userland x86_64: implement ASSERT_MEMCMP

README.adoc

@@ -11606,7 +11606,10 @@ and notice how the error message gives both:
 Other setup sanity checks that you might want to look into include:
 
 * link:userland/arch/empty.S[]
-* link:userland/arch/fail.S[]
+* `FAIL` tests
+** link:userland/arch/fail.S[]
+* `ASSERT_MEMCMP` tests
+** link:userland/arch/x86_64/lkmc_assert_memcmp_fail.S[]
 
 === User vs system assembly
 

path_properties.py

@@ -341,6 +341,8 @@ path_properties_tuples = (
                                     }
                                 ),
                                 'freestanding': freestanding_properties,
+                                'lkmc_assert_eq_fail.S': {'exit_status': 1},
+                                'lkmc_assert_memcmp_fail.S': {'exit_status': 1},
                             }
                         ),
                     }

userland/arch/fail.S

@@ -1,4 +1,4 @@
-/* See what happens on test failure.
+/* See what happens on test failure with FAIL.
  * https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly
  */
 

userland/arch/x86_64/common_arch.h

@@ -3,19 +3,6 @@
 #ifndef COMMON_ARCH_H
 #define COMMON_ARCH_H
 
-#if 0
-#define ASSERT_EQ(reg, const) \
-    push %rax; \
-    push %rbx; \
-    mov reg, %rax; \
-    mov const, %rbx; \
-    cmp %rax, %rbx; \
-    pop %rbx; \
-    pop %rax; \
-    ASSERT(je); \
-;
-#endif
-
 #define ASSERT_EQ(reg, const) \
     mov reg, %rdi; \
     mov const, %rsi; \
@@ -28,11 +15,14 @@
     ASSERT(je); \
 ;
 
-# TODO
-##define ASSERT_MEMCMP(s1, s2, n) \
-#    MEMCMP(s1, s2, n); \
-#    ASSERT_EQ(x0, 0); \
-#;
+#define ASSERT_MEMCMP(label1, label2, const_size) \
+    lea label1(%rip), %rdi; \
+    lea label2(%rip), %rsi; \
+    mov const_size, %rdx; \
+    call assert_memcmp; \
+    cmp $0, %rax; \
+    ASSERT(je); \
+;
 
 /* Program entry point.
  *
@@ -90,12 +80,4 @@ pass: \
     jmp fail; \
 ;
 
-# TODO
-##define MEMCMP(s1, s2, n) \
-#    adr x0, s1; \
-#    adr x1, s2; \
-#    ldr x2, =n; \
-#    bl memcmp; \
-#;
-
 #endif

userland/arch/x86_64/lkmc_assert_eq_fail.S

@@ -0,0 +1,9 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
+
+#include "common.h"
+
+ENTRY
+    mov $1, %rax
+    ASSERT_EQ(%rax, $1)
+    ASSERT_EQ(%rax, $2)
+EXIT

userland/arch/x86_64/lkmc_assert_memcmp_fail.S

@@ -0,0 +1,12 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
+
+#include "common.h"
+
+.data
+    var0: .long 0x11111111, 0x22222222, 0x33333333, 0x44444444
+    var1: .long 0x11111111, 0x22222222, 0x33333333, 0x44444444
+    var2: .long 0x11111111, 0x22222223, 0x23333333, 0x44444444
+ENTRY
+    ASSERT_MEMCMP(var0, var1, $0x10)
+    ASSERT_MEMCMP(var0, var2, $0x10)
+EXIT