commit e95bf7975436a7e28b9ecf4b29e681b583f42485
author Dave Rodgman <dave.rodgman@arm.com> Wed Mar 13 11:47:14 2024 +0000
committer GitHub <noreply@github.com> Wed Mar 13 11:47:14 2024 +0000
tree 673068fa9daf45609eb3be2b80f19a1818043793
parent fb84c7681c4f8a719d3dd0c091689a5e0b9dd30f
parent 386c39f2d5b5dc9efffec04ad0b8a24176c6a9aa

Merge pull request #8922 from daverodgman/gcc-o3

Fix gcc -O3 warnings

library/cmac.c

diff --git a/library/cmac.c b/library/cmac.c
index cd3bd3a..c4f0b54 100644
--- a/library/cmac.c
+++ b/library/cmac.c
@@ -224,6 +224,10 @@
     block_size = mbedtls_cipher_info_get_block_size(ctx->cipher_info);
     state = ctx->cmac_ctx->state;
 
+    /* Without the MBEDTLS_ASSUME below, gcc -O3 will generate a warning of the form
+     * error: writing 16 bytes into a region of size 0 [-Werror=stringop-overflow=] */
+    MBEDTLS_ASSUME(block_size <= MBEDTLS_CMAC_MAX_BLOCK_SIZE);
+
     /* Is there data still to process from the last call, that's greater in
      * size than a block? */
     if (cmac_ctx->unprocessed_len > 0 &&
@@ -291,6 +295,7 @@
 
     cmac_ctx = ctx->cmac_ctx;
     block_size = mbedtls_cipher_info_get_block_size(ctx->cipher_info);
+    MBEDTLS_ASSUME(block_size <= MBEDTLS_CMAC_MAX_BLOCK_SIZE); // silence GCC warning
     state = cmac_ctx->state;
 
     mbedtls_platform_zeroize(K1, sizeof(K1));

library/gcm.c

diff --git a/library/gcm.c b/library/gcm.c
index 90c1d1d..5dfac23 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -412,8 +412,17 @@
         while (iv_len > 0) {
             use_len = (iv_len < 16) ? iv_len : 16;
 
+#if defined(MBEDTLS_COMPILER_IS_GCC) && (MBEDTLS_GCC_VERSION >= 70110)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic warning "-Wstringop-overflow=0"
+#endif
+
             mbedtls_xor(ctx->y, ctx->y, p, use_len);
 
+#if defined(MBEDTLS_COMPILER_IS_GCC) && (MBEDTLS_GCC_VERSION >= 70110)
+#pragma GCC diagnostic pop
+#endif
+
             gcm_mult(ctx, ctx->y, ctx->y);
 
             iv_len -= use_len;