From 204517801a33f1bafab3ce1e80f71f41aa5f61a6 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Fri, 16 Feb 2024 22:19:00 -0500
Subject: Add AVX support

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 Makefile        |  2 +-
 include/accel.h |  4 ++++
 include/info.h  |  1 +
 src/avx_accel.S | 39 +++++++++++++++++++++++++++++++++++++++
 src/main.c      | 21 ++++++++++++++++++++-
 5 files changed, 65 insertions(+), 2 deletions(-)
 create mode 100644 src/avx_accel.S

diff --git a/Makefile b/Makefile
index 9ec939f..bdc65df 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CFLAGS = -pedantic -Iinclude/
 CFILES = src/main.c
-ASMFILES = src/sse_accel.S
+ASMFILES = src/sse_accel.S src/avx_accel.S
 CC = gcc
 
 bin/fobfuscate: $(CFILES) $(ASMFILES)
diff --git a/include/accel.h b/include/accel.h
index f66e3e1..d7bdc96 100644
--- a/include/accel.h
+++ b/include/accel.h
@@ -35,4 +35,8 @@
 __attribute__((naked))
 void accel_invert128(uint64_t addr);
 
+
+__attribute__((naked))
+void accel_invert256(uint64_t addr);
+
 #endif  /* ACCEL_H */
diff --git a/include/info.h b/include/info.h
index c748baa..4c39266 100644
--- a/include/info.h
+++ b/include/info.h
@@ -35,6 +35,7 @@
 struct cpu_info {
     uint8_t has_sse2 : 1;
     uint8_t has_sse3 : 1;
+    uint8_t has_avx  : 1;
 };
 
 #endif      /* INFO_H */
diff --git a/src/avx_accel.S b/src/avx_accel.S
new file mode 100644
index 0000000..9340a84
--- /dev/null
+++ b/src/avx_accel.S
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Osmora nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+.section .text
+.globl accel_invert256
+
+accel_invert256:
+    vmovdqu (%rdi), %ymm1           // Load data into %ymm1
+    vpcmpeqb %ymm0, %ymm0, %ymm0    // Set %ymm0 to all 1s
+
+    vpxor %ymm1, %ymm0, %ymm0       // NOT %xmm1; result stored in %xmm0
+    vmovdqu %ymm0, (%rax)           // Writeback the result
+    retq
diff --git a/src/main.c b/src/main.c
index 0c99ae1..a4a0e3f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -110,6 +110,14 @@ is_sse2_supported(void)
     return (edx & (1 << 26)) != 0;
 }
 
+static inline bool
+is_avx_supported(void)
+{
+    uint32_t ecx, unused;
+    cpuid(0x0000001, unused, unused, ecx, unused);
+    return (ecx & (1 << 28)) != 0;
+}
+
 static void
 amd64_cpu_tests(struct cpu_info *info)
 {
@@ -129,6 +137,11 @@ amd64_cpu_tests(struct cpu_info *info)
             info->has_sse2 = 1;
         }
     }
+
+    if (is_avx_supported()) {
+        printf("[?]: AVX supported, may use as optimization\n");
+        info->has_avx = 1;
+    }
 }
 #endif  /* defined(__x86_64__) */
 
@@ -146,12 +159,15 @@ encrypt(const struct cpu_info *info, char *buf, size_t buf_size)
     if (info->has_sse2 || info->has_sse3) {
         step = 16;         /* Start at 16 bytes (128 bits) */
     }
+    if (info->has_avx) {
+        step = 32;
+    }
 #endif  /* defined(__x86_64__) */
 
     while (current_pos < buf_size) {
         /* Ensure we aren't over 16 bytes and a power of two */
         if (step != 1) {
-            assert((step & 1) == 0 && step <= 16);
+            assert((step & 1) == 0 && step <= 32);
         }
 
         /* Ensure we don't cause any overflows */
@@ -160,6 +176,9 @@ encrypt(const struct cpu_info *info, char *buf, size_t buf_size)
             step >>= 1;
 
         switch (step) {
+        case 32:
+            accel_invert256((uintptr_t)buf + current_pos);
+            break;
         case 16:
             accel_invert128((uintptr_t)buf + current_pos);
             break;
-- 
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