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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-28 12:53:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-28 12:53:24 -0700
commit03b2cd72aad1103127282f39c614e4722e5d9e8f (patch)
tree32592bdc0cded33751b992d13ce29e0abb9cc441 /tools
parent0ff0edb550e256597e505eff308f90d9a0b6677c (diff)
parent7d3d10e0e85fb7c23a86a70f795b1eabd2bc030b (diff)
Merge tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar: - Standardize the crypto asm code so that it looks like compiler- generated code to objtool - so that it can understand it. This enables unwinding from crypto asm code - and also fixes the last known remaining objtool warnings for LTO and more. - x86 decoder fixes: clean up and fix the decoder, and also extend it a bit - Misc fixes and cleanups * tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/crypto: Enable objtool in crypto code x86/crypto/sha512-ssse3: Standardize stack alignment prologue x86/crypto/sha512-avx2: Standardize stack alignment prologue x86/crypto/sha512-avx: Standardize stack alignment prologue x86/crypto/sha256-avx2: Standardize stack alignment prologue x86/crypto/sha1_avx2: Standardize stack alignment prologue x86/crypto/sha_ni: Standardize stack alignment prologue x86/crypto/crc32c-pcl-intel: Standardize jump table x86/crypto/camellia-aesni-avx2: Unconditionally allocate stack buffer x86/crypto/aesni-intel_avx: Standardize stack alignment prologue x86/crypto/aesni-intel_avx: Fix register usage comments x86/crypto/aesni-intel_avx: Remove unused macros objtool: Support asm jump tables objtool: Parse options from OBJTOOL_ARGS objtool: Collate parse_options() users objtool: Add --backup objtool,x86: More ModRM sugar objtool,x86: Rewrite ADD/SUB/AND objtool,x86: Support %riz encodings objtool,x86: Simplify register decode ...
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/arch/x86/decode.c282
-rw-r--r--tools/objtool/arch/x86/include/arch/cfi_regs.h12
-rw-r--r--tools/objtool/builtin-check.c43
-rw-r--r--tools/objtool/builtin-orc.c5
-rw-r--r--tools/objtool/check.c53
-rw-r--r--tools/objtool/include/objtool/arch.h1
-rw-r--r--tools/objtool/include/objtool/builtin.h5
-rw-r--r--tools/objtool/objtool.c64
8 files changed, 299 insertions, 166 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 7e8b5bedd946..cedf3ede7545 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -21,17 +21,6 @@
#include <objtool/warn.h>
#include <arch/elf.h>
-static unsigned char op_to_cfi_reg[][2] = {
- {CFI_AX, CFI_R8},
- {CFI_CX, CFI_R9},
- {CFI_DX, CFI_R10},
- {CFI_BX, CFI_R11},
- {CFI_SP, CFI_R12},
- {CFI_BP, CFI_R13},
- {CFI_SI, CFI_R14},
- {CFI_DI, CFI_R15},
-};
-
static int is_x86_64(const struct elf *elf)
{
switch (elf->ehdr.e_machine) {
@@ -87,6 +76,31 @@ unsigned long arch_jump_destination(struct instruction *insn)
return -1; \
else for (list_add_tail(&op->list, ops_list); op; op = NULL)
+/*
+ * Helpers to decode ModRM/SIB:
+ *
+ * r/m| AX CX DX BX | SP | BP | SI DI |
+ * | R8 R9 R10 R11 | R12 | R13 | R14 R15 |
+ * Mod+----------------+-----+-----+---------+
+ * 00 | [r/m] |[SIB]|[IP+]| [r/m] |
+ * 01 | [r/m + d8] |[S+d]| [r/m + d8] |
+ * 10 | [r/m + d32] |[S+D]| [r/m + d32] |
+ * 11 | r/ m |
+ */
+
+#define mod_is_mem() (modrm_mod != 3)
+#define mod_is_reg() (modrm_mod == 3)
+
+#define is_RIP() ((modrm_rm & 7) == CFI_BP && modrm_mod == 0)
+#define have_SIB() ((modrm_rm & 7) == CFI_SP && mod_is_mem())
+
+#define rm_is(reg) (have_SIB() ? \
+ sib_base == (reg) && sib_index == CFI_SP : \
+ modrm_rm == (reg))
+
+#define rm_is_mem(reg) (mod_is_mem() && !is_RIP() && rm_is(reg))
+#define rm_is_reg(reg) (mod_is_reg() && modrm_rm == (reg))
+
