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objtool updates: 

- Make objtool work for big-endian cross compiles
 
  - Make stack tracking via stack pointer memory operations match push/pop
    semantics to prepare for architectures w/o PUSH/POP instructions.
 
  - Add support for analyzing alternatives
 
  - Improve retpoline detection and handling
 
  - Improve assembly code coverage on x86
 
  - Provide support for inlined stack switching
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Merge tag 'objtool-core-2021-02-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Thomas Gleixner:

 - Make objtool work for big-endian cross compiles

 - Make stack tracking via stack pointer memory operations match
   push/pop semantics to prepare for architectures w/o PUSH/POP
   instructions.

 - Add support for analyzing alternatives

 - Improve retpoline detection and handling

 - Improve assembly code coverage on x86

 - Provide support for inlined stack switching

* tag 'objtool-core-2021-02-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  objtool: Support stack-swizzle
  objtool,x86: Additionally decode: mov %rsp, (%reg)
  x86/unwind/orc: Change REG_SP_INDIRECT
  x86/power: Support objtool validation in hibernate_asm_64.S
  x86/power: Move restore_registers() to top of the file
  x86/power: Annotate indirect branches as safe
  x86/acpi: Support objtool validation in wakeup_64.S
  x86/acpi: Annotate indirect branch as safe
  x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S
  x86/xen/pvh: Annotate indirect branch as safe
  x86/xen: Support objtool vmlinux.o validation in xen-head.S
  x86/xen: Support objtool validation in xen-asm.S
  objtool: Add xen_start_kernel() to noreturn list
  objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC
  objtool: Add asm version of STACK_FRAME_NON_STANDARD
  objtool: Assume only ELF functions do sibling calls
  x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub
  objtool: Support retpoline jump detection for vmlinux.o
  objtool: Fix ".cold" section suffix check for newer versions of GCC
  objtool: Fix retpoline detection in asm code
  ...
master
Linus Torvalds 2021-02-23 09:56:13 -08:00
parent 79db4d2293 aafeb14e9d
commit a56ff24efb
49 changed files with 997 additions and 632 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
arch/x86/include/asm/insn.h
View File

@ -7,9 +7,12 @@
* Copyright (C) IBM Corporation, 2009
*/
#include <asm/byteorder.h>
/* insn_attr_t is defined in inat.h */
#include <asm/inat.h>
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
struct insn_field {
union {
insn_value_t value;
@ -20,6 +23,48 @@ struct insn_field {
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->nbytes = n;
}
static inline void insn_set_byte(struct insn_field *p, unsigned char n,
insn_byte_t v)
{
p->bytes[n] = v;
}
#else
struct insn_field {
insn_value_t value;
union {
insn_value_t little;
insn_byte_t bytes[4];
};
/* !0 if we've run insn_get_xxx() for this field */
unsigned char got;
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->little = __cpu_to_le32(v);
p->nbytes = n;
}
static inline void insn_set_byte(struct insn_field *p, unsigned char n,
insn_byte_t v)
{
p->bytes[n] = v;
p->value = __le32_to_cpu(p->little);
}
#endif
struct insn {
struct insn_field prefixes; /*
* Prefixes

10
arch/x86/include/asm/orc_types.h
View File

@ -40,6 +40,8 @@
#define ORC_REG_MAX 15
#ifndef __ASSEMBLY__
#include <asm/byteorder.h>
/*
* This struct is more or less a vastly simplified version of the DWARF Call
* Frame Information standard. It contains only the necessary parts of DWARF
@ -51,10 +53,18 @@
struct orc_entry {
s16 sp_offset;
s16 bp_offset;
#if defined(__LITTLE_ENDIAN_BITFIELD)
unsigned sp_reg:4;
unsigned bp_reg:4;
unsigned type:2;
unsigned end:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
unsigned bp_reg:4;
unsigned sp_reg:4;
unsigned unused:5;
unsigned end:1;
unsigned type:2;
#endif
} __packed;
#endif /* __ASSEMBLY__ */

13
arch/x86/include/asm/unwind_hints.h
View File

@ -48,17 +48,8 @@
UNWIND_HINT_REGS base=\base offset=\offset partial=1
.endm
.macro UNWIND_HINT_FUNC sp_offset=8
UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=\sp_offset type=UNWIND_HINT_TYPE_CALL
.endm
/*
* RET_OFFSET: Used on instructions that terminate a function; mostly RETURN
* and sibling calls. On these, sp_offset denotes the expected offset from
* initial_func_cfi.
*/
.macro UNWIND_HINT_RET_OFFSET sp_offset=8
UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset
.macro UNWIND_HINT_FUNC
UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC
.endm
#endif /* __ASSEMBLY__ */

1
arch/x86/kernel/acpi/Makefile
View File

@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
OBJECT_FILES_NON_STANDARD_wakeup_$(BITS).o := y
obj-$(CONFIG_ACPI) += boot.o
obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o

4
arch/x86/kernel/acpi/wakeup_64.S
View File

@ -1,12 +1,14 @@
/* SPDX-License-Identifier: GPL-2.0-only */
.text
#include <linux/linkage.h>
#include <linux/objtool.h>
#include <asm/segment.h>
#include <asm/pgtable_types.h>
#include <asm/page_types.h>
#include <asm/msr.h>
#include <asm/asm-offsets.h>
#include <asm/frame.h>
#include <asm/nospec-branch.h>
# Copyright 2003 Pavel Machek <pavel@suse.cz
@ -39,6 +41,7 @@ SYM_FUNC_START(wakeup_long64)
movq saved_rbp, %rbp
movq saved_rip, %rax
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
SYM_FUNC_END(wakeup_long64)
@ -126,6 +129,7 @@ SYM_FUNC_START(do_suspend_lowlevel)
FRAME_END
jmp restore_processor_state
SYM_FUNC_END(do_suspend_lowlevel)
STACK_FRAME_NON_STANDARD do_suspend_lowlevel
.data
saved_rbp: .quad 0

8
arch/x86/kernel/ftrace_64.S
View File

@ -184,6 +184,7 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
* It is also used to copy the retq for trampolines.
*/
SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
UNWIND_HINT_FUNC
retq
SYM_FUNC_END(ftrace_epilogue)
@ -276,7 +277,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
restore_mcount_regs 8
/* Restore flags */
popfq
UNWIND_HINT_RET_OFFSET
UNWIND_HINT_FUNC
jmp ftrace_epilogue
SYM_FUNC_END(ftrace_regs_caller)
@ -333,8 +334,7 @@ SYM_FUNC_START(ftrace_graph_caller)
retq
SYM_FUNC_END(ftrace_graph_caller)
SYM_CODE_START(return_to_handler)
UNWIND_HINT_EMPTY
SYM_FUNC_START(return_to_handler)
subq $24, %rsp
/* Save the return values */
@ -349,5 +349,5 @@ SYM_CODE_START(return_to_handler)
movq (%rsp), %rax
addq $24, %rsp
JMP_NOSPEC rdi
SYM_CODE_END(return_to_handler)
SYM_FUNC_END(return_to_handler)
#endif

5
arch/x86/kernel/unwind_orc.c
View File

@ -471,7 +471,7 @@ bool unwind_next_frame(struct unwind_state *state)
break;
case ORC_REG_SP_INDIRECT:
sp = state->sp + orc->sp_offset;
sp = state->sp;
indirect = true;
break;
@ -521,6 +521,9 @@ bool unwind_next_frame(struct unwind_state *state)
if (indirect) {
if (!deref_stack_reg(state, sp, &sp))
goto err;
if (orc->sp_reg == ORC_REG_SP_INDIRECT)
sp += orc->sp_offset;
}
/* Find IP, SP and possibly regs: */

