[RFC PATCH 28/28] x86/tools: Drop x86_64 support from 'relocs' tool

[Ard Biesheuvel <ardb+git@google.com>]

From: Ard Biesheuvel <ardb@kernel.org>

The relocs tool is no longer used on vmlinux, which is the only 64-bit
ELF executable that it used to operate on in the 64-bit build. (It is
still used for parts of the decompressor)

So drop the 64-bit handling - it is dead code now.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/x86/tools/Makefile        |   2 +-
 arch/x86/tools/relocs.c        | 178 +-------------------
 arch/x86/tools/relocs.h        |   9 +-
 arch/x86/tools/relocs_64.c     |  18 --
 arch/x86/tools/relocs_common.c |  11 +-
 5 files changed, 9 insertions(+), 209 deletions(-)

diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index 7278e2545c35..f7d12a9dccfc 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -40,7 +40,7 @@ $(obj)/insn_sanity.o: $(srctree)/tools/arch/x86/lib/insn.c $(srctree)/tools/arch
 
 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
 hostprogs	+= relocs
-relocs-objs     := relocs_32.o relocs_64.o relocs_common.o
+relocs-objs     := relocs_32.o relocs_common.o
 PHONY += relocs
 relocs: $(obj)/relocs
 	@:
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 22c2d3f07a57..ff5578e63ff8 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -28,12 +28,7 @@ struct relocs {
 static struct relocs		relocs16;
 static struct relocs		relocs32;
 
-#if ELF_BITS == 64
-static struct relocs		relocs64;
-# define FMT PRIu64
-#else
 # define FMT PRIu32
-#endif
 
 struct section {
 				Elf_Shdr         shdr;
@@ -86,10 +81,6 @@ static const char * const	sym_regex_kernel[S_NSYMTYPES] = {
 	"__end_rodata_aligned|"
 	"__initramfs_start|"
 	"(jiffies|jiffies_64)|"
-#if ELF_BITS == 64
-	"__per_cpu_load|"
-	"__end_rodata_hpage_align|"
-#endif
 	"__vvar_page|"
 	"_end)$"
 };
@@ -210,27 +201,6 @@ static const char *rel_type(unsigned type)
 {
 	static const char *type_name[] = {
 #define REL_TYPE(X) [X] = #X
-#if ELF_BITS == 64
-		REL_TYPE(R_X86_64_NONE),
-		REL_TYPE(R_X86_64_64),
-		REL_TYPE(R_X86_64_PC64),
-		REL_TYPE(R_X86_64_PC32),
-		REL_TYPE(R_X86_64_GOT32),
-		REL_TYPE(R_X86_64_PLT32),
-		REL_TYPE(R_X86_64_COPY),
-		REL_TYPE(R_X86_64_GLOB_DAT),
-		REL_TYPE(R_X86_64_JUMP_SLOT),
-		REL_TYPE(R_X86_64_RELATIVE),
-		REL_TYPE(R_X86_64_GOTPCREL),
-		REL_TYPE(R_X86_64_GOTPCRELX),
-		REL_TYPE(R_X86_64_REX_GOTPCRELX),
-		REL_TYPE(R_X86_64_32),
-		REL_TYPE(R_X86_64_32S),
-		REL_TYPE(R_X86_64_16),
-		REL_TYPE(R_X86_64_PC16),
-		REL_TYPE(R_X86_64_8),
-		REL_TYPE(R_X86_64_PC8),
-#else
 		REL_TYPE(R_386_NONE),
 		REL_TYPE(R_386_32),
 		REL_TYPE(R_386_PC32),
@@ -246,7 +216,6 @@ static const char *rel_type(unsigned type)
 		REL_TYPE(R_386_PC8),
 		REL_TYPE(R_386_16),
 		REL_TYPE(R_386_PC16),
-#endif
 #undef REL_TYPE
 	};
 	const char *name = "unknown type rel type name";
@@ -312,19 +281,9 @@ static uint32_t elf32_to_cpu(uint32_t 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 le64_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 int sym_index(Elf_Sym *sym)
 {
@@ -515,10 +474,7 @@ static void print_absolute_symbols(void)
 	int i;
 	const char *format;
 
