Commit c842deea75

Jacob G-W <jacoblevgw@gmail.com>
2023-06-10 02:32:33
os/plan9: fix order of register setting in syscall1
We need to set rbp last because the arguments are stored on the stack. If we clobber rbp first, then we will get a segfault when trying to access the function arguments. I believe I had already done this with the other syscall* functions, but not with syscall1, so this allows single argument syscalls like close to work.
master
1 parent 34d44e0
Changed files (1)
lib
std
os
plan9
x86_64.zig
lib/std/os/plan9/x86_64.zig
@@ -9,8 +9,8 @@ pub fn syscall1(sys: plan9.SYS, arg0: usize) usize {
         \\pop %%r11
         \\pop %%r11
         : [ret] "={rax}" (-> usize),
-        : [syscall_number] "{rbp}" (@enumToInt(sys)),
-          [arg0] "{r8}" (arg0),
+        : [arg0] "{r8}" (arg0),
+          [syscall_number] "{rbp}" (@enumToInt(sys)),
         : "rcx", "rax", "rbp", "r11", "memory"
     );
 }