Commit Graph

478 Commits

Author SHA1 Message Date
Vladimir Sementsov-Ogievskiy
4c5ec47e63 9pfs: make Error **errp const where it is appropriate
Mostly, Error ** is for returning error from the function, so the
callee sets it. However error_append_security_model_hint and
error_append_socket_sockfd_hint get already filled errp
parameter. They don't change the pointer itself, only change the
internal state of referenced Error object. So we can make it Error
*const * errp, to stress the behavior. It will also help coccinelle
script (in future) to distinguish such cases from common errp usage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-Id: <20191205174635.18758-9-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message replaced]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-12-18 08:43:19 +01:00
Dan Schatzberg
68d654daee 9pfs: Fix divide by zero bug
Some filesystems may return 0s in statfs (trivially, a FUSE filesystem
can do so). QEMU should handle this gracefully and just behave the
same as if statfs failed.

Signed-off-by: Dan Schatzberg <dschatzberg@fb.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-11-23 15:51:48 +01:00
Christian Schoenebeck
6b6aa8285d 9p: Use variable length suffixes for inode remapping
Use variable length suffixes for inode remapping instead of the fixed
16 bit size prefixes before. With this change the inode numbers on guest
will typically be much smaller (e.g. around >2^1 .. >2^7 instead of >2^48
with the previous fixed size inode remapping.

Additionally this solution is more efficient, since inode numbers in
practice can take almost their entire 64 bit range on guest as well, so
there is less likely a need for generating and tracking additional suffixes,
which might also be beneficial for nested virtualization where each level of
virtualization would shift up the inode bits and increase the chance of
expensive remapping actions.

The "Exponential Golomb" algorithm is used as basis for generating the
variable length suffixes. The algorithm has a parameter k which controls the
distribution of bits on increasing indeces (minimum bits at low index vs.
maximum bits at high index). With k=0 the generated suffixes look like:

Index Dec/Bin -> Generated Suffix Bin
1 [1] -> [1] (1 bits)
2 [10] -> [010] (3 bits)
3 [11] -> [110] (3 bits)
4 [100] -> [00100] (5 bits)
5 [101] -> [10100] (5 bits)
6 [110] -> [01100] (5 bits)
7 [111] -> [11100] (5 bits)
8 [1000] -> [0001000] (7 bits)
9 [1001] -> [1001000] (7 bits)
10 [1010] -> [0101000] (7 bits)
11 [1011] -> [1101000] (7 bits)
12 [1100] -> [0011000] (7 bits)
...
65533 [1111111111111101] ->  [1011111111111111000000000000000] (31 bits)
65534 [1111111111111110] ->  [0111111111111111000000000000000] (31 bits)
65535 [1111111111111111] ->  [1111111111111111000000000000000] (31 bits)
Hence minBits=1 maxBits=31

And with k=5 they would look like:

Index Dec/Bin -> Generated Suffix Bin
1 [1] -> [000001] (6 bits)
2 [10] -> [100001] (6 bits)
3 [11] -> [010001] (6 bits)
4 [100] -> [110001] (6 bits)
5 [101] -> [001001] (6 bits)
6 [110] -> [101001] (6 bits)
7 [111] -> [011001] (6 bits)
8 [1000] -> [111001] (6 bits)
9 [1001] -> [000101] (6 bits)
10 [1010] -> [100101] (6 bits)
11 [1011] -> [010101] (6 bits)
12 [1100] -> [110101] (6 bits)
...
65533 [1111111111111101] -> [0011100000000000100000000000] (28 bits)
65534 [1111111111111110] -> [1011100000000000100000000000] (28 bits)
65535 [1111111111111111] -> [0111100000000000100000000000] (28 bits)
Hence minBits=6 maxBits=28

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:23 +02:00
Antonios Motakis
f3fe4a2d92 9p: stat_to_qid: implement slow path
stat_to_qid attempts via qid_path_prefixmap to map unique files (which are
identified by 64 bit inode nr and 32 bit device id) to a 64 QID path value.
However this implementation makes some assumptions about inode number
generation on the host.

