When a program maps one of its own modules for reading, and then
crashes, breakpad can emit two entries for that module in the
ModuleList. We have logic to identify this case by checking permissions
on mapped memory regions and report just the module with an executable
region. As currently written, though, the check is asymmetric -- the
entry with the executable region must be the second one encountered for
the preference to kick in.
This change makes the logic symmetric, so that the first-encountered
module will similarly be preferred if it has an executable region but
the second-encountered module does not. This happens for example when
the module in question is the executable itself, which breakpad likes to
report first -- we need to ignore the other entry for that module when
we see it later, even though it may be mapped at a lower virtual
address.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D94629
Add a 'can_connect' parameter to Process plugin initialization, and use
it to filter plugins to these capable of remote connections. This is
used to prevent 'process connect' from picking up a plugin that can only
be used locally, e.g. the legacy FreeBSD plugin.
Differential Revision: https://reviews.llvm.org/D91810
This extends the "memory region" command to
show tagged regions on AArch64 Linux when the MTE
extension is enabled.
(lldb) memory region the_page
[0x0000fffff7ff8000-0x0000fffff7ff9000) rw-
memory tagging: enabled
This is done by adding an optional "flags" field to
the qMemoryRegion packet. The only supported flag is
"mt" but this can be extended.
This "mt" flag is read from /proc/{pid}/smaps on Linux,
other platforms will leave out the "flags" field.
Where this "mt" flag is received "memory region" will
show that it is enabled. If it is not or the target
doesn't support memory tagging, the line is not shown.
(since majority of the time tagging will not be enabled)
Testing is added for the existing /proc/{pid}/maps
parsing and the new smaps parsing.
Minidump parsing has been updated where needed,
though it only uses maps not smaps.
Target specific tests can be run with QEMU and I have
added MTE flags to the existing helper scripts.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D87442
Depends on D90490.
The stop command is simple and invokes the new method Trace::StopTracingThread(thread).
On the other hand, the start command works by delegating its implementation to a CommandObject provided by the Trace plugin. This is necessary because each trace plugin needs different options for this command. There's even the chance that a Trace plugin can't support live tracing, but instead supports offline decoding and analysis, which means that "thread trace dump instructions" works but "thread trace start" doest. Because of this and a few other reasons, it's better to have each plugin provide this implementation.
Besides, I'm using the GetSupportedTraceType method introduced in D90490 to quickly infer what's the trace plug-in that works for the current process.
As an implementation note, I moved CommandObjectIterateOverThreads to its header so that I can use it from the IntelPT plugin. Besides, the actual start and stop logic for intel-pt is not part of this diff.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D90729
When opening a minidump, we might discover that it reports a UUID for a
module that doesn't match the build ID, but rather a hash of the .text
section (according to either of two different hash functions, used by
breakpad and Facebook respectively). The current logic searches for a
module by filename only to check the hash; this change updates it to
first search by directory+filename. This is important when the
directory specified in the minidump must be interpreted relative to a
user-provided sysoort, as the leaf directory won't be in the search path
in that case.
Also add a regression test; without this change, module validation fails
because we have just the placeholder module which reports as its path
the platform path in the minidump.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D89155
Breakpad creates minidump files that can a module loaded multiple times. We found that when a process mmap's the object file for a library, this can confuse breakpad into creating multiple modules in the module list. This patch fixes the GetFilteredModules() to check the linux maps for permissions and use the one that has execute permissions. Typically when people mmap a file into memory they don't map it as executable. This helps people to correctly load minidump files for post mortem analysis.
Differential Revision: https://reviews.llvm.org/D86375
Breakpad will always have a UUID for binaries when it creates minidump files. If an ELF files has a GNU build ID, it will use that. If it doesn't, it will create one by hashing up to the first 4096 bytes of the .text section. LLDB was not able to load these binaries even when we had the right binary because the UUID didn't match. LLDB will use the GNU build ID first as the main UUID for a binary and fallback onto a 8 byte CRC if a binary doesn't have one. With this fix, we will check for the Breakpad hash or the Facebook hash (a modified version of the breakpad hash that collides a bit less) and accept binaries when these hashes match.
