Yet another step toward ARM64 support. With this commit, lldb-gdbserver started on ARM64 target can be accessed by lldb running on desktop PC and it can process simple commands (like 'continue'). Still ARM64 support lacks NativeRegisterContextLinux_arm64.* code which waits to be implemented.
Based on similar files for Linux x86_64 and Darwin ARM64. Due to common code extraction from Darwin related files, lldb should be tested for any unexpected regression on Darwin ARM64 machines too.
See the following for more details:
http://reviews.llvm.org/D4580http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140825/012670.html
Change by Paul Osmialowski.
llvm-svn: 216737
This change:
* properly captures execs in NativeProcessLinux.
* clears out all non-main-thread thread metadata in NativeProcessLinux on exec.
* adds a DidExec() method to the NativeProcessProtocol delegate.
* clears out the auxv data cache when we exec (on Linux).
This is a small part of the llgs for local Linux debugging work going on here:
https://github.com/tfiala/lldb/tree/dev-llgs-local
I'm breaking it into small patches.
llvm-svn: 216670
I copied this originally based on what debugserver was doing. This appears to
be incorrect and unncessary for Linux. The LinuxSignals on the lldb side
don't look for these and therefore they get handled incorrectly.
Leaving the hook in place since I think darwin will continue to need to
translate those signal numbers.
llvm-svn: 216564
More specifically, this change can be summarized as follows:
1) Makes an lldbHostPosix library which contains code common to
all posix platforms.
2) Creates Host/FileSystem.h which defines a common FileSystem
interface.
3) Implements FileSystem.h in Host/windows and Host/posix.
4) Creates Host/FileCache.h, implemented in Host/common, which
defines a class useful for storing handles to open files needed
by the debugger.
Differential Revision: http://reviews.llvm.org/D4889
llvm-svn: 215775
FileAction was previously a nested class in ProcessLaunchInfo.
This led to some unfortunate style consequences, such as requiring
the AddPosixSpawnFileAction() funciton to be defined in the Target
layer, instead of the more appropriate Host layer. This patch
makes FileAction its own independent class in the Target layer,
and then moves AddPosixSpawnFileAction() into Host as a result.
Differential Revision: http://reviews.llvm.org/D4877
llvm-svn: 215649
Added llgs/debugserver gdb-remote tests around SIGABRT and SIGSEGV signal reception
notification. Found a few bugs in exception signal handling in Linux llgs. Fixed those.
llvm-svn: 215458
These fix the broken debian lldb build, which is using g++ 4.7.2.
TypeFormat changes:
1. stopped using the C++11 "dtor = default;" construct.
The generated default destructor in the two derived classes wanted
them to have a different throws() semantic that was causing 4.7 to
fail to generate it. I switched these to empty destructors defined
in the .cpp file.
2. Switched the m_types map from an ordered map to an unordered_map.
g++ 4.7's c++ library supports the C++11 emplace() used by TypeFormat
but the same c++ library's map impl does not. Since TypeFormat didn't
look like it depended on ordering in the map, I just switched it to
a std::unordered_map.
NativeProcessLinux - g++ 4.7 chokes on lexing the "<::" in
static_cast<::pid_t>(wpid). g++ 4.8+ and clang are fine with it.
I just put a space in between the "<" and the "::" and that cleared
it up.
llvm-svn: 212681
See http://reviews.llvm.org/D4366 for details.
Change by Paul Paul Osmialowski
Today this is the only problem that I'm facing trying to cross-compile lldb for AArch64 using Linaro's toolchain.
PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS, PTRACE_SETFPREGS are not defined for AArch64
These things can be defined different ways for other architectures, e.g. for x86_64 Linux, asm/ptrace-abi.h defines them as preprocessor constants while sys/ptrace.h defines them in enum along with corresponding PT_* preprocessor constants
NativeProcessLinux.cpp includes sys/ptrace.h
To avoid accidental redefinition of enums with preprocessor constants, I'm proposing this patch which first checks for PT_* preprocessor constants then checks for PTRACE_* constants then when it still can not find them, it defines preprocessor constants.
