<rdar://problem/11051056>
Found a race condition when sending async packets in the ProcessGDBRemote.
A little background: GDB remote clients can only send one packet at a time. You must send a packet and wait for a response. So when we continue, we obviously can't hold up the calling thread waiting for the process to stop again, so we have an async thread in the ProcessGDBRemote whose only job is to run packets that control the inferior process. When you send a continue packet, the only packet you can send is an interrupt packet (which consists of sending a CTRL+C (or a '\x03' byte)). This then stops the inferior and we can send the async packet, and then resume the target. There was a race condition that often happened during stepping where we are doing a source level single step which consists of many instruction steps and a few runs here and there when we step into a function. So the flow looks like:
inst single step
inst single step
inst single step
inst single step
inst single step
step BP and run
inst single step
inst single step
inst single step
Now if we got an async packet while the program is running we get something like:
send --> continue
send --> interrupt
recv <-- interrupt stop reply packet
send --> async packet
recv <-- async response
send --> continue again and wait for actual stop
Problems arise when this was happening when single stepping a thread where we would get:
send --> step thread 123
send --> interrupt
send --> stop reply for thread 123 (from the step)
Now we _might_ have an extra stop reply packet from the "interrupt" which we weren't checking for and we could end up with:
send --> async packet (like memory read!)
recv <-- async response (which is the interrupt stop reply packet)
Now we have the read memroy reply sitting in our buffer and waiting to be used as the reply for the next packet...
To further complicate things, the single step should have exited the async thread since the run control is finished, but now it will continue if it was interrupted.
The fixes I checked in to two major things:
- watch for the extra stop reply if we need to
- make sure we exit from the async thread run loop when the previous run control (like the instruction level single step) is finished.
Needless to say this makes very fast stepping in Xcode much more reliable.
llvm-svn: 153629
This fix really needed to happen as a previous fix I had submitted for
calculating symbol sizes made many symbols appear to have zero size since
the function that was calculating the symbol size was calling another function
that would cause the calculation to happen again. This resulted in some symbols
having zero size when they shouldn't. This could then cause infinite stack
traces and many other side affects.
llvm-svn: 152244
more of the local path, platform path, associated symbol file, UUID, arch,
object name and object offset. This allows many of the calls that were
GetSharedModule to reduce the number of arguments that were used in a call
to these functions. It also allows a module to be created with a ModuleSpec
which allows many things to be specified prior to any accessors being called
on the Module class itself.
I was running into problems when adding support for "target symbol add"
where you can specify a stand alone debug info file after debugging has started
where I needed to specify the associated symbol file path and if I waited until
after construction, the wrong symbol file had already been located. By using
the ModuleSpec it allows us to construct a module with as little or as much
information as needed and not have to change the parameter list.
llvm-svn: 151476
objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.
Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and
ExecutionContextRef objects.
llvm-svn: 151009
user space programs. The core file support is implemented by making a process
plug-in that will dress up the threads and stack frames by using the core file
memory.
Added many default implementations for the lldb_private::Process functions so
that plug-ins like the ProcessMachCore don't need to override many many
functions only to have to return an error.
Added new virtual functions to the ObjectFile class for extracting the frozen
thread states that might be stored in object files. The default implementations
return no thread information, but any platforms that support core files that
contain frozen thread states (like mach-o) can make a module using the core
file and then extract the information. The object files can enumerate the
threads and also provide the register state for each thread. Since each object
file knows how the thread registers are stored, they are responsible for
creating a suitable register context that can be used by the core file threads.
Changed the process CreateInstace callbacks to return a shared pointer and
to also take an "const FileSpec *core_file" parameter to allow for core file
support. This will also allow for lldb_private::Process subclasses to be made
that could load crash logs. This should be possible on darwin where the crash
logs contain all of the stack frames for all of the threads, yet the crash
logs only contain the registers for the crashed thrad. It should also allow
some variables to be viewed for the thread that crashed.
llvm-svn: 150154
will allow us to represent a process/thread ID using a pointer for the OS
plug-ins where they might want to represent the process or thread ID using
the address of the process or thread structure.
llvm-svn: 145644
1 - the DIE collections no longer have the NULL tags which saves up to 25%
of the memory on typical C++ code
2 - faster parsing by not having to run the SetDIERelations() function anymore
it is done when parsing the DWARF very efficiently.
llvm-svn: 144983
from a process and hooked it up to the new packet that was recently added
to our GDB remote executable named debugserver. Now Process has the following
new calls:
virtual Error
Process::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info);
virtual uint32_t
GetLoadAddressPermissions (lldb::addr_t load_addr);
Only the first one needs to be implemented by subclasses that can add this
support.
