diff options
| author | Bodo Stroesser <bstroesser@fujitsu-siemens.com> | 2005-09-03 15:57:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 00:06:24 -0700 |
| commit | 07bf731e4b95d7c9ea9dbacd1fc4a041120dfffb (patch) | |
| tree | 25ae7f2000421d45e484abac0b7252809476c0d0 /arch/um/sys-i386 | |
| parent | 8b51304ed3184826fb262c1e9d3e58b0b00fd083 (diff) | |
[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>
Diffstat (limited to 'arch/um/sys-i386')
| -rw-r--r-- | arch/um/sys-i386/stub.S | 42 |
1 files changed, 34 insertions, 8 deletions
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 |