If qid_path_prefixmap fails, we still have 48 bits available in the QID
path to fall back to a less memory efficient full mapping.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
       (SHA1 7fc4c49e91).
     - Updated hash calls to new xxhash API.
     - Removed unnecessary parantheses in qpf_lookup_func().
     - Removed unnecessary g_malloc0() result checks.
     - Log error message when running out of prefixes in
       qid_path_fullmap().
     - Log warning message about potential degraded performance in
       qid_path_prefixmap().
     - Wrapped qpf_table initialization to dedicated qpf_table_init()
       function.
     - Fixed typo in comment. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:14 +02:00
Antonios Motakis
1a6ed33cc5 9p: Added virtfs option 'multidevs=remap|forbid|warn'
'warn' (default): Only log an error message (once) on host if more than one
device is shared by same export, except of that just ignore this config
error though. This is the default behaviour for not breaking existing
installations implying that they really know what they are doing.

'forbid': Like 'warn', but except of just logging an error this
also denies access of guest to additional devices.

'remap': Allows to share more than one device per export by remapping
inodes from host to guest appropriately. To support multiple devices on the
9p share, and avoid qid path collisions we take the device id as input to
generate a unique QID path. The lowest 48 bits of the path will be set
equal to the file inode, and the top bits will be uniquely assigned based
on the top 16 bits of the inode and the device id.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
       (SHA1 7fc4c49e91).
     - Added virtfs option 'multidevs', original patch simply did the inode
       remapping without being asked.
     - Updated hash calls to new xxhash API.
     - Updated docs for new option 'multidevs'.
     - Fixed v9fs_do_readdir() not having remapped inodes.
     - Log error message when running out of prefixes in
       qid_path_prefixmap().
     - Fixed definition of QPATH_INO_MASK.
     - Wrapped qpp_table initialization to dedicated qpp_table_init()
       function.
     - Dropped unnecessary parantheses in qpp_lookup_func().
     - Dropped unnecessary g_malloc0() result checks. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug: - Moved "multidevs" parsing to the local backend.
        - Added hint to invalid multidevs option error.
	- Turn "remap" into "x-remap". ]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Antonios Motakis
3b5ee9e86b 9p: Treat multiple devices on one export as an error
The QID path should uniquely identify a file. However, the
inode of a file is currently used as the QID path, which
on its own only uniquely identifies files within a device.
Here we track the device hosting the 9pfs share, in order
to prevent security issues with QID path collisions from
other devices.

We only print a warning for now but a subsequent patch will
allow users to have finer control over the desired behaviour.
Failing the I/O will be one the proposed behaviour, so we
also change stat_to_qid() to return an error here in order to
keep other patches simpler.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Assign dev_id to export root's device already in
       v9fs_device_realize_common(), not postponed in
       stat_to_qid().
     - error_report_once() if more than one device was
       shared by export.
     - Return -ENODEV instead of -ENOSYS in stat_to_qid().
     - Fixed typo in log comment. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug, changed to warning, updated message and changelog]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Greg Kurz
ea52cdd443 fsdev: Add return value to fsdev_throttle_parse_opts()
It is more convenient to use the return value of the function to notify
errors, rather than to be tied up setting up the &local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Greg Kurz
c0da0cb761 9p: Simplify error path of v9fs_device_realize_common()
Make v9fs_device_unrealize_common() idempotent and use it for rollback,
in order to reduce code duplication.

Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:04 +02:00
Antonios Motakis
8703283352 9p: unsigned type for type, version, path
There is no need for signedness on these QID fields for 9p.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Also make QID type unsigned.
     - Adjust donttouch_stat() to new types.
     - Adjust trace-events to new types. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:04 +02:00
Paolo Bonzini
98387d5802 9p: simplify source file selection
Express the complex conditions in Kconfig rather than Makefiles, since Kconfig
is better suited at expressing dependencies and detecting contradictions.

Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-20 17:26:19 +02:00
Markus Armbruster
a27bd6c779 Include hw/qdev-properties.h less
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h.  Include hw/qdev-core.h there
instead.

hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.

While there, delete a few superfluous inclusions of hw/qdev-core.h.

Touching hw/qdev-properties.h now recompiles some 1200 objects.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
2019-08-16 13:31:53 +02:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
650d103d3e Include hw/hw.h exactly where needed
In my "build everything" tree, changing hw/hw.h triggers a recompile
of some 2600 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).

