Fix pointer constraint in bn_mul.h
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/bn_mul.h b/library/bn_mul.h
index c5994f7..0af7ecd 100644
--- a/library/bn_mul.h
+++ b/library/bn_mul.h
@@ -265,7 +265,10 @@
"str x5, [%1], #8 \n\t"
#define MULADDC_X1_STOP \
- : "+r" (c), "+r" (d), "+r" (s), "+m" (*(uint64_t (*)[16]) d) \
+ : "+r" (c), \
+ "+" MBEDTLS_ASM_AARCH64_PTR_CONSTRAINT (d), \
+ "+" MBEDTLS_ASM_AARCH64_PTR_CONSTRAINT (s), \
+ "+m" (*(uint64_t (*)[16]) d) \
: "r" (b), "m" (*(const uint64_t (*)[16]) s) \
: "x4", "x5", "x6", "x7", "cc" \
);
diff --git a/library/common.h b/library/common.h
index b48a1fc..4ee183a 100644
--- a/library/common.h
+++ b/library/common.h
@@ -169,6 +169,24 @@
#endif
/* *INDENT-ON* */
+/*
+ * Define the constraint used for pointer operands to asm.
+ *
+ * This is normally the usual "r", but for aarch64_32 (aka ILP32,
+ * as found in watchos), "p" is required to avoid warnings from clang.
+ */
+#if defined(__aarch64__) && defined(MBEDTLS_HAVE_ASM)
+#if UINTPTR_MAX == 0xfffffffful
+/* ILP32: Specify the pointer operand slightly differently, as per #7787. */
+#define MBEDTLS_ASM_AARCH64_PTR_CONSTRAINT "p"
+#elif UINTPTR_MAX == 0xfffffffffffffffful
+/* Normal case (64-bit pointers): use "r" as the constraint for pointer operands to asm */
+#define MBEDTLS_ASM_AARCH64_PTR_CONSTRAINT "r"
+#else
+#error Unrecognised pointer size for aarch64
+#endif
+#endif
+
/* Always provide a static assert macro, so it can be used unconditionally.
* It will expand to nothing on some systems.
* Can be used outside functions (but don't add a trailing ';' in that case:
diff --git a/library/constant_time.c b/library/constant_time.c
index 5ed087c..c62ec13 100644
--- a/library/constant_time.c
+++ b/library/constant_time.c
@@ -83,13 +83,7 @@
#if defined(__arm__) || defined(__thumb__) || defined(__thumb2__)
asm volatile ("ldr %0, [%1]" : "=r" (r) : "r" (p) :);
#elif defined(__aarch64__)
-#if (UINTPTR_MAX == 0xfffffffful)
- /* ILP32: Specify the pointer operand slightly differently, as per #7787. */
- asm volatile ("ldr %w0, [%1]" : "=r" (r) : "p" (p) :);
-#elif (UINTPTR_MAX == 0xffffffffffffffffull)
- /* aarch64 with 64-bit pointers */
- asm volatile ("ldr %w0, [%1]" : "=r" (r) : "r" (p) :);
-#endif
+ asm volatile ("ldr %w0, [%1]" : "=r" (r) : MBEDTLS_ASM_AARCH64_PTR_CONSTRAINT (p) :);
#endif
return r;
}