119
arch/x86/lib/insn.c
View File

@ -5,6 +5,7 @@
* Copyright (C) IBM Corporation, 2002, 2004, 2009
*/
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <linux/string.h>
#else
@ -15,15 +16,28 @@
#include <asm/emulate_prefix.h>
#define leXX_to_cpu(t, r) \
({ \
__typeof__(t) v; \
switch (sizeof(t)) { \
case 4: v = le32_to_cpu(r); break; \
case 2: v = le16_to_cpu(r); break; \
case 1: v = r; break; \
default: \
BUILD_BUG(); break; \
} \
v; \
})
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
({ t r = *(t*)((insn)->next_byte + n); r; })
({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
@ -147,9 +161,9 @@ found:
b = insn->prefixes.bytes[3];
for (i = 0; i < nb; i++)
if (prefixes->bytes[i] == lb)
prefixes->bytes[i] = b;
insn_set_byte(prefixes, i, b);
}
insn->prefixes.bytes[3] = lb;
insn_set_byte(&insn->prefixes, 3, lb);
}
/* Decode REX prefix */
@ -157,8 +171,7 @@ found:
b = peek_next(insn_byte_t, insn);
attr = inat_get_opcode_attribute(b);
if (inat_is_rex_prefix(attr)) {
insn->rex_prefix.value = b;
insn->rex_prefix.nbytes = 1;
insn_field_set(&insn->rex_prefix, b, 1);
insn->next_byte++;
if (X86_REX_W(b))
/* REX.W overrides opnd_size */
@ -181,13 +194,13 @@ found:
if (X86_MODRM_MOD(b2) != 3)
goto vex_end;
}
insn->vex_prefix.bytes[0] = b;
insn->vex_prefix.bytes[1] = b2;
insn_set_byte(&insn->vex_prefix, 0, b);
insn_set_byte(&insn->vex_prefix, 1, b2);
if (inat_is_evex_prefix(attr)) {
b2 = peek_nbyte_next(insn_byte_t, insn, 2);
insn->vex_prefix.bytes[2] = b2;
insn_set_byte(&insn->vex_prefix, 2, b2);
b2 = peek_nbyte_next(insn_byte_t, insn, 3);
insn->vex_prefix.bytes[3] = b2;
insn_set_byte(&insn->vex_prefix, 3, b2);
insn->vex_prefix.nbytes = 4;
insn->next_byte += 4;
if (insn->x86_64 && X86_VEX_W(b2))
@ -195,7 +208,7 @@ found:
insn->opnd_bytes = 8;
} else if (inat_is_vex3_prefix(attr)) {
b2 = peek_nbyte_next(insn_byte_t, insn, 2);
insn->vex_prefix.bytes[2] = b2;
insn_set_byte(&insn->vex_prefix, 2, b2);
insn->vex_prefix.nbytes = 3;
insn->next_byte += 3;
if (insn->x86_64 && X86_VEX_W(b2))
@ -207,7 +220,7 @@ found:
* Makes it easier to decode vex.W, vex.vvvv,
* vex.L and vex.pp. Masking with 0x7f sets vex.W == 0.
*/
insn->vex_prefix.bytes[2] = b2 & 0x7f;
insn_set_byte(&insn->vex_prefix, 2, b2 & 0x7f);
insn->vex_prefix.nbytes = 2;
insn->next_byte += 2;
}
@ -243,7 +256,7 @@ void insn_get_opcode(struct insn *insn)
/* Get first opcode */
op = get_next(insn_byte_t, insn);
opcode->bytes[0] = op;
insn_set_byte(opcode, 0, op);
opcode->nbytes = 1;
/* Check if there is VEX prefix or not */
@ -295,8 +308,7 @@ void insn_get_modrm(struct insn *insn)
if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
modrm->value = mod;
modrm->nbytes = 1;
insn_field_set(modrm, mod, 1);
if (inat_is_group(insn->attr)) {
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
@ -334,7 +346,7 @@ int insn_rip_relative(struct insn *insn)
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
*/
return (modrm->nbytes && (modrm->value & 0xc7) == 0x5);
return (modrm->nbytes && (modrm->bytes[0] & 0xc7) == 0x5);
}
/**
@ -353,11 +365,11 @@ void insn_get_sib(struct insn *insn)
if (!insn->modrm.got)
insn_get_modrm(insn);
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
modrm = insn->modrm.bytes[0];
if (insn->addr_bytes != 2 &&
X86_MODRM_MOD(modrm) != 3 && X86_MODRM_RM(modrm) == 4) {
insn->sib.value = get_next(insn_byte_t, insn);
insn->sib.nbytes = 1;
insn_field_set(&insn->sib,
get_next(insn_byte_t, insn), 1);
}
}
insn->sib.got = 1;
@ -407,19 +419,18 @@ void insn_get_displacement(struct insn *insn)
if (mod == 3)
goto out;
if (mod == 1) {
insn->displacement.value = get_next(signed char, insn);
insn->displacement.nbytes = 1;
insn_field_set(&insn->displacement,
get_next(signed char, insn), 1);
} else if (insn->addr_bytes == 2) {
if ((mod == 0 && rm == 6) || mod == 2) {
insn->displacement.value =
get_next(short, insn);
insn->displacement.nbytes = 2;
insn_field_set(&insn->displacement,
get_next(short, insn), 2);
}
} else {
if ((mod == 0 && rm == 5) || mod == 2 ||
(mod == 0 && base == 5)) {
insn->displacement.value = get_next(int, insn);
insn->displacement.nbytes = 4;
insn_field_set(&insn->displacement,
get_next(int, insn), 4);
}
}
}
@ -435,18 +446,14 @@ static int __get_moffset(struct insn *insn)
{
switch (insn->addr_bytes) {
case 2:
insn->moffset1.value = get_next(short, insn);
insn->moffset1.nbytes = 2;
insn_field_set(&insn->moffset1, get_next(short, insn), 2);
break;
case 4:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
break;
case 8:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn->moffset2.value = get_next(int, insn);
insn->moffset2.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
insn_field_set(&insn->moffset2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -464,13 +471,11 @@ static int __get_immv32(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case 4:
case 8:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -487,18 +492,15 @@ static int __get_immv(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn->immediate1.nbytes = 4;
break;
case 8:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -515,12 +517,10 @@ static int __get_immptr(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
break;
case 8:
/* ptr16:64 is not exist (no segment) */
@ -528,8 +528,7 @@ static int __get_immptr(struct insn *insn)
default: /* opnd_bytes must be modified manually */
goto err_out;
}
insn->immediate2.value = get_next(unsigned short, insn);
insn->immediate2.nbytes = 2;
insn_field_set(&insn->immediate2, get_next(unsigned short, insn), 2);
insn->immediate1.got = insn->immediate2.got = 1;
return 1;
@ -565,22 +564,17 @@ void insn_get_immediate(struct insn *insn)
switch (inat_immediate_size(insn->attr)) {
case INAT_IMM_BYTE:
insn->immediate.value = get_next(signed char, insn);
insn->immediate.nbytes = 1;
insn_field_set(&insn->immediate, get_next(signed char, insn), 1);
break;
case INAT_IMM_WORD:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case INAT_IMM_DWORD:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
case INAT_IMM_QWORD:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
case INAT_IMM_PTR:
if (!__get_immptr(insn))
@ -599,8 +593,7 @@ void insn_get_immediate(struct insn *insn)
goto err_out;
}
if (inat_has_second_immediate(insn->attr)) {
insn->immediate2.value = get_next(signed char, insn);
insn->immediate2.nbytes = 1;
insn_field_set(&insn->immediate2, get_next(signed char, insn), 1);
}
done:
insn->immediate.got = 1;

2
arch/x86/lib/retpoline.S
View File

@ -28,7 +28,7 @@ SYM_FUNC_START_NOALIGN(__x86_retpoline_\reg)
jmp .Lspec_trap_\@
.Ldo_rop_\@:
mov %\reg, (%_ASM_SP)
UNWIND_HINT_RET_OFFSET
UNWIND_HINT_FUNC
ret
SYM_FUNC_END(__x86_retpoline_\reg)

2
arch/x86/platform/pvh/head.S
View File

@ -16,6 +16,7 @@
#include <asm/boot.h>
#include <asm/processor-flags.h>
#include <asm/msr.h>
#include <asm/nospec-branch.h>
#include <xen/interface/elfnote.h>
__HEAD
@ -105,6 +106,7 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
/* startup_64 expects boot_params in %rsi. */
mov $_pa(pvh_bootparams), %rsi
mov $_pa(startup_64), %rax
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
#else /* CONFIG_X86_64 */

1
arch/x86/power/Makefile
View File

@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
OBJECT_FILES_NON_STANDARD_hibernate_asm_$(BITS).o := y
# __restore_processor_state() restores %gs after S3 resume and so should not
# itself be stack-protected

159
arch/x86/power/hibernate_asm_64.S
View File

@ -21,84 +21,7 @@
#include <asm/asm-offsets.h>
#include <asm/processor-flags.h>
#include <asm/frame.h>
SYM_FUNC_START(swsusp_arch_suspend)
movq $saved_context, %rax
movq %rsp, pt_regs_sp(%rax)
movq %rbp, pt_regs_bp(%rax)
movq %rsi, pt_regs_si(%rax)
movq %rdi, pt_regs_di(%rax)
movq %rbx, pt_regs_bx(%rax)
movq %rcx, pt_regs_cx(%rax)
movq %rdx, pt_regs_dx(%rax)
movq %r8, pt_regs_r8(%rax)
movq %r9, pt_regs_r9(%rax)
movq %r10, pt_regs_r10(%rax)
movq %r11, pt_regs_r11(%rax)
movq %r12, pt_regs_r12(%rax)
movq %r13, pt_regs_r13(%rax)
movq %r14, pt_regs_r14(%rax)
movq %r15, pt_regs_r15(%rax)
pushfq
popq pt_regs_flags(%rax)
/* save cr3 */
movq %cr3, %rax
movq %rax, restore_cr3(%rip)
FRAME_BEGIN
call swsusp_save
FRAME_END
ret
SYM_FUNC_END(swsusp_arch_suspend)
SYM_CODE_START(restore_image)
/* prepare to jump to the image kernel */
movq restore_jump_address(%rip), %r8
movq restore_cr3(%rip), %r9
/* prepare to switch to temporary page tables */
movq temp_pgt(%rip), %rax
movq mmu_cr4_features(%rip), %rbx
/* prepare to copy image data to their original locations */
movq restore_pblist(%rip), %rdx
/* jump to relocated restore code */
movq relocated_restore_code(%rip), %rcx
jmpq *%rcx
SYM_CODE_END(restore_image)
/* code below has been relocated to a safe page */
SYM_CODE_START(core_restore_code)
/* switch to temporary page tables */
movq %rax, %cr3
/* flush TLB */
movq %rbx, %rcx
andq $~(X86_CR4_PGE), %rcx
movq %rcx, %cr4; # turn off PGE
movq %cr3, %rcx; # flush TLB
movq %rcx, %cr3;
movq %rbx, %cr4; # turn PGE back on
.Lloop:
testq %rdx, %rdx
jz .Ldone
/* get addresses from the pbe and copy the page */
movq pbe_address(%rdx), %rsi
movq pbe_orig_address(%rdx), %rdi
movq $(PAGE_SIZE >> 3), %rcx
rep
movsq
/* progress to the next pbe */
movq pbe_next(%rdx), %rdx
jmp .Lloop
.Ldone:
/* jump to the restore_registers address from the image header */
jmpq *%r8
SYM_CODE_END(core_restore_code)
#include <asm/nospec-branch.h>
/* code below belongs to the image kernel */
.align PAGE_SIZE
@ -145,3 +68,83 @@ SYM_FUNC_START(restore_registers)
ret
SYM_FUNC_END(restore_registers)
SYM_FUNC_START(swsusp_arch_suspend)
movq $saved_context, %rax
movq %rsp, pt_regs_sp(%rax)
movq %rbp, pt_regs_bp(%rax)
movq %rsi, pt_regs_si(%rax)
movq %rdi, pt_regs_di(%rax)
movq %rbx, pt_regs_bx(%rax)
movq %rcx, pt_regs_cx(%rax)
movq %rdx, pt_regs_dx(%rax)
movq %r8, pt_regs_r8(%rax)
movq %r9, pt_regs_r9(%rax)
movq %r10, pt_regs_r10(%rax)
movq %r11, pt_regs_r11(%rax)
movq %r12, pt_regs_r12(%rax)
movq %r13, pt_regs_r13(%rax)
movq %r14, pt_regs_r14(%rax)
movq %r15, pt_regs_r15(%rax)
pushfq
popq pt_regs_flags(%rax)
/* save cr3 */
movq %cr3, %rax
movq %rax, restore_cr3(%rip)
FRAME_BEGIN
call swsusp_save
FRAME_END
ret
SYM_FUNC_END(swsusp_arch_suspend)
SYM_FUNC_START(restore_image)
/* prepare to jump to the image kernel */
movq restore_jump_address(%rip), %r8
movq restore_cr3(%rip), %r9
/* prepare to switch to temporary page tables */
movq temp_pgt(%rip), %rax
movq mmu_cr4_features(%rip), %rbx
/* prepare to copy image data to their original locations */
movq restore_pblist(%rip), %rdx
/* jump to relocated restore code */
movq relocated_restore_code(%rip), %rcx
ANNOTATE_RETPOLINE_SAFE
jmpq *%rcx
SYM_FUNC_END(restore_image)
/* code below has been relocated to a safe page */
SYM_FUNC_START(core_restore_code)
/* switch to temporary page tables */
movq %rax, %cr3
/* flush TLB */
movq %rbx, %rcx
andq $~(X86_CR4_PGE), %rcx
movq %rcx, %cr4; # turn off PGE
movq %cr3, %rcx; # flush TLB
movq %rcx, %cr3;
movq %rbx, %cr4; # turn PGE back on
.Lloop:
testq %rdx, %rdx
jz .Ldone
/* get addresses from the pbe and copy the page */
movq pbe_address(%rdx), %rsi
movq pbe_orig_address(%rdx), %rdi
movq $(PAGE_SIZE >> 3), %rcx
rep
movsq
/* progress to the next pbe */
movq pbe_next(%rdx), %rdx
jmp .Lloop
.Ldone:
/* jump to the restore_registers address from the image header */
ANNOTATE_RETPOLINE_SAFE
jmpq *%r8
SYM_FUNC_END(core_restore_code)

