Returning a partial object on error is an invitation for a careless
caller to leak memory. We already fixed things in an earlier
patch to guarantee NULL if visit_start fails ("qapi: Guarantee
NULL obj on input visitor callback error"), but that does not
help the case where visit_start succeeds but some other failure
happens before visit_end, such that we leak a partially constructed
object outside visit_type_FOO(). As no one outside the testsuite
was actually relying on these semantics, it is cleaner to just
document and guarantee that ALL pointer-based visit_type_FOO()
functions always leave a safe value in *obj during an input visitor
(either the new object on success, or NULL if an error is
encountered), so callers can now unconditionally use
qapi_free_FOO() to clean up regardless of whether an error occurred.
The decision is done by adding visit_is_input(), then updating the
generated code to check if additional cleanup is needed based on
the type of visitor in use.
Note that we still leave *obj unchanged after a scalar-based
visit_type_FOO(); I did not feel like auditing all uses of
visit_type_Enum() to see if the callers would tolerate a specific
sentinel value (not to mention having to decide whether it would
be better to use 0 or ENUM__MAX as that sentinel).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The semantics of the list visit are somewhat baroque, with the
following pseudocode when FooList is used:
start()
for (prev = head; cur = next(prev); prev = &cur) {
visit(&cur->value)
}
Note that these semantics (advance before visit) requires that
the first call to next() return the list head, while all other
calls return the next element of the list; that is, every visitor
implementation is required to track extra state to decide whether
to return the input as-is, or to advance. It also requires an
argument of 'GenericList **' to next(), solely because the first
iteration might need to modify the caller's GenericList head, so
that all other calls have to do a layer of dereferencing.
Thankfully, we only have two uses of list visits in the entire
code base: one in spapr_drc (which completely avoids
visit_next_list(), feeding in integers from a different source
than uint8List), and one in qapi-visit.py. That is, all other
list visitors are generated in qapi-visit.c, and share the same
paradigm based on a qapi FooList type, so we can refactor how
lists are laid out with minimal churn among clients.
We can greatly simplify things by hoisting the special case
into the start() routine, and flipping the order in the loop
to visit before advance:
start(head)
for (tail = *head; tail; tail = next(tail)) {
visit(&tail->value)
}
With the simpler semantics, visitors have less state to track,
the argument to next() is reduced to 'GenericList *', and it
also becomes obvious whether an input visitor is allocating a
FooList during visit_start_list() (rather than the old way of
not knowing if an allocation happened until the first
visit_next_list()). As a minor drawback, we now allocate in
two functions instead of one, and have to pass the size to
both functions (unless we were to tweak the input visitors to
cache the size to start_list for reuse during next_list, but
that defeats the goal of less visitor state).
The signature of visit_start_list() is chosen to match
visit_start_struct(), with the new parameters after 'name'.
The spapr_drc case is a virtual visit, done by passing NULL for
list, similarly to how NULL is passed to visit_start_struct()
when a qapi type is not used in those visits. It was easy to
provide these semantics for qmp-output and dealloc visitors,
and a bit harder for qmp-input (several prerequisite patches
refactored things to make this patch straightforward). But it
turned out that the string and opts visitors munge enough other
state during visit_next_list() to make it easier to just
document and require a GenericList visit for now; an assertion
will remind us to adjust things if we need the semantics in the
future.
Several pre-requisite cleanup patches made the reshuffling of
the various visitors easier; particularly the qmp input visitor.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
As shown in the previous commit, the string input visitor was
treating bogus input as an empty list rather than an error.
Fix parse_str() to set errp, then the callers to exit early if
an error was reported.
Meanwhile, fix the testsuite to use the generated
qapi_free_int16List() instead of rolling our own, and to
validate the fixed behavior, while at the same time documenting
one more change that we'd like to make in a later patch (a
failed visit_start_list should guarantee a NULL pointer,
regardless of what things were on input).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-23-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Add two negative tests, one for int and one for int16List. The latter
exposes a bug: nonsensical input results in an empty list instead of
an error.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461325048-14122-1-git-send-email-armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-22-git-send-email-eblake@redhat.com>
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.
Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error. So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().
