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author | Markus Armbruster <armbru@redhat.com> | 2015-09-11 16:51:43 +0200 |
---|---|---|
committer | Markus Armbruster <armbru@redhat.com> | 2015-09-18 14:39:29 +0200 |
commit | f8ed85ac992c48814d916d5df4d44f9a971c5de4 (patch) | |
tree | 125b3e69a5c5393cb0db622f7c3a7f1893f9f9ea /hw/s390x | |
parent | a29a37b994ca3c5a1d39fa0e8934f7e0f2cf57ef (diff) | |
download | qemu-f8ed85ac992c48814d916d5df4d44f9a971c5de4.zip qemu-f8ed85ac992c48814d916d5df4d44f9a971c5de4.tar.gz qemu-f8ed85ac992c48814d916d5df4d44f9a971c5de4.tar.bz2 |
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>
Diffstat (limited to 'hw/s390x')
-rw-r--r-- | hw/s390x/s390-virtio-ccw.c | 2 | ||||
-rw-r--r-- | hw/s390x/sclp.c | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index 27a8360..0e30c0f 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -106,7 +106,7 @@ void s390_memory_init(ram_addr_t mem_size) MemoryRegion *ram = g_new(MemoryRegion, 1); /* allocate RAM for core */ - memory_region_init_ram(ram, NULL, "s390.ram", mem_size, &error_abort); + memory_region_init_ram(ram, NULL, "s390.ram", mem_size, &error_fatal); vmstate_register_ram_global(ram); memory_region_add_subregion(sysmem, 0, ram); diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c index fd277e1..a061b49 100644 --- a/hw/s390x/sclp.c +++ b/hw/s390x/sclp.c @@ -231,7 +231,8 @@ static void assign_storage(SCLPDevice *sclp, SCCB *sccb) this_subregion_size = mhd->standby_subregion_size; } - memory_region_init_ram(standby_ram, NULL, id, this_subregion_size, &error_abort); + memory_region_init_ram(standby_ram, NULL, id, this_subregion_size, + &error_fatal); /* This is a hack to make memory hotunplug work again. Once we have * subdevices, we have to unparent them when unassigning memory, * instead of doing it via the ref count of the MemoryRegion. */ |