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-rw-r--r--arch/x86/entry/thunk_64.S5
-rw-r--r--arch/x86/include/asm/kvm_host.h34
-rw-r--r--arch/x86/include/asm/paravirt.h1
-rw-r--r--arch/x86/kernel/head_64.S4
-rw-r--r--arch/x86/kernel/kvm.c1
-rw-r--r--arch/x86/kvm/emulate.c44
-rw-r--r--arch/x86/kvm/vmx/vmenter.S6
-rw-r--r--arch/x86/lib/copy_user_64.S2
-rw-r--r--arch/x86/lib/getuser.S20
-rw-r--r--arch/x86/lib/putuser.S29
-rw-r--r--arch/x86/lib/usercopy_64.c2
-rw-r--r--include/linux/compiler-gcc.h2
-rw-r--r--include/linux/compiler.h5
-rw-r--r--include/linux/compiler_types.h4
-rw-r--r--kernel/bpf/core.c5
-rw-r--r--kernel/stacktrace.c5
-rw-r--r--tools/objtool/arch.h36
-rw-r--r--tools/objtool/arch/x86/decode.c2
-rw-r--r--tools/objtool/check.c333
-rw-r--r--tools/objtool/check.h3
-rw-r--r--tools/objtool/elf.c8
-rw-r--r--tools/objtool/elf.h5
22 files changed, 311 insertions, 245 deletions
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index cfdca8b42c70..cc20465b2867 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -12,9 +12,7 @@
/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro THUNK name, func, put_ret_addr_in_rdi=0
- .globl \name
- .type \name, @function
-\name:
+ ENTRY(\name)
pushq %rbp
movq %rsp, %rbp
@@ -35,6 +33,7 @@
call \func
jmp .L_restore
+ ENDPROC(\name)
_ASM_NOKPROBE(\name)
.endm
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 0cc5b611a113..8282b8d41209 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1496,25 +1496,29 @@ enum {
#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
+asmlinkage void __noreturn kvm_spurious_fault(void);
+
/*
* Hardware virtualization extension instructions may fault if a
* reboot turns off virtualization while processes are running.
- * Trap the fault and ignore the instruction if that happens.
+ * Usually after catching the fault we just panic; during reboot
+ * instead the instruction is ignored.
*/
-asmlinkage void kvm_spurious_fault(void);
-
-#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \
- "666: " insn "\n\t" \
- "668: \n\t" \
- ".pushsection .fixup, \"ax\" \n" \
- "667: \n\t" \
- cleanup_insn "\n\t" \
- "cmpb $0, kvm_rebooting \n\t" \
- "jne 668b \n\t" \
- __ASM_SIZE(push) " $666b \n\t" \
- "jmp kvm_spurious_fault \n\t" \
- ".popsection \n\t" \
- _ASM_EXTABLE(666b, 667b)
+#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \
+ "666: \n\t" \
+ insn "\n\t" \
+ "jmp 668f \n\t" \
+ "667: \n\t" \
+ "call kvm_spurious_fault \n\t" \
+ "668: \n\t" \
+ ".pushsection .fixup, \"ax\" \n\t" \
+ "700: \n\t" \
+ cleanup_insn "\n\t" \
+ "cmpb $0, kvm_rebooting\n\t" \
+ "je 667b \n\t" \
+ "jmp 668b \n\t" \
+ ".popsection \n\t" \
+ _ASM_EXTABLE(666b, 700b)
#define __kvm_handle_fault_on_reboot(insn) \
____kvm_handle_fault_on_reboot(insn, "")
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index c25c38a05c1c..d6f5ae2c79ab 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -746,6 +746,7 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
PV_RESTORE_ALL_CALLER_REGS \
FRAME_END \
"ret;" \
+ ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \
".popsection")
/* Get a reference to a callee-save function */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index bcd206c8ac90..66b4a7757397 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -253,10 +253,10 @@ END(secondary_startup_64)
* start_secondary() via .Ljump_to_C_code.