Generated code in qapi-visit.c has diffs resembling:
|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
| goto out_obj;
| }
| visit_type_ACPIOSTInfo_members(v, obj, &err);
|- error_propagate(errp, err);
|- err = NULL;
|+ if (err) {
|+ goto out_obj;
|+ }
|+ visit_check_struct(v, &err);
| out_obj:
|- visit_end_struct(v, &err);
|+ visit_end_struct(v);
| out:
and in qapi-event.c:
@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
| visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, ¶m, &err);
|- visit_end_struct(v, err ? NULL : &err);
|+ if (!err) {
|+ visit_check_struct(v, &err);
|+ }
|+ visit_end_struct(v);
| if (err) {
| goto out;
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Tighten assertions in the QMP output visitor, so that:
- qmp_output_get_qobject() can only be called after pairing a
visit_end_* for every visit_start_* (rather than allowing it on
a partially built object)
- qmp_output_get_qobject() cannot be called unless at least one
visit_type_* or visit_start/visit_end pair has occurred since
creation/reset (the accidental return of NULL fixed by commit
ab8bf1d7 would have been much easier to diagnose)
- ensure that we are encountering the expected object or list
type, to provide protection against mismatched push(struct)/
pop(list) or push(list)/pop(struct), similar to the qmp-input
protection added in commit bdd8e6b5.
- ensure that except for the root, 'name' is non-null inside a
dict, and NULL inside a list (this may need changing later if
we add "name.0" support for better error messages for a list,
but for now it makes sure all users are at least consistent)
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The testsuite was the only client that attempted to reuse a
QmpOutputVisitor for a second visit after encountering an
error and/or calling qmp_output_get_qobject() on a first
visit. The next patch is about to tighten the semantics to
be one-shot usage of the visitor, like all other visitors
(which will enable further simplifications down the road).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1462854006-24658-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Now that the QMP output visitor supports an explicit null
output, we should utilize it to make it easier to diagnose
the difference between a missing fdt ('null') vs. a
present-but-empty one ('{}').
(Note that this reverts the behavior of commit ab8bf1d, taking
us back to the behavior of commit 6c2f9a1 [which in turn
stemmed from a crash fix in 1d10b44]; but that this time,
the change is intentional and not an accidental side-effect.)
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <1461879932-9020-17-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Implement the new type_null() callback for the qmp input and
output visitors. While we don't yet have a use for this in QAPI
input (the generator will need some tweaks first), some
potential usages have already been discussed on the list.
Meanwhile, the output visitor could already output explicit null
via type_any, but this gives us finer control.
At any rate, it's easy to test that we can round-trip an explicit
null through manual use of visit_type_null() wrapped by a virtual
visit_start_struct() walk, even if we can't do the visit in a
QAPI type. Repurpose the test_visitor_out_empty test,
particularly since a future patch will tighten semantics to
forbid use of qmp_output_get_qobject() without at least one
intervening visit_type_*.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Right now, qmp-output-visitor happens to produce a QNull result
if nothing is actually visited between the creation of the visitor
and the request for the resulting QObject. A stronger protocol
would require that a QMP output visit MUST visit something. But
to still be able to produce a JSON 'null' output, we need a new
visitor function that states our intentions. Yes, we could say
that such a visit must go through visit_type_any(), but that
feels clunky.
So this patch introduces the new visit_type_null() interface and
its no-op interface in the dealloc visitor, and stubs in the
qmp visitors (the next patch will finish the implementation).
For the visitors that will not implement the callback, document
the situation. The code in qapi-visit-core unconditionally
dereferences the callback pointer, so that a segfault will inform
a developer if they need to implement the callback for their
choice of visitor.
Note that JSON has a primitive null type, with the single value
null; likewise with the QNull type for QObject; but for QAPI,
we just have the 'null' value without a null type. We may
eventually want to add more support in QAPI for null (most likely,
we'd use it via an alternate type that permits 'null' or an
object); but we'll create that usage when we need it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Add a new test, for checking reference counting of qnull(). As
part of the new file, move a previous reference counting change
added in commit a861564 to a more logical place.
Note that while most of the check-q*.c leave visitor stuff to
the test-qmp-*-visitor.c, in this case we actually want the
visitor tests in our new file because we are validating the
reference count of qnull_, which is an internal detail that
test-qmp-*-visitor should not be peeking into (or put another
way, qnull() is the only special case where we don't have
independent allocation of a QObject, so none of the other
visitor tests require the layering violation present in this
test).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-14-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The visitor interface for mapping between QObject/QemuOpts/string
and QAPI is scandalously under-documented, making changes to visitor
core, individual visitors, and users of visitors difficult to
coordinate. Among other questions: when is it safe to pass NULL,
vs. when a string must be provided; which visitors implement which
callbacks; the difference between concrete and virtual visits.