The previous commits have left only the declaration of hw_error() in
hw/hw.h.  This permits dropping most of its inclusions.  Touching it
now recompiles less than 200 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Anthony PERARD
a3434a2d56 xen: Import other xen/io/*.h
A Xen public header have been imported into QEMU (by
f65eadb639 "xen: import ring.h from xen"), but there are other header
that depends on ring.h which come from the system when building QEMU.

This patch resolves the issue of having headers from the system
importing a different copie of ring.h.

This patch is prompt by the build issue described in the previous
patch: 'Revert xen/io/ring.h of "Clean up a few header guard symbols"'

ring.h and the new imported headers are moved to
"include/hw/xen/interface" as those describe interfaces with a guest.

The imported headers are cleaned up a bit while importing them: some
part of the file that QEMU doesn't use are removed (description
of how to make hypercall in grant_table.h have been removed).

Other cleanup:
- xen-mapcache.c and xen-legacy-backend.c don't need grant_table.h.
- xenfb.c doesn't need event_channel.h.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Message-Id: <20190621105441.3025-3-anthony.perard@citrix.com>
2019-06-24 10:42:30 +01:00
Markus Armbruster
f91005e195 Supply missing header guards
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190604181618.19980-5-armbru@redhat.com>
2019-06-12 13:20:21 +02:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Markus Armbruster
dec9776049 trace-events: Fix attribution of trace points to source
Some trace points are attributed to the wrong source file.  Happens
when we neglect to update trace-events for code motion, or add events
in the wrong place, or misspell the file name.

Clean up with help of cleanup-trace-events.pl.  Same funnies as in the
previous commit, of course.  Manually shorten its change to
linux-user/trace-events to */signal.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20190314180929.27722-6-armbru@redhat.com
Message-Id: <20190314180929.27722-6-armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-22 16:18:07 +00:00
Markus Armbruster
500016e5db trace-events: Shorten file names in comments
We spell out sub/dir/ in sub/dir/trace-events' comments pointing to
source files.  That's because when trace-events got split up, the
comments were moved verbatim.

Delete the sub/dir/ part from these comments.  Gets rid of several
misspellings.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190314180929.27722-3-armbru@redhat.com
Message-Id: <20190314180929.27722-3-armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-22 16:18:07 +00:00
Yang Zhong
b42075bb77 virtio: express virtio dependencies with Kconfig
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190123065618.3520-42-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-07 21:45:53 +01:00
Paolo Bonzini
e0e312f352 build: switch to Kconfig
The make_device_config.sh script is replaced by minikconf, which
is modified to support the same command line as its predecessor.

The roots of the parsing are default-configs/*.mak, Kconfig.host and
hw/Kconfig.  One difference with make_device_config.sh is that all symbols
have to be defined in a Kconfig file, including those coming from the
configure script.  This is the reason for the Kconfig.host file introduced
in the previous patch. Whenever a file in default-configs/*.mak used
$(...) to refer to a config-host.mak symbol, this is replaced by a
Kconfig dependency; this part must be done already in this patch
for bisectability.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190123065618.3520-28-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-07 21:45:53 +01:00
Paolo Bonzini
82f5181777 kconfig: introduce kconfig files
The Kconfig files were generated mostly with this script:

  for i in `grep -ho CONFIG_[A-Z0-9_]* default-configs/* | sort -u`; do
    set fnord `git grep -lw $i -- 'hw/*/Makefile.objs' `
    shift
    if test $# = 1; then
      cat >> $(dirname $1)/Kconfig << EOF
config ${i#CONFIG_}
    bool

EOF
      git add $(dirname $1)/Kconfig
    else
      echo $i $*
    fi
  done
  sed -i '$d' hw/*/Kconfig
  for i in hw/*; do
    if test -d $i && ! test -f $i/Kconfig; then
      touch $i/Kconfig
      git add $i/Kconfig
    fi
  done

Whenever a symbol is referenced from multiple subdirectories, the
script prints the list of directories that reference the symbol.
These symbols have to be added manually to the Kconfig files.