Cleaned up the way the new packet was implemented in debugserver to be more
useful as an API inside debugserver. Also found an error where finding a region
for an address actually will pick up the next region that follows the address
in the query so we also need ot make sure that the address we requested the
region for falls into the region that gets returned.
llvm-svn: 144976
turned out to be unitialized data in the ProcessLaunchInfo default constructor.
Turning on MallocScribble in the environment helped track this down.
When we launch and attach using the host layer, we now inform the process that
it shouldn't detach when by calling an accessor.
llvm-svn: 144882
After recent changes we weren't reaping child processes resulting in many
zombie processes.
This was fixed by adding more settings to the ProcessLaunchOptions class
that allow clients to specify a callback function and baton to be notified
when their process dies. If one is not supplied a default callback will be
used that "does the right thing".
Cleaned up a race condition in the ProcessGDBRemote class that would attempt
to monitor when debugserver died.
Added an extra boolean to the process monitor callbacks that indicate if a
process exited or not. If your process exited with a zero exit status and no
signal, both items could be zero.
Modified the process monitor functions to not require a callback function
in order to reap the child process.
llvm-svn: 144780
on internal only (public API hasn't changed) to simplify the paramter list
to the launch calls down into just one argument. Also all of the argument,
envronment and stdio things are now handled in a much more centralized fashion.
llvm-svn: 143656
lldb_private::Error objects the rules are:
- short strings that don't start with a capitol letter unless the name is a
class or anything else that is always capitolized
- no trailing newline character
- should be one line if possible
Implemented a first pass at adding "--gdb-format" support to anything that
accepts format with optional size/count.
llvm-svn: 142999
process IDs, and thread IDs, but was mainly needed for for the UserID's for
Types so that DWARF with debug map can work flawlessly. With DWARF in .o files
the type ID was the DIE offset in the DWARF for the .o file which is not
unique across all .o files, so now the SymbolFileDWARFDebugMap class will
make the .o file index part (the high 32 bits) of the unique type identifier
so it can uniquely identify the types.
llvm-svn: 142534
a watchpoint for either the variable encapsulated by SBValue (Watch) or the pointee
encapsulated by SBValue (WatchPointee).
Removed SBFrame::WatchValue() and SBFrame::WatchLocation() API as a result of that.
Modified the watchpoint related test suite to reflect the change.
Plus replacing WatchpointLocation with Watchpoint throughout the code base.
There are still cleanups to be dome. This patch passes the whole test suite.
Check it in so that we aggressively catch regressions.
llvm-svn: 141925
set up yet, if we're talking to an Apple arm device set the register set based on the
arm device's attributes; this is a safe assumption to make in this particular environment.
llvm-svn: 141265
symbol context that represents an inlined function. This function has been
renamed internally to:
bool
SymbolContext::GetParentOfInlinedScope (const Address &curr_frame_pc,
SymbolContext &next_frame_sc,
Address &next_frame_pc) const;
And externally to:
SBSymbolContext
SBSymbolContext::GetParentOfInlinedScope (const SBAddress &curr_frame_pc,
SBAddress &parent_frame_addr) const;
The correct blocks are now correctly calculated.
Switched the stack backtracing engine (in StackFrameList) and the address
context printing over to using the internal SymbolContext::GetParentOfInlinedScope(...)
so all inlined callstacks will match exactly.
llvm-svn: 140910
etc to specific source files.
Added SB API's to specify these source files & also more than one module.
