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-rw-r--r--arch/powerpc/kernel/entry_64.S27
-rw-r--r--arch/powerpc/kernel/ftrace.c13
2 files changed, 37 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9f61fd61f27..abfc3233047 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -971,6 +971,28 @@ _GLOBAL(ftrace_graph_caller)
_GLOBAL(return_to_handler)
/* need to save return values */
+ std r4, -24(r1)
+ std r3, -16(r1)
+ std r31, -8(r1)
+ mr r31, r1
+ stdu r1, -112(r1)
+
+ bl .ftrace_return_to_handler
+ nop
+
+ /* return value has real return address */
+ mtlr r3
+
+ ld r1, 0(r1)
+ ld r4, -24(r1)
+ ld r3, -16(r1)
+ ld r31, -8(r1)
+
+ /* Jump back to real return address */
+ blr
+
+_GLOBAL(mod_return_to_handler)
+ /* need to save return values */
std r4, -32(r1)
std r3, -24(r1)
/* save TOC */
@@ -979,7 +1001,10 @@ _GLOBAL(return_to_handler)
mr r31, r1
stdu r1, -112(r1)
- /* update the TOC */
+ /*
+ * We are in a module using the module's TOC.
+ * Switch to our TOC to run inside the core kernel.
+ */
LOAD_REG_IMMEDIATE(r4,ftrace_return_to_handler)
ld r2, 8(r4)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 7538b944fa5..5c6dfa97e83 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -567,6 +567,10 @@ int ftrace_disable_ftrace_graph_caller(void)
}
#endif /* CONFIG_DYNAMIC_FTRACE */
+#ifdef CONFIG_PPC64
+extern void mod_return_to_handler(void);
+#endif
+
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info.
@@ -577,12 +581,17 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
unsigned long long calltime;
int faulted;
struct ftrace_graph_ent trace;
- unsigned long return_hooker = (unsigned long)
- &return_to_handler;
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;
+#if CONFIG_PPC64
+ /* non core kernel code needs to save and restore the TOC */
+ if (REGION_ID(self_addr) != KERNEL_REGION_ID)
+ return_hooker = (unsigned long)&mod_return_to_handler;
+#endif
+
return_hooker = GET_ADDR(return_hooker);
/*