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Check if BASEPRI is used properly by NVIC #21

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ilg-ul opened this issue Jul 23, 2016 · 4 comments
Closed

Check if BASEPRI is used properly by NVIC #21

ilg-ul opened this issue Jul 23, 2016 · 4 comments
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@ilg-ul
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ilg-ul commented Jul 23, 2016

Implementing critical sections via BASEPRI does not work as expected.

TODO: check/fix NVIC implementation.

Workaround: use DI/EI to implement critical sections.

@ilg-ul ilg-ul added the bug label Jul 23, 2016
@ilg-ul ilg-ul self-assigned this Jul 23, 2016
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ilg-ul commented Jul 24, 2016

to be noted that the lack of a functional BASEPRI is deadly for RTOS-es that use it for critical sections.

if possible, configure the RTOS to use DI/EI. if this is not possible (like in some FreeRTOS ports), manually patch the port files. use the Cortex-M0 port as inspiration.

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ilg-ul commented Jul 24, 2016

it is confirmed that the current QEMU does not use BASEPRI when processing interrupts.

the instructions to handle BASEPRI are fully implemented, and the value displays correctly in the debug session, but the NVIC emulation ignores it.

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ilg-ul commented Jul 25, 2016

Done.

It was a bit tricky to pass BASEPRI from the CPU state to NVIC (GIC state), but a good old pointer did the job.

The main action was done in gic_update(), when computing the best_prio.

The next challange was to update again when BASEPRI changed, to process pending interrupts when the critical section exited.

3cb3c6c

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ilg-ul commented Jul 27, 2016

fixed in 2.6.0-20160728

@ilg-ul ilg-ul closed this as completed Jul 27, 2016
ilg-ul pushed a commit that referenced this issue Oct 26, 2016
The vhost-user & colo code is poking at the QemuOpts instance
in the CharDriverState struct, not realizing that it is valid
for this to be NULL. e.g. the following crash shows a codepath
where it will be NULL:

 Program terminated with signal SIGSEGV, Segmentation fault.
 #0  0x000055baf6ab4adc in qemu_opt_foreach (opts=0x0, func=0x55baf696b650 <net_vhost_chardev_opts>, opaque=0x7ffc51368c00, errp=0x7ffc51368e48) at util/qemu-option.c:617
 617         QTAILQ_FOREACH(opt, &opts->head, next) {
 [Current thread is 1 (Thread 0x7f1d4970bb40 (LWP 6603))]
 (gdb) bt
 #0  0x000055baf6ab4adc in qemu_opt_foreach (opts=0x0, func=0x55baf696b650 <net_vhost_chardev_opts>, opaque=0x7ffc51368c00, errp=0x7ffc51368e48) at util/qemu-option.c:617
 #1  0x000055baf696b7da in net_vhost_parse_chardev (opts=0x55baf8ff9260, errp=0x7ffc51368e48) at net/vhost-user.c:314
 #2  0x000055baf696b985 in net_init_vhost_user (netdev=0x55baf8ff9250, name=0x55baf879d270 "hostnet2", peer=0x0, errp=0x7ffc51368e48) at net/vhost-user.c:360
 #3  0x000055baf6960216 in net_client_init1 (object=0x55baf8ff9250, is_netdev=true, errp=0x7ffc51368e48) at net/net.c:1051
 #4  0x000055baf6960518 in net_client_init (opts=0x55baf776e7e0, is_netdev=true, errp=0x7ffc51368f00) at net/net.c:1108
 #5  0x000055baf696083f in netdev_add (opts=0x55baf776e7e0, errp=0x7ffc51368f00) at net/net.c:1186
 #6  0x000055baf69608c7 in qmp_netdev_add (qdict=0x55baf7afaf60, ret=0x7ffc51368f50, errp=0x7ffc51368f48) at net/net.c:1205
 #7  0x000055baf6622135 in handle_qmp_command (parser=0x55baf77fb590, tokens=0x7f1d24011960) at /path/to/qemu.git/monitor.c:3978
 #8  0x000055baf6a9d099 in json_message_process_token (lexer=0x55baf77fb598, input=0x55baf75acd20, type=JSON_RCURLY, x=113, y=19) at qobject/json-streamer.c:105
 #9  0x000055baf6abf7aa in json_lexer_feed_char (lexer=0x55baf77fb598, ch=125 '}', flush=false) at qobject/json-lexer.c:319
 #10 0x000055baf6abf8f2 in json_lexer_feed (lexer=0x55baf77fb598, buffer=0x7ffc51369170 "}R\204\367\272U", size=1) at qobject/json-lexer.c:369
 #11 0x000055baf6a9d13c in json_message_parser_feed (parser=0x55baf77fb590, buffer=0x7ffc51369170 "}R\204\367\272U", size=1) at qobject/json-streamer.c:124
 #12 0x000055baf66221f7 in monitor_qmp_read (opaque=0x55baf77fb530, buf=0x7ffc51369170 "}R\204\367\272U", size=1) at /path/to/qemu.git/monitor.c:3994
 #13 0x000055baf6757014 in qemu_chr_be_write_impl (s=0x55baf7610a40, buf=0x7ffc51369170 "}R\204\367\272U", len=1) at qemu-char.c:387
 #14 0x000055baf6757076 in qemu_chr_be_write (s=0x55baf7610a40, buf=0x7ffc51369170 "}R\204\367\272U", len=1) at qemu-char.c:399
 #15 0x000055baf675b3b0 in tcp_chr_read (chan=0x55baf90244b0, cond=G_IO_IN, opaque=0x55baf7610a40) at qemu-char.c:2927
 #16 0x000055baf6a5d655 in qio_channel_fd_source_dispatch (source=0x55baf7610df0, callback=0x55baf675b25a <tcp_chr_read>, user_data=0x55baf7610a40) at io/channel-watch.c:84
 #17 0x00007f1d3e80cbbd in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
 #18 0x000055baf69d3720 in glib_pollfds_poll () at main-loop.c:213
 #19 0x000055baf69d37fd in os_host_main_loop_wait (timeout=126000000) at main-loop.c:258
 #20 0x000055baf69d38ad in main_loop_wait (nonblocking=0) at main-loop.c:506
 #21 0x000055baf676587b in main_loop () at vl.c:1908
 #22 0x000055baf676d3bf in main (argc=101, argv=0x7ffc5136a6c8, envp=0x7ffc5136a9f8) at vl.c:4604
 (gdb) p opts
 $1 = (QemuOpts *) 0x0

