Merge branch 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull exception table generation updates from Ingo Molnar:
 "The biggest change here is to allow the build-time sorting of the
  exception table, to speed up booting.  This is achieved by the
  architecture enabling BUILDTIME_EXTABLE_SORT.  This option is enabled
  for x86 and MIPS currently.

  On x86 a number of fixes and changes were needed to allow build-time
  sorting of the exception table, in particular a relocation invariant
  exception table format was needed.  This required the abstracting out
  of exception table protocol and the removal of 20 years of accumulated
  assumptions about the x86 exception table format.

  While at it, this tree also cleans up various other aspects of
  exception handling, such as early(er) exception handling for
  rdmsr_safe() et al.

  All in one, as the result of these changes the x86 exception code is
  now pretty nice and modern.  As an added bonus any regressions in this
  code will be early and violent crashes, so if you see any of those,
  you'll know whom to blame!"

Fix up trivial conflicts in arch/{mips,x86}/Kconfig files due to nearby
modifications of other core architecture options.

* 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  Revert "x86, extable: Disable presorted exception table for now"
  scripts/sortextable: Handle relative entries, and other cleanups
  x86, extable: Switch to relative exception table entries
  x86, extable: Disable presorted exception table for now
  x86, extable: Add _ASM_EXTABLE_EX() macro
  x86, extable: Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/xsave.h
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/kvm_host.h
  x86, extable: Remove the now-unused __ASM_EX_SEC macros
  x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/um/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/usercopy_32.c
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/putuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/getuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/csum-copy_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_nocache_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/entry_64.S
  ...

