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path: root/arch/um/sys-i386/stub.S
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Diffstat (limited to 'arch/um/sys-i386/stub.S')
-rw-r--r--arch/um/sys-i386/stub.S42
1 files changed, 34 insertions, 8 deletions
diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S
index a0f9506312d1..6a70d9ab5c29 100644
--- a/arch/um/sys-i386/stub.S
+++ b/arch/um/sys-i386/stub.S
@@ -2,24 +2,50 @@
.globl syscall_stub
.section .__syscall_stub, "x"
-syscall_stub:
- int $0x80
- mov %eax, UML_CONFIG_STUB_DATA
- int3
.globl batch_syscall_stub
batch_syscall_stub:
- mov $UML_CONFIG_STUB_DATA, %esp
-again: pop %eax
+ /* load pointer to first operation */
+ mov $(UML_CONFIG_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, UML_CONFIG_STUB_DATA+4
cmpl $0, %eax
jz done
+
+ /* save current pointer */
+ mov %esp, UML_CONFIG_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, UML_CONFIG_STUB_DATA
- jmp again
-done: int3
+
+ /* stop */
+ int3