Kconfig.host and hw/Kconfig were created manually.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20190123065618.3520-27-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-07 21:45:53 +01:00
Paolo Bonzini
3fa749654e 9pfs: remove unnecessary conditionals
The VIRTIO_9P || VIRTFS && XEN condition can be computed in hw/Makefile.objs,
removing an "if" from hw/9pfs/Makefile.objs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-07 21:45:53 +01:00
Paul Durrant
2d0ed5e642 xen: re-name XenDevice to XenLegacyDevice...
...and xen_backend.h to xen-legacy-backend.h

Rather than attempting to convert the existing backend infrastructure to
be QOM compliant (which would be hard to do in an incremental fashion),
subsequent patches will introduce a completely new framework for Xen PV
backends. Hence it is necessary to re-name parts of existing code to avoid
name clashes. The re-named 'legacy' infrastructure will be removed once all
backends have been ported to the new framework.

This patch is purely cosmetic. No functional change.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
2019-01-14 13:45:40 +00:00
Greg Kurz
93aee84f57 9p: remove support for the "handle" backend
The "handle" fsdev backend was deprecated in QEMU 2.12.0 with:

commit db3b3c7281
Author: Greg Kurz <groug@kaod.org>
Date:   Mon Jan 8 11:18:23 2018 +0100

    9pfs: deprecate handle backend

    This backend raise some concerns:

    - doesn't support symlinks
    - fails +100 tests in the PJD POSIX file system test suite [1]
    - requires the QEMU process to run with the CAP_DAC_READ_SEARCH
      capability, which isn't recommended for security reasons

    This backend should not be used and wil be removed. The 'local'
    backend is the recommended alternative.

    [1] https://www.tuxera.com/community/posix-test-suite/

    Signed-off-by: Greg Kurz <groug@kaod.org>
    Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
    Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

It has passed the two release cooling period without any complaint.

Remove it now.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
2018-12-12 14:18:10 +01:00
Greg Kurz
75607e0dcc xen/9pfs: use g_new(T, n) instead of g_malloc(sizeof(T) * n)
Because it is a recommended coding practice (see HACKING).

Signed-off-by: Greg Kurz <groug@kaod.org>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2018-12-12 14:18:10 +01:00
Greg Kurz
1923923bfa 9p: use g_new(T, n) instead of g_malloc(sizeof(T) * n)
Because it is a recommended coding practice (see HACKING).

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2018-12-12 14:18:10 +01:00
Greg Kurz
1d20398694 9p: fix QEMU crash when renaming files
When using the 9P2000.u version of the protocol, the following shell
command line in the guest can cause QEMU to crash:

    while true; do rm -rf aa; mkdir -p a/b & touch a/b/c & mv a aa; done

With 9P2000.u, file renaming is handled by the WSTAT command. The
v9fs_wstat() function calls v9fs_complete_rename(), which calls
v9fs_fix_path() for every fid whose path is affected by the change.
The involved calls to v9fs_path_copy() may race with any other access
to the fid path performed by some worker thread, causing a crash like
shown below:

Thread 12 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8, path=0x0,
 flags=65536, mode=0) at hw/9pfs/9p-local.c:59
59          while (*path && fd != -1) {
(gdb) bt
#0  0x0000555555a25da2 in local_open_nofollow (fs_ctx=0x555557d958b8,
 path=0x0, flags=65536, mode=0) at hw/9pfs/9p-local.c:59
#1  0x0000555555a25e0c in local_opendir_nofollow (fs_ctx=0x555557d958b8,
 path=0x0) at hw/9pfs/9p-local.c:92
#2  0x0000555555a261b8 in local_lstat (fs_ctx=0x555557d958b8,
 fs_path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/9p-local.c:185
#3  0x0000555555a2b367 in v9fs_co_lstat (pdu=0x555557d97498,
 path=0x555556b56858, stbuf=0x7fff84830ef0) at hw/9pfs/cofile.c:53
#4  0x0000555555a1e9e2 in v9fs_stat (opaque=0x555557d97498)
 at hw/9pfs/9p.c:1083
#5  0x0000555555e060a2 in coroutine_trampoline (i0=-669165424, i1=32767)
 at util/coroutine-ucontext.c:116
#6  0x00007fffef4f5600 in __start_context () at /lib64/libc.so.6
#7  0x0000000000000000 in  ()
(gdb)

The fix is to take the path write lock when calling v9fs_complete_rename(),
like in v9fs_rename().

Impact:  DoS triggered by unprivileged guest users.