-	if (ELF_BITS == 64)
-		format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n";
-	else
-		format = "%5d %08"PRIx32"  %5"PRId32" %10s %10s %12s %s\n";
+	format = "%5d %08"PRIx32"  %5"PRId32" %10s %10s %12s %s\n";
 
 	printf("Absolute symbols\n");
 	printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
@@ -559,10 +515,7 @@ static void print_absolute_relocs(void)
 	int i, printed = 0;
 	const char *format;
 
-	if (ELF_BITS == 64)
-		format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64"  %s\n";
-	else
-		format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32"  %s\n";
+	format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32"  %s\n";
 
 	for (i = 0; i < shnum; i++) {
 		struct section *sec = &secs[i];
@@ -694,104 +647,6 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
 	}
 }
 
-#if ELF_BITS == 64
-
-static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
-		      const char *symname)
-{
-	unsigned r_type = ELF64_R_TYPE(rel->r_info);
-	ElfW(Addr) offset = rel->r_offset;
-	int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
-
-	if (sym->st_shndx == SHN_UNDEF)
-		return 0;
-
-	switch (r_type) {
-	case R_X86_64_NONE:
-		/* NONE can be ignored. */
-		break;
-
-	case R_X86_64_PC32:
-	case R_X86_64_PLT32:
-		/*
-		 * PC relative relocations don't need to be adjusted.
-		 *
-		 * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
-		 */
-		break;
-
-	case R_X86_64_PC64:
-		/*
-		 * Only used by jump labels
-		 */
-		break;
-
-	case R_X86_64_32:
-	case R_X86_64_32S:
-	case R_X86_64_64:
-	case R_X86_64_GOTPCREL:
-		if (shn_abs) {
-			/*
-			 * Whitelisted absolute symbols do not require
-			 * relocation.
-			 */
-			if (is_reloc(S_ABS, symname))
-				break;
-
-			die("Invalid absolute %s relocation: %s\n", rel_type(r_type), symname);
-			break;
-		}
-
-		if (r_type == R_X86_64_GOTPCREL) {
-			Elf_Shdr *s = &secs[sec->shdr.sh_info].shdr;
-			unsigned file_off = offset - s->sh_addr + s->sh_offset;
-
-			/*
-			 * GOTPCREL relocations refer to instructions that load
-			 * a 64-bit address via a 32-bit relative reference to
-			 * the GOT.  In this case, it is the GOT entry that
-			 * needs to be fixed up, not the immediate offset in
-			 * the opcode. Note that the linker will have applied an
-			 * addend of -4 to compensate for the delta between the
-			 * relocation offset and the value of RIP when the
-			 * instruction executes, and this needs to be backed out
-			 * again. (Addends other than -4 are permitted in
-			 * principle, but make no sense in practice so they are
-			 * not supported.)
-                         */
-			if (rel->r_addend != -4) {
-				die("invalid addend (%ld) for %s relocation: %s\n",
-				    rel->r_addend, rel_type(r_type), symname);
-				break;
-			}
-			offset += 4 + (int32_t)get_unaligned_le32(elf_image + file_off);
-		}
-
-		/*
-		 * Relocation offsets for 64 bit kernels are output
-		 * as 32 bits and sign extended back to 64 bits when
-		 * the relocations are processed.
-		 * Make sure that the offset will fit.
-		 */
-		if ((int32_t)offset != (int64_t)offset)
-			die("Relocation offset doesn't fit in 32 bits\n");
-
-		if (r_type == R_X86_64_64 || r_type == R_X86_64_GOTPCREL)
-			add_reloc(&relocs64, offset);
-		else
-			add_reloc(&relocs32, offset);
-		break;
-
-	default:
-		die("Unsupported relocation type: %s (%d)\n", rel_type(r_type), r_type);
-		break;
-	}
-
-	return 0;
-}
-
-#else
-
 static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
 		      const char *symname)
 {
@@ -902,8 +757,6 @@ static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const
 	return 0;
 }
 
-#endif
-
 static int cmp_relocs(const void *va, const void *vb)
 {
 	const uint32_t *a, *b;
@@ -939,17 +792,10 @@ static void emit_relocs(int as_text, int use_real_mode)
 	int (*write_reloc)(uint32_t, FILE *) = write32;
 	int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname);
 
