Commit Graph

31 Commits

Author SHA1 Message Date
Markus Armbruster 4b5766488f error: Fix use of error_prepend() with &error_fatal, &error_abort
From include/qapi/error.h:

  * Pass an existing error to the caller with the message modified:
  *     error_propagate(errp, err);
  *     error_prepend(errp, "Could not frobnicate '%s': ", name);

Fei Li pointed out that doing error_propagate() first doesn't work
well when @errp is &error_fatal or &error_abort: the error_prepend()
is never reached.

Since I doubt fixing the documentation will stop people from getting
it wrong, introduce error_propagate_prepend(), in the hope that it
lures people away from using its constituents in the wrong order.
Update the instructions in error.h accordingly.

Convert existing error_prepend() next to error_propagate to
error_propagate_prepend().  If any of these get reached with
&error_fatal or &error_abort, the error messages improve.  I didn't
check whether that's the case anywhere.

Cc: Fei Li <fli@suse.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-2-armbru@redhat.com>
2018-10-19 14:51:34 +02:00
Alistair Francis e43ead1d0b error: Implement the warn and free Error functions
Implement warn_report_err() and warn_reportf_err() functions which
are the same as the error_report_err() and error_reportf_err()
functions except report a warning instead of an error.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <276ff93eadc0b01b8243cc61ffc331f77922c0d0.1499866456.git.alistair.francis@xilinx.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-13 13:50:19 +02:00
Max Reitz 536eeea869 util/error: Fix leak in error_vprepend()
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20170413160952.29918-1-mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24 09:12:59 +02:00
Daniel P. Berrange d59ce6f344 migration: add reporting of errors for outgoing migration
Currently if an application initiates an outgoing migration,
it may or may not, get an error reported back on failure. If
the error occurs synchronously to the 'migrate' command
execution, the client app will see the error message. This
is the case for DNS lookup failures. If the error occurs
asynchronously to the monitor command though, the error
will be thrown away and the client left guessing about
what went wrong. This is the case for failure to connect
to the TCP server (eg due to wrong port, or firewall
rules, or other similar errors).

In the future we'll be adding more scope for errors to
happen asynchronously with the TLS protocol handshake.
TLS errors are hard to diagnose even when they are well
reported, so discarding errors entirely will make it
impossible to debug TLS connection problems.

Management apps which do migration are already using
'query-migrate' / 'info migrate' to check up on progress
of background migration operations and to see their end
status. This is a fine place to also include the error
message when things go wrong.

This patch thus adds an 'error-desc' field to the
MigrationInfo struct, which will be populated when
the 'status' is set to 'failed':

(qemu) migrate -d tcp:localhost:9001
(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off x-postcopy-ram: off
Migration status: failed (Error connecting to socket: Connection refused)
total time: 0 milliseconds

In the HMP, when doing non-detached migration, it is
also possible to display this error message directly
to the app.

(qemu) migrate tcp:localhost:9001
Error connecting to socket: Connection refused

Or with QMP

  {
    "execute": "query-migrate",
    "arguments": {}
  }
  {
    "return": {
      "status": "failed",
      "error-desc": "address resolution failed for myhost:9000: No address associated with hostname"
    }
  }

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-11-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:30 +05:30
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Daniel P. Berrange 20e2dec149 error: ensure errno detail is printed with error_abort
When &error_abort is passed in, the error reporting code
will print the current error message and then abort() the
process. Unfortunately at the time it aborts, we've not
yet appended the errno detail. This makes debugging certain
problems significantly harder as the log is incomplete.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1457544504-8548-22-git-send-email-berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-16 10:55:51 +01:00
Peter Maydell aafd758410 util: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-6-git-send-email-peter.maydell@linaro.org
2016-02-04 17:01:04 +00:00
Markus Armbruster 8277d2aa58 error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:

    frobnicate(arg, &err);
    error_setg(errp, "Can't frobnicate %s: %s",
                     arg, error_get_pretty(err));
    error_free(err);

This is suboptimal, because it loses err's hint (if any).  Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.

