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-rw-r--r--tools/objtool/Makefile10
-rw-r--r--tools/objtool/arch/x86/decode.c2
-rw-r--r--tools/objtool/arch/x86/lib/x86-opcode-map.txt15
-rw-r--r--tools/objtool/builtin-orc.c4
-rw-r--r--tools/objtool/check.c190
-rw-r--r--tools/objtool/check.h3
-rw-r--r--tools/objtool/elf.c4
-rw-r--r--tools/objtool/orc_dump.c7
-rw-r--r--tools/objtool/orc_gen.c7
9 files changed, 186 insertions, 56 deletions
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 0f94af3ccaaa..e6acc281dd37 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -7,9 +7,11 @@ ARCH := x86
endif
# always use the host compiler
-CC = gcc
-LD = ld
-AR = ar
+HOSTCC ?= gcc
+HOSTLD ?= ld
+CC = $(HOSTCC)
+LD = $(HOSTLD)
+AR = ar
ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
@@ -44,7 +46,7 @@ $(OBJTOOL_IN): fixdep FORCE
@$(MAKE) $(build)=objtool
$(OBJTOOL): $(LIBSUBCMD) $(OBJTOOL_IN)
- @./sync-check.sh
+ @$(CONFIG_SHELL) ./sync-check.sh
$(QUIET_LINK)$(CC) $(OBJTOOL_IN) $(LDFLAGS) -o $@
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 8acfc47af70e..540a209b78ab 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -138,7 +138,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
*type = INSN_STACK;
op->src.type = OP_SRC_ADD;
op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
- op->dest.type = OP_SRC_REG;
+ op->dest.type = OP_DEST_REG;
op->dest.reg = CFI_SP;
}
break;
diff --git a/tools/objtool/arch/x86/lib/x86-opcode-map.txt b/tools/objtool/arch/x86/lib/x86-opcode-map.txt
index 12e377184ee4..e0b85930dd77 100644
--- a/tools/objtool/arch/x86/lib/x86-opcode-map.txt
+++ b/tools/objtool/arch/x86/lib/x86-opcode-map.txt
@@ -607,7 +607,7 @@ fb: psubq Pq,Qq | vpsubq Vx,Hx,Wx (66),(v1)
fc: paddb Pq,Qq | vpaddb Vx,Hx,Wx (66),(v1)
fd: paddw Pq,Qq | vpaddw Vx,Hx,Wx (66),(v1)
fe: paddd Pq,Qq | vpaddd Vx,Hx,Wx (66),(v1)
-ff:
+ff: UD0
EndTable
Table: 3-byte opcode 1 (0x0f 0x38)
@@ -717,7 +717,7 @@ AVXcode: 2
7e: vpermt2d/q Vx,Hx,Wx (66),(ev)
7f: vpermt2ps/d Vx,Hx,Wx (66),(ev)
80: INVEPT Gy,Mdq (66)
-81: INVPID Gy,Mdq (66)
+81: INVVPID Gy,Mdq (66)
82: INVPCID Gy,Mdq (66)
83: vpmultishiftqb Vx,Hx,Wx (66),(ev)
88: vexpandps/d Vpd,Wpd (66),(ev)
@@ -896,7 +896,7 @@ EndTable
GrpTable: Grp3_1
0: TEST Eb,Ib
-1:
+1: TEST Eb,Ib
2: NOT Eb
3: NEG Eb
4: MUL AL,Eb
@@ -970,6 +970,15 @@ GrpTable: Grp9
EndTable
GrpTable: Grp10
+# all are UD1
+0: UD1
+1: UD1
+2: UD1
+3: UD1
+4: UD1
+5: UD1
+6: UD1
+7: UD1
EndTable
# Grp11A and Grp11B are expressed as Grp11 in Intel SDM
diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c
index 4c6b5c9ef073..91e8e19ff5e0 100644
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -44,6 +44,9 @@ int cmd_orc(int argc, const char **argv)
const char *objname;
argc--; argv++;
+ if (argc <= 0)
+ usage_with_options(orc_usage, check_options);
+
if (!strncmp(argv[0], "gen", 3)) {
argc = parse_options(argc, argv, check_options, orc_usage, 0);
if (argc != 1)
@@ -52,7 +55,6 @@ int cmd_orc(int argc, const char **argv)
objname = argv[0];
return check(objname, no_fp, no_unreachable, true);
-
}
if (!strcmp(argv[0], "dump")) {
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9b341584eb1b..a8cb69a26576 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -138,6 +138,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
"__reiserfs_panic",
"lbug_with_loc",
"fortify_panic",
+ "usercopy_abort",
};
if (func->bind == STB_WEAK)
@@ -428,6 +429,40 @@ static void add_ignores(struct objtool_file *file)
}
/*
+ * FIXME: For now, just ignore any alternatives which add retpolines. This is
+ * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline.