Differential Revision: https://reviews.llvm.org/D86261
LLDB has a few different styles of header guards and they're not very
consistent because things get moved around or copy/pasted. This patch
unifies the header guards across LLDB and converts everything to match
LLVM's style.
Differential revision: https://reviews.llvm.org/D74743
This is a step towards making the initialize and terminate calls be
generated by CMake, which in turn is towards making it possible to
disable plugins at configuration time.
Differential revision: https://reviews.llvm.org/D74245
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).
This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).
Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73258
Summary:
Normally, on linux we retrieve the process ID from the LinuxProcStatus
stream (which is just the contents of /proc/%d/status pseudo-file).
However, this stream is not strictly required (it's a breakpad
extension), and we are encountering a fair amount of minidumps which do
not have it present. It's not clear whether this is the case with all
these minidumps, but the two known situations where this stream can be
missing are:
- /proc filesystem not mounted (or something to that effect)
- process crashing after exhausting (almost) all file descriptors (so
the minidump writer may not be able to open the /proc file)
Since this is a corner case which will become less and less relevant
(crashpad-generated minidumps should not suffer from this problem), I
work around this problem by hardcoding the PID to 1 in these cases.
The same thing is done by the gdb plugin when talking to a stub which
does not report a process id (e.g. a hardware probe).
Reviewers: jingham, clayborg
Subscribers: markmentovai, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70238
Summary:
Not all minidumps contain information about memory permissions. However,
it is still important to know which regions of memory contain
potentially executable code. This is particularly important for
unwinding on win32, as the default unwind method there relies on
scanning the stack for things which "look like" code pointers.
This patch enables ProcessMinidump to reconstruct the likely permissions
of memory regions using the sections of loaded object files. It only
does this if we don't have a better source (memory info list stream, or
linux /proc/maps) for this information, and only if the information in
the object files does not conflict with the information in the minidump.
Theoretically that last bit could be improved, since the permissions
obtained from the MemoryList streams is also only a very rough guess,
but it did not seem worthwhile to complicate the implementation because
of that because there will generally be no overlap in practice as the
MemoryList will contain the stack contents and not any module data.
The patch adds a test checking that the module section permissions are
entered into the memory region list, and also a test which demonstrate
that now the unwinder is able to correctly find return addresses even in
minidumps without memory info list streams.
There's one TODO left in this patch, which is that the "memory region"
output does not give any indication about the "don't know" values of
memory region permissions (it just prints them as if they permission bit
was set). I address this in a follow up.
Reviewers: amccarth, clayborg
Subscribers: mgrang, lldb-commits
Differential Revision: https://reviews.llvm.org/D69105
The architecture enum contains two kinds of contstants: the "official" ones
defined by Microsoft, and unofficial constants added by breakpad to cover the
architectures not described by the first ones.
Up until now, there was no big need to differentiate between the two. However,
now that Microsoft has defined
https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info
a constant for ARM64, we have a name clash.
This patch renames all breakpad-defined constants with to include the prefix
"BP_". This frees up the name "ARM64", which I'll re-introduce with the new
"official" value in a follow-up patch.
Reviewers: amccarth, clayborg
Subscribers: lldb-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D69285
The goal of this refactor is to enable ProcessMinidump to take into
account the loaded modules and their sections when computing the
permissions of various ranges of memory, as discussed in D66638.
This patch moves some of the responsibility for computing the ranges
from MinidumpParser into ProcessMinidump. MinidumpParser still does the
parsing, but ProcessMinidump becomes responsible for answering the
actual queries about memory ranges. This will enable it (in a follow-up
patch) to augment the information obtained from the parser with data
obtained from actual object files.
The changes in the actual code are fairly straight-forward and just
involve moving code around. MinidumpParser::GetMemoryRegions is renamed
to BuildMemoryRegions to emphasize that it does no caching. The only new
thing is the additional bool flag returned from this function. This
indicates whether the returned regions describe all memory mapped into
the target process. Data obtained from /proc/maps and the MemoryInfoList
stream is considered to be exhaustive. Data obtained from Memory(64)List
is not. This will be used to determine whether we need to augment the
data or not.
