fixes

kernel/arch/x86_64/include/bits/sched.h

@@ -40,7 +40,7 @@ struct arch_context {
     uint64_t ss;
 };
 
-static_assert(sizeof(struct arch_context) == 176);
+static_assert(sizeof(struct arch_context) == 22 * sizeof(uint64_t));
 
 #define ARCH_CTX_NUM  rax
 #define ARCH_CTX_A0   rdi

kernel/arch/x86_64/percpu.c

@@ -30,6 +30,8 @@ union ia32_star {
     };
 };
 
+static_assert(sizeof(union ia32_star) == 8);
+
 static void setup_cpu(struct percpu* cpu) {
     asm_wrmsr(MSR_GS_BASE, (uint64_t)cpu);
     asm_wrmsr(MSR_FS_BASE, 0);

kernel/arch/x86_64/usercopy.c

@@ -82,7 +82,7 @@ bool arch_usercopy_write(__user void* dst, const void* src, size_t len, struct u
         "clac\n"
         "ret\n"
         :
-        : "i"(&read_region)
+        : "i"(&write_region)
         : "memory"
     );
 }