+ * But it at least allows objtool to understand the control flow *around* the
+ * retpoline.
+ */
+static int add_nospec_ignores(struct objtool_file *file)
+{
+ struct section *sec;
+ struct rela *rela;
+ struct instruction *insn;
+
+ sec = find_section_by_name(file->elf, ".rela.discard.nospec");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(rela, &sec->rela_list, list) {
+ if (rela->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s", sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, rela->sym->sec, rela->addend);
+ if (!insn) {
+ WARN("bad .discard.nospec entry");
+ return -1;
+ }
+
+ insn->ignore_alts = true;
+ }
+
+ return 0;
+}
+
+/*
* Find the destination instructions for all jumps.
*/
static int add_jump_destinations(struct objtool_file *file)
@@ -456,6 +491,13 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (rela->sym->sec->idx) {
dest_sec = rela->sym->sec;
dest_off = rela->sym->sym.st_value + rela->addend + 4;
+ } else if (strstr(rela->sym->name, "_indirect_thunk_")) {
+ /*
+ * Retpoline jumps are really dynamic jumps in
+ * disguise, so convert them accordingly.
+ */
+ insn->type = INSN_JUMP_DYNAMIC;
+ continue;
} else {
/* sibling call */
insn->jump_dest = 0;
@@ -502,11 +544,14 @@ static int add_call_destinations(struct objtool_file *file)
dest_off = insn->offset + insn->len + insn->immediate;
insn->call_dest = find_symbol_by_offset(insn->sec,
dest_off);
- if (!insn->call_dest) {
- WARN_FUNC("can't find call dest symbol at offset 0x%lx",
- insn->sec, insn->offset, dest_off);
+
+ if (!insn->call_dest && !insn->ignore) {
+ WARN_FUNC("unsupported intra-function call",
+ insn->sec, insn->offset);
+ WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
return -1;
}
+
} else if (rela->sym->type == STT_SECTION) {
insn->call_dest = find_symbol_by_offset(rela->sym->sec,
rela->addend+4);
@@ -550,7 +595,7 @@ static int handle_group_alt(struct objtool_file *file,
struct instruction *orig_insn,
struct instruction **new_insn)
{
- struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump;
+ struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
unsigned long dest_off;
last_orig_insn = NULL;
@@ -566,28 +611,30 @@ static int handle_group_alt(struct objtool_file *file,
last_orig_insn = insn;
}
- if (!next_insn_same_sec(file, last_orig_insn)) {
- WARN("%s: don't know how to handle alternatives at end of section",
- special_alt->orig_sec->name);
- return -1;
- }
-
- fake_jump = malloc(sizeof(*fake_jump));
- if (!fake_jump) {
- WARN("malloc failed");
- return -1;
+ if (next_insn_same_sec(file, last_orig_insn)) {
+ fake_jump = malloc(sizeof(*fake_jump));
+ if (!fake_jump) {
+ WARN("malloc failed");
+ return -1;
+ }
+ memset(fake_jump, 0, sizeof(*fake_jump));
+ INIT_LIST_HEAD(&fake_jump->alts);
+ clear_insn_state(&fake_jump->state);
+
+ fake_jump->sec = special_alt->new_sec;
+ fake_jump->offset = -1;
+ fake_jump->type = INSN_JUMP_UNCONDITIONAL;
+ fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
+ fake_jump->ignore = true;
}
- memset(fake_jump, 0, sizeof(*fake_jump));
- INIT_LIST_HEAD(&fake_jump->alts);
- clear_insn_state(&fake_jump->state);
-
- fake_jump->sec = special_alt->new_sec;
- fake_jump->offset = -1;
- fake_jump->type = INSN_JUMP_UNCONDITIONAL;
- fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
- fake_jump->ignore = true;
if (!special_alt->new_len) {
+ if (!fake_jump) {
+ WARN("%s: empty alternative at end of section",
+ special_alt->orig_sec->name);
+ return -1;
+ }
+
*new_insn = fake_jump;
return 0;
}
