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Diffstat (limited to 'arch/x86/um/stub_32.S')
-rw-r--r--arch/x86/um/stub_32.S51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/um/stub_32.S b/arch/x86/um/stub_32.S
new file mode 100644
index 000000000000..54a36ec20cb7
--- /dev/null
+++ b/arch/x86/um/stub_32.S
@@ -0,0 +1,51 @@
+#include "as-layout.h"
+
+	.globl syscall_stub
+.section .__syscall_stub, "ax"
+
+	.globl batch_syscall_stub
+batch_syscall_stub:
+	/* load pointer to first operation */
+	mov	$(STUB_DATA+8), %esp
+
+again:
+	/* load length of additional data */
+	mov	0x0(%esp), %eax
+
+	/* if(length == 0) : end of list */
+	/* write possible 0 to header */
+	mov	%eax, STUB_DATA+4
+	cmpl	$0, %eax
+	jz	done
+
+	/* save current pointer */
+	mov	%esp, STUB_DATA+4
+
+	/* skip additional data */
+	add	%eax, %esp
+
+	/* load syscall-# */
+	pop	%eax
+
+	/* load syscall params */
+	pop	%ebx
+	pop	%ecx
+	pop	%edx
+	pop	%esi
+ 	pop	%edi
+	pop	%ebp
+
+	/* execute syscall */
+	int	$0x80
+
+	/* check return value */
+	pop	%ebx
+	cmp	%ebx, %eax
+	je	again
+
+done:
+	/* save return value */
+	mov	%eax, STUB_DATA
+
+	/* stop */
+	int3