Similar approach was already used for PTRACE_GETREGSET and PTRACE_SETREGSET constants; in this case however it was easier, since enum values in sys/ptrace.h and preprocessor constants shared all exactly the same names (e.g. there's no additional PT_GETREGSET name defined).
llvm-svn: 212225
There were a few places where we were not catching the possibility of negative
error codes in waitpid() calls. This change fixes those remaining after
the llgs branch fixes to ProcessMonitor.
Change by Shawn Best.
llvm-svn: 212107
Also moves NativeRegisterContextLinux* files into the Linux directory.
These, like NativeProcessLinux, should only be built on Linux or a cross
compiler with proper headers.
llvm-svn: 212074
This change brings in lldb-gdbserver (llgs) specifically for Linux x86_64.
(More architectures coming soon).
Not every debugserver option is covered yet. Currently
the lldb-gdbserver command line can start unattached,
start attached to a pid (process-name attach not supported yet),
or accept lldb attaching and launching a process or connecting
by process id.
The history of this large change can be found here:
https://github.com/tfiala/lldb/tree/dev-tfiala-native-protocol-linux-x86_64
Until mid/late April, I was not sharing the work and continued
to rebase it off of head (developed via id tfiala@google.com). I switched over to
user todd.fiala@gmail.com in the middle, and once I went to github, I did
merges rather than rebasing so I could share with others.
llvm-svn: 212069
Both NativeProcessLinux (in llgs branch) and Linux Host.cpp had similar code to handle /proc
file reading. I factored that out into a new Linux-specific ProcFileReader class and added a method
that the llgs branch will use for line-by-line parsing.
This change also adds numerous Linux-specific files to Xcode that were missing from the Xcode
project files.
Related to https://github.com/tfiala/lldb/issues/27
llvm-svn: 212015
This is a mechanical change addressing the various sign comparison warnings that
are identified by both clang and gcc. This helps cleanup some of the warning
spew that occurs during builds.
llvm-svn: 205390
On FreeBSD ptrace(PT_KILL) is used to terminate the traced process
(as if PT_CONTINUE had been used with SIGKILL as the signal to be
delivered), and is the desired behaviour for ProcessPOSIX::DoDestroy.
On Linux, after ptrace(PTRACE_KILL) the traced process still exists
and can be interrogated. It is only upon resume that it exits as though
it received SIGKILL.
As the Linux PTRACE_KILL behaviour is not used by LLDB, rename
BringProcessIntoLimbo to Kill, and change the implementation to simply
call kill() instead of using ptrace.
Thanks to Todd F for testing (Ubuntu 12.04, gcc 4.8.2).
Sponsored by: DARPA, AFRL
Differential Revision: http://llvm-reviews.chandlerc.com/D3159
llvm-svn: 205337
Fix Windows build by adding JITLoaderGDB and ProcessElfCore.
RegisterContext: fixes for Windows build: sizeof(GPR::register) didn't work, switched to sizeof(((GPR*)NULL)->register).
llvm-svn: 203667
This change uses a fixed known offset for the Linux i386 DR0 register.
This change also undoes the 32-bit wordsize change from r169645 that
revolved around being 32-bit/64-bit friendly in
WriteRegOperation::Execute within the Linux ProcessMonitor.cpp. I ran
all the tests on x86_64 Linux with no failures. I also ran some simple
tests with 32-bit Linux exe on x86_64 host and 32-bit linux exe on
i686 32-bit host and these worked fine.
Note (from Todd): the UserData struct in the Linux i386 register
context (only used by Linux i386 host running Linux 32-bit inferior)
is out of sync with what shows up in the sys/user.h for an 32-bit
Linux build (per an earlier change of mine to make it look more like
x86_64 host running x86 exe). I think we should (1) make i386 Linux
targets run using the same register context (and correct ones) on i386
and x86_64 linux hosts if that is possible, and (2) we could use some
tests around the register handling, particularly to verify things like
DR0 registers are in the right spots on host/target combos that we can
verify vs. known correct values.
