plt: add API versioning

stsp · Sep 11, 2024 · c95a82d · c95a82d
1 parent f379f4b
commit c95a82d
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Showing 3 changed files with 21 additions and 1 deletion.
diff --git a/src/libc/dj64/plt.S b/src/libc/dj64/plt.S
@@ -249,6 +249,7 @@ plt_init:
     movl %fs:STUBINFO_SELF_SIZE, %ecx
     movl %fs:STUBINFO_MEM_BASE, %edx
     call ctrl
+    jc 2f
     /* free mem */
     movl $0x502, %eax
     movw handle, %di
@@ -275,17 +276,27 @@ plt_init:
     movl $0, %ecx
     movl %fs:STUBINFO_MEM_BASE, %edx
     call ctrl
+    jc 2b
     jmp 11b
 
 ctrl:
     pushal
     movl %esp, %edx
     movl __plt_handle, %eax
-    movl $AUX_CORE, %ebx
+    movl $0, %ebx
+    movb $AUX_CORE, %bl
+    movb $DL_API_VER, %bh
     movl $DL_SET_SYMTAB, %ecx
     movl %cs, %esi
     lcalll *__plt_ctrl
+    testl %eax, %eax
+    jnz 1f
+    popal
+    clc
+    ret
+1:
     popal
+    stc
     ret
 
 .global plt_done

diff --git a/src/libc/dj64/plt.h b/src/libc/dj64/plt.h
@@ -1 +1,2 @@
 #define DL_SET_SYMTAB 0
+#define DL_API_VER 1
diff --git a/src/libc/dj64/thunks.c b/src/libc/dj64/thunks.c
@@ -247,7 +247,15 @@ static void do_early_init(int handle)
 static int dj64_ctrl(int handle, int libid, int fn, unsigned esi, uint8_t *sp)
 {
     dpmi_regs *regs = (dpmi_regs *)sp;
+    int ver = libid >> 8;
     assert(handle < MAX_HANDLES);
+    if (ver != DL_API_VER) {
+        djloudprintf("dj64: API version mismatch, got %i want %i\n",
+                     ver, DL_API_VER);
+        if (ver == 0)  // this doesn't even handle errors, so terminate
+            dj64api->exit(1);
+        return -1;
+    }
     switch (fn) {
     case DL_SET_SYMTAB: {
         struct udisp *u = &udisps[handle];