*/
ENTRY(start_cpu0)
- movq initial_stack(%rip), %rsp
UNWIND_HINT_EMPTY
+ movq initial_stack(%rip), %rsp
jmp .Ljump_to_C_code
-ENDPROC(start_cpu0)
+END(start_cpu0)
#endif
/* Both SMP bootup and ACPI suspend change these variables */
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 82caf01b63dd..6661bd2f08a6 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -838,6 +838,7 @@ asm(
"cmpb $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
"setne %al;"
"ret;"
+".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
".popsection");
#endif
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8e409ad448f9..718f7d9afedc 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -312,29 +312,42 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
-#define FOP_FUNC(name) \
+#define __FOP_FUNC(name) \
".align " __stringify(FASTOP_SIZE) " \n\t" \
".type " name ", @function \n\t" \
name ":\n\t"
-#define FOP_RET "ret \n\t"
+#define FOP_FUNC(name) \
+ __FOP_FUNC(#name)
+
+#define __FOP_RET(name) \
+ "ret \n\t" \
+ ".size " name ", .-" name "\n\t"
+
+#define FOP_RET(name) \
+ __FOP_RET(#name)
#define FOP_START(op) \
extern void em_##op(struct fastop *fake); \
asm(".pushsection .text, \"ax\" \n\t" \
".global em_" #op " \n\t" \
- FOP_FUNC("em_" #op)
+ ".align " __stringify(FASTOP_SIZE) " \n\t" \
+ "em_" #op ":\n\t"
#define FOP_END \
".popsection")
+#define __FOPNOP(name) \
+ __FOP_FUNC(name) \
+ __FOP_RET(name)
+
#define FOPNOP() \
- FOP_FUNC(__stringify(__UNIQUE_ID(nop))) \
- FOP_RET
+ __FOPNOP(__stringify(__UNIQUE_ID(nop)))
#define FOP1E(op, dst) \
- FOP_FUNC(#op "_" #dst) \
- "10: " #op " %" #dst " \n\t" FOP_RET
+ __FOP_FUNC(#op "_" #dst) \
+ "10: " #op " %" #dst " \n\t" \
+ __FOP_RET(#op "_" #dst)
#define FOP1EEX(op, dst) \
FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception)
@@ -366,8 +379,9 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
FOP_END
#define FOP2E(op, dst, src) \
- FOP_FUNC(#op "_" #dst "_" #src) \
- #op " %" #src ", %" #dst " \n\t" FOP_RET
+ __FOP_FUNC(#op "_" #dst "_" #src) \
+ #op " %" #src ", %" #dst " \n\t" \
+ __FOP_RET(#op "_" #dst "_" #src)
#define FASTOP2(op) \
FOP_START(op) \
@@ -405,8 +419,9 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
FOP_END
#define FOP3E(op, dst, src, src2) \
- FOP_FUNC(#op "_" #dst "_" #src "_" #src2) \
- #op " %" #src2 ", %" #src ", %" #dst " \n\t" FOP_RET
+ __FOP_FUNC(#op "_" #dst "_" #src "_" #src2) \
+ #op " %" #src2 ", %" #src ", %" #dst " \n\t"\
+ __FOP_RET(#op "_" #dst "_" #src "_" #src2)
/* 3-operand, word-only, src2=cl */
#define FASTOP3WCL(op) \
@@ -423,7 +438,7 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
".type " #op ", @function \n\t" \
#op ": \n\t" \
#op " %al \n\t" \
- FOP_RET
+ __FOP_RET(#op)
asm(".pushsection .fixup, \"ax\"\n"
".global kvm_fastop_exception \n"
@@ -449,7 +464,10 @@ FOP_SETCC(setle)
FOP_SETCC(setnle)
FOP_END;
-FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET
+FOP_START(salc)
+FOP_FUNC(salc)
+"pushf; sbb %al, %al; popf \n\t"
+FOP_RET(salc)
FOP_END;
/*
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index d4cb1945b2e3..4010d519eb8c 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -54,9 +54,9 @@ ENTRY(vmx_vmenter)
ret
3: cmpb $0, kvm_rebooting
- jne 4f
- call kvm_spurious_fault
-4: ret
+ je 4f
+ ret
+4: ud2
.pushsection .fixup, "ax"
5: jmp 3b
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 378a1f70ae7d..4fe1601dbc5d 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -239,7 +239,7 @@ copy_user_handle_tail:
ret
_ASM_EXTABLE_UA(1b, 2b)
-ENDPROC(copy_user_handle_tail)
+END(copy_user_handle_tail)
/*
* copy_user_nocache - Uncached memory copy with exception handling
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 74fdff968ea3..304f958c27b2 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -115,29 +115,29 @@ ENDPROC(__get_user_8)
EXPORT_SYMBOL(__get_user_8)
+bad_get_user_clac:
+ ASM_CLAC
bad_get_user:
xor %edx,%edx
mov $(-EFAULT),%_ASM_AX
- ASM_CLAC
