This adds __ftrace_regs_caller which, unlike __ftrace_caller,
adds register saving/restoring and livepatch handling if
the pc register gets modified by klp_ftrace_handler.
Signed-off-by: Abel Vesa <abelvesa@xxxxxxxxx>
---
arch/arm/kernel/entry-ftrace.S | 49 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
index c73c403..b6ada5c 100644
--- a/arch/arm/kernel/entry-ftrace.S
+++ b/arch/arm/kernel/entry-ftrace.S
@@ -92,6 +92,46 @@
2: mcount_exit
.endm
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+
+.macro __ftrace_regs_caller suffix
+
+ stmdb sp!, {r0-r15}
+ mov r3, sp
+
+ ldr r10, [sp, #60]
+
+ mcount_get_lr r1 @ lr of instrumented func
+ mcount_adjust_addr r0, lr @ instrumented function
+
+ .globl ftrace_regs_call\suffix
+ftrace_regs_call\suffix:
+ bl ftrace_stub
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl ftrace_regs_graph_call\suffix
+ftrace_regs_graph_call\suffix:
+ mov r0, r0
+#endif
+#ifdef CONFIG_LIVEPATCH
+ ldr r0, [sp, #60]
+ cmp r0, r10
+ beq ftrace_regs_caller_end
+ ldmia sp!, {r0-r12}
+ add sp, sp, #8
+ ldmia sp!, {r11}
+ sub sp, r12, #16
+ str r11, [sp, #12]
+ ldmia sp!, {r11, r12, lr, pc}
+#endif
+ftrace_regs_caller_end\suffix:
+ ldmia sp!, {r0-r14}
+ add sp, sp, #4
+ mov pc, lr
+.endm
+
+#endif
+
.macro __ftrace_caller suffix
mcount_enter
@@ -212,6 +252,15 @@ 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
--
2.7.4
--
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