8
arch/x86/tools/Makefile
View File

@ -29,14 +29,14 @@ posttest: $(obj)/insn_decoder_test vmlinux $(obj)/insn_sanity
hostprogs += insn_decoder_test insn_sanity
# -I needed for generated C source and C source which in the kernel tree.
HOSTCFLAGS_insn_decoder_test.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x86/include/uapi/ -I$(srctree)/arch/x86/include/ -I$(srctree)/arch/x86/lib/ -I$(srctree)/include/uapi/
HOSTCFLAGS_insn_decoder_test.o := -Wall -I$(srctree)/tools/arch/x86/lib/ -I$(srctree)/tools/arch/x86/include/ -I$(objtree)/arch/x86/lib/
HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x86/include/ -I$(srctree)/arch/x86/lib/ -I$(srctree)/include/
HOSTCFLAGS_insn_sanity.o := -Wall -I$(srctree)/tools/arch/x86/lib/ -I$(srctree)/tools/arch/x86/include/ -I$(objtree)/arch/x86/lib/
# Dependencies are also needed.
$(obj)/insn_decoder_test.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
$(obj)/insn_decoder_test.o: $(srctree)/tools/arch/x86/lib/insn.c $(srctree)/tools/arch/x86/lib/inat.c $(srctree)/tools/arch/x86/include/asm/inat_types.h $(srctree)/tools/arch/x86/include/asm/inat.h $(srctree)/tools/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
$(obj)/insn_sanity.o: $(srctree)/tools/arch/x86/lib/insn.c $(srctree)/tools/arch/x86/lib/inat.c $(srctree)/tools/arch/x86/include/asm/inat_types.h $(srctree)/tools/arch/x86/include/asm/inat.h $(srctree)/tools/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
HOST_EXTRACFLAGS += -I$(srctree)/tools/include
hostprogs += relocs

4
arch/x86/tools/insn_sanity.c
View File

@ -14,10 +14,6 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define unlikely(cond) (cond)
#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
#include <asm/insn.h>
#include <inat.c>
#include <insn.c>

1
arch/x86/xen/Makefile
View File

@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
OBJECT_FILES_NON_STANDARD_xen-asm.o := y
ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities

28
arch/x86/xen/xen-asm.S
View File

@ -14,6 +14,7 @@
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/frame.h>
#include <asm/unwind_hints.h>
#include <xen/interface/xen.h>
@ -118,6 +119,7 @@ SYM_FUNC_END(xen_read_cr2_direct);
.macro xen_pv_trap name
SYM_CODE_START(xen_\name)
UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp \name
@ -157,6 +159,7 @@ xen_pv_trap asm_exc_xen_hypervisor_callback
SYM_CODE_START(xen_early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
@ -183,6 +186,7 @@ hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
* rsp->rax }
*/
SYM_CODE_START(xen_iret)
UNWIND_HINT_EMPTY
pushq $0
jmp hypercall_iret
SYM_CODE_END(xen_iret)
@ -203,7 +207,8 @@ SYM_CODE_END(xen_iret)
*/
/* Normal 64-bit system call target */
SYM_FUNC_START(xen_syscall_target)
SYM_CODE_START(xen_syscall_target)
UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@ -216,12 +221,13 @@ SYM_FUNC_START(xen_syscall_target)
movq $__USER_CS, 1*8(%rsp)
jmp entry_SYSCALL_64_after_hwframe
SYM_FUNC_END(xen_syscall_target)
SYM_CODE_END(xen_syscall_target)
#ifdef CONFIG_IA32_EMULATION
/* 32-bit compat syscall target */
SYM_FUNC_START(xen_syscall32_target)
SYM_CODE_START(xen_syscall32_target)
UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@ -234,10 +240,11 @@ SYM_FUNC_START(xen_syscall32_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSCALL_compat_after_hwframe
SYM_FUNC_END(xen_syscall32_target)
SYM_CODE_END(xen_syscall32_target)
/* 32-bit compat sysenter target */
SYM_FUNC_START(xen_sysenter_target)
SYM_CODE_START(xen_sysenter_target)
UNWIND_HINT_EMPTY
/*
* NB: Xen is polite and clears TF from EFLAGS for us. This means
* that we don't need to guard against single step exceptions here.
@ -254,17 +261,18 @@ SYM_FUNC_START(xen_sysenter_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSENTER_compat_after_hwframe
SYM_FUNC_END(xen_sysenter_target)
SYM_CODE_END(xen_sysenter_target)
#else /* !CONFIG_IA32_EMULATION */
SYM_FUNC_START_ALIAS(xen_syscall32_target)
SYM_FUNC_START(xen_sysenter_target)
SYM_CODE_START(xen_syscall32_target)
SYM_CODE_START(xen_sysenter_target)
UNWIND_HINT_EMPTY
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $0
jmp hypercall_iret
SYM_FUNC_END(xen_sysenter_target)
SYM_FUNC_END_ALIAS(xen_syscall32_target)
SYM_CODE_END(xen_sysenter_target)
SYM_CODE_END(xen_syscall32_target)
#endif /* CONFIG_IA32_EMULATION */

5
arch/x86/xen/xen-head.S
View File

@ -68,8 +68,9 @@ SYM_CODE_END(asm_cpu_bringup_and_idle)
.balign PAGE_SIZE
SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
UNWIND_HINT_EMPTY
.skip 32
UNWIND_HINT_FUNC
.skip 31, 0x90
ret
.endr
#define HYPERCALL(n) \

13
include/linux/objtool.h
View File

@ -29,11 +29,14 @@ struct unwind_hint {
*
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
*
* UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
* Useful for code which doesn't have an ELF function annotation.
*/
#define UNWIND_HINT_TYPE_CALL 0
#define UNWIND_HINT_TYPE_REGS 1
#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
#define UNWIND_HINT_TYPE_RET_OFFSET 3
#define UNWIND_HINT_TYPE_FUNC 3
#ifdef CONFIG_STACK_VALIDATION
@ -109,6 +112,12 @@ struct unwind_hint {
.popsection
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.pushsection .discard.func_stack_frame_non_standard, "aw"
.long \func - .
.popsection
.endm
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_STACK_VALIDATION */
@ -122,6 +131,8 @@ struct unwind_hint {
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
#endif
#endif /* CONFIG_STACK_VALIDATION */

45
tools/arch/x86/include/asm/insn.h
View File

@ -7,9 +7,12 @@
* Copyright (C) IBM Corporation, 2009
*/
#include <asm/byteorder.h>
/* insn_attr_t is defined in inat.h */
#include "inat.h"
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
struct insn_field {
union {
insn_value_t value;
@ -20,6 +23,48 @@ struct insn_field {
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->nbytes = n;
}
static inline void insn_set_byte(struct insn_field *p, unsigned char n,
insn_byte_t v)
{
p->bytes[n] = v;
}
#else
struct insn_field {
insn_value_t value;
union {
insn_value_t little;
insn_byte_t bytes[4];
};
/* !0 if we've run insn_get_xxx() for this field */
unsigned char got;
unsigned char nbytes;
};
static inline void insn_field_set(struct insn_field *p, insn_value_t v,
unsigned char n)
{
p->value = v;
p->little = __cpu_to_le32(v);
p->nbytes = n;
}
static inline void insn_set_byte(struct insn_field *p, unsigned char n,
insn_byte_t v)
{
p->bytes[n] = v;
p->value = __le32_to_cpu(p->little);
}
#endif
struct insn {
struct insn_field prefixes; /*
* Prefixes

10
tools/arch/x86/include/asm/orc_types.h
View File

@ -40,6 +40,8 @@
#define ORC_REG_MAX 15
#ifndef __ASSEMBLY__
#include <asm/byteorder.h>
/*
* This struct is more or less a vastly simplified version of the DWARF Call
* Frame Information standard. It contains only the necessary parts of DWARF
@ -51,10 +53,18 @@
struct orc_entry {
s16 sp_offset;
s16 bp_offset;
#if defined(__LITTLE_ENDIAN_BITFIELD)
unsigned sp_reg:4;
unsigned bp_reg:4;
unsigned type:2;
unsigned end:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
unsigned bp_reg:4;
unsigned sp_reg:4;
unsigned unused:5;
unsigned end:1;
unsigned type:2;
#endif
} __packed;
#endif /* __ASSEMBLY__ */