Correct this by retrofitting proper contracts, and document where some
of the interface warts remain (for example, we may want to modify
visit_end_* to require the same 'obj' as the visit_start counterpart,
so the dealloc visitor can be simplified). Later patches in this
series will tackle some, but not all, of these warts.
Add assertions to (partially) enforce the contract. Some of these
were only made possible by recent cleanup commits.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-13-git-send-email-eblake@redhat.com>
[Doc fix from Eric squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
In the QMP input visitor, visiting a list traverses two objects:
the QAPI GenericList of the caller (which gets advanced in
visit_next_list() regardless of this patch), and the QList input
that we are converting to QAPI. For consistency with QDict
visits, we want to consume elements from the input QList during
the visit_type_FOO() for the list element; that is, we want ALL
the code for consuming an input to live in qmp_input_get_object(),
rather than having it split according to whether we are visiting
a dict or a list. Making qmp_input_get_object() the common point
of consumption will make it easier for a later patch to refactor
visit_start_list() to cover the GenericList * head of a QAPI list,
and in turn will get rid of the 'first' flag (which lived in
qmp_input_next_list() pre-patch, and is hoisted to StackObject
by this patch).
This patch is therefore altering the post-condition use of 'entry',
while keeping what gets visited unchanged, from:
start_list next_list type_ELT ... next_list type_ELT next_list end_list
visits 1st elt last elt
entry NULL 1st elt 1st elt last elt last elt NULL gone
where type_ELT() returns (entry ? entry : 1st elt) and next_list() steps
entry
to this usage:
start_list next_list type_ELT ... next_list type_ELT next_list end_list
visits 1st elt last elt
entry 1st elt 1nd elt 2nd elt last elt NULL NULL gone
where type_ELT() steps entry and returns the old entry, and next_list()
leaves entry alone.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Don't embed the root of the visit into the stack of current
containers being visited. That way, we no longer get confused
on whether the first visit of a dictionary is to the dictionary
itself or to one of the members of the dictionary, based on
whether the caller passed name=NULL; and makes the QMP Input
visitor like other visitors where the value of 'name' is now
ignored on the root visit. (We may someday want to revisit
the rules on what 'name' should be on a top-level visit,
rather than just ignoring it; but that would be the topic of
another patch).
An audit of all qmp_input_visitor_new() call sites shows that
there were only two places where callers had previously been
visiting to a QDict with a non-NULL name to bypass a call to
visit_start_struct(), and those were fixed in prior patches.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-11-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The qmp-input visitor was allowing callers to play rather fast
and loose: when visiting a QDict, you could grab members of the
root dictionary without first pushing into the dict; the final
such culprit was the QOM code for converting to and from object
properties. But we are about to tighten the input visitor, at
which point user_creatable_add_type() as called with a QMP input
visitor via qmp_object_add() MUST follow the same paradigms as
everyone else, of pushing into the struct before grabbing its
keys.
The use of 'err ? NULL : &err' is temporary; a later patch will
clean that up when it splits visit_end_struct().
Furthermore, note that both callers always pass qdict, so we can
convert the conditional into an assert and reduce indentation.
The change has no impact to the testsuite now, but is required to
avoid a failure in tests/test-netfilter once qmp-input is made
stricter to detect inconsistent 'name' arguments on the root visit.
Since user_creatable_add_type() is also called with OptsVisitor
through user_creatable_add_opts(), we must also check that there
is no negative impact there; both pre- and post-patch, we see:
$ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio -object secret,id=sec0,data=letmein,format=raw,foo=bar
qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar: Property '.foo' not found
That is, the only new checking that the new visit_end_struct() can
perform is for excess input, but we already catch excess input
earlier in object_property_set().
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The qmp-input visitor was allowing callers to play rather fast
and loose: when visiting a QDict, you could grab members of the
root dictionary without first pushing into the dict; among the
culprit callers was the generated marshal code on the 'arguments'
dictionary of a QMP command. But we are about to tighten the
input visitor, at which point the generated marshal code MUST
follow the same paradigms as everyone else, of pushing into the
struct before grabbing its keys.