Change by Matthew Gardiner.
llvm-svn: 202887
This change fixes up issues with specifying the size of the i386
register infos for FPU registers. The bug was that for the i386
register context, the size of the FPU registers were still being
computed based on the x86_64 FXSAVE structure.
This change permits the FPR_SIZE macro to optionally be defined
outside of RegisterInfos_i386.h, which RegisterContextLinux_i386.cpp
does properly. It redefines the FPR_i386 structure with all the
accessible parts that RegisterInfos_i386.h wants to see, which we had
not done before when we made the overall size of the structure
properly sized a recently.
This change also modifies POSIXThread to create a
RegisterContextLinux_i386 only when the host is 32-bit; otherwise, it
uses the RegisterContextLinux_x86_64, which works properly for 32-bit
and 64-bit inferiors on a 64-bit host.
I tested this debugging a Linux x86 exe on an x86 host (Ubuntu 13.10
x86), and debugging a Linux x86 exe and a Linux x86-64 exe on an
x86-64 host (Ubuntu 12.04 LTS). Those cases all worked.
Thanks to Matthew Gardiner who discoverd may key insights into
tracking down the issue. The motivation for this change and some of
the code originates from him via this thread:
http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140224/010554.html
llvm-svn: 202428
Implement x86_64 debug register read/write in support of hardware
watchpoints. Hoist LinuxThread::TraceNotify code back into
POSIXThread::TraceNotify()
Patch by John Wolfe.
We still need to rework this later to avoid the #ifdef FreeBSD.
llvm-reviews.chandlerc.com/D2572
llvm.org/pr16706
llvm-svn: 201706
This patch addresses a bug where in a multi-threaded program a new
signal from the inferior may be received before all group-stop
messages from an earlier signal have been handled.
Patch by Andrew MacPherson
llvm-svn: 200226
::Fork already does this internally, so this was simply leaking file handles.
This fixes the problem where the test suite would occasionally run out of file handles.
llvm-svn: 192929
To make this work this patch extends LLDB to:
- Explicitly track the link_map address for each module. This is effectively the module handle, not sure why it wasn't already being stored off anywhere. As an extension later, it would be nice if someone were to add support for printing this as part of the modules list.
- Allow reading the per-thread data pointer via ptrace. I have added support for Linux here. I'll be happy to add support for FreeBSD once this is reviewed. OS X does not appear to have __thread variables, so maybe we don't need it there. Windows support should eventually be workable along the same lines.
- Make DWARF expressions track which module they originated from.
- Add support for the DW_OP_GNU_push_tls_address DWARF opcode, as generated by gcc and recent versions of clang. Earlier versions of clang (such as 3.2, which is default on Ubuntu right now) do not generate TLS debug info correctly so can not be supported here.
- Understand the format of the pthread DTV block. This is where it gets tricky. We have three basic options here:
1) Call "dlinfo" or "__tls_get_addr" on the inferior and ask it directly. However this won't work on core dumps, and generally speaking it's not a good idea for the debugger to call functions itself, as it has the potential to not work depending on the state of the target.
2) Use libthread_db. This is what GDB does. However this option requires having a version of libthread_db on the host cross-compiled for each potential target. This places a large burden on the user, and would make it very hard to cross-debug from Windows to Linux, for example. Trying to build a library intended exclusively for one OS on a different one is not pleasant. GDB sidesteps the problem and asks the user to figure it out.
3) Parse the DTV structure ourselves. On initial inspection this seems to be a bad option, as the DTV structure (the format used by the runtime to manage TLS data) is not in fact a kernel data structure, it is implemented entirely in useerland in libc. Therefore the layout of it's fields are version and OS dependent, and are not standardized.
However, it turns out not to be such a problem. All OSes use basically the same algorithm (a per-module lookup table) as detailed in Ulrich Drepper's TLS ELF ABI document, so we can easily write code to decode it ourselves. The only question therefore is the exact field layouts required. Happily, the implementors of libpthread expose the structure of the DTV via metadata exported as symbols from the .so itself, designed exactly for this kind of thing. So this patch simply reads that metadata in, and re-implements libthread_db's algorithm itself. We thereby get cross-platform TLS lookup without either requiring third-party libraries, while still being independent of the version of libpthread being used.
