Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc, X86)
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Eric Blake ebeb0e46f8
qapi: Fix crash on missing alternate member of QAPI struct
If a QAPI struct has a mandatory alternate member which is not
present on input, the input visitor reports an error for the
missing alternate without setting the discriminator, but the
cleanup code for the struct still tries to use the dealloc
visitor to clean up the alternate.

Commit dbf11922 changed visit_start_alternate to set *obj to NULL
when an error occurs, where it was previously left untouched.
Thus, before the patch, the dealloc visitor is blindly trying to
cleanup whatever branch corresponds to (*obj)->type == 0 (that is,
QTYPE_NONE, because *obj still pointed to zeroed memory), which
selects the default branch of the switch and sets an error, but
this second error is ignored by the way the dealloc visitor is
used; but after the patch, the attempt to switch dereferences NULL.

When cleaning up after a partial object parse, we specifically
check for !*obj after visit_start_struct() (see gen_visit_object());
doing the same for alternates fixes the crash. Enhance the testsuite
to give coverage for both missing struct and missing alternate
members.

Also add an abort - we expect visit_start_alternate() to either set an
error or to set (*obj)->type to a valid QType that corresponds to
actual user input, and QTYPE_NONE should never be reachable from valid
input. Had the abort() been in place earlier, we might have noticed
the dealloc visitor dereferencing bogus zeroed memory prior to when
commit dbf11922 forced our hand by setting *obj to NULL and causing a
fault.

Test case:

{'execute':'blockdev-add', 'arguments':{'options':{'driver':'raw'}}}

The choice of 'driver':'raw' selects a BlockdevOptionsGenericFormat
struct, which has a mandatory 'file':'BlockdevRef' in QAPI. Since
'file' is missing as a sibling of 'driver', this should report a
graceful error rather than fault. After this patch, we are back to:

{"error": {"class": "GenericError", "desc": "Parameter 'file' is missing"}}

Generated code in qapi-visit.c changes as:

|@@ -2444,6 +2444,9 @@ void visit_type_BlockdevRef(Visitor *v,
| if (err) {
| goto out;
| }
|+ if (!*obj) {
|+ goto out_obj;
|+ }
| switch ((*obj)->type) {
| case QTYPE_QDICT:
| visit_start_struct(v, name, NULL, 0, &err);
|@@ -2459,10 +2462,13 @@ void visit_type_BlockdevRef(Visitor *v,
| case QTYPE_QSTRING:
| visit_type_str(v, name, &(*obj)->u.reference, &err);
| break;
|+ case QTYPE_NONE:
|+ abort();
| default:
| error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
| "BlockdevRef");
| }
|+out_obj:
| visit_end_alternate(v);

Backports commit 9b4e38fe6a35890bb1d995316d7be08de0b30ee5 from qemu
2018-02-24 23:53:29 -05:00
bindings link to Crystal binding 2017-12-23 00:26:40 +08:00
docs Added note about installing tests dependencies on Mac OS X. Added note about tests failing when required architecture support is disabled in build. (#908) 2017-10-12 19:56:00 +08:00
include include: Move RAMList to ramlist.h 2018-02-20 08:47:51 -05:00
msvc exec: add tb_hash_func5, derived from xxhash 2018-02-24 17:36:35 -05:00
qemu qapi: Fix crash on missing alternate member of QAPI struct 2018-02-24 23:53:29 -05:00
samples Fixed register mistake in comments (#894) 2017-09-17 16:40:01 +07:00
tests add 64-bit test demonstrating setting MSRs and FS/GS segments (#901) 2017-09-29 04:26:23 +08:00
.appveyor.yml MSYS test (#852) 2017-06-25 10:11:35 +08:00
.gitignore arm64eb: add support for ARM64 big endian. 2017-04-24 23:30:01 +08:00
.travis.yml use new travis osx image and brew (#935) 2018-01-05 10:29:49 +08:00
AUTHORS.TXT import 2015-08-21 15:04:50 +08:00
Brewfile Update Brewfile 2017-09-30 17:36:44 +07:00
ChangeLog update ChangeLog 2017-04-20 13:28:02 +08:00
config.mk Fix document file extension 2016-08-08 17:33:49 +09:00
COPYING import 2015-08-21 15:04:50 +08:00
COPYING.LGPL2 LGPL2 for all header files under include/unicorn/ 2017-12-16 10:08:42 +08:00
COPYING_GLIB glib_compat: add COPYING_GLIB 2016-12-27 10:15:08 +08:00
CREDITS.TXT update CREDITS.TXT 2017-04-25 12:56:47 +08:00
install-cmocka-linux.sh Start moving examples in S files (#851) 2017-06-25 10:14:22 +08:00
list.c callback to count number of instructions in uc_emu_start() should be executed first. fix #727 2017-06-16 13:22:38 +08:00
make.sh Added MSVC support for arm64eb. 2017-04-25 14:23:58 +10:00
Makefile crypto: introduce new module for computing hash digests 2018-02-17 15:23:17 -05:00
msvc.bat add msvc.bat 2017-04-21 15:35:40 +08:00
pkgconfig.mk bump extra version to 2 2017-04-21 15:30:40 +08:00
README.md add Clojure 2017-12-23 00:32:33 +08:00
uc.c uc: Move hook freeing code to its own function 2018-02-22 20:00:32 -05:00
windows_export.bat Make the call out to visual studio extremely resilient 2017-01-02 03:32:48 -08:00

Unicorn Engine

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Build Status Build status

Unicorn is a lightweight, multi-platform, multi-architecture CPU emulator framework based on QEMU.

Unicorn offers some unparalleled features:

  • Multi-architecture: ARM, ARM64 (ARMv8), M68K, MIPS, SPARC, and X86 (16, 32, 64-bit)
  • Clean/simple/lightweight/intuitive architecture-neutral API
  • Implemented in pure C language, with bindings for Crystal, Clojure, Visual Basic, Perl, Rust, Ruby, Python, Java, .NET, Go, Delphi/Free Pascal and Haskell.
  • Native support for Windows & *nix (with Mac OSX, Linux, *BSD & Solaris confirmed)
  • High performance via Just-In-Time compilation
  • Support for fine-grained instrumentation at various levels
  • Thread-safety by design
  • Distributed under free software license GPLv2

Further information is available at http://www.unicorn-engine.org

License

This project is released under the GPL license.

Compilation & Docs

See docs/COMPILE.md file for how to compile and install Unicorn.

More documentation is available in docs/README.md.

Contact

Contact us via mailing list, email or twitter for any questions.

Contribute

If you want to contribute, please pick up something from our Github issues.

We also maintain a list of more challenged problems in a TODO list.

CREDITS.TXT records important contributors of our project.