Fixes: CVE-2018-19489
Cc: P J P <ppandit@redhat.com>
Reported-by: zhibin hu <noirfate@gmail.com>
Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-11-23 13:28:03 +01:00
Greg Kurz
5b3c77aa58 9p: take write lock on fid path updates (CVE-2018-19364)
Recent commit 5b76ef50f6 fixed a race where v9fs_co_open2() could
possibly overwrite a fid path with v9fs_path_copy() while it is being
accessed by some other thread, ie, use-after-free that can be detected
by ASAN with a custom 9p client.

It turns out that the same can happen at several locations where
v9fs_path_copy() is used to set the fid path. The fix is again to
take the write lock.

Fixes CVE-2018-19364.

Cc: P J P <ppandit@redhat.com>
Reported-by: zhibin hu <noirfate@gmail.com>
Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-11-20 13:00:35 +01:00
Greg Kurz
5b76ef50f6 9p: write lock path in v9fs_co_open2()
The assumption that the fid cannot be used by any other operation is
wrong. At least, nothing prevents a misbehaving client to create a
file with a given fid, and to pass this fid to some other operation
at the same time (ie, without waiting for the response to the creation
request). The call to v9fs_path_copy() performed by the worker thread
after the file was created can race with any access to the fid path
performed by some other thread. This causes use-after-free issues that
can be detected by ASAN with a custom 9p client.

Unlike other operations that only read the fid path, v9fs_co_open2()
does modify it. It should hence take the write lock.

Cc: P J P <ppandit@redhat.com>
Reported-by: zhibin hu <noirfate@gmail.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-11-08 21:19:05 +01:00
Markus Armbruster
b836723dfe fsdev: Clean up error reporting in qemu_fsdev_add()
Calling error_report() from within a function that takes an Error **
argument is suspicious.  qemu_fsdev_add() does that, and its caller
fsdev_init_func() then fails without setting an error.  Its caller
main(), via qemu_opts_foreach(), is fine with it, but clean it up
anyway.

Cc: Greg Kurz <groug@kaod.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-Id: <20181017082702.5581-32-armbru@redhat.com>
2018-10-19 14:51:34 +02:00
Markus Armbruster
1245402e3c 9pfs: Fix CLI parsing crash on error
Calling error_report() in a function that takes an Error ** argument
is suspicious.  9p-handle.c's handle_parse_opts() does that, and then
fails without setting an error.  Wrong.  Its caller crashes when it
tries to report the error:

    $ qemu-system-x86_64 -nodefaults -fsdev id=foo,fsdriver=handle
    qemu-system-x86_64: -fsdev id=foo,fsdriver=handle: warning: handle backend is deprecated
    qemu-system-x86_64: -fsdev id=foo,fsdriver=handle: fsdev: No path specified
    Segmentation fault (core dumped)

Screwed up when commit 91cda4e8f3 (v2.12.0) converted the function to
Error.  Fix by calling error_setg() instead of error_report().

Fixes: 91cda4e8f3
Cc: Greg Kurz <groug@kaod.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-9-armbru@redhat.com>
2018-10-19 14:51:34 +02:00
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
Keno Fischer
230f1b31c5 9p: darwin: Explicitly cast comparisons of mode_t with -1
Comparisons of mode_t with -1 require an explicit cast, since mode_t
is unsigned on Darwin.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-29 12:32:10 +02:00
Keno Fischer
5c99fa375d cutils: Provide strchrnul
strchrnul is a GNU extension and thus unavailable on a number of targets.
In the review for a commit removing strchrnul from 9p, I was asked to
create a qemu_strchrnul helper to factor out this functionality.
Do so, and use it in a number of other places in the code base that inlined
the replacement pattern in a place where strchrnul could be used.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-29 12:32:10 +02:00
Keno Fischer
aca6897fba 9p: xattr: Properly translate xattrcreate flags
As with unlinkat, these flags come from the client and need to
be translated to their host values. The protocol values happen
to match linux, but that need not be true in general.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:22 +02:00
Keno Fischer
67e8734574 9p: Properly check/translate flags in unlinkat
The 9p-local code previously relied on P9_DOTL_AT_REMOVEDIR and AT_REMOVEDIR
having the same numerical value and deferred any errorchecking to the
syscall itself. However, while the former assumption is true on Linux,
it is not true in general. 9p-handle did this properly however. Move
the translation code to the generic 9p server code and add an error
if unrecognized flags are passed.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:22 +02:00
Keno Fischer
5b7b2f9a85 9p: local: Avoid warning if FS_IOC_GETVERSION is not defined
Both `stbuf` and `local_ioc_getversion` where unused when
FS_IOC_GETVERSION was not defined, causing a compiler warning.