int arch_decode_instruction(const struct elf *elf, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
@@ -94,12 +108,14 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
struct list_head *ops_list)
{
struct insn insn;
- int x86_64, sign, ret;
- unsigned char op1, op2, rex = 0, rex_b = 0, rex_r = 0, rex_w = 0,
- rex_x = 0, modrm = 0, modrm_mod = 0, modrm_rm = 0,
- modrm_reg = 0, sib = 0;
+ int x86_64, ret;
+ unsigned char op1, op2,
+ rex = 0, rex_b = 0, rex_r = 0, rex_w = 0, rex_x = 0,
+ modrm = 0, modrm_mod = 0, modrm_rm = 0, modrm_reg = 0,
+ sib = 0, /* sib_scale = 0, */ sib_index = 0, sib_base = 0;
struct stack_op *op = NULL;
struct symbol *sym;
+ u64 imm;
x86_64 = is_x86_64(elf);
if (x86_64 == -1)
@@ -132,23 +148,27 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
if (insn.modrm.nbytes) {
modrm = insn.modrm.bytes[0];
modrm_mod = X86_MODRM_MOD(modrm);
- modrm_reg = X86_MODRM_REG(modrm);
- modrm_rm = X86_MODRM_RM(modrm);
+ modrm_reg = X86_MODRM_REG(modrm) + 8*rex_r;
+ modrm_rm = X86_MODRM_RM(modrm) + 8*rex_b;
}
- if (insn.sib.nbytes)
+ if (insn.sib.nbytes) {
sib = insn.sib.bytes[0];
+ /* sib_scale = X86_SIB_SCALE(sib); */
+ sib_index = X86_SIB_INDEX(sib) + 8*rex_x;
+ sib_base = X86_SIB_BASE(sib) + 8*rex_b;
+ }
switch (op1) {
case 0x1:
case 0x29:
- if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
+ if (rex_w && rm_is_reg(CFI_SP)) {
/* add/sub reg, %rsp */
ADD_OP(op) {
op->src.type = OP_SRC_ADD;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->src.reg = modrm_reg;
op->dest.type = OP_DEST_REG;
op->dest.reg = CFI_SP;
}
@@ -160,7 +180,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
/* push reg */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ op->src.reg = (op1 & 0x7) + 8*rex_b;
op->dest.type = OP_DEST_PUSH;
}
@@ -172,7 +192,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
ADD_OP(op) {
op->src.type = OP_SRC_POP;
op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[op1 & 0x7][rex_b];
+ op->dest.reg = (op1 & 0x7) + 8*rex_b;
}
break;
@@ -190,12 +210,54 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
*type = INSN_JUMP_CONDITIONAL;
break;
- case 0x81:
- case 0x83:
- if (rex != 0x48)
+ case 0x80 ... 0x83:
+ /*
+ * 1000 00sw : mod OP r/m : immediate
+ *
+ * s - sign extend immediate
+ * w - imm8 / imm32
+ *
+ * OP: 000 ADD 100 AND
+ * 001 OR 101 SUB
+ * 010 ADC 110 XOR
+ * 011 SBB 111 CMP
+ */
+
+ /* 64bit only */
+ if (!rex_w)
+ break;
+
+ /* %rsp target only */
+ if (!rm_is_reg(CFI_SP))
break;
- if (modrm == 0xe4) {
+ imm = insn.immediate.value;
+ if (op1 & 2) { /* sign extend */
+ if (op1 & 1) { /* imm32 */
+ imm <<= 32;
+ imm = (s64)imm >> 32;
+ } else { /* imm8 */
+ imm <<= 56;
+ imm = (s64)imm >> 56;
+ }
+ }
+
+ switch (modrm_reg & 7) {
+ case 5:
+ imm = -imm;
+ /* fallthrough */
+ case 0:
+ /* add/sub imm, %rsp */
+ ADD_OP(op) {
+ op->src.type = OP_SRC_ADD;
+ op->src.reg = CFI_SP;
+ op->src.offset = imm;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
+ break;
+
+ case 4:
/* and imm, %rsp */
ADD_OP(op) {
op->src.type = OP_SRC_AND;
@@ -205,53 +267,48 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->dest.reg = CFI_SP;
}
break;
- }
- if (modrm == 0xc4)
- sign = 1;
- else if (modrm == 0xec)
- sign = -1;
- else
+ default:
+ /* WARN ? */
break;
-
- /* add/sub imm, %rsp */
- ADD_OP(op) {
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_SP;
- op->src.offset = insn.immediate.value * sign;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
}
+
break;
case 0x89:
- if (rex_w && !rex_r && modrm_reg == 4) {
+ if (!rex_w)
+ break;
+
+ if (modrm_reg == CFI_SP) {
- if (modrm_mod == 3) {
+ if (mod_is_reg()) {
/* mov %rsp, reg */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