119
tools/arch/x86/lib/insn.c
View File

@ -5,6 +5,7 @@
* Copyright (C) IBM Corporation, 2002, 2004, 2009
*/
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <linux/string.h>
#else
@ -15,15 +16,28 @@
#include "../include/asm/emulate_prefix.h"
#define leXX_to_cpu(t, r) \
({ \
__typeof__(t) v; \
switch (sizeof(t)) { \
case 4: v = le32_to_cpu(r); break; \
case 2: v = le16_to_cpu(r); break; \
case 1: v = r; break; \
default: \
BUILD_BUG(); break; \
} \
v; \
})
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); })
#define __peek_nbyte_next(t, insn, n) \
({ t r = *(t*)((insn)->next_byte + n); r; })
({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); })
#define get_next(t, insn) \
({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); })
@ -147,9 +161,9 @@ found:
b = insn->prefixes.bytes[3];
for (i = 0; i < nb; i++)
if (prefixes->bytes[i] == lb)
prefixes->bytes[i] = b;
insn_set_byte(prefixes, i, b);
}
insn->prefixes.bytes[3] = lb;
insn_set_byte(&insn->prefixes, 3, lb);
}
/* Decode REX prefix */
@ -157,8 +171,7 @@ found:
b = peek_next(insn_byte_t, insn);
attr = inat_get_opcode_attribute(b);
if (inat_is_rex_prefix(attr)) {
insn->rex_prefix.value = b;
insn->rex_prefix.nbytes = 1;
insn_field_set(&insn->rex_prefix, b, 1);
insn->next_byte++;
if (X86_REX_W(b))
/* REX.W overrides opnd_size */
@ -181,13 +194,13 @@ found:
if (X86_MODRM_MOD(b2) != 3)
goto vex_end;
}
insn->vex_prefix.bytes[0] = b;
insn->vex_prefix.bytes[1] = b2;
insn_set_byte(&insn->vex_prefix, 0, b);
insn_set_byte(&insn->vex_prefix, 1, b2);
if (inat_is_evex_prefix(attr)) {
b2 = peek_nbyte_next(insn_byte_t, insn, 2);
insn->vex_prefix.bytes[2] = b2;
insn_set_byte(&insn->vex_prefix, 2, b2);
b2 = peek_nbyte_next(insn_byte_t, insn, 3);
insn->vex_prefix.bytes[3] = b2;
insn_set_byte(&insn->vex_prefix, 3, b2);
insn->vex_prefix.nbytes = 4;
insn->next_byte += 4;
if (insn->x86_64 && X86_VEX_W(b2))
@ -195,7 +208,7 @@ found:
insn->opnd_bytes = 8;
} else if (inat_is_vex3_prefix(attr)) {
b2 = peek_nbyte_next(insn_byte_t, insn, 2);
insn->vex_prefix.bytes[2] = b2;
insn_set_byte(&insn->vex_prefix, 2, b2);
insn->vex_prefix.nbytes = 3;
insn->next_byte += 3;
if (insn->x86_64 && X86_VEX_W(b2))
@ -207,7 +220,7 @@ found:
* Makes it easier to decode vex.W, vex.vvvv,
* vex.L and vex.pp. Masking with 0x7f sets vex.W == 0.
*/
insn->vex_prefix.bytes[2] = b2 & 0x7f;
insn_set_byte(&insn->vex_prefix, 2, b2 & 0x7f);
insn->vex_prefix.nbytes = 2;
insn->next_byte += 2;
}
@ -243,7 +256,7 @@ void insn_get_opcode(struct insn *insn)
/* Get first opcode */
op = get_next(insn_byte_t, insn);
opcode->bytes[0] = op;
insn_set_byte(opcode, 0, op);
opcode->nbytes = 1;
/* Check if there is VEX prefix or not */
@ -295,8 +308,7 @@ void insn_get_modrm(struct insn *insn)
if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
modrm->value = mod;
modrm->nbytes = 1;
insn_field_set(modrm, mod, 1);
if (inat_is_group(insn->attr)) {
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
@ -334,7 +346,7 @@ int insn_rip_relative(struct insn *insn)
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
*/
return (modrm->nbytes && (modrm->value & 0xc7) == 0x5);
return (modrm->nbytes && (modrm->bytes[0] & 0xc7) == 0x5);
}
/**
@ -353,11 +365,11 @@ void insn_get_sib(struct insn *insn)
if (!insn->modrm.got)
insn_get_modrm(insn);
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
modrm = insn->modrm.bytes[0];
if (insn->addr_bytes != 2 &&
X86_MODRM_MOD(modrm) != 3 && X86_MODRM_RM(modrm) == 4) {
insn->sib.value = get_next(insn_byte_t, insn);
insn->sib.nbytes = 1;
insn_field_set(&insn->sib,
get_next(insn_byte_t, insn), 1);
}
}
insn->sib.got = 1;
@ -407,19 +419,18 @@ void insn_get_displacement(struct insn *insn)
if (mod == 3)
goto out;
if (mod == 1) {
insn->displacement.value = get_next(signed char, insn);
insn->displacement.nbytes = 1;
insn_field_set(&insn->displacement,
get_next(signed char, insn), 1);
} else if (insn->addr_bytes == 2) {
if ((mod == 0 && rm == 6) || mod == 2) {
insn->displacement.value =
get_next(short, insn);
insn->displacement.nbytes = 2;
insn_field_set(&insn->displacement,
get_next(short, insn), 2);
}
} else {
if ((mod == 0 && rm == 5) || mod == 2 ||
(mod == 0 && base == 5)) {
insn->displacement.value = get_next(int, insn);
insn->displacement.nbytes = 4;
insn_field_set(&insn->displacement,
get_next(int, insn), 4);
}
}
}
@ -435,18 +446,14 @@ static int __get_moffset(struct insn *insn)
{
switch (insn->addr_bytes) {
case 2:
insn->moffset1.value = get_next(short, insn);
insn->moffset1.nbytes = 2;
insn_field_set(&insn->moffset1, get_next(short, insn), 2);
break;
case 4:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
break;
case 8:
insn->moffset1.value = get_next(int, insn);
insn->moffset1.nbytes = 4;
insn->moffset2.value = get_next(int, insn);
insn->moffset2.nbytes = 4;
insn_field_set(&insn->moffset1, get_next(int, insn), 4);
insn_field_set(&insn->moffset2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -464,13 +471,11 @@ static int __get_immv32(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case 4:
case 8:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -487,18 +492,15 @@ static int __get_immv(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn->immediate1.nbytes = 4;
break;
case 8:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
default: /* opnd_bytes must be modified manually */
goto err_out;
@ -515,12 +517,10 @@ static int __get_immptr(struct insn *insn)
{
switch (insn->opnd_bytes) {
case 2:
insn->immediate1.value = get_next(short, insn);
insn->immediate1.nbytes = 2;
insn_field_set(&insn->immediate1, get_next(short, insn), 2);
break;
case 4:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
break;
case 8:
/* ptr16:64 is not exist (no segment) */
@ -528,8 +528,7 @@ static int __get_immptr(struct insn *insn)
default: /* opnd_bytes must be modified manually */
goto err_out;
}
insn->immediate2.value = get_next(unsigned short, insn);
insn->immediate2.nbytes = 2;
insn_field_set(&insn->immediate2, get_next(unsigned short, insn), 2);
insn->immediate1.got = insn->immediate2.got = 1;
return 1;
@ -565,22 +564,17 @@ void insn_get_immediate(struct insn *insn)
switch (inat_immediate_size(insn->attr)) {
case INAT_IMM_BYTE:
insn->immediate.value = get_next(signed char, insn);
insn->immediate.nbytes = 1;
insn_field_set(&insn->immediate, get_next(signed char, insn), 1);
break;
case INAT_IMM_WORD:
insn->immediate.value = get_next(short, insn);
insn->immediate.nbytes = 2;
insn_field_set(&insn->immediate, get_next(short, insn), 2);
break;
case INAT_IMM_DWORD:
insn->immediate.value = get_next(int, insn);
insn->immediate.nbytes = 4;
insn_field_set(&insn->immediate, get_next(int, insn), 4);
break;
case INAT_IMM_QWORD:
insn->immediate1.value = get_next(int, insn);
insn->immediate1.nbytes = 4;
insn->immediate2.value = get_next(int, insn);
insn->immediate2.nbytes = 4;
insn_field_set(&insn->immediate1, get_next(int, insn), 4);
insn_field_set(&insn->immediate2, get_next(int, insn), 4);
break;
case INAT_IMM_PTR:
if (!__get_immptr(insn))
@ -599,8 +593,7 @@ void insn_get_immediate(struct insn *insn)
goto err_out;
}
if (inat_has_second_immediate(insn->attr)) {
insn->immediate2.value = get_next(signed char, insn);
insn->immediate2.nbytes = 1;
insn_field_set(&insn->immediate2, get_next(signed char, insn), 1);
}
done:
insn->immediate.got = 1;

13
tools/include/linux/objtool.h
View File

@ -29,11 +29,14 @@ struct unwind_hint {
*
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
*
* UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
* Useful for code which doesn't have an ELF function annotation.
*/
#define UNWIND_HINT_TYPE_CALL 0
#define UNWIND_HINT_TYPE_REGS 1
#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
#define UNWIND_HINT_TYPE_RET_OFFSET 3
#define UNWIND_HINT_TYPE_FUNC 3
#ifdef CONFIG_STACK_VALIDATION
@ -109,6 +112,12 @@ struct unwind_hint {
.popsection
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.pushsection .discard.func_stack_frame_non_standard, "aw"
.long \func - .
.popsection
.endm
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_STACK_VALIDATION */
@ -122,6 +131,8 @@ struct unwind_hint {
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
#endif
#endif /* CONFIG_STACK_VALIDATION */

2
tools/objtool/.gitignore vendored
View File

@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
arch/x86/lib/inat-tables.c
objtool
/objtool
fixdep

14
tools/objtool/Documentation/stack-validation.txt
View File

@ -315,13 +315,15 @@ they mean, and suggestions for how to fix them.
function tracing inserts additional calls, which is not obvious from the
sources).
10. file.o: warning: func()+0x5c: alternative modifies stack
10. file.o: warning: func()+0x5c: stack layout conflict in alternatives
This means that an alternative includes instructions that modify the
stack. The problem is that there is only one ORC unwind table, this means
that the ORC unwind entries must be valid for each of the alternatives.
The easiest way to enforce this is to ensure alternatives do not contain
any ORC entries, which in turn implies the above constraint.
This means that in the use of the alternative() or ALTERNATIVE()
macro, the code paths have conflicting modifications to the stack.
The problem is that there is only one ORC unwind table, which means
that the ORC unwind entries must be consistent for all possible
instruction boundaries regardless of which code has been patched.
This limitation can be overcome by massaging the alternatives with
NOPs to shift the stack changes around so they no longer conflict.
11. file.o: warning: unannotated intra-function call

5
tools/objtool/Makefile
View File

@ -27,6 +27,7 @@ all: $(OBJTOOL)
INCLUDES := -I$(srctree)/tools/include \
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
-I$(srctree)/tools/arch/$(SRCARCH)/include \
-I$(srctree)/tools/objtool/include \
-I$(srctree)/tools/objtool/arch/$(SRCARCH)/include
WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
CFLAGS := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
@ -46,10 +47,6 @@ ifeq ($(SRCARCH),x86)
SUBCMD_ORC := y
endif
ifeq ($(SUBCMD_ORC),y)
CFLAGS += -DINSN_USE_ORC
endif
export SUBCMD_CHECK SUBCMD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include

54
tools/objtool/arch/x86/decode.c
View File

@ -11,11 +11,11 @@
#include "../../../arch/x86/lib/inat.c"
#include "../../../arch/x86/lib/insn.c"
#include "../../check.h"
#include "../../elf.h"
#include "../../arch.h"
#include "../../warn.h"
#include <asm/orc_types.h>
#include <objtool/check.h>
#include <objtool/elf.h>
#include <objtool/arch.h>
#include <objtool/warn.h>
static unsigned char op_to_cfi_reg[][2] = {
{CFI_AX, CFI_R8},
@ -222,15 +222,38 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
break;
case 0x89:
if (rex_w && !rex_r && modrm_mod == 3 && modrm_reg == 4) {
if (rex_w && !rex_r && modrm_reg == 4) {
/* 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];
if (modrm_mod == 3) {
/* 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];
}
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)
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.offset = insn.displacement.value;
}
break;
}
break;
}
@ -259,8 +282,10 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->dest.reg = CFI_BP;
op->dest.offset = insn.displacement.value;
}
break;
}
} else if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
if (rex_w && !rex_b && modrm_rm == 4 && sib == 0x24) {
/* mov reg, disp(%rsp) */
ADD_OP(op) {
@ -270,6 +295,7 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
op->dest.reg = CFI_SP;
op->dest.offset = insn.displacement.value;
}
break;
}
break;
@ -563,8 +589,8 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state)
state->cfa.offset = 8;
/* initial RA (return address) */
state->regs[16].base = CFI_CFA;
state->regs[16].offset = -8;
state->regs[CFI_RA].base = CFI_CFA;
state->regs[CFI_RA].offset = -8;
}
const char *arch_nop_insn(int len)