To avoid these issues, provide means to add to an error's message in
place:

    frobnicate(arg, errp);
    error_prepend(errp, "Can't frobnicate %s: ", arg);

Likewise, reporting an error like

    frobnicate(arg, &err);
    error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));

can lose err's hint.  To avoid:

    error_reportf_err(err, "Can't frobnicate %s: ", arg);

The next commits will put these functions to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2016-01-13 15:16:17 +01:00
Markus Armbruster f4d0064afc error: Improve documentation
While there, tighten error_append_hint()'s assertion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1450452927-8346-6-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-13 15:16:16 +01:00
Markus Armbruster 543202c0dd error: Don't append a newline when printing the error hint
Since commit 50b7b00, we have error_append_hint() to conveniently
accumulate Error member @hint.  error_report_err() prints it with a
newline appended.  Consequently, users of error_append_hint() need to
know whether theirs is the final line of the hint to decide whether it
needs a newline.  Not a nice interface.

Change error_report_err() to print just the hint, and the (still few)
users of error_append_hint() to add the required newline.

Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450370121-5768-7-git-send-email-armbru@redhat.com>
2016-01-13 11:58:58 +01:00
Eric Blake a12a5a1a01 qapi: Simplify error cleanup in test-qmp-*
We have several tests that perform multiple sub-actions that are
expected to fail.  Asserting that an error occurred, then clearing
it up to prepare for the next action, turned into enough
boilerplate that it was sometimes forgotten (for example, a number
of tests added to test-qmp-input-visitor.c in d88f5fd leaked err).
Worse, if an error is not reset to NULL, we risk invalidating
later use of that error (passing a non-NULL err into a function
is generally a bad idea).  Encapsulate the boilerplate into a
single helper function error_free_or_abort(), and consistently
use it.

The new function is added into error.c for use everywhere,
although it is anticipated that testsuites will be the main
client.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-10 08:08:21 +01:00
Markus Armbruster a29a37b994 error: New error_fatal
Similar to error_abort, but doesn't report where the error was
created, and terminates the process with exit(1) rather than abort().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
2015-09-18 14:38:08 +02:00
Eric Blake 88e2ce2915 error: Copy location information in error_copy()
Commit 1e9b65bb forgot to propagate source information to copied
errors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1441902890-23064-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-18 14:34:39 +02:00
Eric Blake 50b7b000c9 hmp: Allow for error message hints on HMP
Commits 7216ae3d and d2828429 disabled some error message hints,
all because a change to use modern error reporting meant that the
hint would be output prior to the actual error.  Fix this by making
hints a first-class member of Error.

For example, we are now back to the pleasant:

 $ qemu-system-x86_64 --nodefaults -S --vnc :0 --chardev null,id=,
 qemu-system-x86_64: --chardev null,id=,: Parameter 'id' expects an identifier
 Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1441901956-21991-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-18 14:34:39 +02:00
Markus Armbruster 1e9b65bb1b error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created.  Looks like this:

    Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
    qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
    Aborted (core dumped)

Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().

To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments.  Not exactly
pretty, but it works.

The macro trickery breaks down when you take the address of an
error_setFOO().  Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL".  Use error_setg_win32_internal() there.  The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.

Code size increases by some 35KiB for me (0.7%).  Tolerable.  Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster 4463dcb85c error: error_set_errno() is unused, drop
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster e7cf59e847 qga: Clean up unnecessarily dirty casts
qga_vss_fsfreeze() casts error_set_win32() from

    void (*)(Error **, int, ErrorClass, const char *, ...)

to

    void (*)(void **, int, int, const char *, ...)

The result is later called.  Since the two types are not compatible,
the call is undefined behavior.  It works in practice anyway.

However, there's no real need for trickery here.  Clean it up as
follows:

* Declare struct Error, and fix the first parameter.

* Switch to error_setg_win32().  This gets rid of the troublesome
  ErrorClass parameter.  Requires converting error_setg_win32() from
  macro to function, but that's trivially easy, because this is the
  only user of error_set_win32().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster a9499ddd82 error: Make error_setg() a function
Saves a tiny amount of code at every call site.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:05 +02:00
Markus Armbruster 552375088a error: De-duplicate code creating Error objects
Duplicated when commit 680d16d added error_set_errno(), and again when
commit 20840d4 added error_set_win32().

