objtool: sync up with the 4.14.47 version of objtool

There are pros and cons of dealing with tools in the kernel directory.
The pros are the fact that development happens fast, and new features
can be added to the kernel and the tools at the same times.  The cons
are when dealing with backported kernel patches, it can be necessary to
backport parts of the tool changes as well.

For 4.9.y so far, we have backported individual patches.  That quickly
breaks down when there are minor differences between how backports were
handled, so grabbing 40+ patch long series can be difficult, not
impossible, but really frustrating to attempt.

To help mitigate this mess, here's a single big patch to sync up the
objtool logic to the 4.14.47 version of the tool.  From this point
forward (after some other minor header file patches are applied), the
tool should be in sync and much easier to maintain over time.

This has survivied my limited testing, and as the codebase is identical
to 4.14.47, I'm pretty comfortable dropping this big change in here in
4.9.y.  Hopefully all goes well...

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 213 insertions, 0 deletions

diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
new file mode 100644
index 000000000000..c3343820916a
--- /dev/null
+++ b/tools/objtool/orc_dump.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <unistd.h>
+#include "orc.h"
+#include "warn.h"
+
+static const char *reg_name(unsigned int reg)
+{
+	switch (reg) {
+	case ORC_REG_PREV_SP:
+		return "prevsp";
+	case ORC_REG_DX:
+		return "dx";
+	case ORC_REG_DI:
+		return "di";
+	case ORC_REG_BP:
+		return "bp";
+	case ORC_REG_SP:
+		return "sp";
+	case ORC_REG_R10:
+		return "r10";
+	case ORC_REG_R13:
+		return "r13";
+	case ORC_REG_BP_INDIRECT:
+		return "bp(ind)";
+	case ORC_REG_SP_INDIRECT:
+		return "sp(ind)";
+	default:
+		return "?";
+	}
+}
+
+static const char *orc_type_name(unsigned int type)
+{
+	switch (type) {
+	case ORC_TYPE_CALL:
+		return "call";
+	case ORC_TYPE_REGS:
+		return "regs";
+	case ORC_TYPE_REGS_IRET:
+		return "iret";
+	default:
+		return "?";
+	}
+}
+
+static void print_reg(unsigned int reg, int offset)
+{
+	if (reg == ORC_REG_BP_INDIRECT)
+		printf("(bp%+d)", offset);
+	else if (reg == ORC_REG_SP_INDIRECT)
+		printf("(sp%+d)", offset);
+	else if (reg == ORC_REG_UNDEFINED)
+		printf("(und)");
+	else
+		printf("%s%+d", reg_name(reg), offset);
+}
+
+int orc_dump(const char *_objname)
+{
+	int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
+	struct orc_entry *orc = NULL;
+	char *name;
+	size_t nr_sections;
+	Elf64_Addr orc_ip_addr = 0;
+	size_t shstrtab_idx;
+	Elf *elf;
+	Elf_Scn *scn;
+	GElf_Shdr sh;
+	GElf_Rela rela;
+	GElf_Sym sym;
+	Elf_Data *data, *symtab = NULL, *rela_orc_ip = NULL;
+
+
+	objname = _objname;
+
+	elf_version(EV_CURRENT);
+
+	fd = open(objname, O_RDONLY);
+	if (fd == -1) {
+		perror("open");
+		return -1;
+	}
+
+	elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+	if (!elf) {
+		WARN_ELF("elf_begin");
+		return -1;
+	}
+
+	if (elf_getshdrnum(elf, &nr_sections)) {
+		WARN_ELF("elf_getshdrnum");
+		return -1;
+	}
+
+	if (elf_getshdrstrndx(elf, &shstrtab_idx)) {
+		WARN_ELF("elf_getshdrstrndx");
+		return -1;
+	}
+
+	for (i = 0; i < nr_sections; i++) {
+		scn = elf_getscn(elf, i);
+		if (!scn) {
+			WARN_ELF("elf_getscn");
+			return -1;
+		}
+
+		if (!gelf_getshdr(scn, &sh)) {
+			WARN_ELF("gelf_getshdr");
+			return -1;
+		}
+
+		name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
+		if (!name) {
+			WARN_ELF("elf_strptr");
+			return -1;
+		}
+
+		data = elf_getdata(scn, NULL);
+		if (!data) {
+			WARN_ELF("elf_getdata");
+			return -1;
+		}
+
+		if (!strcmp(name, ".symtab")) {
+			symtab = data;
+		} else if (!strcmp(name, ".orc_unwind")) {
+			orc = data->d_buf;
+			orc_size = sh.sh_size;
+		} else if (!strcmp(name, ".orc_unwind_ip")) {
+			orc_ip = data->d_buf;
+			orc_ip_addr = sh.sh_addr;
+		} else if (!strcmp(name, ".rela.orc_unwind_ip")) {
+			rela_orc_ip = data;
+		}
+	}
+
+	if (!symtab || !orc || !orc_ip)
+		return 0;
+
+	if (orc_size % sizeof(*orc) != 0) {
+		WARN("bad .orc_unwind section size");
+		return -1;
+	}
+
+	nr_entries = orc_size / sizeof(*orc);
+	for (i = 0; i < nr_entries; i++) {
+		if (rela_orc_ip) {
+			if (!gelf_getrela(rela_orc_ip, i, &rela)) {
+				WARN_ELF("gelf_getrela");
+				return -1;
+			}
+
+			if (!gelf_getsym(symtab, GELF_R_SYM(rela.r_info), &sym)) {
+				WARN_ELF("gelf_getsym");
+				return -1;
+			}
+
+			scn = elf_getscn(elf, sym.st_shndx);
+			if (!scn) {
+				WARN_ELF("elf_getscn");
+				return -1;
+			}
+
+			if (!gelf_getshdr(scn, &sh)) {
+				WARN_ELF("gelf_getshdr");
+				return -1;
+			}
+
+			name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
+			if (!name || !*name) {
+				WARN_ELF("elf_strptr");
+				return -1;
+			}
+
+			printf("%s+%llx:", name, (unsigned long long)rela.r_addend);
+
+		} else {
+			printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
+		}
+
+
+		printf(" sp:");
+
+		print_reg(orc[i].sp_reg, orc[i].sp_offset);
+
+		printf(" bp:");
+
+		print_reg(orc[i].bp_reg, orc[i].bp_offset);
+
+		printf(" type:%s\n", orc_type_name(orc[i].type));
+	}
+
+	elf_end(elf);
+	close(fd);
+
+	return 0;
+}