[PATCH v5 6/8] newlib: libc: aeabi_memmove M-profile PACBTI-enablement

Victor L. Do Nascimento victor.donascimento@arm.com
Wed Dec 21 11:27:01 GMT 2022


Add function prologue/epilogue to conditionally add BTI landing pads
and/or PAC code generation & authentication instructions depending on
compilation flags.
---
 newlib/libc/machine/arm/aeabi_memmove-thumb2.S | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/newlib/libc/machine/arm/aeabi_memmove-thumb2.S b/newlib/libc/machine/arm/aeabi_memmove-thumb2.S
index e9504437b..20ca993e5 100644
--- a/newlib/libc/machine/arm/aeabi_memmove-thumb2.S
+++ b/newlib/libc/machine/arm/aeabi_memmove-thumb2.S
@@ -26,6 +26,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "arm_asm.h"
+
 	.thumb
 	.syntax unified
 	.global __aeabi_memmove
@@ -33,8 +35,10 @@
 	ASM_ALIAS __aeabi_memmove4 __aeabi_memmove
 	ASM_ALIAS __aeabi_memmove8 __aeabi_memmove
 __aeabi_memmove:
+	.fnstart
+	.cfi_startproc
+	prologue 4
 	cmp	r0, r1
-	push	{r4}
 	bls	3f
 	adds	r3, r1, r2
 	cmp	r0, r3
@@ -48,9 +52,10 @@ __aeabi_memmove:
 	strb	r4, [r1, #-1]!
 	bne	1b
 2:
-	pop	{r4}
-	bx	lr
+	.cfi_remember_state
+	epilogue 4
 3:
+	.cfi_restore_state
 	cmp	r2, #0
 	beq	2b
 	add	r2, r2, r1
@@ -60,6 +65,8 @@ __aeabi_memmove:
 	cmp	r2, r1
 	strb	r4, [r3, #1]!
 	bne	4b
-	pop	{r4}
-	bx	lr
+	epilogue 4
+	.cfi_endproc
+	.cantunwind
+	.fnend
 	.size __aeabi_memmove, . - __aeabi_memmove
-- 
2.36.1


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