op->src.reg = CFI_SP;
op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ op->dest.reg = modrm_rm;
}
break;
} else {
- /* skip nontrivial SIB */
- if (modrm_rm == 4 && !(sib == 0x24 && rex_b == rex_x))
- break;
-
/* skip RIP relative displacement */
- if (modrm_rm == 5 && modrm_mod == 0)
+ if (is_RIP())
break;
+ /* skip nontrivial SIB */
+ if (have_SIB()) {
+ modrm_rm = sib_base;
+ if (sib_index != CFI_SP)
+ break;
+ }
+
/* mov %rsp, disp(%reg) */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
op->src.reg = CFI_SP;
op->dest.type = OP_DEST_REG_INDIRECT;
- op->dest.reg = op_to_cfi_reg[modrm_rm][rex_b];
+ op->dest.reg = modrm_rm;
op->dest.offset = insn.displacement.value;
}
break;
@@ -260,12 +317,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
break;
}
- if (rex_w && !rex_b && modrm_mod == 3 && modrm_rm == 4) {
+ if (rm_is_reg(CFI_SP)) {
/* mov reg, %rsp */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->src.reg = modrm_reg;
op->dest.type = OP_DEST_REG;
op->dest.reg = CFI_SP;
}
@@ -274,13 +331,15 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
/* fallthrough */
case 0x88:
- if (!rex_b &&
- (modrm_mod == 1 || modrm_mod == 2) && modrm_rm == 5) {
+ if (!rex_w)
+ break;
+
+ if (rm_is_mem(CFI_BP)) {
/* mov reg, disp(%rbp) */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->src.reg = modrm_reg;
op->dest.type = OP_DEST_REG_INDIRECT;
op->dest.reg = CFI_BP;
op->dest.offset = insn.displacement.value;
@@ -288,12 +347,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
break;
}
- if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
+ if (rm_is_mem(CFI_SP)) {
/* mov reg, disp(%rsp) */
ADD_OP(op) {
op->src.type = OP_SRC_REG;
- op->src.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->src.reg = modrm_reg;
op->dest.type = OP_DEST_REG_INDIRECT;
op->dest.reg = CFI_SP;
op->dest.offset = insn.displacement.value;
@@ -304,7 +363,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
break;
case 0x8b:
- if (rex_w && !rex_b && modrm_mod == 1 && modrm_rm == 5) {
+ if (!rex_w)
+ break;
+
+ if (rm_is_mem(CFI_BP)) {
/* mov disp(%rbp), reg */
ADD_OP(op) {
@@ -312,11 +374,12 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->src.reg = CFI_BP;
op->src.offset = insn.displacement.value;
op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.reg = modrm_reg;
}
+ break;
+ }
- } else if (rex_w && !rex_b && sib == 0x24 &&
- modrm_mod != 3 && modrm_rm == 4) {
+ if (rm_is_mem(CFI_SP)) {
/* mov disp(%rsp), reg */
ADD_OP(op) {
@@ -324,75 +387,48 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->src.reg = CFI_SP;
op->src.offset = insn.displacement.value;
op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
+ op->dest.reg = modrm_reg;
}
+ break;
}
break;
case 0x8d:
- if (sib == 0x24 && rex_w && !rex_b && !rex_x) {
-
- ADD_OP(op) {
- if (!insn.displacement.value) {
- /* lea (%rsp), reg */
- op->src.type = OP_SRC_REG;
- } else {
- /* lea disp(%rsp), reg */
- op->src.type = OP_SRC_ADD;
- op->src.offset = insn.displacement.value;
- }
- op->src.reg = CFI_SP;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];
- }
-
- } else if (rex == 0x48 && modrm == 0x65) {
-
- /* lea disp(%rbp), %rsp */
- ADD_OP(op) {
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_BP;
- op->src.offset = insn.displacement.value;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
- }
+ if (mod_is_reg()) {
+ WARN("invalid LEA encoding at %s:0x%lx", sec->name, offset);
+ break;
+ }
- } else if (rex == 0x49 && modrm == 0x62 &&
- insn.displacement.value == -8) {
+ /* skip non 64bit ops */
+ if (!rex_w)
+ break;
- /*
- * lea -0x8(%r10), %rsp
- *
- * Restoring rsp back to its original value after a
- * stack realignment.
