@@ -12,6 +12,8 @@ OBJCOPYFLAGS := -O binary
LDFLAGS_vmlinux :=
ifeq ($(CONFIG_DYNAMIC_FTRACE),y)
LDFLAGS_vmlinux := --no-relax
+ KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
+ CC_FLAGS_FTRACE := -fpatchable-function-entry=8
endif
ifeq ($(CONFIG_64BIT)$(CONFIG_CMODEL_MEDLOW),yy)
@@ -72,29 +72,56 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target,
return 0;
}
+/*
+ * Put 5 instructions with 16 bytes at the front of function within
+ * patchable function entry nops' area.
+ *
+ * 0: REG_S ra, -SZREG(sp)
+ * 1: auipc ra, 0x?
+ * 2: jalr -?(ra)
+ * 3: REG_L ra, -SZREG(sp)
+ *
+ * So the opcodes is:
+ * 0: 0xfe113c23 (sd)/0xfe112e23 (sw)
+ * 1: 0x???????? -> auipc
+ * 2: 0x???????? -> jalr
+ * 3: 0xff813083 (ld)/0xffc12083 (lw)
+ */
+#if __riscv_xlen == 64
+#define INSN0 0xfe113c23
+#define INSN3 0xff813083
+#elif __riscv_xlen == 32
+#define INSN0 0xfe112e23
+#define INSN3 0xffc12083
+#endif
+
+#define FUNC_ENTRY_SIZE 16
+#define FUNC_ENTRY_JMP 4
+
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
- int ret = ftrace_check_current_call(rec->ip, NULL);
+ unsigned int call[4] = {INSN0, 0, 0, INSN3};
+ unsigned long target = addr;
+ unsigned long caller = rec->ip + FUNC_ENTRY_JMP;
- if (ret)
- return ret;
+ call[1] = to_auipc_insn((unsigned int)(target - caller));
+ call[2] = to_jalr_insn((unsigned int)(target - caller));
- return __ftrace_modify_call(rec->ip, addr, true);
+ if (patch_text_nosync((void *)rec->ip, call, FUNC_ENTRY_SIZE))
+ return -EPERM;
+
+ return 0;
}
int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
unsigned long addr)
{
- unsigned int call[2];
- int ret;
+ unsigned int nops[4] = {NOP4, NOP4, NOP4, NOP4};
- make_call(rec->ip, addr, call);
- ret = ftrace_check_current_call(rec->ip, call);
-
- if (ret)
- return ret;
+ if (patch_text_nosync((void *)rec->ip, nops, FUNC_ENTRY_SIZE))
+ return -EPERM;
- return __ftrace_modify_call(rec->ip, addr, false);
+ return 0;
}
@@ -139,15 +166,16 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr)
{
unsigned int call[2];
+ unsigned long caller = rec->ip + FUNC_ENTRY_JMP;
int ret;
- make_call(rec->ip, old_addr, call);
- ret = ftrace_check_current_call(rec->ip, call);
+ make_call(caller, old_addr, call);
+ ret = ftrace_check_current_call(caller, call);
if (ret)
return ret;
- return __ftrace_modify_call(rec->ip, addr, true);
+ return __ftrace_modify_call(caller, addr, true);
}
#endif
@@ -176,53 +204,30 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
#ifdef CONFIG_DYNAMIC_FTRACE
extern void ftrace_graph_call(void);
+extern void ftrace_graph_regs_call(void);
int ftrace_enable_ftrace_graph_caller(void)
{
- unsigned int call[2];
- static int init_graph = 1;
int ret;
- make_call(&ftrace_graph_call, &ftrace_stub, call);
-
- /*
- * When enabling graph tracer for the first time, ftrace_graph_call
- * should contains a call to ftrace_stub. Once it has been disabled,
- * the 8-bytes at the position becomes NOPs.
- */
- if (init_graph) {
- ret = ftrace_check_current_call((unsigned long)&ftrace_graph_call,
- call);
- init_graph = 0;
- } else {
- ret = ftrace_check_current_call((unsigned long)&ftrace_graph_call,
- NULL);
- }
-
+ ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
+ (unsigned long)&prepare_ftrace_return, true);
if (ret)
return ret;
- return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
(unsigned long)&prepare_ftrace_return, true);
}
int ftrace_disable_ftrace_graph_caller(void)
{
- unsigned int call[2];
int ret;
- make_call(&ftrace_graph_call, &prepare_ftrace_return, call);
-
- /*
- * This is to make sure that ftrace_enable_ftrace_graph_caller
- * did the right thing.