0
tools/objtool/arch/x86/include/cfi_regs.h → tools/objtool/arch/x86/include/arch/cfi_regs.h
View File

0
tools/objtool/arch/x86/include/arch_elf.h → tools/objtool/arch/x86/include/arch/elf.h
View File

9
tools/objtool/arch/x86/include/arch/endianness.h 100644
View File

@ -0,0 +1,9 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ARCH_ENDIANNESS_H
#define _ARCH_ENDIANNESS_H
#include <endian.h>
#define __TARGET_BYTE_ORDER __LITTLE_ENDIAN
#endif /* _ARCH_ENDIANNESS_H */

0
tools/objtool/arch/x86/include/arch_special.h → tools/objtool/arch/x86/include/arch/special.h
View File

6
tools/objtool/arch/x86/special.c
View File

@ -1,8 +1,8 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include <string.h>
#include "../../special.h"
#include "../../builtin.h"
#include <objtool/special.h>
#include <objtool/builtin.h>
#define X86_FEATURE_POPCNT (4 * 32 + 23)
#define X86_FEATURE_SMAP (9 * 32 + 20)
@ -48,7 +48,7 @@ bool arch_support_alt_relocation(struct special_alt *special_alt,
* replacement group.
*/
return insn->offset == special_alt->new_off &&
(insn->type == INSN_CALL || is_static_jump(insn));
(insn->type == INSN_CALL || is_jump(insn));
}
/*

4
tools/objtool/builtin-check.c
View File

@ -15,8 +15,8 @@
#include <subcmd/parse-options.h>
#include <string.h>
#include "builtin.h"
#include "objtool.h"
#include <objtool/builtin.h>
#include <objtool/objtool.h>
bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;

10
tools/objtool/builtin-orc.c
View File

@ -13,8 +13,8 @@
*/
#include <string.h>
#include "builtin.h"
#include "objtool.h"
#include <objtool/builtin.h>
#include <objtool/objtool.h>
static const char *orc_usage[] = {
"objtool orc generate [<options>] file.o",
@ -51,11 +51,7 @@ int cmd_orc(int argc, const char **argv)
if (list_empty(&file->insn_list))
return 0;
ret = create_orc(file);
if (ret)
return ret;
ret = create_orc_sections(file);
ret = orc_create(file);
if (ret)
return ret;

