qemu/hw/display
Markus Armbruster f8ed85ac99 Fix bad error handling after memory_region_init_ram()
Symptom:

    $ qemu-system-x86_64 -m 10000000
    Unexpected error in ram_block_add() at /work/armbru/qemu/exec.c:1456:
    upstream-qemu: cannot set up guest memory 'pc.ram': Cannot allocate memory
    Aborted (core dumped)

Root cause: commit ef701d7 screwed up handling of out-of-memory
conditions.  Before the commit, we report the error and exit(1), in
one place, ram_block_add().  The commit lifts the error handling up
the call chain some, to three places.  Fine.  Except it uses
&error_abort in these places, changing the behavior from exit(1) to
abort(), and thus undoing the work of commit 3922825 "exec: Don't
abort when we can't allocate guest memory".

The three places are:

* memory_region_init_ram()

  Commit 4994653 (right after commit ef701d7) lifted the error
  handling further, through memory_region_init_ram(), multiplying the
  incorrect use of &error_abort.  Later on, imitation of existing
  (bad) code may have created more.

* memory_region_init_ram_ptr()

  The &error_abort is still there.

* memory_region_init_rom_device()

  Doesn't need fixing, because commit 33e0eb5 (soon after commit
  ef701d7) lifted the error handling further, and in the process
  changed it from &error_abort to passing it up the call chain.
  Correct, because the callers are realize() methods.

Fix the error handling after memory_region_init_ram() with a
Coccinelle semantic patch:

    @r@
    expression mr, owner, name, size, err;
    position p;
    @@
            memory_region_init_ram(mr, owner, name, size,
    (
    -                              &error_abort
    +                              &error_fatal
    |
                                   err@p
    )
                                  );
    @script:python@
        p << r.p;
    @@
    print "%s:%s:%s" % (p[0].file, p[0].line, p[0].column)

When the last argument is &error_abort, it gets replaced by
&error_fatal.  This is the fix.

If the last argument is anything else, its position is reported.  This
lets us check the fix is complete.  Four positions get reported:

* ram_backend_memory_alloc()

  Error is passed up the call chain, ultimately through
  user_creatable_complete().  As far as I can tell, it's callers all
  handle the error sanely.

* fsl_imx25_realize(), fsl_imx31_realize(), dp8393x_realize()

  DeviceClass.realize() methods, errors handled sanely further up the
  call chain.

We're good.  Test case again behaves:

    $ qemu-system-x86_64 -m 10000000
    qemu-system-x86_64: cannot set up guest memory 'pc.ram': Cannot allocate memory
    [Exit 1 ]

The next commits will repair the rest of commit ef701d7's damage.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-3-git-send-email-armbru@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
2015-09-18 14:39:29 +02:00
..
Makefile.objs virtio-vga: add virtio gpu device with vga compatibility 2015-06-12 10:13:23 +02:00
ads7846.c savevm: Remove all the unneeded version_minimum_id_old (arm) 2014-05-13 16:09:35 +01:00
blizzard.c blizzard: do not depend on VGA internals 2015-01-15 10:44:13 +03:00
blizzard_template.h display: avoid multi-statement macro 2014-01-31 14:47:33 +00:00
cg3.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
cirrus_vga.c cirrus_vga: QOMify 2015-05-19 11:40:01 +02:00
cirrus_vga_rop.h cirrus: Fix host CPU blits 2014-07-11 10:17:02 +02:00
cirrus_vga_rop2.h hw: move private headers to hw/ subdirectories. 2013-04-08 18:13:16 +02:00
exynos4210_fimd.c maint: avoid useless "if (foo) free(foo)" pattern 2015-09-11 10:21:38 +03:00
framebuffer.c framebuffer: set DIRTY_MEMORY_VGA on RAM that is used for the framebuffer 2015-07-24 13:57:45 +02:00
framebuffer.h framebuffer: set DIRTY_MEMORY_VGA on RAM that is used for the framebuffer 2015-07-24 13:57:45 +02:00
g364fb.c qerror: Move #include out of qerror.h 2015-06-22 18:20:40 +02:00
jazz_led.c jazz_led: Add missing break in switch case 2014-05-24 00:07:56 +04:00
milkymist-tmu2.c savevm: Remove all the unneeded version_minimum_id_old (rest) 2014-05-14 15:24:51 +02:00
milkymist-vgafb.c framebuffer: set DIRTY_MEMORY_VGA on RAM that is used for the framebuffer 2015-07-24 13:57:45 +02:00
milkymist-vgafb_template.h milkymist-vgafb: swap pixel data in source buffer 2014-02-04 19:34:30 +01:00
omap_dss.c arm: Use g_new() & friends where that makes obvious sense 2015-09-07 10:39:27 +01:00
omap_lcd_template.h hw: use ld_p/st_p instead of ld_raw/st_raw 2014-06-05 16:04:17 +02:00
omap_lcdc.c arm: Use g_new() & friends where that makes obvious sense 2015-09-07 10:39:27 +01:00
pl110.c framebuffer: set DIRTY_MEMORY_VGA on RAM that is used for the framebuffer 2015-07-24 13:57:45 +02:00
pl110_template.h display: avoid multi-statement macro 2014-01-31 14:47:33 +00:00
pxa2xx_lcd.c framebuffer: set DIRTY_MEMORY_VGA on RAM that is used for the framebuffer 2015-07-24 13:57:45 +02:00
pxa2xx_template.h display: avoid multi-statement macro 2014-01-31 14:47:33 +00:00
qxl-logger.c hw/display/qxl-logger.c: Constify some variable 2015-06-23 20:23:39 +03:00
qxl-render.c typofixes - v4 2015-09-11 10:45:43 +03:00
qxl.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
qxl.h qxl: allow to specify head limit to qxl driver 2015-07-16 17:31:05 +02:00
sm501.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
sm501_template.h hw: use ld_p/st_p instead of ld_raw/st_raw 2014-06-05 16:04:17 +02:00
ssd0303.c savevm: Remove all the unneeded version_minimum_id_old (arm) 2014-05-13 16:09:35 +01:00
ssd0323.c ssd0323: fix buffer overun on invalid state load 2014-05-05 22:15:02 +02:00
tc6393xb.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
tc6393xb_template.h display: avoid multi-statement macro 2014-01-31 14:47:33 +00:00
tcx.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
vga-helpers.h vga: Rename vga_template.h to vga-helpers.h 2014-09-30 13:34:09 +02:00
vga-isa-mm.c vga: allow non-global vmstate 2014-04-28 10:21:55 +02:00
vga-isa.c isa: remove isa_mem_base variable 2015-02-13 14:09:28 +00:00
vga-pci.c virtio-vga: add virtio gpu device with vga compatibility 2015-06-12 10:13:23 +02:00
vga.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
vga.h hw: move private headers to hw/ subdirectories. 2013-04-08 18:13:16 +02:00
vga_int.h virtio-vga: add virtio gpu device with vga compatibility 2015-06-12 10:13:23 +02:00
virtio-gpu-pci.c virtio-gpu: use virtio_instance_init_common, fixup properties 2015-07-07 11:23:18 +02:00
virtio-gpu.c virtio: get_features() can fail 2015-07-27 18:11:53 +03:00
virtio-vga.c virtio-gpu: use virtio_instance_init_common, fixup properties 2015-07-07 11:23:18 +02:00
vmware_vga.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
xenfb.c Add tracing to xenfb. 2015-02-10 09:27:19 +03:00