Generated code grows as follows:
|@@ -515,7 +641,12 @@ void qmp_marshal_blockdev_backup(QDict *
| BlockdevBackup arg = {0};
|
| v = qmp_input_get_visitor(qiv);
|+ visit_start_struct(v, NULL, NULL, 0, &err);
|+ if (err) {
|+ goto out;
|+ }
| visit_type_BlockdevBackup_members(v, &arg, &err);
|+ visit_end_struct(v, err ? NULL : &err);
| if (err) {
| goto out;
| }
|@@ -527,7 +715,9 @@ out:
| qmp_input_visitor_cleanup(qiv);
| qdv = qapi_dealloc_visitor_new();
| v = qapi_dealloc_get_visitor(qdv);
|+ visit_start_struct(v, NULL, NULL, 0, NULL);
| visit_type_BlockdevBackup_members(v, &arg, NULL);
|+ visit_end_struct(v, NULL);
| qapi_dealloc_visitor_cleanup(qdv);
| }
The use of 'err ? NULL : &err' is temporary; a later patch will
clean that up when it splits visit_end_struct().
Prior to this patch, the fact that there was no final
visit_end_struct() meant that even though we are using a strict
input visit, the marshalling code was not detecting excess input
at the top level (only in nested levels). Fortunately, we have
code in monitor.c:qmp_check_client_args() that also checks for
no excess arguments at the top level. But as the generated code
is more compact than the manual check, a later patch will clean
up monitor.c to drop the redundancy added here.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-9-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Commit e8316d7 mistakenly passed consume=true within
qmp_input_optional() when checking if an optional member was
present, but the mistake was silently ignored since the code
happily let us extract a member more than once. Fix
qmp_input_optional() to not consume anything, then tighten up
the input visitor to ensure that a member is consumed exactly
once (all generated code follows this pattern; and the new
assert will catch any hand-written code that tries to visit
the same key more than once).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The following uses of a QMP input visitor should be strict
(that is, excess keys in QDict input should be flagged if not
converted to QAPI):
- Testsuite code unrelated to explicitly testing non-strict
mode (test-qmp-commands, test-visitor-serialization); since
we want more code to be strict by default, having more tests
of strict mode doesn't hurt
- Code used for cloning QAPI objects (replay-input.c,
qemu-sockets.c); we are reparsing a QObject just barely
produced by the qmp output visitor and which therefore should
not have any garbage, so while it is extra work to be strict,
it validates that our clone is correct [note that a later patch
series will simplify these two uses by creating an actual
clone visitor that is much more efficient than a
generate/reparse cycle]
- qmp_object_add(), which calls into user_creatable_add_type().
Since command line parsing for '-object' uses the same
user_creatable_add_type() through the OptsVisitor, and that is
always strict, we want to ensure that any nested dictionaries
would be treated the same in QMP and from the command line (I
don't actually know if such nested dictionaries exist). Note
that on this code change, strictness only matters for nested
dictionaries (if even possible), since we already flag excess
input at the top level during an earlier object_property_set()
on an unknown key, whether from QemuOpts:
$ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio -object secret,id=sec0,data=letmein,format=raw,foo=bar
qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar: Property '.foo' not found
or from QMP:
$ ./x86_64-softmmu/qemu-system-x86_64 -nographic -nodefaults -qmp stdio
{"QMP": {"version": {"qemu": {"micro": 93, "minor": 5, "major": 2}, "package": ""}, "capabilities": []}}
{"execute":"qmp_capabilities"}
{"return": {}}
{"execute":"object-add","arguments":{"qom-type":"secret","id":"sec0","props":{"format":"raw","data":"letmein","foo":"bar"}}}
{"error": {"class": "GenericError", "desc": "Property '.foo' not found"}}
The only remaining uses of non-strict input visits are:
- QMP 'qom-set' (which eventually executes
object_property_set_qobject()) - mark it as something to revisit
in the future (I didn't want to spend any more time on this patch
auditing if we have any QOM dictionary properties that might be
impacted, and couldn't easily prove whether this code path is
shared with anything else).
- test-qmp-input-visitor: explicit tests of non-strict mode. If
we later get rid of users that don't need strictness, then this
test should be merged with test-qmp-input-strict
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-7-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Rather than having two separate ways to create a QMP input
visitor, where the safer approach has the more verbose name,
it is better to consolidate things into a single function
where the caller must explicitly choose whether to be strict
or to ignore excess input. This patch is the strictly
mechanical conversion; the next patch will then audit which
uses can be made stricter.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-6-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Management of the top of stack was a bit verbose; creating a
temporary variable and adding some comments makes the existing
code more legible before the next few patches improve things.