Make the original copy in error_set() reusable by factoring out
error_setv(), then rewrite error_set_errno() and error_set_win32() on
top of it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:05 +02:00
Markus Armbruster 565f65d271 error: Use error_report_err() where appropriate
Coccinelle semantic patch:

    @@
    expression E;
    @@
    -    error_report("%s", error_get_pretty(E));
    -    error_free(E);
    +    error_report_err(E);
    @@
    expression E, S;
    @@
    -    error_report("%s", error_get_pretty(E));
    +    error_report_err(E);
    (
         exit(S);
    |
         abort();
    )

Trivial manual touch-ups in block/sheepdog.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-18 10:51:09 +01:00
Markus Armbruster 2ee2f1e415 error: New convenience function error_report_err()
I've typed error_report("%s", error_get_pretty(ERR)) too many times
already, and I've fixed too many instances of qerror_report_err(ERR)
to error_report("%s", error_get_pretty(ERR)) as well.  Capture the
pattern in a convenience function.

Since it's almost invariably followed by error_free(), stuff that into
the convenience function as well.

The next patch will put it to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-18 10:50:43 +01:00
Markus Armbruster d2e064a73e error: error_is_set() is finally unused; remove
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-05-21 11:57:58 +02:00
Markus Armbruster 64dfefed16 error: Consistently name Error ** objects errp, and not err
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09 09:11:30 -04:00
Cole Robinson 073a341151 error: Remove some unused headers
Makes it a bit clear how the interdependencies work.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Peter Crosthwaite 732c66ce64 Revert "error: Don't use error_report() for assertion msgs."
This reverts commit d32934c84c.

The original implementation before this patch makes abortive error
messages much more friendly. The underlying bug that required this
change is now fixed. Revert.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2014-01-17 09:50:11 +10:00
Peter Crosthwaite d32934c84c error: Don't use error_report() for assertion msgs.
Use fprintf(stderr instead. This removes dependency of libqemuutil.a
on the monitor.

We can further justify this change, in that this code path should only
trigger under a fatal error condition. fprintf-stderr is probably the
appropriate medium as under a fatal error conidition the monitor itself
may be down and out for the count. So assertion failure messages should
go lowest common denominator - straight to stderr.

Fixes the build as reported by Kevin Wolf. Issue debugged and change
suggested by Luiz Capitulino. Issue introduced by
5d24ee70bc.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2014-01-15 15:36:48 +10:00
Peter Crosthwaite 5d24ee70bc error: Add error_abort
Add a special Error * that can be passed to error handling APIs to
signal that any errors are fatal and should abort QEMU. There are two
advantages to this:

- allows for brevity when wishing to assert success of Error **
  accepting APIs. No need for this pattern:
        Error * local_err = NULL;
        api_call(foo, bar, &local_err);
        assert_no_error(local_err);
  This also removes the need for _nofail variants of APIs with
  asserting call sites now reduced to 1LOC.
- SIGABRT happens from within the offending API. When a fatal error
  occurs in an API call (when the caller is asserting sucess) failure
  often means the API itself is broken. With the abort happening in the
  API call now, the stack frames into the call are available at debug
  time. In the assert_no_error scheme the abort happens after the fact.

The exact semantic is that when an error is raised, if the argument
Error ** matches &error_abort, then the abort occurs immediately. The
error messaged is reported.

For error_propagate, if the destination error is &error_abort, then
the abort happens at propagation time.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 14:01:53 -05:00
Max Reitz b276d24994 util/error: Save errno from clobbering
There may be calls to error_setg() and especially error_setg_errno()
which blindly (and until now wrongly) assume these functions not to
clobber errno (e.g., they pass errno to error_setg_errno() and return
-errno afterwards). Instead of trying to find and fix all of these
constructs, just make sure error_setg() and error_setg_errno() indeed do
not clobber errno.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-28 10:30:52 +01:00
Tomoki Sekiyama 20840d4cfe error: Add error_set_win32 and error_setg_win32
These functions help maintaining homogeneous formatting of error messages
with Windows error code and description (generated by
g_win32_error_message()).

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-09-09 14:17:57 -05:00
Luiz Capitulino 54028d7542 error: add error_setg_file_open() helper
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2013-06-17 11:01:14 -04:00
Paolo Bonzini baacf04799 build: move libqemuutil.a components to util/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-01-12 18:42:50 +01:00