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-rw-r--r--arch/arm/kernel/entry-ftrace.S100
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
index c73c4030ca5d..efcd9f25a14b 100644
--- a/arch/arm/kernel/entry-ftrace.S
+++ b/arch/arm/kernel/entry-ftrace.S
@@ -92,12 +92,95 @@
2: mcount_exit
.endm
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+
+.macro __ftrace_regs_caller
+
+ sub sp, sp, #8 @ space for PC and CPSR OLD_R0,
+ @ OLD_R0 will overwrite previous LR
+
+ add ip, sp, #12 @ move in IP the value of SP as it was
+ @ before the push {lr} of the mcount mechanism
+
+ str lr, [sp, #0] @ store LR instead of PC
+
+ ldr lr, [sp, #8] @ get previous LR
+
+ str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR
+
+ stmdb sp!, {ip, lr}
+ stmdb sp!, {r0-r11, lr}
+
+ @ stack content at this point:
+ @ 0 4 48 52 56 60 64 68 72
+ @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 |
+
+ mov r3, sp @ struct pt_regs*
+
+ ldr r2, =function_trace_op
+ ldr r2, [r2] @ pointer to the current
+ @ function tracing op
+
+ ldr r1, [sp, #S_LR] @ lr of instrumented func
+
+ ldr lr, [sp, #S_PC] @ get LR
+
+ mcount_adjust_addr r0, lr @ instrumented function
+
+ .globl ftrace_regs_call
+ftrace_regs_call:
+ bl ftrace_stub
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl ftrace_graph_regs_call
+ftrace_graph_regs_call:
+ mov r0, r0
+#endif
+
+ @ pop saved regs
+ ldmia sp!, {r0-r12} @ restore r0 through r12
+ ldr ip, [sp, #8] @ restore PC
+ ldr lr, [sp, #4] @ restore LR
+ ldr sp, [sp, #0] @ restore SP
+ mov pc, ip @ return
+.endm
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.macro __ftrace_graph_regs_caller
+
+ sub r0, fp, #4 @ lr of instrumented routine (parent)
+
+ @ called from __ftrace_regs_caller
+ ldr r1, [sp, #S_PC] @ instrumented routine (func)
+ mcount_adjust_addr r1, r1
+
+ mov r2, fp @ frame pointer
+ bl prepare_ftrace_return
+
+ @ pop registers saved in ftrace_regs_caller
+ ldmia sp!, {r0-r12} @ restore r0 through r12
+ ldr ip, [sp, #8] @ restore PC
+ ldr lr, [sp, #4] @ restore LR
+ ldr sp, [sp, #0] @ restore SP
+ mov pc, ip @ return
+
+.endm
+#endif
+#endif
+
.macro __ftrace_caller suffix
mcount_enter
mcount_get_lr r1 @ lr of instrumented func
mcount_adjust_addr r0, lr @ instrumented function
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ ldr r2, =function_trace_op
+ ldr r2, [r2] @ pointer to the current
+ @ function tracing op
+ mov r3, #0 @ regs is NULL
+#endif
+
.globl ftrace_call\suffix
ftrace_call\suffix:
bl ftrace_stub
@@ -212,6 +295,15 @@ UNWIND(.fnstart)
__ftrace_caller
UNWIND(.fnend)
ENDPROC(ftrace_caller)
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ENTRY(ftrace_regs_caller)
+UNWIND(.fnstart)
+ __ftrace_regs_caller
+UNWIND(.fnend)
+ENDPROC(ftrace_regs_caller)
+#endif
+
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -220,6 +312,14 @@ UNWIND(.fnstart)
__ftrace_graph_caller
UNWIND(.fnend)
ENDPROC(ftrace_graph_caller)
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ENTRY(ftrace_graph_regs_caller)
+UNWIND(.fnstart)
+ __ftrace_graph_regs_caller
+UNWIND(.fnend)
+ENDPROC(ftrace_graph_regs_caller)
+#endif
#endif
.purgem mcount_enter