Joseph S. Myers writes:

This patch fixes some of the ARM EABI code to be interworking-safe, using 
bx where appropriate.  (This code went in around the same time as the 
Thumb patches, hence not being fixed by those patches.)

libc/sysdeps/linux/arm/__longjmp.S

@@ -61,7 +61,11 @@ __longjmp:
 # endif
 #endif	
 
+#if defined(__USE_BX__)
+	bx	lr
+#else
 	mov pc, lr
+#endif
 
 .size __longjmp,.-__longjmp
 libc_hidden_def(__longjmp)

libc/sysdeps/linux/arm/mmap64.S

@@ -52,7 +52,11 @@ mmap64:
 	DO_CALL (mmap2)
 	cmn	r0, $4096
 	ldmfd	sp!, {r4, r5}
+#if defined(__USE_BX__)
+	bxcc	lr
+#else
 	movcc	pc, lr
+#endif
 	b	__syscall_error
 .Linval:
 	mov	r0, $-EINVAL

libc/sysdeps/linux/arm/syscall-eabi.S

@@ -37,7 +37,11 @@ syscall:
 	swi	0x0
 	ldmfd	sp!, {r4, r5, r6, r7}
 	cmn	r0, #4096
+#if defined(__USE_BX__)
+	bxcc	lr
+#else
 	movcc	pc, lr
+#endif
 	b	__syscall_error
 
 .size syscall,.-syscall