New subject: [Bug 42353] OllyDbg Step In on a "jump to self" instruction never stops if it' s the first instruction executed by debuggee

1 Feb 2017


      https://bugs.winehq.org/show_bug.cgi?id=42353
Bug ID: 42353
           Summary: OllyDbg Step In on a "jump to self" instruction never
                    stops if it's the first instruction executed by
                    debuggee
           Product: Wine
           Version: 2.0
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: dbghelp
          Assignee: wine-bugs@winehq.org
          Reporter: b7.10110111@gmail.com
      Distribution: ---
To reproduce
1. Launch OllyDbg (tested on 2.01)
2. Open an application, e.g. Test.exe coming in the OllyDbg distribution
3. After it loads, press <Space>, then in Assemble dialog type
dw 0xfeeb
and press <Enter> (or click Assemble button). This should assemble a `jmp short
<ModuleEntryPoint>` instruction.
4. Close Assemble dialog
5. Press F7 (shortcut for Step In)
6. See that right-bottom corner of the window (right-hand side of status bar)
has "Step in" text, which never switches back to Paused.
This result is wrong: the Step In action should set TF in EFLAGS, so that next
pass of control to debuggee will trap after executing one instruction. In
Windows XP OllyDbg gets control back immediately after pressing F7, while in
Wine this never happens at all with `jmp short $` instruction unless EIP
changes.
The same happens if instead of `EB FE` instruction you use `E9 FB FF FF FF`,
which is `jmp near $`.
Note that if you press F7 before step 3, everything works as expected.
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[Bug 42353] New: OllyDbg Step In on a "jump to self" instruction never stops if it' s the first instruction executed by debuggee