Subject: [PATCH 5/8] ARM: ftrace: avoid unnecessary literal loads

From: Ard Biesheuvel <[email-masked]>
Date: Tue, 25 Jan 2022 16:36:53 +0100

Avoid explicit literal loads and instead, use accessor macros that
generate the optimal sequence depending on the architecture revision
being targeted.

Signed-off-by: Ard Biesheuvel <[email-masked]>
---
 arch/arm/kernel/entry-ftrace.S | 27 ++++++++------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
index 67548c38a567..99720064a4c5 100644
--- a/arch/arm/kernel/entry-ftrace.S
+++ b/arch/arm/kernel/entry-ftrace.S
@@ -35,23 +35,20 @@
 
 .macro __mcount suffix
 	mcount_enter
-	ldr	r0, =ftrace_trace_function
-	ldr	r2, [r0]
+	ldr_va	r2, ftrace_trace_function
 	badr	r0, .Lftrace_stub
 	cmp	r0, r2
 	bne	1f
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	ldr     r1, =ftrace_graph_return
-	ldr     r2, [r1]
-	cmp     r0, r2
-	bne     ftrace_graph_caller\suffix
-
-	ldr     r1, =ftrace_graph_entry
-	ldr     r2, [r1]
-	ldr     r0, =ftrace_graph_entry_stub
-	cmp     r0, r2
-	bne     ftrace_graph_caller\suffix
+	ldr_va	r2, ftrace_graph_return
+	cmp	r0, r2
+	bne	ftrace_graph_caller\suffix
+
+	ldr_va	r2, ftrace_graph_entry
+	mov_l	r0, ftrace_graph_entry_stub
+	cmp	r0, r2
+	bne	ftrace_graph_caller\suffix
 #endif
 
 	mcount_exit
@@ -87,8 +84,7 @@
 
 	mov	r3, sp				@ struct pt_regs*
 
-	ldr r2, =function_trace_op
-	ldr r2, [r2]				@ pointer to the current
+	ldr_va	r2, function_trace_op		@ pointer to the current
 						@ function tracing op
 
 	ldr	r1, [sp, #S_LR]			@ lr of instrumented func
@@ -141,8 +137,7 @@ ftrace_graph_regs_call:
 	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
+	ldr_va	r2, function_trace_op		@ pointer to the current
 						@ function tracing op
 	mov r3, #0				@ regs is NULL
 #endif
-- 
2.30.2

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