This reshuffle means that it is no longer possible/easy to test some of
this code via unit tests, as constructing a ProcessMinidump instance is
hard. Instead, I update the unit tests to only test the parsing of the
actual data, and test the answering of queries through a lit test using
the "memory region" command. The patch also includes some tweaks to the
MemoryRegion class to make the unit tests easier to write.
Reviewers: amccarth, clayborg
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D69035
Summary:
The minidump exception stream can report an exception record with
signal 0. If we try to create a stop reason with signal zero, processing
of the stop event won't find anything, and the debugger will hang.
So, simply early-out of RefreshStateAfterStop in this case.
Also set the UnixSignals object in DoLoadCore as is done for
ProcessElfCore.
Reviewers: labath, clayborg, jfb
Reviewed By: labath, clayborg
Subscribers: dexonsmith, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68096
llvm-svn: 375244
Summary: The types defined for it in LLDB are now redundant with core types.
Reviewers: labath, clayborg
Reviewed By: clayborg
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68658
llvm-svn: 375243
Stack unwinding was sometimes failing when trying to unwind stacks in 32 bit ARM. I discovered this was because the EH frame register numbers were not set. This patch fixes this issue and adds a unit test to verify this doesn't regress.
Differential Revision: https://reviews.llvm.org/D68088
llvm-svn: 374246
Summary: The PlaceholderObjectFile has an assert in SetLoadAddress that fires if "m_base == value" is not true. To avoid this, we create check that the base address matches, and if it doesn't we clear the module that was found using the UUID so that we create a new PlaceholderObjectFile. Added a test to cover this issue.
Reviewers: labath, aadsm, dvlahovski
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68106
llvm-svn: 374242
This recommits r368416, which was reverted in r368838 because of test
failures under ASAN. These have been dealt with by llvm r369370.
The original commit message was:
When opening a minidump, we were failing to find an executable because
we were searching for i386-unknown-windows, whereas we recognize the
pe/coff files as i386-pc-windows. This fixes the triple computation code
in the minidump parser to match pe/coff, and adds an appropriate test.
NB: I'm not sure setting the vendor to "pc" is really correct for
arm(64) windows, but right now that seems to match what we do in the
pe/coff case (ArchSpec.cpp:935).
Reviewers: clayborg, amccarth
Subscribers: javed.absar, kristof.beyls, rnk, markmentovai, lldb-commits
Differential Revision: https://reviews.llvm.org/D65955
llvm-svn: 369523
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368933
Although there is nothing wrong with this patch, the test added here
uncovers a problem in other parts of the code which cause the test to
fail when running under asan. Reverting the patch until I can fix the
underlying issue(s).
This reverts commit r368416.
llvm-svn: 368838
Summary:
When opening a minidump, we were failing to find an executable because
we were searching for i386-unknown-windows, whereas we recognize the
pe/coff files as i386-pc-windows. This fixes the triple computation code
in the minidump parser to match pe/coff, and adds an appropriate test.
NB: I'm not sure setting the vendor to "pc" is really correct for
arm(64) windows, but right now that seems to match what we do in the
pe/coff case (ArchSpec.cpp:935).
Reviewers: clayborg, amccarth
Subscribers: javed.absar, kristof.beyls, rnk, markmentovai, lldb-commits
Differential Revision: https://reviews.llvm.org/D65955
llvm-svn: 368416
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]
This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.
This is the command I ran and I to fix and format the code base:
```
run-clang-tidy.py \
-header-filter='.*' \
-checks='-*,modernize-use-nullptr' \
-fix ~/dev/llvm-project/lldb/.* \
-format \
-style LLVM \
-p ~/llvm-builds/debug-ninja-gcc
```
NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.
NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.
Reviewers: martong, espindola, shafik, #lldb, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D61847
llvm-svn: 361484
This can cause us to return paths to files on the local filesystem even
if we don't end up using that file (for instance because the file is not
a real module).
llvm-svn: 360432
Summary:
According to [C128] "Virtual functions should specify exactly one
of `virtual`, `override`, or `final`", I've added override where a
virtual function is overriden but the explicit `override` keyword
was missing. Whenever both `virtual` and `override` were specified,
I removed `virtual`. As C.128 puts it:
> [...] writing more than one of these three is both redundant and
> a potential source of errors.