Test case included.
llvm-svn: 192922
Use 32-bit register enums without gaps on 64-bit hosts.
Don't show 64-bit registers when debugging 32-bit targets.
Add psuedo gpr registers (ax, ah, al, etc.)
Add mmx registers.
Fix TestRegisters.py to not read ymm15 register on 32-bit targets.
Fill out and move gcc/dwarf/gdb register enums to RegisterContext_x86.h
llvm-svn: 192263
scan-build was complaining about:
The return value from the call to 'setgid' is not checked. If an error occurs in 'setgid', the following code may execute with unexpected privileges
llvm-svn: 191618
- ProcessMonitor::[Do|Serve]Operation no longer depend on file descriptors!
- removed unused member functions CloseFD and EnableIPC
- add semaphores to signal when an Operation is ready to be processed/complete.
This commit fixes a bug that was identified under stress-testing (i.e. build
LLVM while running tests) that led to LLDB becoming unresponsive because the
read/write operations on file descriptors in ProcessMonitor were not checked.
Other test runner improvement/convenience:
- pickup environment variables LLDB_LINUX_LOG and LLDB_LINUX_LOG_OPTIONS to
enable (Linux) logging when running the test suite. Example usage:
$ LLDB_LINUX_LOG="mylog.txt" LLDB_LINUX_LOG_OPTIONS="process thread" python dotest.py
llvm-svn: 190820
On Linux there is no separate notion of a process (vs. a thread) for
ptrace(); each thread needs to be individually detached. On FreeBSD
we have a separate process context, and we detach just it.
Review: http://llvm-reviews.chandlerc.com/D1418
llvm-svn: 189666
Created new LinuxThread class inherited from POSIXThread and removed linux / freebsd ifdefs
Removed several un-needed set thread name calls
CR (and multiple suggestions): mkopec
llvm-svn: 187545
Usage: 'lldb a.out -c core'.
TODO: FreeBSD support.
TODO: Support for AVX registers.
TODO: Refactor so that RegisterContextCore* don't inherit from classes that use ProcessMonitor
to fix the build on OS/X.
llvm-svn: 186516
RegisterContextCoreLinux_x86_64 inherits from RegisterContextLinux_x86_64 which inherits from RegisterContext_x86_64 which uses has:
ProcessMonitor &GetMonitor();
This register context used by the core file can't use this since the process plug-in will be ProcessElfCore and the implementation of GetMonitor() does:
ProcessMonitor &
RegisterContext_x86_64::GetMonitor()
{
ProcessSP base = CalculateProcess();
ProcessPOSIX *process = static_cast<ProcessPOSIX*>(base.get());
return process->GetMonitor();
}
ProcessELFCore doesn't, nor should it inherit from ProcessPOSIX and any call to GetMonitor() will fail for ELF core files.
Suggested cleanups:
- Make a register context class that is a base class that doesn't have any reading smarts, then make one that uses ProcessPOSIX and the has the GetMonitor() call, and one that gets its data straight from the core file.
llvm-svn: 186223
-Remove tracing of fork/vfork until we add support for tracing inferiors' children on Linux.
-Add trace exec option for ptrace so that we don't receive legacy SIGTRAP signals on execve calls.
-Add handling of SIGCHLD sent by kernel (for now, deliver the signal to the inferior).
llvm-svn: 182153
<rdar://problem/13594769>
Main changes in this patch include:
- cleanup plug-in interface and use ConstStrings for plug-in names
- Modfiied the BSD Archive plug-in to be able to pick out the correct .o file when .a files contain multiple .o files with the same name by using the timestamp
- Modified SymbolFileDWARFDebugMap to properly verify the timestamp on .o files it loads to ensure we don't load updated .o files and cause problems when debugging
The plug-in interface changes:
Modified the lldb_private::PluginInterface class that all plug-ins inherit from:
Changed:
virtual const char * GetPluginName() = 0;
To:
virtual ConstString GetPluginName() = 0;
Removed:
virtual const char * GetShortPluginName() = 0;
- Fixed up all plug-in to adhere to the new interface and to return lldb_private::ConstString values for the plug-in names.
