functrace traces the function calls a program makes.
It's like strace, but for userspace.
It works by using Debugging functionality to insert breakpoints
at call&ret instructions.
POSIX says, "Conforming applications should not assume that the returned
contents of the symbolic link are null-terminated."
If we do include the null terminator into the returning string, Python
believes it to actually be a part of the returned name, and gets unhappy
about that later. This suggests other systems Python runs in don't include
it, so let's do that too.
Also, make our userspace support non-null-terminated realpath().
Previously, a breakpoint was removed after it was tripped.
After a breakpoint trips, we have to undo the 'int3' patch
from the instruction in order to continue the exceution.
To make a breakpoint persist, we switch to "single step" mode,
which stops the execution after a single instruction, and then we
insert the breakpoint at the previous instruction.
There is also some code that deals with an edge case where there are
breakpoints in two consecutive instructions.
For some reaason, some magic is required to convince gcc to give us
the implementation for "__cxa_demangle"
Thanks @predmond for finding this simpler form of magic :)
PT_SETTREGS sets the regsiters of the traced thread. It can only be
used when the tracee is stopped.
Also, refactor ptrace.
The implementation was getting long and cluttered the alraedy large
Process.cpp file.
This commit moves the bulk of the implementation to Kernel/Ptrace.cpp,
and factors out peek & poke to separate methods of the Process class.
This was a missing feature in the PT_TRACEME command.
This feature allows the tracer to interact with the tracee before the
tracee has started executing its program.
It will be useful for automatically inserting a breakpoint at a
debugged program's entry point.
PT_POKE writes a single word to the tracee's address space.
Some caveats:
- If the user requests to write to an address in a read-only region, we
temporarily change the page's protections to allow it.
- If the user requests to write to a region that's backed by a
SharedInodeVMObject, we replace the vmobject with a PrivateIndoeVMObject.
This is really just a workaround to keep SystemMonitor's process table
working right wrt selection retention during resorts (while also doing
full index invalidation on things like ProfileViewer inversion.)
It's starting to feel like the model abstraction is not super great
and we'll need a better approach if we want to actually build some more
dynamic functionality into our views.
`IRCChannelMemberListModel->nick_at` returns the nick name of a channel
member at the specified index.
`IRCClient->nick_without_prefix` returns a formatted nick name without
privilege prefix.
Some IRC clients use /hop to part and re-join a channel; however this
can be confused with granting half-op (+h) channel privileges to a user.
The general convention used by other IRC clients is /cycle.
Major changes are:
The layout and mouse handling has been rewritten to always center
images in the window.
QuickShow now accepts multiple images on drag and drop. The first
image gets opened in the current window, further images are opened in
new processes.
QSWidget now loads images on its own with QSWidget::load_from_file().
An on_drop callback has been introduced for QSWidget.
Added an open menu.
Added an about box and placeholder icons to the application.
QuickShow now starts without loading the sunset-retro wallpaper.
