linux/arch/um/sys-i386/stub.S
Bodo Stroesser 07bf731e4b [PATCH] uml: skas0 stubs now check system call return values
Change syscall-stub's data to include a "expected retval".

Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.

run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.

one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.

Using the stub with additional data (modify_ldt via stub)
is prepared also.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:24 -07:00

52 lines
808 B
ArmAsm

#include "uml-config.h"
.globl syscall_stub
.section .__syscall_stub, "x"
.globl batch_syscall_stub
batch_syscall_stub:
/* 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
/* stop */
int3