asm: make use regular asserts that will just work on baremetal

Previously had wonky line pointer in asm_main. New interface simpler and more portable.

Add tests for ASSERT_EQ_ and family in arm and aarch64, previously on x86_64.

ASSERT_EQ_ and family in ARM can now either take =123, =addr or var, before this
the = was added on macros so var was not possible.

Define the main function directly in assembly, the C driver was useless.

userland/arch/x86_64/add.S

@@ -1,9 +1,9 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
     mov $1, %rax
     add $2, %rax
     LKMC_ASSERT_EQ(%rax, $3)
-LKMC_EXIT
+LKMC_EPILOGUE

userland/arch/x86_64/addpd.S

@@ -3,9 +3,9 @@
  * Add a bunch of floating point numbers in one go.
  */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
 .bss
     output:       .skip 16
 .data
@@ -28,4 +28,4 @@ LKMC_ENTRY
     /* 2x 64-bit */
     TEST(d)
 #undef TEST
-LKMC_EXIT
+LKMC_EPILOGUE

userland/arch/x86_64/common_arch.h

@@ -1,87 +0,0 @@
-/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly-c-standard-library */
-
-#ifndef COMMON_ARCH_H
-#define COMMON_ARCH_H
-
-/* This and other macros may make C function calls, and therefore can destroy
- * non-callee saved registers. */
-#define LKMC_ASSERT_EQ(general1, general2) \
-    mov general2, %rdi; \
-    push %rdi; \
-    mov general1, %rdi; \
-    pop %rsi; \
-    LKMC_ASSERT_EQ_DO(64); \
-;
-
-#define LKMC_ASSERT_EQ_DO(bits) \
-    call lkmc_assert_eq_ ## bits; \
-    cmp $0, %rax; \
-    LKMC_ASSERT(je); \
-;
-
-#define LKMC_ASSERT_MEMCMP(label1, label2, const_size) \
-    lea label1(%rip), %rdi; \
-    lea label2(%rip), %rsi; \
-    mov const_size, %rdx; \
-    call lkmc_assert_memcmp; \
-    cmp $0, %rax; \
-    LKMC_ASSERT(je); \
-;
-
-/* Program entry point.
- *
- * Return with LKMC_EXIT.
- *
- * Basically implements an x86_64 prologue:
- *
- * - save callee saved registers
- *   x86_64 explained at: https://stackoverflow.com/questions/18024672/what-registers-are-preserved-through-a-linux-x86-64-function-call/55207335#55207335
- * - save register arguments for later usage
- */
-#define LKMC_ENTRY \
-.text; \
-.global asm_main; \
-asm_main: \
-    push %rbp; \
-    mov %rsp, %rbp; \
-    push %r15; \
-    push %r14; \
-    push %r13; \
-    push %r12; \
-    push %rbx; \
-    push %rdi; \
-    sub $8, %rsp; \
-asm_main_after_prologue: \
-;
-
-/* Meant to be called at the end of LKMC_ENTRY.*
- *
- * Branching to "fail" makes tests fail with exit status 1.
- *
- * If LKMC_EXIT is reached, the program ends successfully.
- */
-#define LKMC_EXIT \
-    mov $0, %rax; \
-    jmp pass; \
-fail: \
-    /* -0x30(%rbp) is argument 1 which we pushed at prologue */ \
-    mov -0x30(%rbp), %rbx; \
-    movl %eax, (%rbx); \
-    mov $1, %rax; \
-pass: \
-    add $16, %rsp; \
-    pop %rbx; \
-    pop %r12; \
-    pop %r13; \
-    pop %r14; \
-    pop %r15; \
-    pop %rbp; \
-    ret; \
-;
-
-#define LKMC_FAIL \
-    mov $__LINE__, %eax; \
-    jmp fail; \
-;
-
-#endif

userland/arch/x86_64/gas_data_sizes.S

@@ -1,8 +1,8 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#gnu-gas-assembler data sizes */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
 #define ASSERT_DIFF(label1, label2, result) \
     lea label2(%rip), %rax; \
     lea label1(%rip), %rbx; \
@@ -15,7 +15,7 @@ LKMC_ENTRY
     ASSERT_DIFF(myquad, myocta, 8)
     ASSERT_DIFF(myocta, theend, 16)
 #undef ASSERT_DIF
-LKMC_EXIT
+LKMC_EPILOGUE
 mybyte:
     .byte 0x12
 myword:

userland/arch/x86_64/lkmc_assert_eq_fail.S

@@ -1,16 +1,26 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
     mov $0x123456789ABCDEF0, %r12
     mov $0x123456789ABCDEF0, %r13
+
+    /* Passing examples. */
+
+    /* Register immediate. */
     LKMC_ASSERT_EQ(%r12, $0x123456789ABCDEF0)
-    LKMC_ASSERT_EQ(%r12, %r13)
-    LKMC_ASSERT_EQ(%r12, myvar)
     LKMC_ASSERT_EQ($0x123456789ABCDEF0, %r12)
+
+    /* Register register. */
+    LKMC_ASSERT_EQ(%r12, %r13)
     LKMC_ASSERT_EQ(%r13, %r12)
+
+    /* Register memory. */
+    LKMC_ASSERT_EQ(%r12, myvar)
     LKMC_ASSERT_EQ(myvar, %r12)
+
+    /* Now let's fail. */
     LKMC_ASSERT_EQ(%r12, $0x123456789ABCDEF1)
-LKMC_EXIT
+LKMC_EPILOGUE
 myvar: .quad 0x123456789ABCDEF0

userland/arch/x86_64/lkmc_assert_memcmp_fail.S

@@ -1,11 +1,15 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
+    /* Pass */
     LKMC_ASSERT_MEMCMP(var0, var1, $0x10)
+    LKMC_ASSERT_MEMCMP(var0, var1, size)
+    /* Fail */
     LKMC_ASSERT_MEMCMP(var0, var2, $0x10)
-LKMC_EXIT
+LKMC_EPILOGUE
     var0: .long 0x11111111, 0x22222222, 0x33333333, 0x44444444
     var1: .long 0x11111111, 0x22222222, 0x33333333, 0x44444444
     var2: .long 0x11111111, 0x22222223, 0x23333333, 0x44444444
+    size: .quad 0x10

userland/arch/x86_64/paddq.S

@@ -5,9 +5,9 @@
  * The different variants basically determine if carries get forwarded or not.
  */
 
-#include "common.h"
+#include <lkmc.h>
 
-LKMC_ENTRY
+LKMC_PROLOGUE
 .data
     input0:       .long 0xF1F1F1F1, 0xF2F2F2F2, 0xF3F3F3F3, 0xF4F4F4F4
     input1:       .long 0x12121212, 0x13131313, 0x14141414, 0x15151515
@@ -35,4 +35,4 @@ LKMC_ENTRY
     /* 2x 16-bit */
     TEST(q)
 #undef TEST
-LKMC_EXIT
+LKMC_EPILOGUE