scripts/sorttable: Rename 'sortextable' to 'sorttable'

Use a more generic name for additional table sorting usecases,
such as the upcoming ORC table sorting feature. This tool is
not tied to exception table sorting anymore.

No functional changes intended.

[ mingo: Rewrote the changelog. ]

Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-6-shile.zhang@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 210 insertions, 0 deletions

diff --git a/scripts/sorttable.h b/scripts/sorttable.h
new file mode 100644
index 000000000000..82589ff90e25
--- /dev/null
+++ b/scripts/sorttable.h
@@ -0,0 +1,210 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * sorttable.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.
+ */
+
+#undef extable_ent_size
+#undef compare_extable
+#undef do_sort
+#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 SORTTABLE_64
+# define extable_ent_size	16
+# define compare_extable	compare_extable_64
+# define do_sort		do_sort_64
+# 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_sort		do_sort_32
+# 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 int do_sort(Elf_Ehdr *ehdr,
+		   char const *const fname,
+		   table_sort_t custom_sort)
+{
+	Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
+	Elf_Shdr *strtab_sec = NULL;
+	Elf_Shdr *symtab_sec = NULL;
+	Elf_Shdr *extab_sec = NULL;
+	Elf_Sym *sym;
+	const Elf_Sym *symtab;
+	Elf32_Word *symtab_shndx = NULL;
+	Elf_Sym *sort_needed_sym = NULL;
+	Elf_Shdr *sort_needed_sec;
+	Elf_Rel *relocs = NULL;
+	int relocs_size = 0;
+	uint32_t *sort_needed_loc;
+	const char *secstrings;
+	const char *strtab;
+	char *extab_image;
+	int extab_index = 0;
+	int i;
+	int idx;
+	unsigned int shnum;
+	unsigned int shstrndx;
+
+	shstrndx = r2(&ehdr->e_shstrndx);
+	if (shstrndx == SHN_XINDEX)
+		shstrndx = r(&shdr[0].sh_link);
+	secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset);
+
+	shnum = r2(&ehdr->e_shnum);
+	if (shnum == SHN_UNDEF)
+		shnum = _r(&shdr[0].sh_size);
+
+	for (i = 0, s = shdr; s < shdr + shnum; i++, s++) {
+		idx = r(&s->sh_name);
+		if (!strcmp(secstrings + idx, "__ex_table")) {
+			extab_sec = s;
+			extab_index = i;
+		}
+		if (!strcmp(secstrings + idx, ".symtab"))
+			symtab_sec = s;
+		if (!strcmp(secstrings + idx, ".strtab"))
+			strtab_sec = s;
+
+		if ((r(&s->sh_type) == SHT_REL ||
+		     r(&s->sh_type) == SHT_RELA) &&
+		    r(&s->sh_info) == extab_index) {
+			relocs = (void *)ehdr + _r(&s->sh_offset);
+			relocs_size = _r(&s->sh_size);
+		}
+		if (r(&s->sh_type) == SHT_SYMTAB_SHNDX)
+			symtab_shndx = (Elf32_Word *)((const char *)ehdr +
+						      _r(&s->sh_offset));
+	}
+
+	if (!extab_sec) {
+		fprintf(stderr,	"no __ex_table in file: %s\n", fname);
+		return -1;
+	}
+
+	if (!symtab_sec) {
+		fprintf(stderr,	"no .symtab in file: %s\n", fname);
+		return -1;
+	}
+
+	if (!strtab_sec) {
+		fprintf(stderr,	"no .strtab in file: %s\n", fname);
+		return -1;
+	}
+
+	extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
+	strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
+	symtab = (const Elf_Sym *)((const char *)ehdr +
+						  _r(&symtab_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 the flag main_extable_sort_needed */
+	for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
+	     sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym);
+	     sym++) {
+		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
+			continue;
+		if (!strcmp(strtab + r(&sym->st_name),
+			    "main_extable_sort_needed")) {
+			sort_needed_sym = sym;
+			break;
+		}
+	}
+
+	if (!sort_needed_sym) {
+		fprintf(stderr,
+			"no main_extable_sort_needed symbol in file: %s\n",
+			fname);
+		return -1;
+	}
+
+	sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
+					     sort_needed_sym - symtab,
+					     symtab_shndx)];
+	sort_needed_loc = (void *)ehdr +
+		_r(&sort_needed_sec->sh_offset) +
+		_r(&sort_needed_sym->st_value) -
+		_r(&sort_needed_sec->sh_addr);
+
+	/* extable has been sorted, clear the flag */
+	w(0, sort_needed_loc);
+
+	return 0;
+}