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path: root/arch/um/sys-x86/stub_32.S
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Diffstat (limited to 'arch/um/sys-x86/stub_32.S')
-rw-r--r--arch/um/sys-x86/stub_32.S51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/um/sys-x86/stub_32.S b/arch/um/sys-x86/stub_32.S
new file mode 100644
index 000000000000..54a36ec20cb7
--- /dev/null
+++ b/arch/um/sys-x86/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