ret
-END(bad_get_user)
#ifdef CONFIG_X86_32
+bad_get_user_8_clac:
+ ASM_CLAC
bad_get_user_8:
xor %edx,%edx
xor %ecx,%ecx
mov $(-EFAULT),%_ASM_AX
- ASM_CLAC
ret
-END(bad_get_user_8)
#endif
- _ASM_EXTABLE_UA(1b, bad_get_user)
- _ASM_EXTABLE_UA(2b, bad_get_user)
- _ASM_EXTABLE_UA(3b, bad_get_user)
+ _ASM_EXTABLE_UA(1b, bad_get_user_clac)
+ _ASM_EXTABLE_UA(2b, bad_get_user_clac)
+ _ASM_EXTABLE_UA(3b, bad_get_user_clac)
#ifdef CONFIG_X86_64
- _ASM_EXTABLE_UA(4b, bad_get_user)
+ _ASM_EXTABLE_UA(4b, bad_get_user_clac)
#else
- _ASM_EXTABLE_UA(4b, bad_get_user_8)
- _ASM_EXTABLE_UA(5b, bad_get_user_8)
+ _ASM_EXTABLE_UA(4b, bad_get_user_8_clac)
+ _ASM_EXTABLE_UA(5b, bad_get_user_8_clac)
#endif
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index d2e5c9c39601..14bf78341d3c 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -32,8 +32,6 @@
*/
#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX
-#define EXIT ASM_CLAC ; \
- ret
.text
ENTRY(__put_user_1)
@@ -43,7 +41,8 @@ ENTRY(__put_user_1)
ASM_STAC
1: movb %al,(%_ASM_CX)
xor %eax,%eax
- EXIT
+ ASM_CLAC
+ ret
ENDPROC(__put_user_1)
EXPORT_SYMBOL(__put_user_1)
@@ -56,7 +55,8 @@ ENTRY(__put_user_2)
ASM_STAC
2: movw %ax,(%_ASM_CX)
xor %eax,%eax
- EXIT
+ ASM_CLAC
+ ret
ENDPROC(__put_user_2)
EXPORT_SYMBOL(__put_user_2)
@@ -69,7 +69,8 @@ ENTRY(__put_user_4)
ASM_STAC
3: movl %eax,(%_ASM_CX)
xor %eax,%eax
- EXIT
+ ASM_CLAC
+ ret
ENDPROC(__put_user_4)
EXPORT_SYMBOL(__put_user_4)
@@ -85,19 +86,21 @@ ENTRY(__put_user_8)
5: movl %edx,4(%_ASM_CX)
#endif
xor %eax,%eax
- EXIT
+ ASM_CLAC
+ RET
ENDPROC(__put_user_8)
EXPORT_SYMBOL(__put_user_8)
+bad_put_user_clac:
+ ASM_CLAC
bad_put_user:
movl $-EFAULT,%eax
- EXIT
-END(bad_put_user)
+ RET
- _ASM_EXTABLE_UA(1b, bad_put_user)
- _ASM_EXTABLE_UA(2b, bad_put_user)
- _ASM_EXTABLE_UA(3b, bad_put_user)
- _ASM_EXTABLE_UA(4b, bad_put_user)
+ _ASM_EXTABLE_UA(1b, bad_put_user_clac)
+ _ASM_EXTABLE_UA(2b, bad_put_user_clac)
+ _ASM_EXTABLE_UA(3b, bad_put_user_clac)
+ _ASM_EXTABLE_UA(4b, bad_put_user_clac)
#ifdef CONFIG_X86_32
- _ASM_EXTABLE_UA(5b, bad_put_user)
+ _ASM_EXTABLE_UA(5b, bad_put_user_clac)
#endif
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index e0e006f1624e..fff28c6f73a2 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -60,7 +60,7 @@ EXPORT_SYMBOL(clear_user);
* but reuse __memcpy_mcsafe in case a new read error is encountered.
* clac() is handled in _copy_to_iter_mcsafe().
*/
-__visible unsigned long
+__visible notrace unsigned long
mcsafe_handle_tail(char *to, char *from, unsigned len)
{
for (; len; --len, to++, from++) {
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index e8579412ad21..d7ee4c6bad48 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -170,3 +170,5 @@
#else
#define __diag_GCC_8(s)
#endif
+
+#define __no_fgcse __attribute__((optimize("-fno-gcse")))
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 8aaf7cd026b0..f0fd5636fddb 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -116,9 +116,14 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
".pushsection .discard.unreachable\n\t" \
".long 999b - .\n\t" \
".popsection\n\t"
+
+/* Annotate a C jump table to allow objtool to follow the code flow */
+#define __annotate_jump_table __section(".rodata..c_jump_table")
+
#else
#define annotate_reachable()
#define annotate_unreachable()
+#define __annotate_jump_table
#endif
#ifndef ASM_UNREACHABLE
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 095d55c3834d..599c27b56c29 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -189,6 +189,10 @@ struct ftrace_likely_data {
#define asm_volatile_goto(x...) asm goto(x)
#endif
+#ifndef __no_fgcse
+# define __no_fgcse
+#endif
+
/* Are two types/vars the same type (ignoring qualifiers)? */
#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 16079550db6d..8191a7db2777 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1295,11 +1295,11 @@ bool bpf_opcode_in_insntable(u8 code)
*
* Decode and execute eBPF instructions.