Added an "exact" option to CompileUnit's FindLineEntry API.
llvm-svn: 140362
stdarg formats to use __attribute__ format so the compiler can flag
incorrect uses. Fix all incorrect uses. Most of these are innocuous,
a few were resulting in crashes.
llvm-svn: 140185
data sent back to the debugger. On the debugger side, use the opportunity during the
StopInfoMachException::CreateStopReasonWithMachException() method to set the hardware index
for the very watchpoint location.
llvm-svn: 139975
plug-ins are add on plug-ins for the lldb_private::Process class that can add
thread contexts that are read from memory. It is common in kernels to have
a lot of threads that are not currently executing on any cores (JTAG debugging
also follows this sort of thing) and are context switched out whose state is
stored in memory data structures. Clients can now subclass the OperatingSystem
plug-ins and then make sure their Create functions correcltly only enable
themselves when the right binary/target triple are being debugged. The
operating system plug-ins get a chance to attach themselves to processes just
after launching or attaching and are given a lldb_private::Process object
pointer which can be inspected to see if the main executable, target triple,
or any shared libraries match a case where the OS plug-in should be used.
Currently the OS plug-ins can create new threads, define the register contexts
for these threads (which can all be different if desired), and populate and
manage the thread info (stop reason, registers in the register context) as
the debug session goes on.
llvm-svn: 138228
This is helping us track down some extra references to ModuleSP objects that
are causing things to get kept around for too long.
Added a module pointer accessor to target and change a lot of code to use
it where it would be more efficient.
"taret delete" can now specify "--clean=1" which will cleanup the global module
list for any orphaned module in the shared module cache which can save memory
and also help track down module reference leaks like we have now.
llvm-svn: 137294
10 second timeout zone. When launching we increase the
timeout to 10 seconds to ensure we have time to launch a
process, and then set it back.
llvm-svn: 137256
ability to dump more information about modules in "target modules list". We
can now dump the shared pointer reference count for modules, the pointer to
the module itself (in case performance tools can help track down who has
references to said pointer), and the modification time.
Added "target delete [target-idx ...]" to be able to delete targets when they
are no longer needed. This will help track down memory usage issues and help
to resolve when module ref counts keep getting incremented. If the command gets
no arguments, the currently selected target will be deleted. If any arguments
are given, they must all be valid target indexes (use the "target list"
command to get the current target indexes).
Took care of a bunch of "no newline at end of file" warnings.
TimeValue objects can now dump their time to a lldb_private::Stream object.
Modified the "target modules list --global" command to not error out if there
are no targets since it doesn't require a target.
Fixed an issue in the MacOSX DYLD dynamic loader plug-in where if a shared
library was updated on disk, we would keep using the older one, even if it was
updated.
Don't allow the ModuleList::GetSharedModule(...) to return an empty module.
Previously we could specify a valid path on disc to a module, and specify an
architecture that wasn't contained in that module and get a shared pointer to
a module that wouldn't be able to return an object file or a symbol file. We
now make sure an object file can be extracted prior to adding the shared pointer
to the module to get added to the shared list.
llvm-svn: 137196
method so process plug-ins that are requested by name can answer yes when
asked if they can debug a target that might not have any file in the target.
Modified the ConnectionFileDescriptor to have both a read and a write file
descriptor. This allows us to support UDP, and eventually will allow us to
support pipes. The ConnectionFileDescriptor class also has a file descriptor
type for each of the read and write file decriptors so we can use the correct
read/recv/recvfrom call when reading, or write/send/sendto for writing.
Finished up an initial implementation of UDP where you can use the "udp://"
URL to specify a host and port to connect to:
(lldb) process connect --plugin kdp-remote udp://host:41139
This will cause a ConnectionFileDescriptor to be created that can send UDP
packets to "host:41139", and it will also bind to a localhost port that can
be given out to receive the connectionless UDP reply.
Added the ability to get to the IPv4/IPv6 socket port number from a
ConnectionFileDescriptor instance if either file descriptor is a socket.
The ProcessKDP can now successfully connect to a remote kernel and detach
using the above "processs connect" command!!! So far we have the following
packets working:
KDP_CONNECT
KDP_DISCONNECT
KDP_HOSTINFO
KDP_VERSION
KDP_REATTACH
Now that the packets are working, adding new packets will go very quickly.
llvm-svn: 135363
connected process connection.