The crash occurred when attaching vhost-user net via QMP:

{
    "execute": "chardev-add",
    "arguments": {
        "id": "charnet2",
        "backend": {
            "type": "socket",
            "data": {
                "addr": {
                    "type": "unix",
                    "data": {
                        "path": "/var/run/openvswitch/vhost-user1"
                    }
                },
                "wait": false,
                "server": false
            }
        }
    },
    "id": "libvirt-19"
}
{
    "return": {

    },
    "id": "libvirt-19"
}
{
    "execute": "netdev_add",
    "arguments": {
        "type": "vhost-user",
        "chardev": "charnet2",
        "id": "hostnet2"
    },
    "id": "libvirt-20"
}

Code using chardevs should not be poking at the internals of the
CharDriverState struct. What vhost-user wants is a chardev that is
operating as reconnectable network service, along with the ability
to do FD passing over the connection. The colo code simply wants
a network service. Add a feature concept to the char drivers so
that chardev users can query the actual features they wish to have
supported. The QemuOpts member is removed to prevent future mistakes
in this area.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
ilg-ul pushed a commit that referenced this issue Oct 26, 2016
The vnc_server_info_get will allocate the VncServerInfo
struct and then call vnc_init_basic_info_from_server_addr
to populate the basic fields. If this returns an error
though, the qapi_free_VncServerInfo call will then crash
because the VncServerInfo struct instance was not properly
NULL-initialized and thus contains random stack garbage.