*/
-static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
+static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
{
#define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
- static const void *jumptable[256] = {
+ static const void * const jumptable[256] __annotate_jump_table = {
[0 ... 255] = &&default_label,
/* Now overwrite non-defaults ... */
BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
@@ -1558,7 +1558,6 @@ out:
BUG_ON(1);
return 0;
}
-STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */
#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
#define DEFINE_BPF_PROG_RUN(stack_size) \
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index e6a02b274b73..f5440abb7532 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -226,12 +226,17 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
.store = store,
.size = size,
};
+ mm_segment_t fs;
/* Trace user stack if not a kernel thread */
if (current->flags & PF_KTHREAD)
return 0;
+ fs = get_fs();
+ set_fs(USER_DS);
arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));
+ set_fs(fs);
+
return c.len;
}
#endif
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index 580e344db3dd..ced3765c4f44 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -11,22 +11,24 @@
#include "elf.h"
#include "cfi.h"
-#define INSN_JUMP_CONDITIONAL 1
-#define INSN_JUMP_UNCONDITIONAL 2
-#define INSN_JUMP_DYNAMIC 3
-#define INSN_CALL 4
-#define INSN_CALL_DYNAMIC 5
-#define INSN_RETURN 6
-#define INSN_CONTEXT_SWITCH 7
-#define INSN_STACK 8
-#define INSN_BUG 9
-#define INSN_NOP 10
-#define INSN_STAC 11
-#define INSN_CLAC 12
-#define INSN_STD 13
-#define INSN_CLD 14
-#define INSN_OTHER 15
-#define INSN_LAST INSN_OTHER
+enum insn_type {
+ INSN_JUMP_CONDITIONAL,
+ INSN_JUMP_UNCONDITIONAL,
+ INSN_JUMP_DYNAMIC,
+ INSN_JUMP_DYNAMIC_CONDITIONAL,
+ INSN_CALL,
+ INSN_CALL_DYNAMIC,
+ INSN_RETURN,
+ INSN_CONTEXT_SWITCH,
+ INSN_STACK,
+ INSN_BUG,
+ INSN_NOP,
+ INSN_STAC,
+ INSN_CLAC,
+ INSN_STD,
+ INSN_CLD,
+ INSN_OTHER,
+};
enum op_dest_type {
OP_DEST_REG,
@@ -68,7 +70,7 @@ void arch_initial_func_cfi_state(struct cfi_state *state);
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
- unsigned int *len, unsigned char *type,
+ unsigned int *len, enum insn_type *type,
unsigned long *immediate, struct stack_op *op);
bool arch_callee_saved_reg(unsigned char reg);
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 584568f27a83..0567c47a91b1 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -68,7 +68,7 @@ bool arch_callee_saved_reg(unsigned char reg)
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
- unsigned int *len, unsigned char *type,
+ unsigned int *len, enum insn_type *type,
unsigned long *immediate, struct stack_op *op)
{
struct insn insn;
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 172f99195726..5f26620f13f5 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -18,6 +18,8 @@
#define FAKE_JUMP_OFFSET -1
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
struct alternative {
struct list_head list;
struct instruction *insn;
@@ -95,6 +97,20 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
+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);
+
+ if (insn->type != INSN_JUMP_CONDITIONAL &&
+ insn->type != INSN_JUMP_UNCONDITIONAL)
+ return false;
+
+ /* add_jump_destinations() sets insn->call_dest for sibling calls. */
+ return !!insn->call_dest;
+}
+
/*
* This checks to see if the given function is a "noreturn" function.
*
@@ -103,14 +119,9 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
*
* For local functions, we have to detect them manually by simply looking for
* the lack of a return instruction.
- *
- * Returns:
- * -1: error
- * 0: no dead end
- * 1: dead end
*/
-static int __dead_end_function(struct objtool_file *file, struct symbol *func,
- int recursion)
+static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
+ int recursion)
{
int i;
struct instruction *insn;
@@ -136,30 +147,33 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
"rewind_stack_do_exit",
};
+ if (!func)
+ return false;
+
if (func->bind == STB_WEAK)
- return 0;
+ return false;
if (func->bind == STB_GLOBAL)
for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
if (!strcmp(func->name, global_noreturns[i]))
- return 1;
+ return true;
if (!func->len)
- return 0;
+ return false;
insn = find_insn(file, func->sec, func->offset);
if (!insn->func)
- return 0;
+ return false;
func_for_each_insn_all(file, func, insn) {
empty = false;
if (insn->type == INSN_RETURN)
- return 0;
+ return false;
}
if (empty)
- return 0;
+ return false;
/*
* A function can have a sibling call instead of a return. In that
@@ -167,40 +181,31 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
* of the sibling call returns.
*/
func_for_each_insn_all(file, func, insn) {
- if (insn->type == INSN_JUMP_UNCONDITIONAL) {
+ if (is_sibling_call(insn)) {
struct instruction *dest = insn->jump_dest;
if (!dest)
/* sibling call to another file */
- return 0;
-
- if (dest->func && dest->func->pfunc != insn->func->pfunc) {
+ return false;
- /* local sibling call */
- if (recursion == 5) {
- /*
- * Infinite recursion: two functions
- * have sibling calls to each other.
- * This is a very rare case. It means
- * they aren't dead ends.