No semantic changes other than asserting that we are always
visiting a QObject, and not a NULL value. In particular, the
check for 'name && qobject_type(qobj) == QTYPE_QDICT)' is a
bit overkill (a dict visit should always have a name); a later
patch revisits that, while this patch is only changing one
layer of indentation due to dropping 'if (qobj)'.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Ever since QMP was first added back in commit 43c20a43, we have
never had any QmpCommandType other than QCT_NORMAL. It's
pointless to carry around the cruft.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Our existing input visitors were not very consistent on errors in a
function taking 'TYPE **obj'. These are start_struct(),
start_alternate(), type_str(), and type_any(). next_list() is
similar, but can't fail (see commit 08f9541). While all of them set
'*obj' to allocated storage on success, it was not obvious whether
'*obj' was guaranteed safe on failure, or whether it was left
uninitialized. But a future patch wants to guarantee that
visit_type_FOO() does not leak a partially-constructed obj back to
the caller; it is easier to implement this if we can reliably state
that input visitors assign '*obj' regardless of success or failure,
and that on failure *obj is NULL. Add assertions to enforce
consistency in the final setting of err vs. *obj.
The opts-visitor start_struct() doesn't set an error, but it
also was doing a weird check for 0 size; all callers pass in
non-zero size if obj is non-NULL.
The testsuite has at least one spot where we no longer need
to pre-initialize a variable prior to a visit; valgrind confirms
that the test is still fine with the cleanup.
A later patch will document the design constraint implemented
here.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-3-git-send-email-eblake@redhat.com>
[visit_start_alternate()'s assertion tightened, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
We have three classes of QAPI visitors: input, output, and dealloc.
Currently, all implementations of these visitors have one thing in
common based on their visitor type: the implementation used for the
visit_type_enum() callback. But since we plan to add more such
common behavior, in relation to documenting and further refining
the semantics, it makes more sense to have the visitor
implementations advertise which class they belong to, so the common
qapi-visit-core code can use that information in multiple places.
A later patch will better document the types of visitors directly
in visitor.h.
For this patch, knowing the class of a visitor implementation lets
us make input_type_enum() and output_type_enum() become static
functions, by replacing the callback function Visitor.type_enum()
with the simpler enum member Visitor.type. Share a common
assertion in qapi-visit-core as part of the refactoring.
Move comments in opts-visitor.c to match the refactored layout.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Call vbe_update_vgaregs() when the guest touches GFX, SEQ or CRT
registers, to make sure the vga registers will always have the
values needed by vbe mode. This makes sure the sanity checks
applied by vbe_fixup_regs() are effective.
Without this guests can muck with shift_control, can turn on planar
vga modes or text mode emulation while VBE is active, making qemu
take code paths meant for CGA compatibility, but with the very
large display widths and heigts settable using VBE registers.
Which is good for one or another buffer overflow. Not that
critical as they typically read overflows happening somewhere
in the display code. So guests can DoS by crashing qemu with a
segfault, but it is probably not possible to break out of the VM.
Fixes: CVE-2016-3712
Reported-by: Zuozhi Fzz <zuozhi.fzz@alibaba-inc.com>
Reported-by: P J P <ppandit@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Call the new vbe_update_vgaregs() function on vbe configuration
changes, to make sure vga registers are up-to-date.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
When enabling vbe mode qemu will setup a bunch of vga registers to make
sure the vga emulation operates in correct mode for a linear
framebuffer. Move that code to a separate function so we can call it
from other places too.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
vga allows banked access to video memory using the window at 0xa00000
and it supports a different access modes with different address
calculations.
The VBE bochs extentions support banked access too, using the
VBE_DISPI_INDEX_BANK register. The code tries to take the different
address calculations into account and applies different limits to
VBE_DISPI_INDEX_BANK depending on the current access mode.
Which is probably effective in stopping misprogramming by accident.
But from a security point of view completely useless as an attacker
can easily change access modes after setting the bank register.
Drop the bogus check, add range checks to vga_mem_{readb,writeb}
instead.