@@ -600,6 +647,8 @@ static int handle_group_alt(struct objtool_file *file,
last_new_insn = insn;
+ insn->ignore = orig_insn->ignore_alts;
+
if (insn->type != INSN_JUMP_CONDITIONAL &&
insn->type != INSN_JUMP_UNCONDITIONAL)
continue;
@@ -608,8 +657,14 @@ static int handle_group_alt(struct objtool_file *file,
continue;
dest_off = insn->offset + insn->len + insn->immediate;
- if (dest_off == special_alt->new_off + special_alt->new_len)
+ if (dest_off == special_alt->new_off + special_alt->new_len) {
+ if (!fake_jump) {
+ WARN("%s: alternative jump to end of section",
+ special_alt->orig_sec->name);
+ return -1;
+ }
insn->jump_dest = fake_jump;
+ }
if (!insn->jump_dest) {
WARN_FUNC("can't find alternative jump destination",
@@ -624,7 +679,8 @@ static int handle_group_alt(struct objtool_file *file,
return -1;
}
- list_add(&fake_jump->list, &last_new_insn->list);
+ if (fake_jump)
+ list_add(&fake_jump->list, &last_new_insn->list);
return 0;
}
@@ -671,12 +727,6 @@ static int add_special_section_alts(struct objtool_file *file)
return ret;
list_for_each_entry_safe(special_alt, tmp, &special_alts, list) {
- alt = malloc(sizeof(*alt));
- if (!alt) {
- WARN("malloc failed");
- ret = -1;
- goto out;
- }
orig_insn = find_insn(file, special_alt->orig_sec,
special_alt->orig_off);
@@ -712,6 +762,13 @@ static int add_special_section_alts(struct objtool_file *file)
goto out;
}
+ alt = malloc(sizeof(*alt));
+ if (!alt) {
+ WARN("malloc failed");
+ ret = -1;
+ goto out;
+ }
+
alt->insn = new_insn;
list_add_tail(&alt->list, &orig_insn->alts);
@@ -795,8 +852,14 @@ static int add_switch_table(struct objtool_file *file, struct symbol *func,
* This is a fairly uncommon pattern which is new for GCC 6. As of this
* writing, there are 11 occurrences of it in the allmodconfig kernel.
*
+ * As of GCC 7 there are quite a few more of these and the 'in between' code
+ * is significant. Esp. with KASAN enabled some of the code between the mov
+ * and jmpq uses .rodata itself, which can confuse things.
+ *
* TODO: Once we have DWARF CFI and smarter instruction decoding logic,
* ensure the same register is used in the mov and jump instructions.
+ *
+ * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
*/
static struct rela *find_switch_table(struct objtool_file *file,
struct symbol *func,
@@ -818,12 +881,25 @@ static struct rela *find_switch_table(struct objtool_file *file,
text_rela->addend + 4);
if (!rodata_rela)
return NULL;
+
file->ignore_unreachables = true;
return rodata_rela;
}
/* case 3 */
- func_for_each_insn_continue_reverse(file, func, insn) {
+ /*
+ * Backward search using the @first_jump_src links, these help avoid
+ * much of the 'in between' code. Which avoids us getting confused by
+ * it.
+ */
+ for (insn = list_prev_entry(insn, list);
+
+ &insn->list != &file->insn_list &&
+ insn->sec == func->sec &&
+ insn->offset >= func->offset;
+
+ insn = insn->first_jump_src ?: list_prev_entry(insn, list)) {
+
if (insn->type == INSN_JUMP_DYNAMIC)
break;
@@ -853,14 +929,32 @@ static struct rela *find_switch_table(struct objtool_file *file,
return NULL;
}
+
static int add_func_switch_tables(struct objtool_file *file,
struct symbol *func)
{
- struct instruction *insn, *prev_jump = NULL;
+ struct instruction *insn, *last = NULL, *prev_jump = NULL;
struct rela *rela, *prev_rela = NULL;
int ret;
func_for_each_insn(file, func, insn) {
+ if (!last)
+ last = insn;
+
+ /*
+ * Store back-pointers for unconditional forward jumps such
+ * that find_switch_table() can back-track using those and
+ * avoid some potentially confusing code.