- */
- ret = ftrace_check_current_call((unsigned long)&ftrace_graph_call,
- call);
-
+ ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
+ (unsigned long)&prepare_ftrace_return, false);
if (ret)
return ret;
- return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
(unsigned long)&prepare_ftrace_return, false);
}
#endif /* CONFIG_DYNAMIC_FTRACE */
@@ -13,224 +13,186 @@
.text
- .macro SAVE_ABI_STATE
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi sp, sp, -48
- sd s0, 32(sp)
- sd ra, 40(sp)
- addi s0, sp, 48
- sd t0, 24(sp)
- sd t1, 16(sp)
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- sd t2, 8(sp)
-#endif
-#else
- addi sp, sp, -16
- sd s0, 0(sp)
- sd ra, 8(sp)
- addi s0, sp, 16
-#endif
+#define FENTRY_RA_OFFSET 12
+#define ABI_SIZE_ON_STACK 72
+#define ABI_A0 0
+#define ABI_A1 8
+#define ABI_A2 16
+#define ABI_A3 24
+#define ABI_A4 32
+#define ABI_A5 40
+#define ABI_A6 48
+#define ABI_A7 56
+#define ABI_RA 64
+
+ .macro SAVE_ABI
+ addi sp, sp, -SZREG
+ addi sp, sp, -ABI_SIZE_ON_STACK
+
+ REG_S a0, ABI_A0(sp)
+ REG_S a1, ABI_A1(sp)
+ REG_S a2, ABI_A2(sp)
+ REG_S a3, ABI_A3(sp)
+ REG_S a4, ABI_A4(sp)
+ REG_S a5, ABI_A5(sp)
+ REG_S a6, ABI_A6(sp)
+ REG_S a7, ABI_A7(sp)
+ REG_S ra, ABI_RA(sp)
.endm
- .macro RESTORE_ABI_STATE
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- ld s0, 32(sp)
- ld ra, 40(sp)
- addi sp, sp, 48
-#else
- ld ra, 8(sp)
- ld s0, 0(sp)
- addi sp, sp, 16
-#endif
+ .macro RESTORE_ABI
+ REG_L a0, ABI_A0(sp)
+ REG_L a1, ABI_A1(sp)
+ REG_L a2, ABI_A2(sp)
+ REG_L a3, ABI_A3(sp)
+ REG_L a4, ABI_A4(sp)
+ REG_L a5, ABI_A5(sp)
+ REG_L a6, ABI_A6(sp)
+ REG_L a7, ABI_A7(sp)
+ REG_L ra, ABI_RA(sp)
+
+ addi sp, sp, ABI_SIZE_ON_STACK
+ addi sp, sp, SZREG
.endm
- .macro RESTORE_GRAPH_ARGS
- ld a0, 24(sp)
- ld a1, 16(sp)
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- ld a2, 8(sp)
-#endif
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ .macro SAVE_ALL
+ addi sp, sp, -SZREG
+ addi sp, sp, -PT_SIZE_ON_STACK
+
+ REG_S x1, PT_EPC(sp)
+ addi sp, sp, PT_SIZE_ON_STACK
+ REG_L x1, (sp)
+ addi sp, sp, -PT_SIZE_ON_STACK
+ REG_S x1, PT_RA(sp)
+ REG_L x1, PT_EPC(sp)
+
+ REG_S x2, PT_SP(sp)
+ REG_S x3, PT_GP(sp)
+ REG_S x4, PT_TP(sp)
+ REG_S x5, PT_T0(sp)
+ REG_S x6, PT_T1(sp)
+ REG_S x7, PT_T2(sp)
+ REG_S x8, PT_S0(sp)
+ REG_S x9, PT_S1(sp)
+ REG_S x10, PT_A0(sp)
+ REG_S x11, PT_A1(sp)
+ REG_S x12, PT_A2(sp)
+ REG_S x13, PT_A3(sp)
+ REG_S x14, PT_A4(sp)
+ REG_S x15, PT_A5(sp)
+ REG_S x16, PT_A6(sp)
+ REG_S x17, PT_A7(sp)
+ REG_S x18, PT_S2(sp)
+ REG_S x19, PT_S3(sp)
+ REG_S x20, PT_S4(sp)
+ REG_S x21, PT_S5(sp)
+ REG_S x22, PT_S6(sp)
+ REG_S x23, PT_S7(sp)
+ REG_S x24, PT_S8(sp)
+ REG_S x25, PT_S9(sp)
+ REG_S x26, PT_S10(sp)
+ REG_S x27, PT_S11(sp)
+ REG_S x28, PT_T3(sp)
+ REG_S x29, PT_T4(sp)
+ REG_S x30, PT_T5(sp)
+ REG_S x31, PT_T6(sp)
.endm
-ENTRY(ftrace_graph_caller)
- addi sp, sp, -16
- sd s0, 0(sp)
- sd ra, 8(sp)
- addi s0, sp, 16
-ftrace_graph_call:
- .global ftrace_graph_call
- /*
- * Calling ftrace_enable/disable_ftrace_graph_caller would overwrite the
- * call below. Check ftrace_modify_all_code for details.
