Re: [PATCH V2] mips: function tracer: Fix broken function tracing

[Wladislav Wiebe]

Hi,

I have a bad experience with MIPS 64 Bit Architecture on Kernel 3.8.
The Kernel doesn't boot when enabling CONFIG_FUNCTION_TRACER,
it hangs at early startup directly after u-boot init:

..
## Loading Linux kernel with entry point: 0xffffffff805e23c0 ...
Bootloader: Done loading app on coremask: 0x3f
setting up named block for __uboot_log at 0xfcf4000
...

Basically, I temporary workaround it with 
diff --git a/linux/arch/mips/kernel/mcount.S b/linux/arch/mips/kernel/mcount.S
index 1658676..4438c74 100644
--- a/linux/arch/mips/kernel/mcount.S
+++ b/linux/arch/mips/kernel/mcount.S
@@ -46,9 +46,8 @@
        PTR_L   a5, PT_R9(sp)
        PTR_L   a6, PT_R10(sp)
        PTR_L   a7, PT_R11(sp)
-#else
-       PTR_ADDIU       sp, PT_SIZE
 #endif
+       PTR_ADDIU       sp, PT_SIZE
 .endm
 
        .macro RETURN_BACK
@@ -68,7 +67,11 @@ NESTED(ftrace_caller, PT_SIZE, ra)
        .globl _mcount
 _mcount:
        b       ftrace_stub
+#ifdef CONFIG_64BIT
+       nop
+#else
        addiu sp,sp,8
+#endif
 
        /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
        lw      t1, function_trace_stop


Are you going to fix this for 3.9 release?

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