- */
- ADD_OP(op) {
- op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R10;
- op->src.offset = -8;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
- }
+ /* skip RIP relative displacement */
+ if (is_RIP())
+ break;
- } else if (rex == 0x49 && modrm == 0x65 &&
- insn.displacement.value == -16) {
+ /* skip nontrivial SIB */
+ if (have_SIB()) {
+ modrm_rm = sib_base;
+ if (sib_index != CFI_SP)
+ break;
+ }
- /*
- * lea -0x10(%r13), %rsp
- *
- * Restoring rsp back to its original value after a
- * stack realignment.
- */
- ADD_OP(op) {
+ /* lea disp(%src), %dst */
+ ADD_OP(op) {
+ op->src.offset = insn.displacement.value;
+ if (!op->src.offset) {
+ /* lea (%src), %dst */
+ op->src.type = OP_SRC_REG;
+ } else {
+ /* lea disp(%src), %dst */
op->src.type = OP_SRC_ADD;
- op->src.reg = CFI_R13;
- op->src.offset = -16;
- op->dest.type = OP_DEST_REG;
- op->dest.reg = CFI_SP;
}
+ op->src.reg = modrm_rm;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = modrm_reg;
}
-
break;
case 0x8f:
@@ -479,9 +515,17 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
* mov bp, sp
* pop bp
*/
- ADD_OP(op)
- op->dest.type = OP_DEST_LEAVE;
-
+ ADD_OP(op) {
+ op->src.type = OP_SRC_REG;
+ op->src.reg = CFI_BP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_SP;
+ }
+ ADD_OP(op) {
+ op->src.type = OP_SRC_POP;
+ op->dest.type = OP_DEST_REG;
+ op->dest.reg = CFI_BP;
+ }
break;
case 0xe3:
diff --git a/tools/objtool/arch/x86/include/arch/cfi_regs.h b/tools/objtool/arch/x86/include/arch/cfi_regs.h
index 79bc517efba8..0579d22c433c 100644
--- a/tools/objtool/arch/x86/include/arch/cfi_regs.h
+++ b/tools/objtool/arch/x86/include/arch/cfi_regs.h
@@ -4,13 +4,13 @@
#define _OBJTOOL_CFI_REGS_H
#define CFI_AX 0
-#define CFI_DX 1
-#define CFI_CX 2
+#define CFI_CX 1
+#define CFI_DX 2
#define CFI_BX 3
-#define CFI_SI 4
-#define CFI_DI 5
-#define CFI_BP 6
-#define CFI_SP 7
+#define CFI_SP 4
+#define CFI_BP 5
+#define CFI_SI 6
+#define CFI_DI 7
#define CFI_R8 8
#define CFI_R9 9
#define CFI_R10 10
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index c3a85d8f6c5c..8b38b5d6fec7 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -15,16 +15,23 @@
#include <subcmd/parse-options.h>
#include <string.h>
+#include <stdlib.h>
#include <objtool/builtin.h>
#include <objtool/objtool.h>
-bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux, mcount, noinstr;
+bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
+ validate_dup, vmlinux, mcount, noinstr, backup;
static const char * const check_usage[] = {
"objtool check [<options>] file.o",
NULL,
};
+static const char * const env_usage[] = {
+ "OBJTOOL_ARGS=\"<options>\"",
+ NULL,
+};
+
const struct option check_options[] = {
OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
@@ -37,20 +44,44 @@ const struct option check_options[] = {
OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"),
OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"),
+ OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"),
OPT_END(),
};
+int cmd_parse_options(int argc, const char **argv, const char * const usage[])
+{
+ const char *envv[16] = { };
+ char *env;
+ int envc;
+
+ env = getenv("OBJTOOL_ARGS");
+ if (env) {
+ envv[0] = "OBJTOOL_ARGS";
+ for (envc = 1; envc < ARRAY_SIZE(envv); ) {
+ envv[envc++] = env;
+ env = strchr(env, ' ');
+ if (!env)
+ break;
+ *env = '\0';
+ env++;
+ }
+
+ parse_options(envc, envv, check_options, env_usage, 0);
+ }
+
+ argc = parse_options(argc, argv, check_options, usage, 0);
