From 83868a0e455dd41ba7c70b64ae6d2cd36d066c3d Mon Sep 17 00:00:00 2001 From: Simon Butcher Date: Sun, 24 Jun 2018 12:58:31 +0100 Subject: [PATCH 1/3] Add ebx to the i386 clobber list for MPI assembly This fix adds the ebx register to the clobber list for the i386 inline assembly for the multiply helper function. ebx was used but not listed, so when the compiler chose to also use it, ebx was getting corrupted. I'm surprised this wasn't spotted sooner. Fixes Github issues #1550. --- include/mbedtls/bn_mul.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h index f4b2b561d..e04926043 100644 --- a/include/mbedtls/bn_mul.h +++ b/include/mbedtls/bn_mul.h @@ -142,7 +142,7 @@ "movl %%esi, %3 \n\t" \ : "=m" (t), "=m" (c), "=m" (d), "=m" (s) \ : "m" (t), "m" (s), "m" (d), "m" (c), "m" (b) \ - : "eax", "ecx", "edx", "esi", "edi" \ + : "eax", "ebx", "ecx", "edx", "esi", "edi" \ ); #else @@ -154,7 +154,7 @@ "movl %%esi, %3 \n\t" \ : "=m" (t), "=m" (c), "=m" (d), "=m" (s) \ : "m" (t), "m" (s), "m" (d), "m" (c), "m" (b) \ - : "eax", "ecx", "edx", "esi", "edi" \ + : "eax", "ebx", "ecx", "edx", "esi", "edi" \ ); #endif /* SSE2 */ #endif /* i386 */ From c6bf5b4953359c938640fa666ac8deedd437b21d Mon Sep 17 00:00:00 2001 From: Simon Butcher Date: Sun, 24 Jun 2018 16:20:56 +0100 Subject: [PATCH 2/3] Add fix for #1550 and credit to the ChangeLog --- ChangeLog | 2 ++ 1 file changed, 2 insertions(+) diff --git a/ChangeLog b/ChangeLog index 49400160b..c9480ec97 100644 --- a/ChangeLog +++ b/ChangeLog @@ -3,6 +3,8 @@ mbed TLS ChangeLog (Sorted per branch, date) = mbed TLS x.x.x branch released xxxx-xx-xx Bugfix + * Fix the inline assembly for the MPI multiply helper function for i386 and + i386 with SSE2. Found by László Langó. Fixes #1550 * Change the shebang line in Perl scripts to look up perl in the PATH. Contributed by fbrosson in #1533. * Fix a memory leak in mbedtls_x509_csr_parse(), found by catenacyber, From d064b5c87b263b8836d461da178d88f76717f6fd Mon Sep 17 00:00:00 2001 From: Simon Butcher Date: Tue, 10 Jul 2018 20:18:29 +0100 Subject: [PATCH 3/3] Disable use of the i386 assembly for option -O0 We don't compile in the assembly code if compiler optimisations are disabled as the number of registers used in the assembly code doesn't work with the -O0 option. Also anyone select -O0 probably doesn't want to compile in the assembly code anyway. --- include/mbedtls/bn_mul.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h index e04926043..438aa8cea 100644 --- a/include/mbedtls/bn_mul.h +++ b/include/mbedtls/bn_mul.h @@ -49,7 +49,14 @@ /* armcc5 --gnu defines __GNUC__ but doesn't support GNU's extended asm */ #if defined(__GNUC__) && \ ( !defined(__ARMCC_VERSION) || __ARMCC_VERSION >= 6000000 ) -#if defined(__i386__) + +/* + * Disable use of the i386 assembly code below if option -O0, to disable all + * compiler optimisations, is passed, detected with __OPTIMIZE__ + * This is done as the number of registers used in the assembly code doesn't + * work with the -O0 option. + */ +#if defined(__i386__) && !defined(__OPTIMIZE__) #define MULADDC_INIT \ asm( \