Also added support for more kinds of continue packet when multiple threads
need to continue where some want to continue with signals.
llvm-svn: 133785
and set the address as an opcode address or as a callable address. This is
needed in various places in the thread plans to make sure that addresses that
might be found in symbols or runtime might already have extra bits set (ARM/Thumb).
The new functions are:
bool
Address::SetCallableLoadAddress (lldb::addr_t load_addr, Target *target);
bool
Address::SetOpcodeLoadAddress (lldb::addr_t load_addr, Target *target);
SetCallableLoadAddress will initialize a section offset address if it can,
and if so it might possibly set some bits in the address to make the address
callable (bit zero might get set for ARM for Thumb functions).
SetOpcodeLoadAddress will initialize a section offset address using the
specified target and it will strip any special address bits if needed
depending on the target.
Fixed the ABIMacOSX_arm::GetArgumentValues() function to require arguments
1-4 to be in the needed registers (previously this would incorrectly fallback
to the stack) and return false if unable to get the register values. The
function was also modified to first look for the generic argument registers
and then fall back to finding the registers by name.
Fixed the objective trampoline handler to use the new Address::SetOpcodeLoadAddress
function when needed to avoid address mismatches when trying to complete
steps into objective C methods. Make similar fixes inside the
AppleThreadPlanStepThroughObjCTrampoline::ShouldStop() function.
Modified ProcessGDBRemote::BuildDynamicRegisterInfo(...) to be able to deal with
the new generic argument registers.
Modified RNBRemote::HandlePacket_qRegisterInfo() to handle the new generic
argument registers on the debugserver side.
Modified DNBArchMachARM::NumSupportedHardwareBreakpoints() to be able to
detect how many hardware breakpoint registers there are using a darwin sysctl.
Did the same for hardware watchpoints in
DNBArchMachARM::NumSupportedHardwareWatchpoints().
llvm-svn: 131834
Modified ClangUserExpression and ClangUtilityFunction to display the actual
error (if one is available) that made the JIT fail instead of a canned
response.
Fixed the restoring of all register values when the 'G' packet doesn't work
to use the correct data.
llvm-svn: 131454
over when running JITed expressions. The allocated memory cache will cache
allocate memory a page at a time for each permission combination and divvy up
the memory and hand it out in 16 byte increments.
llvm-svn: 131453
thread plan. In order to get the return value, you can call:
void
ThreadPlanCallFunction::RequestReturnValue (lldb::ValueSP &return_value_sp);
This registers a shared pointer to a return value that will get filled in if
everything goes well. After the thread plan is run the return value will be
extracted for you.
Added an ifdef to be able to switch between the LLVM MCJIT and the standand JIT.
We currently have the standard JIT selected because we have some work to do to
get the MCJIT fuctioning properly.
Added the ability to call functions with 6 argument in the x86_64 ABI.
Added the ability for GDBRemoteCommunicationClient to detect if the allocate
and deallocate memory packets are supported and to not call allocate memory
("_M") or deallocate ("_m") if we find they aren't supported.
Modified the ProcessGDBRemote::DoAllocateMemory(...) and ProcessGDBRemote::DoDeallocateMemory(...)
to be able to deal with the allocate and deallocate memory packets not being
supported. If they are not supported, ProcessGDBRemote will switch to calling
"mmap" and "munmap" to allocate and deallocate memory instead using our
trivial function call support.
Modified the "void ProcessGDBRemote::DidLaunchOrAttach()" to correctly ignore
the qHostInfo triple information if any was specified in the target. Currently
if the target only specifies an architecture when creating the target:
(lldb) target create --arch i386 a.out
Then the vendor, os and environemnt will be adopted by the target.
If the target was created with any triple that specifies more than the arch:
(lldb) target create --arch i386-unknown-unknown a.out
Then the target will maintain its triple and not adopt any new values. This
can be used to help force bare board debugging where the dynamic loader for
static files will get used and users can then use "target modules load ..."
to set addressses for any files that are desired.
Added back some convenience functions to the lldb_private::RegisterContext class
for writing registers with unsigned values. Also made all RegisterContext
constructors explicit to make sure we know when an integer is being converted
to a RegisterValue.
llvm-svn: 131370