+ if (argc != 1)
+ usage_with_options(usage, check_options);
+ return argc;
+}
+
int cmd_check(int argc, const char **argv)
{
const char *objname;
struct objtool_file *file;
int ret;
- argc = parse_options(argc, argv, check_options, check_usage, 0);
-
- if (argc != 1)
- usage_with_options(check_usage, check_options);
-
+ argc = cmd_parse_options(argc, argv, check_usage);
objname = argv[0];
file = objtool_open_read(objname);
diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c
index 8273bbf7cebb..17f8b9307738 100644
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -34,10 +34,7 @@ int cmd_orc(int argc, const char **argv)
struct objtool_file *file;
int ret;
- argc = parse_options(argc, argv, check_options, orc_usage, 0);
- if (argc != 1)
- usage_with_options(orc_usage, check_options);
-
+ argc = cmd_parse_options(argc, argv, orc_usage);
objname = argv[0];
file = objtool_open_read(objname);
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 1f4154f9b04b..9ed1a4cd00dc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -108,6 +108,18 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
+static bool is_jump_table_jump(struct instruction *insn)
+{
+ struct alt_group *alt_group = insn->alt_group;
+
+ if (insn->jump_table)
+ return true;
+
+ /* Retpoline alternative for a jump table? */
+ return alt_group && alt_group->orig_group &&
+ alt_group->orig_group->first_insn->jump_table;
+}
+
static bool is_sibling_call(struct instruction *insn)
{
/*
@@ -120,7 +132,7 @@ static bool is_sibling_call(struct instruction *insn)
/* An indirect jump is either a sibling call or a jump to a table. */
if (insn->type == INSN_JUMP_DYNAMIC)
- return list_empty(&insn->alts);
+ return !is_jump_table_jump(insn);
/* add_jump_destinations() sets insn->call_dest for sibling calls. */
return (is_static_jump(insn) && insn->call_dest);
@@ -1969,8 +1981,9 @@ static void restore_reg(struct cfi_state *cfi, unsigned char reg)
* 41 5d pop %r13
* c3 retq
*/
-static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
- struct stack_op *op)
+static int update_cfi_state(struct instruction *insn,
+ struct instruction *next_insn,
+ struct cfi_state *cfi, struct stack_op *op)
{
struct cfi_reg *cfa = &cfi->cfa;
struct cfi_reg *regs = cfi->regs;
@@ -2029,7 +2042,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
}
else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP &&
- cfa->base == CFI_BP) {
+ (cfa->base == CFI_BP || cfa->base == cfi->drap_reg)) {
/*
* mov %rbp, %rsp
@@ -2171,7 +2184,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
}
- if (op->dest.reg == cfi->cfa.base) {
+ if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) {
WARN_FUNC("unsupported stack register modification",
insn->sec, insn->offset);
return -1;
@@ -2226,7 +2239,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
cfa->offset = 0;
cfi->drap_offset = -1;
- } else if (regs[op->dest.reg].offset == -cfi->stack_size) {
+ } else if (cfi->stack_size == -regs[op->dest.reg].offset) {
/* pop %reg */
restore_reg(cfi, op->dest.reg);
@@ -2367,26 +2380,6 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
- case OP_DEST_LEAVE:
- if ((!cfi->drap && cfa->base != CFI_BP) ||
- (cfi->drap && cfa->base != cfi->drap_reg)) {
- WARN_FUNC("leave instruction with modified stack frame",
- insn->sec, insn->offset);
- return -1;
- }
-
- /* leave (mov %rbp, %rsp; pop %rbp) */
-
- cfi->stack_size = -cfi->regs[CFI_BP].offset - 8;
- restore_reg(cfi, CFI_BP);
-