 #0  0x00007f1987c8e6f5 in raise () at /lib64/libc.so.6
 #1  0x00007f1987c902fa in abort () at /lib64/libc.so.6
 #2  0x00007f1987ccf600 in __libc_message () at /lib64/libc.so.6
 #3  0x00007f1987cd7d4a in _int_free () at /lib64/libc.so.6
 #4  0x00007f1987cdb2ac in free () at /lib64/libc.so.6
 #5  0x00007f198b654f6e in g_free () at /lib64/libglib-2.0.so.0
 #6  0x0000559193cdcf54 in visit_type_str (v=v@entry=
     0x5591972f14b0, name=name@entry=0x559193de1e29 "host", obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899d80)
     at qapi/qapi-visit-core.c:255
 #7  0x0000559193cca8f3 in visit_type_VncBasicInfo_members (v=v@entry=
     0x5591972f14b0, obj=obj@entry=0x5591961dbfa0, errp=errp@entry=0x7fffd7899dc0) at qapi-visit.c:12307
 #8  0x0000559193ccb523 in visit_type_VncServerInfo_members (v=v@entry=
     0x5591972f14b0, obj=0x5591961dbfa0, errp=errp@entry=0x7fffd7899e00) at qapi-visit.c:12632
 #9  0x0000559193ccb60b in visit_type_VncServerInfo (v=v@entry=
     0x5591972f14b0, name=name@entry=0x0, obj=obj@entry=0x7fffd7899e48, errp=errp@entry=0x0) at qapi-visit.c:12658
 #10 0x0000559193cb53d8 in qapi_free_VncServerInfo (obj=<optimized out>) at qapi-types.c:3970
 #11 0x0000559193c1e6ba in vnc_server_info_get (vd=0x7f1951498010) at ui/vnc.c:233
 #12 0x0000559193c24275 in vnc_connect (vs=0x559197b2f200, vs=0x559197b2f200, event=QAPI_EVENT_VNC_CONNECTED) at ui/vnc.c:284
 #13 0x0000559193c24275 in vnc_connect (vd=vd@entry=0x7f1951498010, sioc=sioc@entry=0x559196bf9c00, skipauth=skipauth@entry=tru e, websocket=websocket@entry=false) at ui/vnc.c:3039
 #14 0x0000559193c25806 in vnc_display_add_client (id=<optimized out>, csock=<optimized out>, skipauth=<optimized out>)
     at ui/vnc.c:3877
 #15 0x0000559193a90c28 in qmp_marshal_add_client (args=<optimized out>, ret=<optimized out>, errp=0x7fffd7899f90)
     at qmp-marshal.c:105
 #16 0x000055919399c2b7 in handle_qmp_command (parser=<optimized out>, tokens=<optimized out>)
     at /home/berrange/src/virt/qemu/monitor.c:3971
 #17 0x0000559193ce3307 in json_message_process_token (lexer=0x559194ab0838, input=0x559194a6d940, type=JSON_RCURLY, x=111, y=1 2) at qobject/json-streamer.c:105
 #18 0x0000559193cfa90d in json_lexer_feed_char (lexer=lexer@entry=0x559194ab0838, ch=125 '}', flush=flush@entry=false)
     at qobject/json-lexer.c:319
 #19 0x0000559193cfaa1e in json_lexer_feed (lexer=0x559194ab0838, buffer=<optimized out>, size=<optimized out>)
     at qobject/json-lexer.c:369
 #20 0x0000559193ce33c9 in json_message_parser_feed (parser=<optimized out>, buffer=<optimized out>, size=<optimized out>)
     at qobject/json-streamer.c:124
 #21 0x000055919399a85b in monitor_qmp_read (opaque=<optimized out>, buf=<optimized out>, size=<optimized out>)
     at /home/berrange/src/virt/qemu/monitor.c:3987
 #22 0x0000559193a87d00 in tcp_chr_read (chan=<optimized out>, cond=<optimized out>, opaque=0x559194a7d900)
     at qemu-char.c:2895
 #23 0x00007f198b64f703 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
 #24 0x0000559193c484b3 in main_loop_wait () at main-loop.c:213
 #25 0x0000559193c484b3 in main_loop_wait (timeout=<optimized out>) at main-loop.c:258
 #26 0x0000559193c484b3 in main_loop_wait (nonblocking=<optimized out>) at main-loop.c:506
 #27 0x0000559193964c55 in main () at vl.c:1908
 #28 0x0000559193964c55 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4603

This was introduced in

  commit 98481bf
  Author: Eric Blake <eblake@redhat.com>
  Date:   Mon Oct 26 16:34:45 2015 -0600

    vnc: Hoist allocation of VncBasicInfo to callers

which added error reporting for vnc_init_basic_info_from_server_addr
but didn't change the g_malloc calls to g_malloc0.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1470134726-15697-3-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
ilg-ul pushed a commit that referenced this issue Oct 26, 2016
ahci-test /x86_64/ahci/io/dma/lba28/retry triggers the following leak:

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x7fc4b2a25e20 in malloc (/lib64/libasan.so.3+0xc6e20)
    #1 0x7fc4993bce58 in g_malloc (/lib64/libglib-2.0.so.0+0x4ee58)
    #2 0x556a187d4b34 in ahci_populate_sglist hw/ide/ahci.c:896
    #3 0x556a187d8237 in ahci_dma_prepare_buf hw/ide/ahci.c:1367
    #4 0x556a187b5a1a in ide_dma_cb hw/ide/core.c:844
    #5 0x556a187d7eec in ahci_start_dma hw/ide/ahci.c:1333
    #6 0x556a187b650b in ide_start_dma hw/ide/core.c:921
    #7 0x556a187b61e6 in ide_sector_start_dma hw/ide/core.c:911
    #8 0x556a187b9e26 in cmd_write_dma hw/ide/core.c:1486
    #9 0x556a187bd519 in ide_exec_cmd hw/ide/core.c:2027
    #10 0x556a187d71c5 in handle_reg_h2d_fis hw/ide/ahci.c:1204
    #11 0x556a187d7681 in handle_cmd hw/ide/ahci.c:1254
    #12 0x556a187d168a in check_cmd hw/ide/ahci.c:510
    #13 0x556a187d0afc in ahci_port_write hw/ide/ahci.c:314
    #14 0x556a187d105d in ahci_mem_write hw/ide/ahci.c:435
    #15 0x556a1831d959 in memory_region_write_accessor /home/elmarco/src/qemu/memory.c:525
    #16 0x556a1831dc35 in access_with_adjusted_size /home/elmarco/src/qemu/memory.c:591
    #17 0x556a18323ce3 in memory_region_dispatch_write /home/elmarco/src/qemu/memory.c:1262
    #18 0x556a1828cf67 in address_space_write_continue /home/elmarco/src/qemu/exec.c:2578
    #19 0x556a1828d20b in address_space_write /home/elmarco/src/qemu/exec.c:2635
    #20 0x556a1828d92b in address_space_rw /home/elmarco/src/qemu/exec.c:2737
    #21 0x556a1828daf7 in cpu_physical_memory_rw /home/elmarco/src/qemu/exec.c:2746
    #22 0x556a183068d3 in cpu_physical_memory_write /home/elmarco/src/qemu/include/exec/cpu-common.h:72
    #23 0x556a18308194 in qtest_process_command /home/elmarco/src/qemu/qtest.c:382
    #24 0x556a18309999 in qtest_process_inbuf /home/elmarco/src/qemu/qtest.c:573
    #25 0x556a18309a4a in qtest_read /home/elmarco/src/qemu/qtest.c:585
    #26 0x556a18598b85 in qemu_chr_be_write_impl /home/elmarco/src/qemu/qemu-char.c:387
    #27 0x556a18598c52 in qemu_chr_be_write /home/elmarco/src/qemu/qemu-char.c:399
    #28 0x556a185a2afa in tcp_chr_read /home/elmarco/src/qemu/qemu-char.c:2902
    #29 0x556a18cbaf52 in qio_channel_fd_source_dispatch io/channel-watch.c:84

Follow John Snow recommendation:
  Everywhere else ncq_err is used, it is accompanied by a list cleanup
  except for ncq_cb, which is the case you are fixing here.

  Move the sglist destruction inside of ncq_err and then delete it from
  the other two locations to keep it tidy.

  Call dma_buf_commit in ide_dma_cb after the early return. Though, this
  is also a little wonky because this routine does more than clear the
  list, but it is at the moment the centralized "we're done with the
  sglist" function and none of the other side effects that occur in
  dma_buf_commit will interfere with the reset that occurs from
  ide_restart_bh, I think

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
ilg-ul pushed a commit that referenced this issue Oct 26, 2016
Since aa5cb7f, the chardevs are being cleaned up when leaving
qemu. However, the monitor has still references to them, which may
lead to crashes when running atexit() and trying to send monitor
events:

 #0  0x00007fffdb18f6f5 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
 #1  0x00007fffdb1912fa in __GI_abort () at abort.c:89
 #2  0x0000555555c263e7 in error_exit (err=22, msg=0x555555d47980 <__func__.13537> "qemu_mutex_lock") at util/qemu-thread-posix.c:39
 #3  0x0000555555c26488 in qemu_mutex_lock (mutex=0x5555567a2420) at util/qemu-thread-posix.c:66
 #4  0x00005555558c52db in qemu_chr_fe_write (s=0x5555567a2420, buf=0x55555740dc40 "{\"timestamp\": {\"seconds\": 1470041716, \"microseconds\": 989699}, \"event\": \"SPICE_DISCONNECTED\", \"data\": {\"server\": {\"port\": \"5900\", \"family\": \"ipv4\", \"host\": \"127.0.0.1\"}, \"client\": {\"port\": \"40272\", \"f"..., len=240) at qemu-char.c:280
 #5  0x0000555555787cad in monitor_flush_locked (mon=0x5555567bd9e0) at /home/elmarco/src/qemu/monitor.c:311
 #6  0x0000555555787e46 in monitor_puts (mon=0x5555567bd9e0, str=0x5555567a44ef "") at /home/elmarco/src/qemu/monitor.c:353
 #7  0x00005555557880fe in monitor_json_emitter (mon=0x5555567bd9e0, data=0x5555567c73a0) at /home/elmarco/src/qemu/monitor.c:401
 #8  0x00005555557882d2 in monitor_qapi_event_emit (event=QAPI_EVENT_SPICE_DISCONNECTED, qdict=0x5555567c73a0) at /home/elmarco/src/qemu/monitor.c:472
 #9  0x000055555578838f in monitor_qapi_event_queue (event=QAPI_EVENT_SPICE_DISCONNECTED, qdict=0x5555567c73a0, errp=0x7fffffffca88) at /home/elmarco/src/qemu/monitor.c:497
 #10 0x0000555555c15541 in qapi_event_send_spice_disconnected (server=0x5555571139d0, client=0x5555570d0db0, errp=0x5555566c0428 <error_abort>) at qapi-event.c:1038
 #11 0x0000555555b11bc6 in channel_event (event=3, info=0x5555570d6c00) at ui/spice-core.c:248
 #12 0x00007fffdcc9983a in adapter_channel_event (event=3, info=0x5555570d6c00) at reds.c:120
 #13 0x00007fffdcc99a25 in reds_handle_channel_event (reds=0x5555567a9d60, event=3, info=0x5555570d6c00) at reds.c:324
 #14 0x00007fffdcc7d4c4 in main_dispatcher_self_handle_channel_event (self=0x5555567b28b0, event=3, info=0x5555570d6c00) at main-dispatcher.c:175
 #15 0x00007fffdcc7d5b1 in main_dispatcher_channel_event (self=0x5555567b28b0, event=3, info=0x5555570d6c00) at main-dispatcher.c:194
 #16 0x00007fffdcca7674 in reds_stream_push_channel_event (s=0x5555570d9910, event=3) at reds-stream.c:354
 #17 0x00007fffdcca749b in reds_stream_free (s=0x5555570d9910) at reds-stream.c:323
 #18 0x00007fffdccb5dad in snd_disconnect_channel (channel=0x5555576a89a0) at sound.c:229
 #19 0x00007fffdccb9e57 in snd_detach_common (worker=0x555557739720) at sound.c:1589
 #20 0x00007fffdccb9f0e in snd_detach_playback (sin=0x5555569fe3f8) at sound.c:1602
 #21 0x00007fffdcca3373 in spice_server_remove_interface (sin=0x5555569fe3f8) at reds.c:3387
 #22 0x00005555558ff6e2 in line_out_fini (hw=0x5555569fe370) at audio/spiceaudio.c:152
 #23 0x00005555558f909e in audio_atexit () at audio/audio.c:1754
 #24 0x00007fffdb1941e8 in __run_exit_handlers (status=0, listp=0x7fffdb5175d8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82
 #25 0x00007fffdb194235 in __GI_exit (status=<optimized out>) at exit.c:104
 #26 0x00007fffdb17b738 in __libc_start_main (main=0x5555558d7874 <main>, argc=67, argv=0x7fffffffcf48, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffcf38) at ../csu/libc-start.c:323

Add a monitor_cleanup() functions to remove all the monitors before
cleaning up the chardev. Note that we are "losing" some events that
used to be sent during atexit().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20160801112343.29082-2-marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
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