linux/arch/um/sys-x86_64/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

66 lines
1.1 KiB
ArmAsm

#include "uml-config.h"
.globl syscall_stub
.section .__syscall_stub, "x"
syscall_stub:
syscall
/* We don't have 64-bit constants, so this constructs the address
* we need.
*/
movq $(UML_CONFIG_STUB_DATA >> 32), %rbx
salq $32, %rbx
movq $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx
or %rcx, %rbx
movq %rax, (%rbx)
int3
.globl batch_syscall_stub
batch_syscall_stub:
mov $(UML_CONFIG_STUB_DATA >> 32), %rbx
sal $32, %rbx
mov $(UML_CONFIG_STUB_DATA & 0xffffffff), %rax
or %rax, %rbx
/* load pointer to first operation */
mov %rbx, %rsp
add $0x10, %rsp
again:
/* load length of additional data */
mov 0x0(%rsp), %rax
/* if(length == 0) : end of list */
/* write possible 0 to header */
mov %rax, 8(%rbx)
cmp $0, %rax
jz done
/* save current pointer */
mov %rsp, 8(%rbx)
/* skip additional data */
add %rax, %rsp
/* load syscall-# */
pop %rax
/* load syscall params */
pop %rdi
pop %rsi
pop %rdx
pop %r10
pop %r8
pop %r9
/* execute syscall */
syscall
/* check return value */
pop %rcx
cmp %rcx, %rax
je again
done:
/* save return value */
mov %rax, (%rbx)
/* stop */
int3