- */
- return 0;
- }
-
- return __dead_end_function(file, dest->func,
- recursion + 1);
+ /* local sibling call */
+ if (recursion == 5) {
+ /*
+ * Infinite recursion: two functions have
+ * sibling calls to each other. This is a very
+ * rare case. It means they aren't dead ends.
+ */
+ return false;
}
- }
- if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
- /* sibling call */
- return 0;
+ return __dead_end_function(file, dest->func, recursion+1);
+ }
}
- return 1;
+ return true;
}
-static int dead_end_function(struct objtool_file *file, struct symbol *func)
+static bool dead_end_function(struct objtool_file *file, struct symbol *func)
{
return __dead_end_function(file, func, 0);
}
@@ -262,19 +267,12 @@ static int decode_instructions(struct objtool_file *file)
if (ret)
goto err;
- if (!insn->type || insn->type > INSN_LAST) {
- WARN_FUNC("invalid instruction type %d",
- insn->sec, insn->offset, insn->type);
- ret = -1;
- goto err;
- }
-
hash_add(file->insn_hash, &insn->hash, insn->offset);
list_add_tail(&insn->list, &file->insn_list);
}
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
+ if (func->type != STT_FUNC || func->alias != func)
continue;
if (!find_insn(file, sec, func->offset)) {
@@ -284,8 +282,7 @@ static int decode_instructions(struct objtool_file *file)
}
func_for_each_insn(file, func, insn)
- if (!insn->func)
- insn->func = func;
+ insn->func = func;
}
}
@@ -488,6 +485,7 @@ static const char *uaccess_safe_builtin[] = {
/* misc */
"csum_partial_copy_generic",
"__memcpy_mcsafe",
+ "mcsafe_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
@@ -505,7 +503,7 @@ static void add_uaccess_safe(struct objtool_file *file)
if (!func)
continue;
- func->alias->uaccess_safe = true;
+ func->uaccess_safe = true;
}
}
@@ -577,13 +575,16 @@ static int add_jump_destinations(struct objtool_file *file)
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
*/
- insn->type = INSN_JUMP_DYNAMIC;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL)
+ insn->type = INSN_JUMP_DYNAMIC;
+ else
+ insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+
insn->retpoline_safe = true;
continue;
} else {
- /* sibling call */
+ /* external sibling call */
insn->call_dest = rela->sym;
- insn->jump_dest = NULL;
continue;
}
@@ -623,7 +624,7 @@ static int add_jump_destinations(struct objtool_file *file)
* However this code can't completely replace the
* read_symbols() code because this doesn't detect the
* case where the parent function's only reference to a
- * subfunction is through a switch table.
+ * subfunction is through a jump table.
*/
if (!strstr(insn->func->name, ".cold.") &&
strstr(insn->jump_dest->func->name, ".cold.")) {
@@ -633,9 +634,8 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
insn->jump_dest->offset == insn->jump_dest->func->offset) {
- /* sibling class */
+ /* internal sibling call */
insn->call_dest = insn->jump_dest->func;
- insn->jump_dest = NULL;
}
}
}
@@ -896,20 +896,26 @@ out:
return ret;
}
-static int add_switch_table(struct objtool_file *file, struct instruction *insn,
- struct rela *table, struct rela *next_table)
+static int add_jump_table(struct objtool_file *file, struct instruction *insn,
+ struct rela *table)
{
struct rela *rela = table;
- struct instruction *alt_insn;
+ struct instruction *dest_insn;
struct alternative *alt;
struct symbol *pfunc = insn->func->pfunc;
unsigned int prev_offset = 0;
- list_for_each_entry_from(rela, &table->rela_sec->rela_list, list) {
- if (rela == next_table)
+ /*
+ * Each @rela is a switch table relocation which points to the target
+ * instruction.
+ */
+ list_for_each_entry_from(rela, &table->sec->rela_list, list) {
+
+ /* Check for the end of the table: */
+ if (rela != table && rela->jump_table_start)
break;
- /* Make sure the switch table entries are consecutive: */
+ /* Make sure the table entries are consecutive: */
if (prev_offset && rela->offset != prev_offset + 8)
break;
@@ -918,12 +924,12 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
rela->addend == pfunc->offset)
break;
- alt_insn = find_insn(file, rela->sym->sec, rela->addend);
- if (!alt_insn)
+ dest_insn = find_insn(file, rela->sym->sec, rela->addend);
+ if (!dest_insn)
break;
- /* Make sure the jmp dest is in the function or subfunction: */
- if (alt_insn->func->pfunc != pfunc)
+ /* Make sure the destination is in the same function: */
+ if (!dest_insn->func || dest_insn->func->pfunc != pfunc)
break;
alt = malloc(sizeof(*alt));
@@ -932,7 +938,7 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
return -1;
}
- alt->insn = alt_insn;
+ alt->insn = dest_insn;
list_add_tail(&alt->list, &insn->alts);
prev_offset = rela->offset;
}
@@ -947,7 +953,7 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
}
/*
- * find_switch_table() - Given a dynamic jump, find the switch jump table in
+ * find_jump_table() - Given a dynamic jump, find the switch jump table in
* .rodata associated with it.