402
tools/objtool/check.c
View File

@ -6,21 +6,20 @@
#include <string.h>
#include <stdlib.h>
#include "builtin.h"
#include "cfi.h"
#include "arch.h"
#include "check.h"
#include "special.h"
#include "warn.h"
#include "arch_elf.h"
#include <arch/elf.h>
#include <objtool/builtin.h>
#include <objtool/cfi.h>
#include <objtool/arch.h>
#include <objtool/check.h>
#include <objtool/special.h>
#include <objtool/warn.h>
#include <objtool/endianness.h>
#include <linux/objtool.h>
#include <linux/hashtable.h>
#include <linux/kernel.h>
#include <linux/static_call_types.h>
#define FAKE_JUMP_OFFSET -1
struct alternative {
struct list_head list;
struct instruction *insn;
@ -111,15 +110,20 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
static bool is_sibling_call(struct instruction *insn)
{
/*
* Assume only ELF functions can make sibling calls. This ensures
* sibling call detection consistency between vmlinux.o and individual
* objects.
*/
if (!insn->func)
return false;
/* 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);
if (!is_static_jump(insn))
return false;
/* add_jump_destinations() sets insn->call_dest for sibling calls. */
return !!insn->call_dest;
return (is_static_jump(insn) && insn->call_dest);
}
/*
@ -156,6 +160,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"machine_real_restart",
"rewind_stack_do_exit",
"kunit_try_catch_throw",
"xen_start_kernel",
};
if (!func)
@ -787,22 +792,16 @@ static int add_jump_destinations(struct objtool_file *file)
if (!is_static_jump(insn))
continue;
if (insn->offset == FAKE_JUMP_OFFSET)
continue;
reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
insn->offset, insn->len);
if (!reloc) {
dest_sec = insn->sec;
dest_off = arch_jump_destination(insn);
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
arch_dest_reloc_offset(reloc->addend);
} else if (strstr(reloc->sym->name, "_indirect_thunk_")) {
} else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
!strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@ -814,14 +813,21 @@ static int add_jump_destinations(struct objtool_file *file)
insn->retpoline_safe = true;
continue;
} else {
/* external sibling call */
} else if (insn->func) {
/* internal or external sibling call (with reloc) */
insn->call_dest = reloc->sym;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->static_call_node,
&file->static_call_list);
}
continue;
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
arch_dest_reloc_offset(reloc->addend);
} else {
/* non-func asm code jumping to another file */
continue;
}
insn->jump_dest = find_insn(file, dest_sec, dest_off);
@ -862,15 +868,15 @@ static int add_jump_destinations(struct objtool_file *file)
* case where the parent function's only reference to a
* subfunction is through a jump table.
*/
if (!strstr(insn->func->name, ".cold.") &&
strstr(insn->jump_dest->func->name, ".cold.")) {
if (!strstr(insn->func->name, ".cold") &&
strstr(insn->jump_dest->func->name, ".cold")) {
insn->func->cfunc = insn->jump_dest->func;
insn->jump_dest->func->pfunc = insn->func;
} else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
insn->jump_dest->offset == insn->jump_dest->func->offset) {
/* internal sibling call */
/* internal sibling call (without reloc) */
insn->call_dest = insn->jump_dest->func;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->static_call_node,
@ -983,73 +989,83 @@ static int add_call_destinations(struct objtool_file *file)
}
/*
* The .alternatives section requires some extra special care, over and above
* what other special sections require:
*
* 1. Because alternatives are patched in-place, we need to insert a fake jump
* instruction at the end so that validate_branch() skips all the original
* replaced instructions when validating the new instruction path.
*
* 2. An added wrinkle is that the new instruction length might be zero. In
* that case the old instructions are replaced with noops. We simulate that
* by creating a fake jump as the only new instruction.
*
* 3. In some cases, the alternative section includes an instruction which
* conditionally jumps to the _end_ of the entry. We have to modify these
* jumps' destinations to point back to .text rather than the end of the
* entry in .altinstr_replacement.
* The .alternatives section requires some extra special care over and above
* other special sections because alternatives are patched in place.
*/
static int handle_group_alt(struct objtool_file *file,
struct special_alt *special_alt,
struct instruction *orig_insn,
struct instruction **new_insn)
{
static unsigned int alt_group_next_index = 1;
struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
unsigned int alt_group = alt_group_next_index++;
struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL;
struct alt_group *orig_alt_group, *new_alt_group;
unsigned long dest_off;
orig_alt_group = malloc(sizeof(*orig_alt_group));
if (!orig_alt_group) {
WARN("malloc failed");
return -1;
}
orig_alt_group->cfi = calloc(special_alt->orig_len,
sizeof(struct cfi_state *));
if (!orig_alt_group->cfi) {
WARN("calloc failed");
return -1;
}
last_orig_insn = NULL;
insn = orig_insn;
sec_for_each_insn_from(file, insn) {
if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
break;
insn->alt_group = alt_group;
insn->alt_group = orig_alt_group;
last_orig_insn = insn;
}
orig_alt_group->orig_group = NULL;
orig_alt_group->first_insn = orig_insn;
orig_alt_group->last_insn = last_orig_insn;
if (next_insn_same_sec(file, last_orig_insn)) {
fake_jump = malloc(sizeof(*fake_jump));
if (!fake_jump) {
new_alt_group = malloc(sizeof(*new_alt_group));
if (!new_alt_group) {
WARN("malloc failed");
return -1;
}
if (special_alt->new_len < special_alt->orig_len) {
/*
* Insert a fake nop at the end to make the replacement
* alt_group the same size as the original. This is needed to
* allow propagate_alt_cfi() to do its magic. When the last
* instruction affects the stack, the instruction after it (the
* nop) will propagate the new state to the shared CFI array.
*/
nop = malloc(sizeof(*nop));
if (!nop) {
WARN("malloc failed");
return -1;
}
memset(fake_jump, 0, sizeof(*fake_jump));
INIT_LIST_HEAD(&fake_jump->alts);
INIT_LIST_HEAD(&fake_jump->stack_ops);
init_cfi_state(&fake_jump->cfi);
memset(nop, 0, sizeof(*nop));
INIT_LIST_HEAD(&nop->alts);
INIT_LIST_HEAD(&nop->stack_ops);
init_cfi_state(&nop->cfi);
fake_jump->sec = special_alt->new_sec;
fake_jump->offset = FAKE_JUMP_OFFSET;
fake_jump->type = INSN_JUMP_UNCONDITIONAL;
fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
fake_jump->func = orig_insn->func;
nop->sec = special_alt->new_sec;
nop->offset = special_alt->new_off + special_alt->new_len;
nop->len = special_alt->orig_len - special_alt->new_len;
nop->type = INSN_NOP;
nop->func = orig_insn->func;
nop->alt_group = new_alt_group;
nop->ignore = orig_insn->ignore_alts;
}
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;
*new_insn = nop;
goto end;
}
last_new_insn = NULL;
alt_group = alt_group_next_index++;
insn = *new_insn;
sec_for_each_insn_from(file, insn) {
struct reloc *alt_reloc;
@ -1061,7 +1077,7 @@ static int handle_group_alt(struct objtool_file *file,
insn->ignore = orig_insn->ignore_alts;
insn->func = orig_insn->func;
insn->alt_group = alt_group;
insn->alt_group = new_alt_group;
/*
* Since alternative replacement code is copy/pasted by the
@ -1088,14 +1104,8 @@ static int handle_group_alt(struct objtool_file *file,
continue;
dest_off = arch_jump_destination(insn);
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 (dest_off == special_alt->new_off + special_alt->new_len)
insn->jump_dest = next_insn_same_sec(file, last_orig_insn);
if (!insn->jump_dest) {
WARN_FUNC("can't find alternative jump destination",
@ -1110,9 +1120,13 @@ static int handle_group_alt(struct objtool_file *file,
return -1;
}
if (fake_jump)
list_add(&fake_jump->list, &last_new_insn->list);
if (nop)
list_add(&nop->list, &last_new_insn->list);
end:
new_alt_group->orig_group = orig_alt_group;
new_alt_group->first_insn = *new_insn;
new_alt_group->last_insn = nop ? : last_new_insn;
new_alt_group->cfi = orig_alt_group->cfi;
return 0;
}
@ -1404,13 +1418,20 @@ static int add_jump_table_alts(struct objtool_file *file)
return 0;
}
static void set_func_state(struct cfi_state *state)
{
state->cfa = initial_func_cfi.cfa;
memcpy(&state->regs, &initial_func_cfi.regs,
CFI_NUM_REGS * sizeof(struct cfi_reg));
state->stack_size = initial_func_cfi.cfa.offset;
}
static int read_unwind_hints(struct objtool_file *file)
{
struct section *sec, *relocsec;
struct reloc *reloc;
struct unwind_hint *hint;
struct instruction *insn;
struct cfi_reg *cfa;
int i;
sec = find_section_by_name(file->elf, ".discard.unwind_hints");
@ -1445,22 +1466,20 @@ static int read_unwind_hints(struct objtool_file *file)
return -1;
}
cfa = &insn->cfi.cfa;
insn->hint = true;
if (hint->type == UNWIND_HINT_TYPE_RET_OFFSET) {
insn->ret_offset = hint->sp_offset;
if (hint->type == UNWIND_HINT_TYPE_FUNC) {
set_func_state(&insn->cfi);
continue;
}
insn->hint = true;
if (arch_decode_hint_reg(insn, hint->sp_reg)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
}
cfa->offset = hint->sp_offset;
insn->cfi.cfa.offset = bswap_if_needed(hint->sp_offset);
insn->cfi.type = hint->type;
insn->cfi.end = hint->end;
}
@ -1716,27 +1735,18 @@ static bool is_fentry_call(struct instruction *insn)
static bool has_modified_stack_frame(struct instruction *insn, struct insn_state *state)
{
u8 ret_offset = insn->ret_offset;
struct cfi_state *cfi = &state->cfi;
int i;
if (cfi->cfa.base != initial_func_cfi.cfa.base || cfi->drap)
return true;
if (cfi->cfa.offset != initial_func_cfi.cfa.offset + ret_offset)
if (cfi->cfa.offset != initial_func_cfi.cfa.offset)
return true;
if (cfi->stack_size != initial_func_cfi.cfa.offset + ret_offset)
if (cfi->stack_size != initial_func_cfi.cfa.offset)
return true;
/*
* If there is a ret offset hint then don't check registers
* because a callee-saved register might have been pushed on
* the stack.
*/
if (ret_offset)
return false;
for (i = 0; i < CFI_NUM_REGS; i++) {
if (cfi->regs[i].base != initial_func_cfi.regs[i].base ||
cfi->regs[i].offset != initial_func_cfi.regs[i].offset)
@ -1746,12 +1756,20 @@ static bool has_modified_stack_frame(struct instruction *insn, struct insn_state
return false;
}
static bool check_reg_frame_pos(const struct cfi_reg *reg,
int expected_offset)
{
return reg->base == CFI_CFA &&
reg->offset == expected_offset;
}
static bool has_valid_stack_frame(struct insn_state *state)
{
struct cfi_state *cfi = &state->cfi;
if (cfi->cfa.base == CFI_BP && cfi->regs[CFI_BP].base == CFI_CFA &&
cfi->regs[CFI_BP].offset == -16)
if (cfi->cfa.base == CFI_BP &&
check_reg_frame_pos(&cfi->regs[CFI_BP], -cfi->cfa.offset) &&
check_reg_frame_pos(&cfi->regs[CFI_RA], -cfi->cfa.offset + 8))
return true;
if (cfi->drap && cfi->regs[CFI_BP].base == CFI_BP)
@ -1880,8 +1898,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
case OP_SRC_REG:
if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP &&
cfa->base == CFI_SP &&
regs[CFI_BP].base == CFI_CFA &&
regs[CFI_BP].offset == -cfa->offset) {
check_reg_frame_pos(&regs[CFI_BP], -cfa->offset)) {
/* mov %rsp, %rbp */
cfa->base = op->dest.reg;
@ -1941,6 +1958,38 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
cfa->offset = -cfi->vals[op->src.reg].offset;
cfi->stack_size = cfa->offset;
} else if (cfa->base == CFI_SP &&
cfi->vals[op->src.reg].base == CFI_SP_INDIRECT &&
cfi->vals[op->src.reg].offset == cfa->offset) {
/*
* Stack swizzle:
*
* 1: mov %rsp, (%[tos])
* 2: mov %[tos], %rsp
* ...
* 3: pop %rsp
*
* Where:
*
* 1 - places a pointer to the previous
* stack at the Top-of-Stack of the
* new stack.
*
* 2 - switches to the new stack.
*
* 3 - pops the Top-of-Stack to restore
* the original stack.
*
* Note: we set base to SP_INDIRECT
* here and preserve offset. Therefore
* when the unwinder reaches ToS it
* will dereference SP and then add the
* offset to find the next frame, IOW:
* (%rsp) + offset.
*/
cfa->base = CFI_SP_INDIRECT;
} else {
cfa->base = CFI_UNDEFINED;
cfa->offset = 0;
@ -1966,6 +2015,17 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
}
if (!cfi->drap && op->src.reg == CFI_SP &&
op->dest.reg == CFI_BP && cfa->base == CFI_SP &&
check_reg_frame_pos(&regs[CFI_BP], -cfa->offset + op->src.offset)) {
/* lea disp(%rsp), %rbp */
cfa->base = CFI_BP;
cfa->offset -= op->src.offset;
cfi->bp_scratch = false;
break;
}
if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
/* drap: lea disp(%rsp), %drap */
@ -2032,6 +2092,13 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
case OP_SRC_POP:
case OP_SRC_POPF:
if (op->dest.reg == CFI_SP && cfa->base == CFI_SP_INDIRECT) {
/* pop %rsp; # restore from a stack swizzle */
cfa->base = CFI_SP;
break;
}
if (!cfi->drap && op->dest.reg == cfa->base) {
/* pop %rbp */
@ -2060,6 +2127,14 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
case OP_SRC_REG_INDIRECT:
if (!cfi->drap && op->dest.reg == cfa->base &&
op->dest.reg == CFI_BP) {
/* mov disp(%rsp), %rbp */
cfa->base = CFI_SP;
cfa->offset = cfi->stack_size;
}
if (cfi->drap && op->src.reg == CFI_BP &&
op->src.offset == cfi->drap_offset) {
@ -2081,6 +2156,12 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
/* mov disp(%rbp), %reg */
/* mov disp(%rsp), %reg */
restore_reg(cfi, op->dest.reg);
} else if (op->src.reg == CFI_SP &&
op->src.offset == regs[op->dest.reg].offset + cfi->stack_size) {
/* mov disp(%rsp), %reg */
restore_reg(cfi, op->dest.reg);
}
break;
@ -2158,6 +2239,18 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
/* mov reg, disp(%rsp) */
save_reg(cfi, op->src.reg, CFI_CFA,
op->dest.offset - cfi->cfa.offset);
} else if (op->dest.reg == CFI_SP) {
/* mov reg, disp(%rsp) */
save_reg(cfi, op->src.reg, CFI_CFA,
op->dest.offset - cfi->stack_size);
} else if (op->src.reg == CFI_SP && op->dest.offset == 0) {
/* mov %rsp, (%reg); # setup a stack swizzle. */
cfi->vals[op->dest.reg].base = CFI_SP_INDIRECT;
cfi->vals[op->dest.reg].offset = cfa->offset;
}
break;
@ -2205,22 +2298,47 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
return 0;
}
/*
* The stack layouts of alternatives instructions can sometimes diverge when
* they have stack modifications. That's fine as long as the potential stack
* layouts don't conflict at any given potential instruction boundary.
*
* Flatten the CFIs of the different alternative code streams (both original
* and replacement) into a single shared CFI array which can be used to detect
* conflicts and nicely feed a linear array of ORC entries to the unwinder.
*/
static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn)
{
struct cfi_state **alt_cfi;
int group_off;
if (!insn->alt_group)
return 0;
alt_cfi = insn->alt_group->cfi;
group_off = insn->offset - insn->alt_group->first_insn->offset;
if (!alt_cfi[group_off]) {
alt_cfi[group_off] = &insn->cfi;
} else {
if (memcmp(alt_cfi[group_off], &insn->cfi, sizeof(struct cfi_state))) {
WARN_FUNC("stack layout conflict in alternatives",
insn->sec, insn->offset);
return -1;
}
}
return 0;
}
static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
{
struct stack_op *op;
list_for_each_entry(op, &insn->stack_ops, list) {
struct cfi_state old_cfi = state->cfi;
int res;
res = update_cfi_state(insn, &state->cfi, op);
if (res)
return res;
if (insn->alt_group && memcmp(&state->cfi, &old_cfi, sizeof(struct cfi_state))) {
WARN_FUNC("alternative modifies stack", insn->sec, insn->offset);
return -1;
}
if (update_cfi_state(insn, &state->cfi, op))
return 1;
if (op->dest.type == OP_DEST_PUSHF) {
if (!state->uaccess_stack) {
@ -2410,28 +2528,20 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct
return 0;
}
/*
* Alternatives should not contain any ORC entries, this in turn means they
* should not contain any CFI ops, which implies all instructions should have
* the same same CFI state.
*
* It is possible to constuct alternatives that have unreachable holes that go
* unreported (because they're NOPs), such holes would result in CFI_UNDEFINED
* states which then results in ORC entries, which we just said we didn't want.
*
* Avoid them by copying the CFI entry of the first instruction into the whole
* alternative.
*/
static void fill_alternative_cfi(struct objtool_file *file, struct instruction *insn)
static struct instruction *next_insn_to_validate(struct objtool_file *file,
struct instruction *insn)
{
struct instruction *first_insn = insn;
int alt_group = insn->alt_group;
struct alt_group *alt_group = insn->alt_group;
sec_for_each_insn_continue(file, insn) {
if (insn->alt_group != alt_group)
break;
insn->cfi = first_insn->cfi;
}
/*
* Simulate the fact that alternatives are patched in-place. When the
* end of a replacement alt_group is reached, redirect objtool flow to
* the end of the original alt_group.
*/
if (alt_group && insn == alt_group->last_insn && alt_group->orig_group)
return next_insn_same_sec(file, alt_group->orig_group->last_insn);
return next_insn_same_sec(file, insn);
}
/*
@ -2452,7 +2562,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
sec = insn->sec;
while (1) {
next_insn = next_insn_same_sec(file, insn);
next_insn = next_insn_to_validate(file, insn);
if (file->c_file && func && insn->func && func != insn->func->pfunc) {
WARN("%s() falls through to next function %s()",
@ -2485,6 +2595,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
insn->visited |= visited;
if (propagate_alt_cfi(file, insn))
return 1;
if (!insn->ignore_alts && !list_empty(&insn->alts)) {
bool skip_orig = false;
@ -2500,9 +2613,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
}
}
if (insn->alt_group)
fill_alternative_cfi(file, insn);
if (skip_orig)
return 0;
}
@ -2540,7 +2650,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
if (func && is_sibling_call(insn)) {
if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
@ -2562,7 +2672,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_DYNAMIC:
case INSN_JUMP_DYNAMIC_CONDITIONAL:
if (func && is_sibling_call(insn)) {
if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
@ -2605,15 +2715,19 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
break;
case INSN_STD:
if (state.df)
if (state.df) {
WARN_FUNC("recursive STD", sec, insn->offset);
return 1;
}
state.df = true;
break;
case INSN_CLD:
if (!state.df && func)
if (!state.df && func) {
WARN_FUNC("redundant CLD", sec, insn->offset);
return 1;
}
state.df = false;
break;
@ -2736,9 +2850,6 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
!strcmp(insn->sec->name, ".altinstr_aux"))
return true;
if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->offset == FAKE_JUMP_OFFSET)
return true;
if (!insn->func)
return false;
@ -2824,10 +2935,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
continue;
init_insn_state(&state, sec);
state.cfi.cfa = initial_func_cfi.cfa;
memcpy(&state.cfi.regs, &initial_func_cfi.regs,
CFI_NUM_REGS * sizeof(struct cfi_reg));
state.cfi.stack_size = initial_func_cfi.cfa.offset;
set_func_state(&state.cfi);
warnings += validate_symbol(file, sec, func, &state);
}

