##bits##_##type
+
+#define Elf_Addr ElfW(Addr)
+#define Elf_Ehdr ElfW(Ehdr)
+#define Elf_Phdr ElfW(Phdr)
+#define Elf_Shdr ElfW(Shdr)
+#define Elf_Sym ElfW(Sym)
+
+static Elf_Ehdr ehdr;
+static unsigned long shnum;
+static unsigned int shstrndx;
+
+struct relocs {
+ uint32_t *offset;
+ unsigned long count;
+ unsigned long size;
+};
+
+static struct relocs relocs64;
+#define FMT PRIu64
+
+struct section {
+ Elf_Shdr shdr;
+ struct section *link;
+ Elf_Rel *reltab;
+};
+static struct section *secs;
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define le16_to_cpu(val) (val)
+#define le32_to_cpu(val) (val)
+#define le64_to_cpu(val) (val)
+#define be16_to_cpu(val) bswap_16(val)
+#define be32_to_cpu(val) bswap_32(val)
+#define be64_to_cpu(val) bswap_64(val)
+#endif
+
+#if BYTE_ORDER == BIG_ENDIAN
+#define le16_to_cpu(val) bswap_16(val)
+#define le32_to_cpu(val) bswap_32(val)
+#define le64_to_cpu(val) bswap_64(val)
+#define be16_to_cpu(val) (val)
+#define be32_to_cpu(val) (val)
+#define be64_to_cpu(val) (val)
+#endif
+
+static uint16_t elf16_to_cpu(uint16_t val)
+{
+ if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+ return le16_to_cpu(val);
+ else
+ return be16_to_cpu(val);
+}
+
+static uint32_t elf32_to_cpu(uint32_t val)
+{
+ if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+ return le32_to_cpu(val);
+ else
+ return be32_to_cpu(val);
+}
+
+#define elf_half_to_cpu(x) elf16_to_cpu(x)
+#define elf_word_to_cpu(x) elf32_to_cpu(x)
+
+#if ELF_BITS == 64
+static uint64_t elf64_to_cpu(uint64_t val)
+{
+ return be64_to_cpu(val);
+}
+#define elf_addr_to_cpu(x) elf64_to_cpu(x)
+#define elf_off_to_cpu(x) elf64_to_cpu(x)
+#define elf_xword_to_cpu(x) elf64_to_cpu(x)
+#else
+#define elf_addr_to_cpu(x) elf32_to_cpu(x)
+#define elf_off_to_cpu(x) elf32_to_cpu(x)
+#define elf_xword_to_cpu(x) elf32_to_cpu(x)
+#endif
+
+static void die(char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ exit(1);
+}
+
+static void read_ehdr(FILE *fp)
+{
+ if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
+ die("Cannot read ELF header: %s\n",
+ strerror(errno));
+ }
+ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0)
+ die("No ELF magic\n");
+ if (ehdr.e_ident[EI_CLASS] != ELF_CLASS)
+ die("Not a %d bit executable\n", ELF_BITS);
+ if (ehdr.e_ident[EI_DATA] != ELF_ENDIAN)
+ die("ELF endian mismatch\n");
+ if (ehdr.e_ident[EI_VERSION] != EV_CURRENT)
+ die("Unknown ELF version\n");
+
+ /* Convert the fields to native endian */
+ ehdr.e_type = elf_half_to_cpu(ehdr.e_type);
+ ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine);
+ ehdr.e_version = elf_word_to_cpu(ehdr.e_version);
+ ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry);
+ ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff);
+ ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff);
+ ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags);
+ ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize);
+ ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize);
+ ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum);
+ ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize);
+ ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
+ ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx);
+
+ shnum = ehdr.e_shnum;
+ shstrndx = ehdr.e_shstrndx;
+
+ if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN))
+ die("Unsupported ELF header type\n");
+ if (ehdr.e_machine != ELF_MACHINE)
+ die("Not for %s\n", ELF_MACHINE_NAME);
+ if (ehdr.e_version != EV_CURRENT)
+ die("Unknown ELF version\n");
+ if (ehdr.e_ehsize != sizeof(Elf_Ehdr))
+ die("Bad Elf header size\n");
+ if (ehdr.e_phentsize != sizeof(Elf_Phdr))
+ die("Bad program header entry\n");
+ if (ehdr.e_shentsize != sizeof(Elf_Shdr))
+ die("Bad section header entry\n");
+
+ if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) {
+ Elf_Shdr shdr;
+
+ if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0)
+ die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno));
+
+ if (fread(&shdr, sizeof(shdr), 1, fp) != 1)
+ die("Cannot read initial ELF section header: %s\n", strerror(errno));
+
+ if (shnum == SHN_UNDEF)
+ shnum = elf_xword_to_cpu(shdr.sh_size);
+
+ if (shstrndx == SHN_XINDEX)
+ shstrndx = elf_word_to_cpu(shdr.sh_link);
+ }
+
+ if (shstrndx >= shnum)
+ die("String table index out of bounds\n");
+}
+
+static void read_shdrs(FILE *fp)
+{
+ int i;
+ Elf_Shdr shdr;
+
+ secs = calloc(shnum, sizeof(struct section));
+ if (!secs)