*
* There are 3 basic patterns:
@@ -989,13 +995,13 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
*
* NOTE: RETPOLINE made it harder still to decode dynamic jumps.
*/
-static struct rela *find_switch_table(struct objtool_file *file,
+static struct rela *find_jump_table(struct objtool_file *file,
struct symbol *func,
struct instruction *insn)
{
- struct rela *text_rela, *rodata_rela;
+ struct rela *text_rela, *table_rela;
struct instruction *orig_insn = insn;
- struct section *rodata_sec;
+ struct section *table_sec;
unsigned long table_offset;
/*
@@ -1028,42 +1034,52 @@ static struct rela *find_switch_table(struct objtool_file *file,
continue;
table_offset = text_rela->addend;
- rodata_sec = text_rela->sym->sec;
+ table_sec = text_rela->sym->sec;
if (text_rela->type == R_X86_64_PC32)
table_offset += 4;
/*
* Make sure the .rodata address isn't associated with a
- * symbol. gcc jump tables are anonymous data.
+ * symbol. GCC jump tables are anonymous data.
+ *
+ * Also support C jump tables which are in the same format as
+ * switch jump tables. For objtool to recognize them, they
+ * need to be placed in the C_JUMP_TABLE_SECTION section. They
+ * have symbols associated with them.
*/
- if (find_symbol_containing(rodata_sec, table_offset))
+ if (find_symbol_containing(table_sec, table_offset) &&
+ strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
continue;
- rodata_rela = find_rela_by_dest(rodata_sec, table_offset);
- if (rodata_rela) {
- /*
- * Use of RIP-relative switch jumps is quite rare, and
- * indicates a rare GCC quirk/bug which can leave dead
- * code behind.
- */
- if (text_rela->type == R_X86_64_PC32)
- file->ignore_unreachables = true;
+ /* Each table entry has a rela associated with it. */
+ table_rela = find_rela_by_dest(table_sec, table_offset);
+ if (!table_rela)
+ continue;
- return rodata_rela;
- }
+ /*
+ * Use of RIP-relative switch jumps is quite rare, and
+ * indicates a rare GCC quirk/bug which can leave dead code
+ * behind.
+ */
+ if (text_rela->type == R_X86_64_PC32)
+ file->ignore_unreachables = true;
+
+ return table_rela;
}
return NULL;
}
-
-static int add_func_switch_tables(struct objtool_file *file,
- struct symbol *func)
+/*
+ * First pass: Mark the head of each jump table so that in the next pass,
+ * we know when a given jump table ends and the next one starts.
+ */
+static void mark_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
{
- struct instruction *insn, *last = NULL, *prev_jump = NULL;
- struct rela *rela, *prev_rela = NULL;
- int ret;
+ struct instruction *insn, *last = NULL;
+ struct rela *rela;
func_for_each_insn_all(file, func, insn) {
if (!last)
@@ -1071,7 +1087,7 @@ static int add_func_switch_tables(struct objtool_file *file,
/*
* Store back-pointers for unconditional forward jumps such
- * that find_switch_table() can back-track using those and
+ * that find_jump_table() can back-track using those and
* avoid some potentially confusing code.
*/
if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
@@ -1086,27 +1102,25 @@ static int add_func_switch_tables(struct objtool_file *file,
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- rela = find_switch_table(file, func, insn);
- if (!rela)
- continue;
-
- /*
- * We found a switch table, but we don't know yet how big it
- * is. Don't add it until we reach the end of the function or
- * the beginning of another switch table in the same function.
- */
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, rela);
- if (ret)
- return ret;
+ rela = find_jump_table(file, func, insn);
+ if (rela) {
+ rela->jump_table_start = true;
+ insn->jump_table = rela;
}
-
- prev_jump = insn;
- prev_rela = rela;
}
+}
+
+static int add_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
+{
+ struct instruction *insn;
+ int ret;
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, NULL);
+ func_for_each_insn_all(file, func, insn) {
+ if (!insn->jump_table)
+ continue;
+
+ ret = add_jump_table(file, insn, insn->jump_table);
if (ret)
return ret;
}
@@ -1119,7 +1133,7 @@ static int add_func_switch_tables(struct objtool_file *file,
* section which contains a list of addresses within the function to jump to.
* This finds these jump tables and adds them to the insn->alts lists.
*/
-static int add_switch_table_alts(struct objtool_file *file)
+static int add_jump_table_alts(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
@@ -1133,7 +1147,8 @@ static int add_switch_table_alts(struct objtool_file *file)
if (func->type != STT_FUNC)
continue;
- ret = add_func_switch_tables(file, func);
+ mark_func_jump_tables(file, func);
+ ret = add_func_jump_tables(file, func);
if (ret)
return ret;
}
@@ -1277,13 +1292,18 @@ static void mark_rodata(struct objtool_file *file)
bool found = false;
/*
- * This searches for the .rodata section or multiple .rodata.func_name
- * sections if -fdata-sections is being used. The .str.1.1 and .str.1.8
- * rodata sections are ignored as they don't contain jump tables.