40
tools/objtool/elf.c
View File

@ -15,10 +15,10 @@
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include "builtin.h"
#include <objtool/builtin.h>
#include "elf.h"
#include "warn.h"
#include <objtool/elf.h>
#include <objtool/warn.h>
#define MAX_NAME_LEN 128
@ -814,25 +814,27 @@ static int elf_rebuild_rel_reloc_section(struct section *sec, int nr)
{
struct reloc *reloc;
int idx = 0, size;
GElf_Rel *relocs;
void *buf;
/* Allocate a buffer for relocations */
size = nr * sizeof(*relocs);
relocs = malloc(size);
if (!relocs) {
size = nr * sizeof(GElf_Rel);
buf = malloc(size);
if (!buf) {
perror("malloc");
return -1;
}
sec->data->d_buf = relocs;
sec->data->d_buf = buf;
sec->data->d_size = size;
sec->data->d_type = ELF_T_REL;
sec->sh.sh_size = size;
idx = 0;
list_for_each_entry(reloc, &sec->reloc_list, list) {
relocs[idx].r_offset = reloc->offset;
relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
reloc->rel.r_offset = reloc->offset;
reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
gelf_update_rel(sec->data, idx, &reloc->rel);
idx++;
}
@ -843,26 +845,28 @@ static int elf_rebuild_rela_reloc_section(struct section *sec, int nr)
{
struct reloc *reloc;
int idx = 0, size;
GElf_Rela *relocs;
void *buf;
/* Allocate a buffer for relocations with addends */
size = nr * sizeof(*relocs);
relocs = malloc(size);
if (!relocs) {
size = nr * sizeof(GElf_Rela);
buf = malloc(size);
if (!buf) {
perror("malloc");
return -1;
}
sec->data->d_buf = relocs;
sec->data->d_buf = buf;
sec->data->d_size = size;
sec->data->d_type = ELF_T_RELA;
sec->sh.sh_size = size;
idx = 0;
list_for_each_entry(reloc, &sec->reloc_list, list) {
relocs[idx].r_offset = reloc->offset;
relocs[idx].r_addend = reloc->addend;
relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
reloc->rela.r_offset = reloc->offset;
reloc->rela.r_addend = reloc->addend;
reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
gelf_update_rela(sec->data, idx, &reloc->rela);
idx++;
}

8
tools/objtool/arch.h → tools/objtool/include/objtool/arch.h
View File

@ -8,12 +8,8 @@
#include <stdbool.h>
#include <linux/list.h>
#include "objtool.h"
#include "cfi.h"
#ifdef INSN_USE_ORC
#include <asm/orc_types.h>
#endif
#include <objtool/objtool.h>
#include <objtool/cfi.h>
enum insn_type {
INSN_JUMP_CONDITIONAL,

0
tools/objtool/builtin.h → tools/objtool/include/objtool/builtin.h
View File

2
tools/objtool/cfi.h → tools/objtool/include/objtool/cfi.h
View File

@ -6,7 +6,7 @@
#ifndef _OBJTOOL_CFI_H
#define _OBJTOOL_CFI_H
#include "cfi_regs.h"
#include <arch/cfi_regs.h>
#define CFI_UNDEFINED -1
#define CFI_CFA -2

38
tools/objtool/check.h → tools/objtool/include/objtool/check.h
View File

@ -7,8 +7,8 @@
#define _CHECK_H
#include <stdbool.h>
#include "cfi.h"
#include "arch.h"
#include <objtool/cfi.h>
#include <objtool/arch.h>
struct insn_state {
struct cfi_state cfi;
@ -19,6 +19,23 @@ struct insn_state {
s8 instr;
};
struct alt_group {
/*
* Pointer from a replacement group to the original group. NULL if it
* *is* the original group.
*/
struct alt_group *orig_group;
/* First and last instructions in the group */
struct instruction *first_insn, *last_insn;
/*
* Byte-offset-addressed len-sized array of pointers to CFI structs.
* This is shared with the other alt_groups in the same alternative.
*/
struct cfi_state **cfi;
};
struct instruction {
struct list_head list;
struct hlist_node hash;
@ -33,8 +50,7 @@ struct instruction {
bool retpoline_safe;
s8 instr;
u8 visited;
u8 ret_offset;
int alt_group;
struct alt_group *alt_group;
struct symbol *call_dest;
struct instruction *jump_dest;
struct instruction *first_jump_src;
@ -43,9 +59,6 @@ struct instruction {
struct symbol *func;
struct list_head stack_ops;
struct cfi_state cfi;
#ifdef INSN_USE_ORC
struct orc_entry orc;
#endif
};
static inline bool is_static_jump(struct instruction *insn)
@ -54,6 +67,17 @@ static inline bool is_static_jump(struct instruction *insn)
insn->type == INSN_JUMP_UNCONDITIONAL;
}
static inline bool is_dynamic_jump(struct instruction *insn)
{
return insn->type == INSN_JUMP_DYNAMIC ||
insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL;
}
static inline bool is_jump(struct instruction *insn)
{
return is_static_jump(insn) || is_dynamic_jump(insn);
}
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset);

0
tools/objtool/elf.h → tools/objtool/include/objtool/elf.h
View File

38
tools/objtool/include/objtool/endianness.h 100644
View File

@ -0,0 +1,38 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _OBJTOOL_ENDIANNESS_H
#define _OBJTOOL_ENDIANNESS_H
#include <arch/endianness.h>
#include <linux/kernel.h>
#include <endian.h>
#ifndef __TARGET_BYTE_ORDER
#error undefined arch __TARGET_BYTE_ORDER
#endif
#if __BYTE_ORDER != __TARGET_BYTE_ORDER
#define __NEED_BSWAP 1
#else
#define __NEED_BSWAP 0
#endif
/*
* Does a byte swap if target endianness doesn't match the host, i.e. cross
* compilation for little endian on big endian and vice versa.
* To be used for multi-byte values conversion, which are read from / about
* to be written to a target native endianness ELF file.
*/
#define bswap_if_needed(val) \
({ \
__typeof__(val) __ret; \
switch (sizeof(val)) { \
case 8: __ret = __NEED_BSWAP ? bswap_64(val) : (val); break; \
case 4: __ret = __NEED_BSWAP ? bswap_32(val) : (val); break; \
case 2: __ret = __NEED_BSWAP ? bswap_16(val) : (val); break; \
default: \
BUILD_BUG(); break; \
} \
__ret; \
})
#endif /* _OBJTOOL_ENDIANNESS_H */

5
tools/objtool/objtool.h → tools/objtool/include/objtool/objtool.h
View File

@ -10,7 +10,7 @@
#include <linux/list.h>
#include <linux/hashtable.h>
#include "elf.h"
#include <objtool/elf.h>
#define __weak __attribute__((weak))
@ -26,7 +26,6 @@ struct objtool_file *objtool_open_read(const char *_objname);
int check(struct objtool_file *file);
int orc_dump(const char *objname);
int create_orc(struct objtool_file *file);
int create_orc_sections(struct objtool_file *file);
int orc_create(struct objtool_file *file);
#endif /* _OBJTOOL_H */

4
tools/objtool/special.h → tools/objtool/include/objtool/special.h
View File

@ -7,8 +7,8 @@
#define _SPECIAL_H
#include <stdbool.h>
#include "check.h"
#include "elf.h"
#include <objtool/check.h>
#include <objtool/elf.h>
#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"

2
tools/objtool/warn.h → tools/objtool/include/objtool/warn.h
View File

@ -11,7 +11,7 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "elf.h"
#include <objtool/elf.h>
extern const char *objname;

6
tools/objtool/objtool.c
View File

@ -21,9 +21,9 @@
#include <subcmd/pager.h>
#include <linux/kernel.h>
#include "builtin.h"
#include "objtool.h"
#include "warn.h"
#include <objtool/builtin.h>
#include <objtool/objtool.h>
#include <objtool/warn.h>
struct cmd_struct {
const char *name;

11
tools/objtool/orc_dump.c
View File

@ -6,8 +6,9 @@
#include <unistd.h>
#include <linux/objtool.h>
#include <asm/orc_types.h>
#include "objtool.h"
#include "warn.h"
#include <objtool/objtool.h>
#include <objtool/warn.h>
#include <objtool/endianness.h>
static const char *reg_name(unsigned int reg)
{
@ -54,7 +55,7 @@ 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);
printf("(sp)%+d", offset);
else if (reg == ORC_REG_UNDEFINED)
printf("(und)");
else
@ -197,11 +198,11 @@ int orc_dump(const char *_objname)
printf(" sp:");
print_reg(orc[i].sp_reg, orc[i].sp_offset);
print_reg(orc[i].sp_reg, bswap_if_needed(orc[i].sp_offset));
printf(" bp:");
print_reg(orc[i].bp_reg, orc[i].bp_offset);
print_reg(orc[i].bp_reg, bswap_if_needed(orc[i].bp_offset));
printf(" type:%s end:%d\n",
orc_type_name(orc[i].type), orc[i].end);