Fixes: CVE-2016-3710
Reported-by: Qinghao Tang <luodalongde@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Fixes build failure with --enable-xfsctl and
new linux headers (>=4.5) and older xfsprogs(<4.5):
In file included from /usr/include/xfs/xfs.h:38:0,
from /var/tmp/portage/app-emulation/qemu-2.5.0-r1/work/qemu-2.5.0/block/raw-posix.c:97:
/usr/include/xfs/xfs_fs.h:42:8: error: redefinition of ‘struct fsxattr’
struct fsxattr {
^
In file included from /var/tmp/portage/app-emulation/qemu-2.5.0-r1/work/qemu-2.5.0/block/raw-posix.c:60:0:
/usr/include/linux/fs.h:155:8: note: originally defined here
struct fsxattr {
This is really a bug in the system headers, but we can work around it
by defining HAVE_FSXATTR in the QEMU headers if linux/fs.h provides
the struct, so that xfs_fs.h doesn't try to define it as well.
CC: qemu-trivial@nongnu.org
CC: Markus Armbruster <armbru@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Stefan Weil <sw@weilnetz.de>
Tested-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Jan Vesely <jano.vesely@gmail.com>
[PMM: adjusted commit message, comments]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Minor, obvious fix only affecting BE hosts.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
acpi: last minute fix for 2.6
Minor, obvious fix only affecting BE hosts.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Sun 01 May 2016 13:43:28 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg: aka "Michael S. Tsirkin <mst@redhat.com>"
* remotes/mst/tags/for_upstream:
acpi: fix bios linker loadder COMMAND_ALLOCATE on bigendian host
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
'make check' fails with:
ERROR:tests/bios-tables-test.c:493:load_expected_aml:
assertion failed: (g_file_test(aml_file, G_FILE_TEST_EXISTS))
since commit:
caf50c7166
tests: pc: acpi: drop not needed 'expected SSDT' blobs
Assert happens because qemu-system-x86_64 generates
SSDT table and test looks for a corresponding expected
table to compare with.
However there is no expected SSDT blob anymore, since
QEMU souldn't generate one. As it happens BIOS is not
able to read ACPI tables from QEMU and fallbacks to
embeded legacy ACPI codepath, which generates SSDT.
That happens due to wrongly sized endiannes conversion
which makes
uint8_t BiosLinkerLoaderEntry.alloc.zone
end up with 0 due to truncation of 32 bit integer
which on host is 1 or 2.
Fix it by dropping invalid cpu_to_le32() as uint8_t
doesn't require any conversion.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1330174
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Commit d5941dd documented that it leaves the default volume name as it
was ("QEMU VVFAT"), but it doesn't actually implement this. You get an
empty name (eleven space characters) instead.
This fixes the implementation to apply the advertised default.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Commit d5941dd made the volume name configurable, but it didn't consider
that the rw code compares the volume name string to assert that the
first directory entry is the volume name. This made vvfat crash in rw
mode.
This fixes the assertion to compare with the configured volume name
instead of a literal string.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Make sure the error message for visit_type_uint64() gracefully
handles a NULL 'name' when called from the top level or a list
context, as not all the world behaves like glibc in allowing
NULL through a printf-family %s.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-21-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
On Darwin, connect, sendto and friends want the exact size of the sockaddr,
not more (and in particular, not sizeof(struct sockaddr_storaget))
This commit adds the sockaddr_size helper to be used when passing a sockaddr
size to such function, and makes use of it int sendto and connect calls.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This just has one, last-minute, fix for a serious regression of memory
hotplug.
Patch author's comment:
Really sorry for the way last-minute fix, but without this memory
hotplug is totally broken :( Hoping to get this in for Wednesday's
RC4, which I think will be the final before release.
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Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.6-20160426' into staging
ppc patch queue for 2016-04-26 (last minute qemu-2.6 fix)
This just has one, last-minute, fix for a serious regression of memory
hotplug.
Patch author's comment:
Really sorry for the way last-minute fix, but without this memory
hotplug is totally broken :( Hoping to get this in for Wednesday's
RC4, which I think will be the final before release.
# gpg: Signature made Tue 26 Apr 2016 03:52:20 BST using RSA key ID 20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg: aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg: aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg: It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E 87DC 6C38 CACA 20D9 B392
* remotes/dgibson/tags/ppc-for-2.6-20160426:
spapr_drc: fix aborts during DRC-count based hotplug
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Commit b00c72180c ("target-mips: add PC, XNP reg numbers to RDHWR")
changed the rdhwr helpers to use check_hwrena() to check the register
being accessed is enabled in CP0_HWREna when used from user mode. If
that check fails an EXCP_RI exception is raised at the host PC
calculated with GETPC().