- */
- call ftrace_stub
- ld ra, 8(sp)
- ld s0, 0(sp)
- addi sp, sp, 16
- ret
-ENDPROC(ftrace_graph_caller)
+ .macro RESTORE_ALL
+ REG_L x1, PT_RA(sp)
+ addi sp, sp, PT_SIZE_ON_STACK
+ REG_S x1, (sp)
+ addi sp, sp, -PT_SIZE_ON_STACK
+ REG_L x1, PT_EPC(sp)
+ REG_L x2, PT_SP(sp)
+ REG_L x3, PT_GP(sp)
+ REG_L x4, PT_TP(sp)
+ REG_L x5, PT_T0(sp)
+ REG_L x6, PT_T1(sp)
+ REG_L x7, PT_T2(sp)
+ REG_L x8, PT_S0(sp)
+ REG_L x9, PT_S1(sp)
+ REG_L x10, PT_A0(sp)
+ REG_L x11, PT_A1(sp)
+ REG_L x12, PT_A2(sp)
+ REG_L x13, PT_A3(sp)
+ REG_L x14, PT_A4(sp)
+ REG_L x15, PT_A5(sp)
+ REG_L x16, PT_A6(sp)
+ REG_L x17, PT_A7(sp)
+ REG_L x18, PT_S2(sp)
+ REG_L x19, PT_S3(sp)
+ REG_L x20, PT_S4(sp)
+ REG_L x21, PT_S5(sp)
+ REG_L x22, PT_S6(sp)
+ REG_L x23, PT_S7(sp)
+ REG_L x24, PT_S8(sp)
+ REG_L x25, PT_S9(sp)
+ REG_L x26, PT_S10(sp)
+ REG_L x27, PT_S11(sp)
+ REG_L x28, PT_T3(sp)
+ REG_L x29, PT_T4(sp)
+ REG_L x30, PT_T5(sp)
+ REG_L x31, PT_T6(sp)
+
+ addi sp, sp, PT_SIZE_ON_STACK
+ addi sp, sp, SZREG
+ .endm
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
ENTRY(ftrace_caller)
- /*
- * a0: the address in the caller when calling ftrace_caller
- * a1: the caller's return address
- * a2: the address of global variable function_trace_op
- */
- ld a1, -8(s0)
- addi a0, ra, -MCOUNT_INSN_SIZE
- la t5, function_trace_op
- ld a2, 0(t5)
+ SAVE_ABI
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- /*
- * the graph tracer (specifically, prepare_ftrace_return) needs these
- * arguments but for now the function tracer occupies the regs, so we
- * save them in temporary regs to recover later.
- */
- addi t0, s0, -8
- mv t1, a0
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- ld t2, -16(s0)
-#endif
-#endif
+ addi a0, ra, -FENTRY_RA_OFFSET
+ la a1, function_trace_op
+ REG_L a2, 0(a1)
+ REG_L a1, ABI_SIZE_ON_STACK(sp)
+ mv a3, sp
- SAVE_ABI_STATE
ftrace_call:
.global ftrace_call
- /*
- * For the dynamic ftrace to work, here we should reserve at least
- * 8 bytes for a functional auipc-jalr pair. The following call
- * serves this purpose.
- *
- * Calling ftrace_update_ftrace_func would overwrite the nops below.
- * Check ftrace_modify_all_code for details.