+ */
+ if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
+ insn->offset > last->offset &&
+ insn->jump_dest->offset > insn->offset &&
+ !insn->jump_dest->first_jump_src) {
+
+ insn->jump_dest->first_jump_src = insn;
+ last = insn->jump_dest;
+ }
+
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
@@ -1028,11 +1122,11 @@ static int decode_sections(struct objtool_file *file)
add_ignores(file);
- ret = add_jump_destinations(file);
+ ret = add_nospec_ignores(file);
if (ret)
return ret;
- ret = add_call_destinations(file);
+ ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1040,6 +1134,10 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ ret = add_call_destinations(file);
+ if (ret)
+ return ret;
+
ret = add_switch_table_alts(file);
if (ret)
return ret;
@@ -1663,10 +1761,12 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
insn->visited = true;
- list_for_each_entry(alt, &insn->alts, list) {
- ret = validate_branch(file, alt->insn, state);
- if (ret)
- return 1;
+ if (!insn->ignore_alts) {
+ list_for_each_entry(alt, &insn->alts, list) {
+ ret = validate_branch(file, alt->insn, state);
+ if (ret)
+ return 1;
+ }
}
switch (insn->type) {
@@ -1836,13 +1936,19 @@ static bool ignore_unreachable_insn(struct instruction *insn)
if (is_kasan_insn(insn) || is_ubsan_insn(insn))
return true;
- if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) {
- insn = insn->jump_dest;
- continue;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL) {
+ if (insn->jump_dest &&
+ insn->jump_dest->func == insn->func) {
+ insn = insn->jump_dest;
+ continue;
+ }
+
+ break;
}
if (insn->offset + insn->len >= insn->func->offset + insn->func->len)
break;
+
insn = list_next_entry(insn, list);
}
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 47d9ea70a83d..23a1d065cae1 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -44,9 +44,10 @@ struct instruction {
unsigned int len;
unsigned char type;
unsigned long immediate;
- bool alt_group, visited, dead_end, ignore, hint, save, restore;
+ bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
struct symbol *call_dest;
struct instruction *jump_dest;
+ struct instruction *first_jump_src;
struct list_head alts;
struct symbol *func;
struct stack_op stack_op;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 24460155c82c..c1c338661699 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -26,6 +26,7 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <errno.h>
#include "elf.h"
#include "warn.h"
@@ -358,7 +359,8 @@ struct elf *elf_open(const char *name, int flags)
elf->fd = open(name, flags);
if (elf->fd == -1) {
- perror("open");
+ fprintf(stderr, "objtool: Can't open '%s': %s\n",
+ name, strerror(errno));
goto err;
}
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index 36c5bf6a2675..c3343820916a 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -76,7 +76,8 @@ int orc_dump(const char *_objname)
int fd, nr_entries, i, *orc_ip = NULL, orc_size = 0;
struct orc_entry *orc = NULL;
char *name;
- unsigned long nr_sections, orc_ip_addr = 0;
+ size_t nr_sections;
+ Elf64_Addr orc_ip_addr = 0;
size_t shstrtab_idx;
Elf *elf;
Elf_Scn *scn;
@@ -187,10 +188,10 @@ int orc_dump(const char *_objname)
return -1;
}
- printf("%s+%lx:", name, rela.r_addend);
+ printf("%s+%llx:", name, (unsigned long long)rela.r_addend);
} else {
- printf("%lx:", orc_ip_addr + (i * sizeof(int)) + orc_ip[i]);
+ printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
}
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e5ca31429c9b..18384d9be4e1 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -98,6 +98,11 @@ static int create_orc_entry(struct section *u_sec, struct section *ip_relasec,
struct orc_entry *orc;
struct rela *rela;
+ if (!insn_sec->sym) {
+ WARN("missing symbol for section %s", insn_sec->name);
+ return -1;
+ }
+
/* populate ORC data */
orc = (struct orc_entry *)u_sec->data->d_buf + idx;
memcpy(orc, o, sizeof(*orc));
@@ -165,6 +170,8 @@ int create_orc_sections(struct objtool_file *file)
/* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx);
+ if (!sec)
+ return -1;
ip_relasec = elf_create_rela_section(file->elf, sec);
if (!ip_relasec)
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-10 12:03:05 +0000