However check_hwrena() may not be fully inlined as the
do_raise_exception() part of it is common regardless of the arguments.
This causes GETPC() to calculate the address in the call in the helper
instead of the generated code calling the helper. No TB will be found
and the EPC reported with the resulting guest RI exception points to the
beginning of the TB instead of the RDHWR instruction.
We can't reliably force check_hwrena() to be inlined, and converting it
to a macro would be ugly, so instead pass the host PC in as an argument,
with each rdhwr helper passing GETPC(). This should avoid any dependence
on compiler behaviour, and in practice seems to ensure the full inlining
of check_hwrena() on x86_64.
This issue causes failures when running a MIPS KVM (trap & emulate)
guest in a MIPS QEMU TCG guest, as the inner guest kernel will do a
RDHWR of counter, which is disabled in the outer guest's CP0_HWREna by
KVM so it can emulate the inner guest's counter. The emulation fails and
the RI exception is passed to the inner guest.
Fixes: b00c72180c ("target-mips: add PC, XNP reg numbers to RDHWR")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
qemu_opts_foreach() runs its callback with the error location set to
the option's location. Any errors the callback reports use the
option's location automatically.
Commit 90998d5 moved the actual error reporting from "inside"
qemu_opts_foreach() to after it. Here's a typical hunk:
if (qemu_opts_foreach(qemu_find_opts("object"),
- object_create,
- object_create_initial, NULL)) {
+ user_creatable_add_opts_foreach,
+ object_create_initial, &err)) {
+ error_report_err(err);
exit(1);
}
Before, object_create() reports from within qemu_opts_foreach(), using
the option's location. Afterwards, we do it after
qemu_opts_foreach(), using whatever location happens to be current
there. Commonly a "none" location.
This is because Error objects don't have location information.
Problematic.
Reproducer:
$ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar
qemu-system-x86_64: Property '.foo' not found
Note no location. This commit restores it:
qemu-system-x86_64: -object secret,id=foo,foo=bar: Property '.foo' not found
Note that the qemu_opts_foreach() bug just fixed could mask the bug
here: if the location it leaves dangling hasn't been clobbered, yet,
it's the correct one.
Reported-by: Eric Blake <eblake@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-4-git-send-email-armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Paragraph on Error added to commit message]
replay_configure() pushes and pops a Location with automatic storage
duration. Except it fails to pop when -icount parameter "rr" isn't
given. cur_loc then points to unused stack space, and will most
likely get clobbered in short order.
Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.
Broken in commit 890ad55.
I didn't take the time to find a reproducer.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
qemu_opts_foreach() pushes and pops a Location with automatic storage
duration. Except it fails to pop when @func() returns non-zero.
cur_loc then points to unused stack space, and will most likely get
clobbered in short order.
Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.
Affects several qemu command line options as well as qemu-img,
qemu-io, qemu-nbd -object, and blkdebug's configuration file.
Broken in commit a4c7367, v2.4.0.
Reproducer:
$ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar
main() reports "Property '.foo' not found" like this:
if (qemu_opts_foreach(qemu_find_opts("object"),
user_creatable_add_opts_foreach,
object_create_delayed, &err)) {
error_report_err(err);
exit(1);
}
cur_loc then points to where qemu_opts_foreach()'s Location used to
be, i.e. unused stack space. With optimization, this Location doesn't
get clobbered for me, and also happens to be the correct location.
Without optimization, it does get clobbered in a way that makes
error_report_err() report no location.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
CPU/memory resources can be signalled en-masse via
spapr_hotplug_req_add_by_count(), and when doing so, actually change
the meaning of the 'drc' parameter passed to
spapr_hotplug_req_event() to be a count rather than an index.
f40eb92 added a hook in spapr_hotplug_req_event() to record when a
device had been 'signalled' to the guest, but that code assumes that
drc is always an index. In cases where it's a count, such as memory
hotplug, the DRC lookup will fail, leading to an assert.
Fix this by only explicitly setting the signalled state for cases where
we are doing PCI hotplug.
For other resources types, since we cannot selectively track whether a
resource has been signalled in cases where we signal attach as a count,
set the 'signalled' state to true immediately upon making the
resource available via drck->attach().
Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: david@gibson.dropbear.id.au
Cc: qemu-ppc@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
