Commit Graph

4 Commits

Author SHA1 Message Date
Pavel Labath aaff480c68 Object/Minidump: Add support for reading the ModuleList stream
Summary:
The ModuleList stream consists of an integer giving the number of
entries in the list, followed by the list itself. Each entry in the list
describes a module (dynamically loaded objects which were loaded in the
process when it crashed (or when the minidump was generated).

The code for reading the list is relatively straight-forward, with a
single gotcha. Some minidump writers are emitting padding after the
"count" field in order to align the subsequent list on 8 byte boundary
(this depends on how their ModuleList type was defined and the native
alignment of various types on their platform). Fortunately, the minidump
format contains enough redundancy (in the form of the stream length
field in the stream directory), which allows us to detect this situation
and correct it.

This patch just adds the ability to parse the stream. Code for
conversion to/from yaml will come in a follow-up patch.

Reviewers: zturner, amccarth, jhenderson, clayborg

Subscribers: jdoerfert, markmentovai, lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60121

llvm-svn: 357897
2019-04-08 09:57:29 +00:00
Pavel Labath 51d9fa0a22 Minidump: Add support for reading/writing strings
Summary:
Strings in minidump files are stored as a 32-bit length field, giving
the length of the string in *bytes*, which is followed by the
appropriate number of UTF16 code units. The string is also supposed to
be null-terminated, and the null-terminator is not a part of the length
field. This patch:
- adds support for reading these strings out of the minidump file (this
  implementation does not depend on proper null-termination)
- adds support for writing them to a minidump file
- using the previous two pieces implements proper (de)serialization of
  the CSDVersion field of the SystemInfo stream. Previously, this was
  only read/written as hex, and no attempt was made to access the
  referenced string -- now this string is read and written correctly.

The changes are tested via yaml2obj|obj2yaml round-trip as well as a
unit test which checks the corner cases of the string deserialization
logic.

Reviewers: jhenderson, zturner, clayborg

Subscribers: llvm-commits, aprantl, markmentovai, amccarth, lldb-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59775

llvm-svn: 357749
2019-04-05 08:06:26 +00:00
Pavel Labath 045b8544fd Fix two more issues with r356652
The first problem was a use-after-free in the tests (detected by asan
bots). The temporary array created for the "create" call is guaranteed
to live only until the end of the statement. The fix there is to store
the test data in a local variable to ensure it has the right lifetime

The second issue is broken BUILD_SHARED_LIBS build, which I fix by
adding the appropriate BinaryFormat dependency to the Object unit tests.

llvm-svn: 356655
2019-03-21 10:21:55 +00:00
Pavel Labath 581d79a440 [Object] Add basic minidump support
Summary:
This patch adds basic support for reading minidump files. It contains
the definitions of various important minidump data structures (header,
stream directory), and of one minidump stream (SystemInfo). The ability
to read other streams will be added in follow-up patches. However, all
streams can be read even now as raw data, which means lldb's minidump
support (where this code is taken from) can be immediately rebased on
top of this patch as soon as it lands.

As we don't have any support for generating minidump files (yet), this
tests the code via unit tests with some small handcrafted binaries in
the form of c char arrays.

Reviewers: Bigcheese, jhenderson, zturner

Subscribers: srhines, dschuff, mgorny, fedor.sergeev, lemo, clayborg, JDevlieghere, aprantl, lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59291

llvm-svn: 356652
2019-03-21 09:18:59 +00:00