I anticipate a discussion about whether or not to add `override` to
destructors but I went for it because of an example in [ISOCPP1000].
Let me repeat the comment for you here:
Consider this code:
```
struct Base {
virtual ~Base(){}
};
struct SubClass : Base {
~SubClass() {
std::cout << "It works!\n";
}
};
int main() {
std::unique_ptr<Base> ptr = std::make_unique<SubClass>();
}
```
If for some odd reason somebody removes the `virtual` keyword from the
`Base` struct, the code will no longer print `It works!`. So adding
`override` to destructors actively protects us from accidentally
breaking our code at runtime.
[C128]: https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c128-virtual-functions-should-specify-exactly-one-of-virtual-override-or-final
[ISOCPP1000]: https://github.com/isocpp/CppCoreGuidelines/issues/1000#issuecomment-476951555
Reviewers: teemperor, JDevlieghere, davide, shafik
Reviewed By: teemperor
Subscribers: kwk, arphaman, kadircet, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61440
llvm-svn: 359868
Address an ambiguity between lldb_private::Thread and
llvm::minidump::Thread. Follow-up to llvm r359762 (which introduced the
second type).
llvm-svn: 359765
Summary:
D59433 added code to swap bytes UUIDs coming from minidump files, but
only enabled it for apple platforms. Based on my research, I believe
this is the correct thing to do for windows as well, as the natural way
of printing U(G)UIDs on this platforms is to print the first three
components as (4 or 2)-byte integers printed in natural (big-endian)
order. This makes the UUID string coming out of lldb match the strings
produced by other windows tools.
The decision to byte-swap the age field is somewhat arbitrary, because
the age field is usually printed separately from the file GUID (and
often in decimal). However, for our purposes (telling whether two files
are identical), including it in the UUID is correct, and printing it in
big-endian makes it easier to recognize the age value.
This also makes the UUIDs generated here (almost) match up with the
UUIDs computed for breakpad symbol files
(BreakpadRecords.cpp:parseModuleId), which already implemented the
byte-swapping. The "almost" is here because ObjectFileBreakpad does not
swap the age field, but I'll fix that in a follow-up.
There is no UUID support in ObjectFileCOFF at the moment, but ideally
the algorithms used here and in ObjectFileCOFF should be in sync so that
object file matching works correctly.
Reviewers: clayborg, amccarth, markmentovai, asmith
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D60501
llvm-svn: 358169
In this patch, I just remove the structure definitions for the
ModuleList stream and the associated parsing code. The rest of the code
is converted to work with the definitions in llvm. NFC.
llvm-svn: 358070
Add a flag to control whether the ModulesDidLoad notification is
called when a module is added. If the notifications are disabled,
the caller must call ModulesDidLoad after adding all the new modules,
but postponing this notification until they're all batched up can
allow for better efficiency than notifying one-by-one.
Change the name of the ModuleList notifier functions that a subclass
can implement to start with 'Notify' to make it clear what they are.
Add a NotifyModulesRemoved.
Add header documentation for the changed/updated methods.
Added defaulted-value 'notify' argument to ModuleList Append,
AppendIfNeeded, and Remove because callers working with a local
ModuleList don't have an obvious idea of what notify means in this
context. When the ModuleList is a part of the Target class, the
notify behavior matters.
DynamicLoaderDarwin has been updated so that libraries being
added/removed are correctly batched up before notifications are
sent. Added the TestModuleLoadedNotifys.py test to run on
Darwin to test this.
<rdar://problem/48293064>
Differential Revision: https://reviews.llvm.org/D60172
llvm-svn: 357955
I also update the tests for SystemInfo parsing to use the yaml2minidump
capabilities in llvm instead of relying on checked-in binaries.
llvm-svn: 357896
This patch removes the lower layers of the minidump parsing code from
the MinidumpParser class, and replaces it with the minidump parser in
llvm.
Not all functionality is already avaiable in the llvm class, but it is
enough for us to be able to stop enumerating streams manually, and rely
on the minidump directory parsing code from the llvm class.