Reorganize the code to avoid this warning.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:22 +02:00
Keno Fischer
a647502c58 9p: xattr: Fix crashes due to free of uninitialized value
If the size returned from llistxattr/lgetxattr is 0, we skipped
the malloc call, leaving xattr.value uninitialized. However, this
value is later passed to `g_free` without any further checks,
causing an error. Fix that by always calling g_malloc unconditionally.
If `size` is 0, it will return NULL, which is safe to pass to g_free.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:22 +02:00
Keno Fischer
ec70b956fd 9p: Move a couple xattr functions to 9p-util
These functions will need custom implementations on Darwin. Since the
implementation is very similar among all of them, and 9p-util already
has the _nofollow version of fgetxattrat, let's move them all there.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:22 +02:00
Keno Fischer
2306271c38 9p: local: Properly set errp in fstatfs error path
In the review of

    9p: Avoid warning if FS_IOC_GETVERSION is not defined

Grep Kurz noted this error path was failing to set errp.
Fix that.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
[added local: to commit title, Greg Kurz]
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:21 +02:00
Keno Fischer
fde1f3e4a0 9p: proxy: Fix size passed to connect
The size to pass to the `connect` call is the size of the entire
`struct sockaddr_un`. Passing anything shorter than this causes errors
on darwin.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-06-07 12:17:21 +02:00
Paolo Bonzini
b5dfdb082f hw: make virtio devices configurable via default-configs/
This is only half of the work, because the proxy devices (virtio-*-pci,
virtio-*-ccw, etc.) are still included unconditionally.  It is still a
move in the right direction.

Based-on: <20180522194943.24871-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01 15:14:31 +02:00
Paul Durrant
58560f2ae7 xen: remove other open-coded use of libxengnttab
Now that helpers are available in xen_backend, use them throughout all
Xen PV backends.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22 11:43:21 -07:00
Greg Kurz
8f9c64bfa5 9p: add trace event for v9fs_setattr()
Don't print the tv_nsec part of atime and mtime, to stay below the 10
argument limit of trace events.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-05-02 08:59:24 +02:00
Marc-André Lureau
6ce7177ae2 9p: fix leak in synth_name_to_path()
Leak found thanks to ASAN:

Direct leak of 8 byte(s) in 1 object(s) allocated from:
    #0 0x55995789ac90 in __interceptor_malloc (/home/elmarco/src/qemu/build/x86_64-softmmu/qemu-system-x86_64+0x1510c90)
    #1 0x7f0a91190f0c in g_malloc /home/elmarco/src/gnome/glib/builddir/../glib/gmem.c:94
    #2 0x5599580a281c in v9fs_path_copy /home/elmarco/src/qemu/hw/9pfs/9p.c:196:17
    #3 0x559958f9ec5d in coroutine_trampoline /home/elmarco/src/qemu/util/coroutine-ucontext.c:116:9
    #4 0x7f0a8766ebbf  (/lib64/libc.so.6+0x50bbf)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-02-19 18:27:32 +01:00
Marc-André Lureau
e446a1eb5e 9p: v9fs_path_copy() readability
lhs/rhs doesn't tell much about how argument are handled, dst/src is
and const arguments is clearer in my mind. Use g_memdup() while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2018-02-19 18:27:15 +01:00
Markus Armbruster
922a01a013 Move include qemu/option.h from qemu-common.h to actual users
qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter.  Drop the include, and add it
to the places that actually need it.

While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.

This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-09 13:52:16 +01:00
Markus Armbruster
e688df6bc4 Include qapi/error.h exactly where needed
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2018-02-09 13:50:17 +01:00
Greg Kurz
357e2f7f4e tests: virtio-9p: add FLUSH operation test
The idea is to send a victim request that will possibly block in the
server and to send a flush request to cancel the victim request.

This patch adds two test to verifiy that:
- the server does not reply to a victim request that was actually
  cancelled
- the server replies to the flush request after replying to the
  victim request if it could not cancel it

9p request cancellation reference:

http://man.cat-v.org/plan_9/5/flush

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(groug, change the test to only write a single byte to avoid
        any alignment or endianess consideration)
2018-02-02 11:11:55 +01:00