+ * Search for the following rodata sections, each of which can
+ * potentially contain jump tables:
+ *
+ * - .rodata: can contain GCC switch tables
+ * - .rodata.<func>: same, if -fdata-sections is being used
+ * - .rodata..c_jump_table: contains C annotated jump tables
+ *
+ * .rodata.str1.* sections are ignored; they don't contain jump tables.
*/
for_each_sec(file, sec) {
- if (!strncmp(sec->name, ".rodata", 7) &&
- !strstr(sec->name, ".str1.")) {
+ if ((!strncmp(sec->name, ".rodata", 7) && !strstr(sec->name, ".str1.")) ||
+ !strcmp(sec->name, C_JUMP_TABLE_SECTION)) {
sec->rodata = true;
found = true;
}
@@ -1325,7 +1345,7 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- ret = add_switch_table_alts(file);
+ ret = add_jump_table_alts(file);
if (ret)
return ret;
@@ -1873,12 +1893,12 @@ static bool insn_state_match(struct instruction *insn, struct insn_state *state)
static inline bool func_uaccess_safe(struct symbol *func)
{
if (func)
- return func->alias->uaccess_safe;
+ return func->uaccess_safe;
return false;
}
-static inline const char *insn_dest_name(struct instruction *insn)
+static inline const char *call_dest_name(struct instruction *insn)
{
if (insn->call_dest)
return insn->call_dest->name;
@@ -1890,13 +1910,13 @@ static int validate_call(struct instruction *insn, struct insn_state *state)
{
if (state->uaccess && !func_uaccess_safe(insn->call_dest)) {
WARN_FUNC("call to %s() with UACCESS enabled",
- insn->sec, insn->offset, insn_dest_name(insn));
+ insn->sec, insn->offset, call_dest_name(insn));
return 1;
}
if (state->df) {
WARN_FUNC("call to %s() with DF set",
- insn->sec, insn->offset, insn_dest_name(insn));
+ insn->sec, insn->offset, call_dest_name(insn));
return 1;
}
@@ -1920,13 +1940,12 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st
* each instruction and validate all the rules described in
* tools/objtool/Documentation/stack-validation.txt.
*/
-static int validate_branch(struct objtool_file *file, struct instruction *first,
- struct insn_state state)
+static int validate_branch(struct objtool_file *file, struct symbol *func,
+ struct instruction *first, struct insn_state state)
{
struct alternative *alt;
struct instruction *insn, *next_insn;
struct section *sec;
- struct symbol *func = NULL;
int ret;
insn = first;
@@ -1947,9 +1966,6 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
return 1;
}
- if (insn->func)
- func = insn->func->pfunc;
-
if (func && insn->ignore) {
WARN_FUNC("BUG: why am I validating an ignored function?",
sec, insn->offset);
@@ -1971,7 +1987,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
i = insn;
save_insn = NULL;
- func_for_each_insn_continue_reverse(file, insn->func, i) {
+ func_for_each_insn_continue_reverse(file, func, i) {
if (i->save) {
save_insn = i;
break;
@@ -2017,7 +2033,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (alt->skip_orig)
skip_orig = true;
- ret = validate_branch(file, alt->insn, state);
+ ret = validate_branch(file, func, alt->insn, state);
if (ret) {
if (backtrace)
BT_FUNC("(alt)", insn);
@@ -2055,7 +2071,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (state.bp_scratch) {
WARN("%s uses BP as a scratch register",
- insn->func->name);
+ func->name);
return 1;
}
@@ -2067,36 +2083,28 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (ret)
return ret;
- if (insn->type == INSN_CALL) {
- if (is_fentry_call(insn))
- break;
-
- ret = dead_end_function(file, insn->call_dest);
- if (ret == 1)
- return 0;
- if (ret == -1)
- return 1;
- }
-
- if (!no_fp && func && !has_valid_stack_frame(&state)) {
+ if (!no_fp && func && !is_fentry_call(insn) &&
+ !has_valid_stack_frame(&state)) {
WARN_FUNC("call without frame pointer save/setup",
sec, insn->offset);
return 1;
}
+
+ if (dead_end_function(file, insn->call_dest))
+ return 0;
+
break;
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
- if (func && !insn->jump_dest) {
+ if (func && is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
- } else if (insn->jump_dest &&
- (!func || !insn->jump_dest->func ||
- insn->jump_dest->func->pfunc == func)) {
- ret = validate_branch(file, insn->jump_dest,
- state);
+ } else if (insn->jump_dest) {
+ ret = validate_branch(file, func,
+ insn->jump_dest, state);
if (ret) {
if (backtrace)
BT_FUNC("(branch)", insn);
@@ -2110,13 +2118,17 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_JUMP_DYNAMIC:
- if (func && list_empty(&insn->alts)) {
