[PATCH 2/2] [PATCH 2/2] powerpc64/ftrace: use PACA to retrieve TOC in mod_return_to_handler

[Steven Rostedt]

From: Steven Rostedt <srostedt@xxxxxxxxxx>

The mod_return_to_handler needs to switch to the kernel TOC before
jumping to a the kernel code. It currently does this by looking
at the kernel function data and retrieves the TOC that way.

Not only is this inefficient, it also breaks with a relocatable kernel.
The PACA contains the kernel TOC and we can easily retrieve it that
way.

Reported-by: Sachin Sant <sachinp@xxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 arch/powerpc/kernel/entry_64.S |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 900e0ee..f9fd54b 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1038,8 +1038,7 @@ _GLOBAL(mod_return_to_handler)
 	 * 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)
+	ld	r2, PACATOC(r13)
 
 	bl	.ftrace_return_to_handler
 	nop
-- 
1.6.3.3


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