Merge branch 'contrib/github_pr_17582' into 'master'

mahavirj · mahavirj · commit 5cf6b6d36d6b · 2025-09-29T09:19:05.000+05:30
fix(mbedtls): prevent vectorization fault in clang O2 optimization (GitHub PR)

Closes IDFGH-16450

See merge request espressif/esp-idf!41973
diff --git a/components/mbedtls/port/esp_ds/esp_rsa_dec_alt.c b/components/mbedtls/port/esp_ds/esp_rsa_dec_alt.c
@@ -62,6 +62,9 @@ static int esp_ds_rsaes_pkcs1_v15_unpadding(unsigned char *input,
     }
 
     /* Verify padding bytes are non-zero in constant time */
+#if defined(__clang__) && defined(__xtensa__)
+    #pragma clang loop vectorize(disable)
+#endif
     for (size_t i = 2; i < ilen; i++) {
         unsigned char in_padding = (i < pad_count + 2);
         unsigned char is_zero = (input[i] == 0x00);
diff --git a/tools/test_apps/system/clang_build_test/sdkconfig.ci.clang_libclang_rt_perf b/tools/test_apps/system/clang_build_test/sdkconfig.ci.clang_libclang_rt_perf
@@ -0,0 +1,2 @@
+CONFIG_COMPILER_RT_LIB_CLANGRT=y
+CONFIG_COMPILER_OPTIMIZATION_PERF=y

Original file line number	Diff line number	Diff line change
`@@ -62,6 +62,9 @@ static int esp_ds_rsaes_pkcs1_v15_unpadding(unsigned char *input,`
`62`	`62`	`}`
`63`	`63`
`64`	`64`	`/* Verify padding bytes are non-zero in constant time */`
	`65`	`+#if defined(__clang__) && defined(__xtensa__)`
	`66`	`+ #pragma clang loop vectorize(disable)`
	`67`	`+#endif`
`65`	`68`	`for (size_t i = 2; i < ilen; i++) {`
`66`	`69`	`unsigned char in_padding = (i < pad_count + 2);`
`67`	`70`	`unsigned char is_zero = (input[i] == 0x00);`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+CONFIG_COMPILER_RT_LIB_CLANGRT=y`
	`2`	`+CONFIG_COMPILER_OPTIMIZATION_PERF=y`