- Fixed all plug-ins to return simple names with no prefixes. Some plug-ins had prefixes and most ones didn't, so now they all don't have prefixed names, just simple names like "linux", "gdb-remote", etc.
llvm-svn: 181631
- Eliminated the use of static for methods that read m_register_infos, so that these routines can be implemented in the base class.
- Eliminated m_register_infos in the base class because this is not used when derived classes call UpdateRegisterInfo.
- Also moved the namespace using declarations from headers to source files.
Thanks to Daniel and Samuel for their review feedback.
llvm-svn: 181538
- Required for platform-independant handling of general purpose registers (i.e. for core dumps).
Thanks to Samuel Jacob for this patch.
llvm-svn: 180878
- Adds unique enums for ymm registers to the ABI and the POSIX register context.
- Reworks the register context data structures to support a union of FXSAVE and XSAVE
--- Allows the same code base to deal with the FPU independent of the availability of AVX.
- Determine if AVX is supported by attempting to read XSAVE using ptrace.
--- Support an extended register set for avx registers if available.
- Provide a mechanism to assemble/parse register halves into a single ymm buffer for use with RegisterValue.
--- Reworked Read/WriteRegister routines to read/write/parse ymm registers.
Adds tests for ymm register write with read-back, and expressions involving ymm registers.
- Tests vary depending on the availability of an avx register set.
Thanks to Daniel and Matt for their reviews.
llvm-svn: 180572
- All Linux logging channels now use a single global instance of lldb_private::Log, to handle the case of logging during process tear down.
- Also removed a single use of LogSP in FreeBSD and fixed a typo in a comment while reading through ProcessKDPLog.
Reviewed by Daniel Malea.
llvm-svn: 178242
- generate-vers.pl has to be called by cmake to generate the version number
- parallel builds not yet supported; dependency on clang must be explicitly specified
Tested on Linux.
- Building on Mac will require code-signing logic to be implemented.
- Building on Windows will require OS-detection logic and some selective directory inclusion
Thanks to Carlo Kok (who originally prepared these CMakefiles for Windows) and Ben Langmuir
who ported them to Linux!
llvm-svn: 175795
- remove unused members
- add NO_PEDANTIC to selected Makefiles
- fix return values (removed NULL as needed)
- disable warning about four-char-constants
- remove unneeded const from operator*() declaration
- add missing lambda function return types
- fix printf() with no format string
- change sizeof to use a type name instead of variable name
- fix Linux ProcessMonitor.cpp to be 32/64 bit friendly
- disable warnings emitted by swig-generated C++ code
Patch by Matt Kopec!
llvm-svn: 169645
- add new header lldb-python.h to be included before other system headers
- short term fix (eventually python dependencies must be cleaned up)
Patch by Matt Kopec!
llvm-svn: 169341
- Handle EINVAL return code from ptrace(GETSIGINFO, ...): not an error, but 'group-stop' state on Linux
- propagate SIGSTOP to inferior in above case
- this commit resolves the failure in expression_command/timeout testcase
Thanks to Sean Callanan & Matt Kopec for helping debug this problem
llvm-svn: 168523
This patch fixes an issue where if lldb fails to attach to a process (ie. invalid pid) on Linux, the process monitor thread gets stuck waiting for a signal from the attach thread, which never comes due to not being signaled. It also implements StopOpThread which is used for both attach/launch cases as I'm not aware of any special handling needed for the attach case. Also, propagate 'Error' from the Detach function instead of using a bool.
llvm-svn: 166055
The attached patch adds support for debugging 32-bit processes when running a 64-bit lldb on an x86_64 Linux system.