- */
call ftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- RESTORE_GRAPH_ARGS
- call ftrace_graph_caller
+ addi a0, sp, ABI_SIZE_ON_STACK
+ REG_L a1, ABI_RA(sp)
+ addi a1, a1, -FENTRY_RA_OFFSET
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ mv a2, s0
#endif
-
- RESTORE_ABI_STATE
+ftrace_graph_call:
+ .global ftrace_graph_call
+ call ftrace_stub
+#endif
+ RESTORE_ABI
ret
ENDPROC(ftrace_caller)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- .macro SAVE_ALL
- addi sp, sp, -(PT_SIZE_ON_STACK+16)
- sd s0, (PT_SIZE_ON_STACK)(sp)
- sd ra, (PT_SIZE_ON_STACK+8)(sp)
- addi s0, sp, (PT_SIZE_ON_STACK+16)
-
- sd x1, PT_RA(sp)
- sd x2, PT_SP(sp)
- sd x3, PT_GP(sp)
- sd x4, PT_TP(sp)
- sd x5, PT_T0(sp)
- sd x6, PT_T1(sp)
- sd x7, PT_T2(sp)
- sd x8, PT_S0(sp)
- sd x9, PT_S1(sp)
- sd x10, PT_A0(sp)
- sd x11, PT_A1(sp)
- sd x12, PT_A2(sp)
- sd x13, PT_A3(sp)
- sd x14, PT_A4(sp)
- sd x15, PT_A5(sp)
- sd x16, PT_A6(sp)
- sd x17, PT_A7(sp)
- sd x18, PT_S2(sp)
- sd x19, PT_S3(sp)
- sd x20, PT_S4(sp)
- sd x21, PT_S5(sp)
- sd x22, PT_S6(sp)
- sd x23, PT_S7(sp)
- sd x24, PT_S8(sp)
- sd x25, PT_S9(sp)
- sd x26, PT_S10(sp)
- sd x27, PT_S11(sp)
- sd x28, PT_T3(sp)
- sd x29, PT_T4(sp)
- sd x30, PT_T5(sp)
- sd x31, PT_T6(sp)
- .endm
-
- .macro RESTORE_ALL
- ld x1, PT_RA(sp)
- ld x2, PT_SP(sp)
- ld x3, PT_GP(sp)
- ld x4, PT_TP(sp)
- ld x5, PT_T0(sp)
- ld x6, PT_T1(sp)
- ld x7, PT_T2(sp)
- ld x8, PT_S0(sp)
- ld x9, PT_S1(sp)
- ld x10, PT_A0(sp)
- ld x11, PT_A1(sp)
- ld x12, PT_A2(sp)
- ld x13, PT_A3(sp)
- ld x14, PT_A4(sp)
- ld x15, PT_A5(sp)
- ld x16, PT_A6(sp)
- ld x17, PT_A7(sp)
- ld x18, PT_S2(sp)
- ld x19, PT_S3(sp)
- ld x20, PT_S4(sp)
- ld x21, PT_S5(sp)
- ld x22, PT_S6(sp)
- ld x23, PT_S7(sp)
- ld x24, PT_S8(sp)
- ld x25, PT_S9(sp)
- ld x26, PT_S10(sp)
- ld x27, PT_S11(sp)
- ld x28, PT_T3(sp)
- ld x29, PT_T4(sp)
- ld x30, PT_T5(sp)
- ld x31, PT_T6(sp)
-
- ld s0, (PT_SIZE_ON_STACK)(sp)
- ld ra, (PT_SIZE_ON_STACK+8)(sp)
- addi sp, sp, (PT_SIZE_ON_STACK+16)
- .endm
-
- .macro RESTORE_GRAPH_REG_ARGS
- ld a0, PT_T0(sp)
- ld a1, PT_T1(sp)
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- ld a2, PT_T2(sp)
-#endif
- .endm
-
-/*
- * Most of the contents are the same as ftrace_caller.
- */
ENTRY(ftrace_regs_caller)
- /*
- * a3: the address of all registers in the stack
- */
- ld a1, -8(s0)
- addi a0, ra, -MCOUNT_INSN_SIZE
- la t5, function_trace_op
- ld a2, 0(t5)
- addi a3, sp, -(PT_SIZE_ON_STACK+16)
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi t0, s0, -8
- mv t1, a0
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- ld t2, -16(s0)
-#endif
-#endif
SAVE_ALL
+ addi a0, ra, -FENTRY_RA_OFFSET
+ la a1, function_trace_op
+ REG_L a2, 0(a1)
+ REG_L a1, PT_SIZE_ON_STACK(sp)
+ mv a3, sp
+
ftrace_regs_call:
.global ftrace_regs_call
call ftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- RESTORE_GRAPH_REG_ARGS
- call ftrace_graph_caller
+ addi a0, sp, PT_RA
+ REG_L a1, PT_EPC(sp)
+ addi a1, a1, -FENTRY_RA_OFFSET
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ mv a2, s0
+#endif
+ftrace_graph_regs_call:
+ .global ftrace_graph_regs_call
+ call ftrace_stub
#endif
RESTORE_ALL