lib: implement read and write EFLAGS helper functions

Signed-off-by: Pawel Wieczorkiewicz <[email protected]>
KernelTestFramework · Nov 13, 2023 · 62ea54f · 62ea54f
1 parent 31d23bf
commit 62ea54f
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Showing 2 changed files with 8 additions and 10 deletions.
diff --git a/include/arch/x86/asm-macros.h b/include/arch/x86/asm-macros.h
@@ -323,8 +323,10 @@ name ## _end:
     "pop %%" STR(_ASM_BX) "\n"
 
 #if defined(__x86_64__)
+#define PUSHF() "pushfq\n"
 #define POPF() "popfq\n"
 #else
+#define PUSHF() "pushf\n"
 #define POPF() "popf\n"
 #endif
 

diff --git a/include/lib.h b/include/lib.h
@@ -171,22 +171,18 @@ static inline void int3(void) {
     asm volatile("int3");
 }
 
-static inline unsigned long read_flags(void) {
+static inline unsigned long read_eflags(void) {
     unsigned long flags;
 
-    asm volatile(
-#if defined(__i386__)
-        "pushfd;"
-        "popl %0"
-#elif defined(__x86_64__)
-        "pushfq;"
-        "popq %0"
-#endif
-        : "=r"(flags));
+    asm volatile(PUSHF() "pop %0" : "=r"(flags));
 
     return flags;
 }
 
+static inline void write_eflags(unsigned long flags) {
+    asm volatile("push %0\n" POPF()::"r"(flags));
+}
+
 static inline unsigned long read_cs(void) {
     unsigned long cs;