Making this work required two basic changes:
1) Getting lldb to report that it could debug 32-bit processes
2) Changing an assumption about how ptrace works when debugging cross-platform
For the first change, I took a conservative approach and only enabled this for x86_64 Linux platforms. It may be that the change I made in Host.cpp could be extended to other 64-bit Linux platforms, but I'm not familiar enough with the other platforms to know for sure.
For the second change, the Linux ProcessMonitor class was assuming that ptrace(PTRACE_[PEEK|POKE]DATA...) would read/write a "word" based on the child process word size. However, the ptrace documentation says that the "word" size read or written is "determined by the OS variant." I verified experimentally that when ptracing a 32-bit child from a 64-bit parent a 64-bit word is read or written.
llvm-svn: 163398
This patch combines common code from Linux and FreeBSD into
a new POSIX platform. It also contains fixes for 64bit FreeBSD.
The patch is based on changes by Mark Peek <mp@FreeBSD.org> and
"K. Macy" <kmacy@freebsd.org> in their github repo located at
https://github.com/fbsd/lldb.
llvm-svn: 147613
a new POSIX platform. It also contains fixes for 64bit FreeBSD.
The patch is based on changes by Mark Peek <mp@FreeBSD.org> and
"K. Macy" <kmacy@freebsd.org> in their github repo located at
https://github.com/fbsd/lldb.
llvm-svn: 147609
Joel Dillon that fixed 64 debugging for Linux.
I also added a patch to fix up the ProcessLinux::DoLaunch() to be up to date.
I wasn't able to verify it compiles, but it should b really close.
llvm-svn: 143772
Removed ifdeffed out functions and added the implementation of
WriteRegister for x86_64 architecture.
Signed-off-by: Johnny Chen <johnny.chen@apple.com>
llvm-svn: 131696
solve the build break due to the lack of this method.
It also propose a solution to the API changes in RegisterContext.
I upgraded also the the python version in the makefile. My linux
installation has python2.7 and AFAIK also the latest ubuntu
has this version of python so maybe is worth upgrading.
Patch by Marco Minutoli <mminutoli@gmail.com>
[Note: I had to hand merge in the diffs since patch thinks it is a corrupt patch.]
llvm-svn: 131313
This patch upgrades the Linux process plugin to handle a larger range of signal
events. For example, we can detect when the inferior has "crashed" and why,
interrupt a running process, deliver an arbitrary signal, and so on.
llvm-svn: 128547
it should live and the lldb_private::Process takes care of managing the
auto pointer to the dynamic loader instance.
Also, now that the ArchSpec contains the target triple, we are able to
correctly set the Target architecture in DidLaunch/DidAttach in the subclasses,
and then the lldb_private::Process will find the dynamic loader plug-in
by letting the dynamic loader plug-ins inspect the arch/triple in the target.
So now the ProcessGDBRemote plug-in is another step closer to be purely
process/platform agnostic.
I updated the ProcessMacOSX and the ProcessLinux plug-ins accordingly.
llvm-svn: 125650
takes separate file handles for stdin, stdout, and stder and also allows for
the working directory to be specified.
Added support to "process launch" to a new option: --working-dir=PATH. We
can now set the working directory. If this is not set, it defaults to that
of the process that has LLDB loaded. Added the working directory to the
host LaunchInNewTerminal function to allows the current working directory
to be set in processes that are spawned in their own terminal. Also hooked this
up to the lldb_private::Process and all mac plug-ins. The linux plug-in had its
API changed, but nothing is making use of it yet. Modfied "debugserver" and
"darwin-debug" to also handle the current working directory options and modified
the code in LLDB that spawns these tools to pass the info along.
Fixed ProcessGDBRemote to properly pass along all file handles for stdin, stdout
and stderr.
After clearing the default values for the stdin/out/err file handles for
process to be NULL, we had a crasher in UserSettingsController::UpdateStringVariable
which is now fixed. Also fixed the setting of boolean values to be able to
be set as "true", "yes", "on", "1" for true (case insensitive) and "false", "no",
"off", or "0" for false.
