From 07bf731e4b95d7c9ea9dbacd1fc4a041120dfffb Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Sat, 3 Sep 2005 15:57:50 -0700 Subject: [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 Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/sys-x86_64/stub.S | 50 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 10 deletions(-) (limited to 'arch/um/sys-x86_64') diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S index 957f2eff32ca..03c279735784 100644 --- a/arch/um/sys-x86_64/stub.S +++ b/arch/um/sys-x86_64/stub.S @@ -16,21 +16,51 @@ syscall_stub: .globl batch_syscall_stub batch_syscall_stub: - movq $(UML_CONFIG_STUB_DATA >> 32), %rbx - salq $32, %rbx - movq $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx - or %rcx, %rbx - movq %rbx, %rsp -again: pop %rax - cmpq $0, %rax -jz done + 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) - jmp again -done: int3 + + /* stop */ + int3 -- cgit v1.2.3