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-i386/stub.S | 42 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) (limited to 'arch/um/sys-i386/stub.S') diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S index a0f9506312d..6a70d9ab5c2 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 -- cgit v1.2.3