Fixed debugserver to properly handle files for STDIN, STDOUT and STDERR that are not
already opened. Previous to this fix debugserver would only correctly open and dupe
file handles for the slave side of a pseudo terminal. It now correctly handles
getting STDIN for the inferior from a file, and spitting STDOUT and STDERR out to
files. Also made sure the file handles were correctly opened with the NOCTTY flag
for terminals.
llvm-svn: 124060
This patch removes a potential race condition between a process monitor thread
and its parent waiting to interrogate the success/failure of the launch.
llvm-svn: 123803
The previous implementation of HardwareSingleStep wrongly resumed the thread and
single-stepped over the next instruction. Use the proper call to ProcessMonitor.
llvm-svn: 123800
Previous version simply resumed the associated thread to single step over a
single instruction which is not the intended semantics for this method. Set the
appropriate bit in the rflags register instead.
llvm-svn: 123799
This patch is enough to have shared objects recognized by LLDB. We can handle
position independent executables. We can handle dynamically loaded modules
brought in via dlopen.
The DYLDRendezvous class provides an interface to a structure present in the
address space of ELF-based processes. This structure provides the address of a
function which is called by the linker each time a shared object is loaded and
unloaded (thus a breakpoint at that address will let LLDB intercept such
events), a list of entries describing the currently loaded shared objects, plus
a few other things.
On Linux, processes are brought up with an auxiliary vector on the stack. One
element in this vector contains the (possibly dynamic) entry address of the
process. One does not need to walk the stack to find this information as it is
also available under /proc/<pid>/auxv. The new AuxVector class provides a
convenient read-only view of this auxiliary vector information. We use the
dynamic entry address and the address as specified in the object file to compute
the actual load address of the inferior image. This strategy works for both
normal executables and PIE's.
llvm-svn: 123592
This code was a temporary workaround due to the lack of a dynamic loader plugin
for the Linux platform that has bit rotted over time. Instead of replacing this
hack with another a proper plugin will be developed instead.
llvm-svn: 122837
The Unwind and RegisterContext subclasses still need
to be finished; none of this code is used by lldb at
this point (unless you call into it by hand).
The ObjectFile class now has an UnwindTable object.
The UnwindTable object has a series of FuncUnwinders
objects (Function Unwinders) -- one for each function
in that ObjectFile we've backtraced through during this
debug session.
The FuncUnwinders object has a few different UnwindPlans.
UnwindPlans are a generic way of describing how to find
the canonical address of a given function's stack frame
(the CFA idea from DWARF/eh_frame) and how to restore the
caller frame's register values, if they have been saved
by this function.
UnwindPlans are created from different sources. One source is the
eh_frame exception handling information generated by the compiler
for unwinding an exception throw. Another source is an assembly
language inspection class (UnwindAssemblyProfiler, uses the Plugin
architecture) which looks at the instructions in the funciton
prologue and describes the stack movements/register saves that are
done.
Two additional types of UnwindPlans that are worth noting are
the "fast" stack UnwindPlan which is useful for making a first
pass over a thread's stack, determining how many stack frames there
are and retrieving the pc and CFA values for each frame (enough
to create StackFrameIDs). Only a minimal set of registers is
recovered during a fast stack walk.
The final UnwindPlan is an architectural default unwind plan.
These are provided by the ArchDefaultUnwindPlan class (which uses
the plugin architecture). When no symbol/function address range can
be found for a given pc value -- when we have no eh_frame information
and when we don't have a start address so we can't examine the assembly
language instrucitons -- we have to make a best guess about how to
unwind. That's when we use the architectural default UnwindPlan.
On x86_64, this would be to assume that rbp is used as a stack pointer
and we can use that to find the caller's frame pointer and pc value.
It's a last-ditch best guess about how to unwind out of a frame.
There are heuristics about when to use one UnwindPlan versues the other --
this will all happen in the still-begin-written UnwindLLDB subclass of
Unwind which runs the UnwindPlans.
llvm-svn: 113581
This component is still at an early stage, but allows for simple
breakpoint/step-over operations and basic process control.
The makefiles are set up to build the plugin under Linux only.
llvm-svn: 109318
Todd Fiala