331
tools/objtool/orc_gen.c
View File

@ -9,93 +9,91 @@
#include <linux/objtool.h>
#include <asm/orc_types.h>
#include "check.h"
#include "warn.h"
#include <objtool/check.h>
#include <objtool/warn.h>
#include <objtool/endianness.h>
int create_orc(struct objtool_file *file)
static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi)
{
struct instruction *insn;
struct instruction *insn = container_of(cfi, struct instruction, cfi);
struct cfi_reg *bp = &cfi->regs[CFI_BP];
for_each_insn(file, insn) {
struct orc_entry *orc = &insn->orc;
struct cfi_reg *cfa = &insn->cfi.cfa;
struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
memset(orc, 0, sizeof(*orc));
if (!insn->sec->text)
continue;
orc->end = cfi->end;
orc->end = insn->cfi.end;
if (cfa->base == CFI_UNDEFINED) {
orc->sp_reg = ORC_REG_UNDEFINED;
continue;
}
switch (cfa->base) {
case CFI_SP:
orc->sp_reg = ORC_REG_SP;
break;
case CFI_SP_INDIRECT:
orc->sp_reg = ORC_REG_SP_INDIRECT;
break;
case CFI_BP:
orc->sp_reg = ORC_REG_BP;
break;
case CFI_BP_INDIRECT:
orc->sp_reg = ORC_REG_BP_INDIRECT;
break;
case CFI_R10:
orc->sp_reg = ORC_REG_R10;
break;
case CFI_R13:
orc->sp_reg = ORC_REG_R13;
break;
case CFI_DI:
orc->sp_reg = ORC_REG_DI;
break;
case CFI_DX:
orc->sp_reg = ORC_REG_DX;
break;
default:
WARN_FUNC("unknown CFA base reg %d",
insn->sec, insn->offset, cfa->base);
return -1;
}
switch(bp->base) {
case CFI_UNDEFINED:
orc->bp_reg = ORC_REG_UNDEFINED;
break;
case CFI_CFA:
orc->bp_reg = ORC_REG_PREV_SP;
break;
case CFI_BP:
orc->bp_reg = ORC_REG_BP;
break;
default:
WARN_FUNC("unknown BP base reg %d",
insn->sec, insn->offset, bp->base);
return -1;
}
orc->sp_offset = cfa->offset;
orc->bp_offset = bp->offset;
orc->type = insn->cfi.type;
if (cfi->cfa.base == CFI_UNDEFINED) {
orc->sp_reg = ORC_REG_UNDEFINED;
return 0;
}
switch (cfi->cfa.base) {
case CFI_SP:
orc->sp_reg = ORC_REG_SP;
break;
case CFI_SP_INDIRECT:
orc->sp_reg = ORC_REG_SP_INDIRECT;
break;
case CFI_BP:
orc->sp_reg = ORC_REG_BP;
break;
case CFI_BP_INDIRECT:
orc->sp_reg = ORC_REG_BP_INDIRECT;
break;
case CFI_R10:
orc->sp_reg = ORC_REG_R10;
break;
case CFI_R13:
orc->sp_reg = ORC_REG_R13;
break;
case CFI_DI:
orc->sp_reg = ORC_REG_DI;
break;
case CFI_DX:
orc->sp_reg = ORC_REG_DX;
break;
default:
WARN_FUNC("unknown CFA base reg %d",
insn->sec, insn->offset, cfi->cfa.base);
return -1;
}
switch (bp->base) {
case CFI_UNDEFINED:
orc->bp_reg = ORC_REG_UNDEFINED;
break;
case CFI_CFA:
orc->bp_reg = ORC_REG_PREV_SP;
break;
case CFI_BP:
orc->bp_reg = ORC_REG_BP;
break;
default:
WARN_FUNC("unknown BP base reg %d",
insn->sec, insn->offset, bp->base);
return -1;
}
orc->sp_offset = cfi->cfa.offset;
orc->bp_offset = bp->offset;
orc->type = cfi->type;
return 0;
}
static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
unsigned int idx, struct section *insn_sec,
unsigned long insn_off, struct orc_entry *o)
static int write_orc_entry(struct elf *elf, struct section *orc_sec,
struct section *ip_rsec, unsigned int idx,
struct section *insn_sec, unsigned long insn_off,
struct orc_entry *o)
{
struct orc_entry *orc;
struct reloc *reloc;
/* populate ORC data */
orc = (struct orc_entry *)u_sec->data->d_buf + idx;
orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
memcpy(orc, o, sizeof(*orc));
orc->sp_offset = bswap_if_needed(orc->sp_offset);
orc->bp_offset = bswap_if_needed(orc->bp_offset);
/* populate reloc for ip */
reloc = malloc(sizeof(*reloc));
@ -114,102 +112,149 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti
reloc->type = R_X86_64_PC32;
reloc->offset = idx * sizeof(int);
reloc->sec = ip_relocsec;
reloc->sec = ip_rsec;
elf_add_reloc(elf, reloc);
return 0;
}
int create_orc_sections(struct objtool_file *file)
{
struct instruction *insn, *prev_insn;
struct section *sec, *u_sec, *ip_relocsec;
unsigned int idx;
struct orc_list_entry {
struct list_head list;
struct orc_entry orc;
struct section *insn_sec;
unsigned long insn_off;
};
struct orc_entry empty = {
.sp_reg = ORC_REG_UNDEFINED,
static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,
struct section *sec, unsigned long offset)
{
struct orc_list_entry *entry = malloc(sizeof(*entry));
if (!entry) {
WARN("malloc failed");
return -1;
}
entry->orc = *orc;
entry->insn_sec = sec;
entry->insn_off = offset;
list_add_tail(&entry->list, orc_list);
return 0;
}
static unsigned long alt_group_len(struct alt_group *alt_group)
{
return alt_group->last_insn->offset +
alt_group->last_insn->len -
alt_group->first_insn->offset;
}
int orc_create(struct objtool_file *file)
{
struct section *sec, *ip_rsec, *orc_sec;
unsigned int nr = 0, idx = 0;
struct orc_list_entry *entry;
struct list_head orc_list;
struct orc_entry null = {
.sp_reg = ORC_REG_UNDEFINED,
.bp_reg = ORC_REG_UNDEFINED,
.type = UNWIND_HINT_TYPE_CALL,
};
/* Build a deduplicated list of ORC entries: */
INIT_LIST_HEAD(&orc_list);
for_each_sec(file, sec) {
struct orc_entry orc, prev_orc = {0};
struct instruction *insn;
bool empty = true;
if (!sec->text)
continue;
sec_for_each_insn(file, sec, insn) {
struct alt_group *alt_group = insn->alt_group;
int i;
if (!alt_group) {
if (init_orc_entry(&orc, &insn->cfi))
return -1;
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
continue;
if (orc_list_add(&orc_list, &orc, sec,
insn->offset))
return -1;
nr++;
prev_orc = orc;
empty = false;
continue;
}
/*
* Alternatives can have different stack layout
* possibilities (but they shouldn't conflict).
* Instead of traversing the instructions, use the
* alt_group's flattened byte-offset-addressed CFI
* array.
*/
for (i = 0; i < alt_group_len(alt_group); i++) {
struct cfi_state *cfi = alt_group->cfi[i];
if (!cfi)
continue;
if (init_orc_entry(&orc, cfi))
return -1;
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
continue;
if (orc_list_add(&orc_list, &orc, insn->sec,
insn->offset + i))
return -1;
nr++;
prev_orc = orc;
empty = false;
}
/* Skip to the end of the alt_group */
insn = alt_group->last_insn;
}
/* Add a section terminator */
if (!empty) {
orc_list_add(&orc_list, &null, sec, sec->len);
nr++;
}
}
if (!nr)
return 0;
/* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */
sec = find_section_by_name(file->elf, ".orc_unwind");
if (sec) {
WARN("file already has .orc_unwind section, skipping");
return -1;
}
/* count the number of needed orcs */
idx = 0;
for_each_sec(file, sec) {
if (!sec->text)
continue;
prev_insn = NULL;
sec_for_each_insn(file, sec, insn) {
if (!prev_insn ||
memcmp(&insn->orc, &prev_insn->orc,
sizeof(struct orc_entry))) {
idx++;
}
prev_insn = insn;
}
/* section terminator */
if (prev_insn)
idx++;
}
if (!idx)
orc_sec = elf_create_section(file->elf, ".orc_unwind", 0,
sizeof(struct orc_entry), nr);
if (!orc_sec)
return -1;
/* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), idx);
sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
if (!sec)
return -1;
ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
if (!ip_relocsec)
ip_rsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
if (!ip_rsec)
return -1;
/* create .orc_unwind section */
u_sec = elf_create_section(file->elf, ".orc_unwind", 0,
sizeof(struct orc_entry), idx);
/* populate sections */
idx = 0;
for_each_sec(file, sec) {
if (!sec->text)
continue;
prev_insn = NULL;
sec_for_each_insn(file, sec, insn) {
if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
sizeof(struct orc_entry))) {
if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
insn->sec, insn->offset,
&insn->orc))
return -1;
idx++;
}
prev_insn = insn;
}
/* section terminator */
if (prev_insn) {
if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
prev_insn->sec,
prev_insn->offset + prev_insn->len,
&empty))
return -1;
idx++;
}
/* Write ORC entries to sections: */
list_for_each_entry(entry, &orc_list, list) {
if (write_orc_entry(file->elf, orc_sec, ip_rsec, idx++,
entry->insn_sec, entry->insn_off,
&entry->orc))
return -1;
}
if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
if (elf_rebuild_reloc_section(file->elf, ip_rsec))
return -1;
return 0;

14
tools/objtool/special.c
View File

@ -11,10 +11,11 @@
#include <stdlib.h>
#include <string.h>
#include "builtin.h"
#include "special.h"
#include "warn.h"
#include "arch_special.h"
#include <arch/special.h>
#include <objtool/builtin.h>
#include <objtool/special.h>
#include <objtool/warn.h>
#include <objtool/endianness.h>
struct special_entry {
const char *sec;
@ -77,8 +78,9 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
if (entry->feature) {
unsigned short feature;
feature = *(unsigned short *)(sec->data->d_buf + offset +
entry->feature);
feature = bswap_if_needed(*(unsigned short *)(sec->data->d_buf +
offset +
entry->feature));
arch_handle_alternative(feature, alt);
}

9
tools/objtool/weak.c
View File

@ -7,7 +7,7 @@
#include <stdbool.h>
#include <errno.h>
#include "objtool.h"
#include <objtool/objtool.h>
#define UNSUPPORTED(name) \
({ \
@ -25,12 +25,7 @@ int __weak orc_dump(const char *_objname)
UNSUPPORTED("orc");
}
int __weak create_orc(struct objtool_file *file)
{
UNSUPPORTED("orc");
}
int __weak create_orc_sections(struct objtool_file *file)
int __weak orc_create(struct objtool_file *file)
{
UNSUPPORTED("orc");
}