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-rw-r--r--arch/riscv/kernel/mcount-dyn.S117
1 files changed, 68 insertions, 49 deletions
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index 745dd4c4a69c..48f6c4f7dca0 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -13,7 +13,6 @@
.text
-#define FENTRY_RA_OFFSET 8
#define ABI_SIZE_ON_STACK 80
#define ABI_A0 0
#define ABI_A1 8
@@ -56,16 +55,13 @@
addi sp, sp, ABI_SIZE_ON_STACK
.endm
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
-
/**
* SAVE_ABI_REGS - save regs against the ftrace_regs struct
*
* After the stack is established,
*
* 0(sp) stores the PC of the traced function which can be accessed
-* by &(fregs)->epc in tracing function. Note that the real
-* function entry address should be computed with -FENTRY_RA_OFFSET.
+* by &(fregs)->epc in tracing function.
*
* 8(sp) stores the function return address (i.e. parent IP) that
* can be accessed by &(fregs)->ra in tracing function.
@@ -86,17 +82,20 @@
* +++++++++
**/
.macro SAVE_ABI_REGS
- mv t4, sp // Save original SP in T4
addi sp, sp, -FREGS_SIZE_ON_STACK
-
REG_S t0, FREGS_EPC(sp)
REG_S x1, FREGS_RA(sp)
- REG_S t4, FREGS_SP(sp) // Put original SP on stack
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
REG_S x8, FREGS_S0(sp)
#endif
REG_S x6, FREGS_T1(sp)
-
+#ifdef CONFIG_CC_IS_CLANG
+ REG_S x7, FREGS_T2(sp)
+ REG_S x28, FREGS_T3(sp)
+ REG_S x29, FREGS_T4(sp)
+ REG_S x30, FREGS_T5(sp)
+ REG_S x31, FREGS_T6(sp)
+#endif
// save the arguments
REG_S x10, FREGS_A0(sp)
REG_S x11, FREGS_A1(sp)
@@ -106,16 +105,25 @@
REG_S x15, FREGS_A5(sp)
REG_S x16, FREGS_A6(sp)
REG_S x17, FREGS_A7(sp)
+ mv a0, sp
+ addi a0, a0, FREGS_SIZE_ON_STACK
+ REG_S a0, FREGS_SP(sp) // Put original SP on stack
.endm
- .macro RESTORE_ABI_REGS, all=0
+ .macro RESTORE_ABI_REGS
REG_L t0, FREGS_EPC(sp)
REG_L x1, FREGS_RA(sp)
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
REG_L x8, FREGS_S0(sp)
#endif
REG_L x6, FREGS_T1(sp)
-
+#ifdef CONFIG_CC_IS_CLANG
+ REG_L x7, FREGS_T2(sp)
+ REG_L x28, FREGS_T3(sp)
+ REG_L x29, FREGS_T4(sp)
+ REG_L x30, FREGS_T5(sp)
+ REG_L x31, FREGS_T6(sp)
+#endif
// restore the arguments
REG_L x10, FREGS_A0(sp)
REG_L x11, FREGS_A1(sp)
@@ -130,60 +138,71 @@
.endm
.macro PREPARE_ARGS
- addi a0, t0, -FENTRY_RA_OFFSET
+ addi a0, t0, -MCOUNT_JALR_SIZE // ip (callsite's jalr insn)
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ mv a1, ra // parent_ip
+ REG_L a2, -16(t0) // op
+ REG_L ra, FTRACE_OPS_FUNC(a2) // op->func
+#else
la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
+ REG_L a2, 0(a1) // op
+ mv a1, ra // parent_ip
+#endif
+ mv a3, sp // regs
.endm
-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
-
-#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
SYM_FUNC_START(ftrace_caller)
- SAVE_ABI
-
- addi a0, t0, -FENTRY_RA_OFFSET
- la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ /*
+ * When CALL_OPS is enabled (2 or 4) nops [8B] are placed before the
+ * function entry, these are later overwritten with the pointer to the
+ * associated struct ftrace_ops.
+ *
+ * -8: &ftrace_ops of the associated tracer function.
+ *<ftrace enable>:
+ * 0: auipc t0/ra, 0x?
+ * 4: jalr t0/ra, ?(t0/ra)
+ *
+ * -8: &ftrace_nop_ops
+ *<ftrace disable>:
+ * 0: nop
+ * 4: nop
+ *
+ * t0 is set to ip+8 after the jalr is executed at the callsite,
+ * so we find the associated op at t0-16.
+ */
+ REG_L t1, -16(t0) // op Should be SZ_REG instead of 16
-SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
- call ftrace_stub
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi a0, sp, ABI_RA
- REG_L a1, ABI_T0(sp)
- addi a1, a1, -FENTRY_RA_OFFSET
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv a2, s0
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ /*
+ * If the op has a direct call, handle it immediately without
+ * saving/restoring registers.
+ */
+ REG_L t1, FTRACE_OPS_DIRECT_CALL(t1)
+ bnez t1, ftrace_caller_direct
#endif
-SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
- call ftrace_stub
#endif
- RESTORE_ABI
- jr t0
-SYM_FUNC_END(ftrace_caller)
-
-#else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
-SYM_FUNC_START(ftrace_caller)
- mv t1, zero
SAVE_ABI_REGS
PREPARE_ARGS
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
+ jalr ra
+#else
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
- call ftrace_stub
-
+ REG_L ra, ftrace_call_dest
+ jalr ra, 0(ra)
+#endif
RESTORE_ABI_REGS
- bnez t1, .Ldirect
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ bnez t1, ftrace_caller_direct
+#endif
jr t0
-.Ldirect:
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_INNER_LABEL(ftrace_caller_direct, SYM_L_LOCAL)
jr t1
+#endif
SYM_FUNC_END(ftrace_caller)
-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
-
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
SYM_CODE_START(ftrace_stub_direct_tramp)
jr t0