+ die("Unable to allocate %ld section headers\n", shnum);
+
+ if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0)
+ die("Seek to %" FMT " failed: %s\n", ehdr.e_shoff, strerror(errno));
+
+ for (i = 0; i < shnum; i++) {
+ struct section *sec = &secs[i];
+
+ if (fread(&shdr, sizeof(shdr), 1, fp) != 1)
+ die("Cannot read ELF section headers %d/%ld: %s\n",
+ i, shnum, strerror(errno));
+
+ sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
+ sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
+ sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
+ sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr);
+ sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset);
+ sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size);
+ sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link);
+ sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
+ sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
+ sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
+
+ if (sec->shdr.sh_link < shnum)
+ sec->link = &secs[sec->shdr.sh_link];
+ }
+
+}
+
+static void read_relocs(FILE *fp)
+{
+ int i, j;
+
+ for (i = 0; i < shnum; i++) {
+ struct section *sec = &secs[i];
+
+ if (sec->shdr.sh_type != SHT_REL_TYPE)
+ continue;
+
+ sec->reltab = malloc(sec->shdr.sh_size);
+ if (!sec->reltab)
+ die("malloc of %" FMT " bytes for relocs failed\n", sec->shdr.sh_size);
+
+ if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0)
+ die("Seek to %" FMT " failed: %s\n", sec->shdr.sh_offset, strerror(errno));
+
+ if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) != sec->shdr.sh_size)
+ die("Cannot read symbol table: %s\n", strerror(errno));
+
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+
+ rel->r_offset = elf_addr_to_cpu(rel->r_offset);
+ rel->r_info = elf_xword_to_cpu(rel->r_info);
+#if (SHT_REL_TYPE == SHT_RELA)
+ rel->r_addend = elf_xword_to_cpu(rel->r_addend);
+#endif
+ }
+ }
+}
+
+static void add_reloc(struct relocs *r, uint32_t offset)
+{
+ if (r->count == r->size) {
+ unsigned long newsize = r->size + 50000;
+ void *mem = realloc(r->offset, newsize * sizeof(r->offset[0]));
+
+ if (!mem)
+ die("realloc of %ld entries for relocs failed\n", newsize);
+
+ r->offset = mem;
+ r->size = newsize;
+ }
+ r->offset[r->count++] = offset;
+}
+
+static int do_reloc(struct section *sec, Elf_Rel *rel)
+{
+ unsigned int r_type = ELF64_R_TYPE(rel->r_info);
+
+ ElfW(Addr) offset = rel->r_offset;
+
+ switch (r_type) {
+ case R_390_NONE:
+ case R_390_PC32:
+ case R_390_PC64:
+ case R_390_PC16DBL:
+ case R_390_PC32DBL:
+ case R_390_PLT32DBL:
+ case R_390_GOTENT:
+ break;
+ case R_390_64:
+ add_reloc(&relocs64, offset);
+ break;
+ default:
+ die("Unsupported relocation type: %d\n", r_type);
+ break;
+ }
+
+ return 0;
+}
+
+static void walk_relocs(void)
+{
+ int i;
+ /* Walk through the relocations */
+ for (i = 0; i < shnum; i++) {
+ struct section *sec_applies;
+ int j;
+ struct section *sec = &secs[i];
+
+ if (sec->shdr.sh_type != SHT_REL_TYPE)
+ continue;
+
+ sec_applies = &secs[sec->shdr.sh_info];
+ if (!(sec_applies->shdr.sh_flags & SHF_ALLOC))
+ continue;
+
+ for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
+ Elf_Rel *rel = &sec->reltab[j];
+
+ do_reloc(sec, rel);
+ }
+ }
+}
+
+static int cmp_relocs(const void *va, const void *vb)
+{
+ const uint32_t *a, *b;
+
+ a = va; b = vb;
+ return (*a == *b) ? 0 : (*a > *b) ? 1 : -1;
+}
+
+static void sort_relocs(struct relocs *r)
+{
+ qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
+}
+
+static int print_reloc(uint32_t v)
+{
+ return fprintf(stdout, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1;
+}
+
+static void emit_relocs(void)
+{
+ int i;
+
+ walk_relocs();
+ sort_relocs(&relocs64);
+
+ printf(".section \".vmlinux.relocs_64\",\"a\"\n");
+ for (i = 0; i < relocs64.count; i++)
+ print_reloc(relocs64.offset[i]);
+}
+
+static void process(FILE *fp)
+{
+ read_ehdr(fp);
+ read_shdrs(fp);
+ read_relocs(fp);
+ emit_relocs();
+}
+
+static void usage(void)
+{
+ die("relocs vmlinux\n");
+}
+
+int main(int argc, char **argv)
+{
+ const char *fname;
+ FILE *fp;
+ unsigned char e_ident[EI_NIDENT];
+
+ fname = NULL;
+
+ if (argc != 2)
+ usage();
+
+ fname = argv[1];
+
+ fp = fopen(fname, "r");
+ if (!fp)
+ die("Cannot open %s: %s\n", fname, strerror(errno));
+
+ if (fread(&e_ident, 1, EI_NIDENT, fp) != EI_NIDENT)
+ die("Cannot read %s: %s", fname, strerror(errno));
+
+ rewind(fp);
+
+ process(fp);
+
+ fclose(fp);
+ return 0;
+}
--
2.40.1