- if (!cfi->drap) {
- cfa->base = CFI_SP;
- cfa->offset -= 8;
- }
-
- break;
-
case OP_DEST_MEM:
if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) {
WARN_FUNC("unknown stack-related memory operation",
@@ -2443,13 +2436,15 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn
return 0;
}
-static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
+static int handle_insn_ops(struct instruction *insn,
+ struct instruction *next_insn,
+ struct insn_state *state)
{
struct stack_op *op;
list_for_each_entry(op, &insn->stack_ops, list) {
- if (update_cfi_state(insn, &state->cfi, op))
+ if (update_cfi_state(insn, next_insn, &state->cfi, op))
return 1;
if (!insn->alt_group)
@@ -2732,7 +2727,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
return 0;
}
- if (handle_insn_ops(insn, &state))
+ if (handle_insn_ops(insn, next_insn, &state))
return 1;
switch (insn->type) {
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 48b540a9d9e9..062bb6e9b865 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -35,7 +35,6 @@ enum op_dest_type {
OP_DEST_MEM,
OP_DEST_PUSH,
OP_DEST_PUSHF,
- OP_DEST_LEAVE,
};
struct op_dest {
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index 2502bb27de17..15ac0b7d3d6a 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -8,7 +8,10 @@
#include <subcmd/parse-options.h>
extern const struct option check_options[];
-extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux, mcount, noinstr;
+extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
+ validate_dup, vmlinux, mcount, noinstr, backup;
+
+extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]);
extern int cmd_check(int argc, const char **argv);
extern int cmd_orc(int argc, const char **argv);
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 3a3ea1b4e4da..e21db8bce493 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -17,6 +17,7 @@
#include <stdbool.h>
#include <string.h>
#include <stdlib.h>
+#include <unistd.h>
#include <subcmd/exec-cmd.h>
#include <subcmd/pager.h>
#include <linux/kernel.h>
@@ -44,6 +45,64 @@ bool help;
const char *objname;
static struct objtool_file file;
+static bool objtool_create_backup(const char *_objname)
+{
+ int len = strlen(_objname);
+ char *buf, *base, *name = malloc(len+6);
+ int s, d, l, t;
+
+ if (!name) {
+ perror("failed backup name malloc");
+ return false;
+ }
+
+ strcpy(name, _objname);
+ strcpy(name + len, ".orig");
+
+ d = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+ if (d < 0) {
+ perror("failed to create backup file");
+ return false;
+ }
+
+ s = open(_objname, O_RDONLY);
+ if (s < 0) {
+ perror("failed to open orig file");
+ return false;
+ }
+
+ buf = malloc(4096);
+ if (!buf) {
+ perror("failed backup data malloc");
+ return false;
+ }
+
+ while ((l = read(s, buf, 4096)) > 0) {
+ base = buf;
+ do {
+ t = write(d, base, l);
+ if (t < 0) {
+ perror("failed backup write");
+ return false;
+ }
+ base += t;
+ l -= t;
+ } while (l);
+ }
+
+ if (l < 0) {
+ perror("failed backup read");
+ return false;
+ }
+
+ free(name);
+ free(buf);
+ close(d);
+ close(s);
+
+ return true;
+}
+
struct objtool_file *objtool_open_read(const char *_objname)
{
if (objname) {
@@ -59,6 +118,11 @@ struct objtool_file *objtool_open_read(const char *_objname)
if (!file.elf)
return NULL;
+ if (backup && !objtool_create_backup(objname)) {
+ WARN("can't create backup file");
+ return NULL;
+ }
+
INIT_LIST_HEAD(&file.insn_list);
hash_init(file.insn_hash);
INIT_LIST_HEAD(&file.retpoline_call_list);