1 files changed, 191 insertions, 0 deletions

diff --git a/scripts/sortextable.h b/scripts/sortextable.h
new file mode 100644
index 000000000000..e4fd45b7e456
--- /dev/null
+++ b/scripts/sortextable.h
@@ -0,0 +1,191 @@
+/*
+ * sortextable.h
+ *
+ * Copyright 2011 - 2012 Cavium, Inc.
+ *
+ * Some of this code was taken out of recordmcount.h written by:
+ *
+ * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
+ * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
+ *
+ *
+ * Licensed under the GNU General Public License, version 2 (GPLv2).
+ */
+
+#undef extable_ent_size
+#undef compare_extable
+#undef do_func
+#undef Elf_Addr
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Rel
+#undef Elf_Rela
+#undef Elf_Sym
+#undef ELF_R_SYM
+#undef Elf_r_sym
+#undef ELF_R_INFO
+#undef Elf_r_info
+#undef ELF_ST_BIND
+#undef ELF_ST_TYPE
+#undef fn_ELF_R_SYM
+#undef fn_ELF_R_INFO
+#undef uint_t
+#undef _r
+#undef _w
+
+#ifdef SORTEXTABLE_64
+# define extable_ent_size	16
+# define compare_extable	compare_extable_64
+# define do_func		do64
+# define Elf_Addr		Elf64_Addr
+# define Elf_Ehdr		Elf64_Ehdr
+# define Elf_Shdr		Elf64_Shdr
+# define Elf_Rel		Elf64_Rel
+# define Elf_Rela		Elf64_Rela
+# define Elf_Sym		Elf64_Sym
+# define ELF_R_SYM		ELF64_R_SYM
+# define Elf_r_sym		Elf64_r_sym
+# define ELF_R_INFO		ELF64_R_INFO
+# define Elf_r_info		Elf64_r_info
+# define ELF_ST_BIND		ELF64_ST_BIND
+# define ELF_ST_TYPE		ELF64_ST_TYPE
+# define fn_ELF_R_SYM		fn_ELF64_R_SYM
+# define fn_ELF_R_INFO		fn_ELF64_R_INFO
+# define uint_t			uint64_t
+# define _r			r8
+# define _w			w8
+#else
+# define extable_ent_size	8
+# define compare_extable	compare_extable_32
+# define do_func		do32
+# define Elf_Addr		Elf32_Addr
+# define Elf_Ehdr		Elf32_Ehdr
+# define Elf_Shdr		Elf32_Shdr
+# define Elf_Rel		Elf32_Rel
+# define Elf_Rela		Elf32_Rela
+# define Elf_Sym		Elf32_Sym
+# define ELF_R_SYM		ELF32_R_SYM
+# define Elf_r_sym		Elf32_r_sym
+# define ELF_R_INFO		ELF32_R_INFO
+# define Elf_r_info		Elf32_r_info
+# define ELF_ST_BIND		ELF32_ST_BIND
+# define ELF_ST_TYPE		ELF32_ST_TYPE
+# define fn_ELF_R_SYM		fn_ELF32_R_SYM
+# define fn_ELF_R_INFO		fn_ELF32_R_INFO
+# define uint_t			uint32_t
+# define _r			r
+# define _w			w
+#endif
+
+static int compare_extable(const void *a, const void *b)
+{
+	Elf_Addr av = _r(a);
+	Elf_Addr bv = _r(b);
+
+	if (av < bv)
+		return -1;
+	if (av > bv)
+		return 1;
+	return 0;
+}
+
+static void
+do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
+{
+	Elf_Shdr *shdr;
+	Elf_Shdr *shstrtab_sec;
+	Elf_Shdr *strtab_sec = NULL;
+	Elf_Shdr *symtab_sec = NULL;
+	Elf_Shdr *extab_sec = NULL;
+	Elf_Sym *sym;
+	Elf_Sym *sort_needed_sym;
+	Elf_Shdr *sort_needed_sec;
+	Elf_Rel *relocs = NULL;
+	int relocs_size;
+	uint32_t *sort_done_location;
+	const char *secstrtab;
+	const char *strtab;
+	char *extab_image;
+	int extab_index = 0;
+	int i;
+	int idx;
+
+	shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
+	shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
+	secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
+	for (i = 0; i < r2(&ehdr->e_shnum); i++) {
+		idx = r(&shdr[i].sh_name);
+		if (strcmp(secstrtab + idx, "__ex_table") == 0) {
+			extab_sec = shdr + i;
+			extab_index = i;
+		}
+		if ((r(&shdr[i].sh_type) == SHT_REL ||
+		     r(&shdr[i].sh_type) == SHT_RELA) &&
+		    r(&shdr[i].sh_info) == extab_index) {
+			relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
+			relocs_size = _r(&shdr[i].sh_size);
+		}
+		if (strcmp(secstrtab + idx, ".symtab") == 0)
+			symtab_sec = shdr + i;
+		if (strcmp(secstrtab + idx, ".strtab") == 0)
+			strtab_sec = shdr + i;
+	}
+	if (strtab_sec == NULL) {
+		fprintf(stderr,	"no .strtab in  file: %s\n", fname);
+		fail_file();
+	}
+	if (symtab_sec == NULL) {
+		fprintf(stderr,	"no .symtab in  file: %s\n", fname);
+		fail_file();
+	}
+	if (extab_sec == NULL) {
+		fprintf(stderr,	"no __ex_table in  file: %s\n", fname);
+		fail_file();
+	}
+	strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
+
+	extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
+
+	if (custom_sort) {
+		custom_sort(extab_image, _r(&extab_sec->sh_size));
+	} else {
+		int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
+		qsort(extab_image, num_entries,
+		      extable_ent_size, compare_extable);
+	}
+	/* If there were relocations, we no longer need them. */
+	if (relocs)
+		memset(relocs, 0, relocs_size);
+
+	/* find main_extable_sort_needed */
+	sort_needed_sym = NULL;
+	for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
+		sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
+		sym += i;
+		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
+			continue;
+		idx = r(&sym->st_name);
+		if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
+			sort_needed_sym = sym;
+			break;
+		}
+	}
+	if (sort_needed_sym == NULL) {
+		fprintf(stderr,
+			"no main_extable_sort_needed symbol in  file: %s\n",
+			fname);
+		fail_file();
+	}
+	sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)];
+	sort_done_location = (void *)ehdr +
+		_r(&sort_needed_sec->sh_offset) +
+		_r(&sort_needed_sym->st_value) -
+		_r(&sort_needed_sec->sh_addr);
+
+#if 1
+	printf("sort done marker at %lx\n",
+	       (unsigned long)((char *)sort_done_location - (char *)ehdr));
+#endif
+	/* We sorted it, clear the flag. */
+	w(0, sort_done_location);
+}