-#if ELF_BITS == 64
-	if (!use_real_mode)
-		do_reloc = do_reloc64;
-	else
-		die("--realmode not valid for a 64-bit ELF file");
-#else
 	if (!use_real_mode)
 		do_reloc = do_reloc32;
 	else
 		do_reloc = do_reloc_real;
-#endif
 
 	/* Collect up the relocations */
 	walk_relocs(do_reloc);
@@ -959,11 +805,7 @@ static void emit_relocs(int as_text, int use_real_mode)
 
 	/* Order the relocations for more efficient processing */
 	sort_relocs(&relocs32);
-#if ELF_BITS == 64
-	sort_relocs(&relocs64);
-#else
 	sort_relocs(&relocs16);
-#endif
 
 	/* Print the relocations */
 	if (as_text) {
@@ -984,16 +826,6 @@ static void emit_relocs(int as_text, int use_real_mode)
 		for (i = 0; i < relocs32.count; i++)
 			write_reloc(relocs32.offset[i], stdout);
 	} else {
-#if ELF_BITS == 64
-		/* Print a stop */
-		write_reloc(0, stdout);
-
-		/* Now print each relocation */
-		for (i = 0; i < relocs64.count; i++)
-			if (!i || relocs64.offset[i] != relocs64.offset[i - 1])
-				write_reloc(relocs64.offset[i], stdout);
-#endif
-
 		/* Print a stop */
 		write_reloc(0, stdout);
 
@@ -1027,12 +859,6 @@ static void print_reloc_info(void)
 	walk_relocs(do_reloc_info);
 }
 
-#if ELF_BITS == 64
-# define process process_64
-#else
-# define process process_32
-#endif
-
 void process(FILE *fp, int use_real_mode, int as_text,
 	     int show_absolute_syms, int show_absolute_relocs,
 	     int show_reloc_info)
diff --git a/arch/x86/tools/relocs.h b/arch/x86/tools/relocs.h
index 7a509604ff92..ef9eec96bd62 100644
--- a/arch/x86/tools/relocs.h
+++ b/arch/x86/tools/relocs.h
@@ -32,10 +32,7 @@ enum symtype {
 	S_NSYMTYPES
 };
 
-void process_32(FILE *fp, int use_real_mode, int as_text,
-		int show_absolute_syms, int show_absolute_relocs,
-		int show_reloc_info);
-void process_64(FILE *fp, int use_real_mode, int as_text,
-		int show_absolute_syms, int show_absolute_relocs,
-		int show_reloc_info);
+void process(FILE *fp, int use_real_mode, int as_text,
+	     int show_absolute_syms, int show_absolute_relocs,
+	     int show_reloc_info);
 #endif /* RELOCS_H */
diff --git a/arch/x86/tools/relocs_64.c b/arch/x86/tools/relocs_64.c
deleted file mode 100644
index 9029cb619cb1..000000000000
--- a/arch/x86/tools/relocs_64.c
+++ /dev/null
@@ -1,18 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include "relocs.h"
-
-#define ELF_BITS 64
-
-#define ELF_MACHINE             EM_X86_64
-#define ELF_MACHINE_NAME        "x86_64"
-#define SHT_REL_TYPE            SHT_RELA
-#define Elf_Rel                 Elf64_Rela
-
-#define ELF_CLASS               ELFCLASS64
-#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)
-
-#include "relocs.c"
diff --git a/arch/x86/tools/relocs_common.c b/arch/x86/tools/relocs_common.c
index 6634352a20bc..167985ecd544 100644
--- a/arch/x86/tools/relocs_common.c
+++ b/arch/x86/tools/relocs_common.c
@@ -72,14 +72,9 @@ int main(int argc, char **argv)
 		die("Cannot read %s: %s", fname, strerror(errno));
 	}
 	rewind(fp);
-	if (e_ident[EI_CLASS] == ELFCLASS64)
-		process_64(fp, use_real_mode, as_text,
-			   show_absolute_syms, show_absolute_relocs,
-			   show_reloc_info);
-	else
-		process_32(fp, use_real_mode, as_text,
-			   show_absolute_syms, show_absolute_relocs,
-			   show_reloc_info);
+	process(fp, use_real_mode, as_text,
+		show_absolute_syms, show_absolute_relocs,
+		show_reloc_info);
 	fclose(fp);
 	return 0;
 }
-- 
2.46.0.792.g87dc391469-goog