+ case INSN_JUMP_DYNAMIC_CONDITIONAL:
+ if (func && is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
}
- return 0;
+ if (insn->type == INSN_JUMP_DYNAMIC)
+ return 0;
+
+ break;
case INSN_CONTEXT_SWITCH:
if (func && (!next_insn || !next_insn->hint)) {
@@ -2162,7 +2174,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_CLAC:
- if (!state.uaccess && insn->func) {
+ if (!state.uaccess && func) {
WARN_FUNC("redundant UACCESS disable", sec, insn->offset);
return 1;
}
@@ -2183,7 +2195,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_CLD:
- if (!state.df && insn->func)
+ if (!state.df && func)
WARN_FUNC("redundant CLD", sec, insn->offset);
state.df = false;
@@ -2222,7 +2234,7 @@ static int validate_unwind_hints(struct objtool_file *file)
for_each_insn(file, insn) {
if (insn->hint && !insn->visited) {
- ret = validate_branch(file, insn, state);
+ ret = validate_branch(file, insn->func, insn, state);
if (ret && backtrace)
BT_FUNC("<=== (hint)", insn);
warnings += ret;
@@ -2345,16 +2357,25 @@ static int validate_functions(struct objtool_file *file)
for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC || func->pfunc != func)
+ if (func->type != STT_FUNC)
+ continue;
+
+ if (!func->len) {
+ WARN("%s() is missing an ELF size annotation",
+ func->name);
+ warnings++;
+ }
+
+ if (func->pfunc != func || func->alias != func)
continue;
insn = find_insn(file, sec, func->offset);
- if (!insn || insn->ignore)
+ if (!insn || insn->ignore || insn->visited)
continue;
- state.uaccess = func->alias->uaccess_safe;
+ state.uaccess = func->uaccess_safe;
- ret = validate_branch(file, insn, state);
+ ret = validate_branch(file, func, insn, state);
if (ret && backtrace)
BT_FUNC("<=== (func)", insn);
warnings += ret;
@@ -2407,7 +2428,7 @@ int check(const char *_objname, bool orc)
objname = _objname;
- file.elf = elf_open(objname, orc ? O_RDWR : O_RDONLY);
+ file.elf = elf_read(objname, orc ? O_RDWR : O_RDONLY);
if (!file.elf)
return 1;
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index cb60b9acf5cf..b881fafcf55d 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -31,13 +31,14 @@ struct instruction {
struct section *sec;
unsigned long offset;
unsigned int len;
- unsigned char type;
+ enum insn_type type;
unsigned long immediate;
bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
bool retpoline_safe;
struct symbol *call_dest;
struct instruction *jump_dest;
struct instruction *first_jump_src;
+ struct rela *jump_table;
struct list_head alts;
struct symbol *func;
struct stack_op stack_op;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index e99e1be19ad9..edba4745f25a 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -278,7 +278,7 @@ static int read_symbols(struct elf *elf)
}
if (sym->offset == s->offset) {
- if (sym->len == s->len && alias == sym)
+ if (sym->len && sym->len == s->len && alias == sym)
alias = s;
if (sym->len >= s->len) {
@@ -385,7 +385,7 @@ static int read_relas(struct elf *elf)
rela->offset = rela->rela.r_offset;
symndx = GELF_R_SYM(rela->rela.r_info);
rela->sym = find_symbol_by_index(elf, symndx);
- rela->rela_sec = sec;
+ rela->sec = sec;
if (!rela->sym) {
WARN("can't find rela entry symbol %d for %s",
symndx, sec->name);
@@ -401,7 +401,7 @@ static int read_relas(struct elf *elf)
return 0;
}
-struct elf *elf_open(const char *name, int flags)
+struct elf *elf_read(const char *name, int flags)
{
struct elf *elf;
Elf_Cmd cmd;
@@ -463,7 +463,7 @@ struct section *elf_create_section(struct elf *elf, const char *name,
{
struct section *sec, *shstrtab;
size_t size = entsize * nr;
- struct Elf_Scn *s;
+ Elf_Scn *s;
Elf_Data *data;
sec = malloc(sizeof(*sec));
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index e44ca5d51871..44150204db4d 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -57,11 +57,12 @@ struct rela {
struct list_head list;
struct hlist_node hash;
GElf_Rela rela;
- struct section *rela_sec;
+ struct section *sec;
struct symbol *sym;
unsigned int type;
unsigned long offset;
int addend;
+ bool jump_table_start;
};
struct elf {
@@ -74,7 +75,7 @@ struct elf {
};
-struct elf *elf_open(const char *name, int flags);
+struct elf *elf_read(const char *name, int flags);
struct section *find_section_by_name(struct elf *elf, const char *name);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_name(struct elf *elf, const char *name);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-18 01:09:54 +0000