This also removes some checked-in binaries which were used to test error
handling in the parser, as the error handling is now done (and tested)
in llvm. Instead I just add one test that ensures we correctly propagate
the errors reported by the llvm parser. The input for this test can be
written in yaml instead of a checked-in binary.
llvm-svn: 357748
Allow partial UUID matching in Minidump core file plug-in
Breakpad had bugs in earlier versions where it would take a 20 byte ELF build ID and put it into the minidump file as a 16 byte PDB70 UUID with an age of zero. This would make it impossible to do postmortem debugging with one of these older minidump files.
This fix allows partial matching of UUIDs. To do this we first try and match with the full UUID value, and then fall back to removing the original directory path from the module specification and we remove the UUID requirement, and then manually do the matching ourselves. This allows scripts to find symbols files using a symbol server, place them all in a directory, use the "setting set target.exec-search-paths" setting to specify the directory, and then load the core file. The Target::GetSharedModule() can then find the correct file without doing any other matching and load it.
Tests were added to cover a partial UUID match where the breakpad file has a 16 byte UUID and the actual file on disk has a 20 byte UUID, both where the first 16 bytes match, and don't match.
Differential Revision: https://reviews.llvm.org/D60001
llvm-svn: 357603
See discussion in https://reviews.llvm.org/D60001.
Revert Clean up windows build bot.
This reverts r357504 (git commit 380c2420ec)
Revert Fix buildbot where paths were not matching up.
This reverts r357491 (git commit 5050586860)
Revert Allow partial UUID matching in Minidump core file plug-in
This reverts r357482 (git commit 838bba9c34)
llvm-svn: 357534
Breakpad had bugs in earlier versions where it would take a 20 byte ELF build ID and put it into the minidump file as a 16 byte PDB70 UUID with an age of zero. This would make it impossible to do postmortem debugging with one of these older minidump files.
This fix allows partial matching of UUIDs. To do this we first try and match with the full UUID value, and then fall back to removing the original directory path from the module specification and we remove the UUID requirement, and then manually do the matching ourselves. This allows scripts to find symbols files using a symbol server, place them all in a directory, use the "setting set target.exec-search-paths" setting to specify the directory, and then load the core file. The Target::GetSharedModule() can then find the correct file without doing any other matching and load it.
Tests were added to cover a partial UUID match where the breakpad file has a 16 byte UUID and the actual file on disk has a 20 byte UUID, both where the first 16 bytes match, and don't match.
Differential Revision: https://reviews.llvm.org/D60001
llvm-svn: 357482
This re-commits r354263, which was because it uncovered with handling of
modules with empty (zero) UUIDs. This would cause us to treat two
modules as intentical even though they were not. This caused an assert
in PlaceholderObjectFile::SetLoadAddress to fire, because we were trying
to load the module twice even though it was designed to be only loaded
at a specific address. (The same problem also existed with the previous
implementation, but it had no asserts to warn us about this.) These
issues have now been fixed in r356896.
windows bot. The issue there was that ObjectFilePECOFF vended its base
address through the incorrect interface. SymbolFilePDB depended on that,
which lead to assertion failures when SymbolFilePDB was attempting to
use the placeholder object files as a base. This has been fixed in
r354258
The original commit message was:
The reason this wasn't working was that ProcessMinidump was creating odd
object-file-less modules, and SymbolFileBreakpad required the module to
have an associated object file because it needed to get its base
address.
This fixes that by introducing a PlaceholderObjectFile to serve as a
dummy object file. The general idea for this is taken from D55142, but
I've reworked it a bit to avoid the need for the PlaceholderModule
class. Now that we have an object file, our modules are sufficiently
similar to regular modules that we can use the regular Module class
almost out of the box -- the only thing I needed to tweak was the
Module::CreateModuleFromObjectFile functon to set the module's FileSpec
in addition to it's architecture. This wasn't needed for ObjectFileJIT
(the other user of CreateModuleFromObjectFile), but it shouldn't hurt it
either, and the change seems like a straightforward extension of this
function.
Reviewers: clayborg, lemo, amccarth
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D57751
llvm-svn: 357060
This is the next step in moving the minidump parsing into llvm. I remove
the minidump structures already defined in the llvm Object library and
convert our parser to use those. NFC.
llvm-svn: 356992
Raphael Isemann