Re: [Qemu-block] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file
在 2017/6/6 11:50, Peter Xu 写道: On Tue, Jun 06, 2017 at 11:38:05AM +0800, QingFeng Hao wrote: 在 2017/6/6 11:03, Peter Xu 写道: On Mon, Jun 05, 2017 at 12:48:51PM +0200, QingFeng Hao wrote: In load_vmstate, mis->from_src_file is freed twice, the first free is by qemu_fclose, the second is by migration_incoming_state_destroy and it causes Illegal instruction exception. The fix is just to remove the first free. This problem is found by qemu-iotests case 068 since commit "660819b migration: shut src return path unconditionally". The error is: 068 1s ... - output mismatch (see 068.out.bad) --- tests/qemu-iotests/068.out 2017-05-06 01:00:26.417270437 +0200 +++ 068.out.bad2017-06-03 13:59:55.360274640 +0200 @@ -6,6 +6,8 @@ QEMU X.Y.Z monitor - type 'help' for more information (qemu) savevm 0 (qemu) quit +./common.config: line 107: 242472 Illegal instruction (core dumped) ( if [ -n "${QEMU_NEED_PID}" ]; then +echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"; +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" ) QEMU X.Y.Z monitor - type 'help' for more information -(qemu) quit -*** done +(qemu) *** done Signed-off-by: QingFeng Hao --- migration/savevm.c | 1 - 1 file changed, 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f59d0..853e14e34e 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp) aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); -qemu_fclose(f); aio_context_release(aio_context); migration_incoming_state_destroy(); Thanks QingFeng for the fix! Reviewed-by: Peter Xu Though here instead of removing the fclose(), not sure whether this is nicer: diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f5..1feb519 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2233,7 +2233,6 @@ int load_snapshot(const char *name, Error **errp) QEMUFile *f; int ret; AioContext *aio_context; -MigrationIncomingState *mis = migration_incoming_get_current(); if (!bdrv_all_can_snapshot(&bs)) { error_setg(errp, @@ -2286,7 +2285,6 @@ int load_snapshot(const char *name, Error **errp) } qemu_system_reset(SHUTDOWN_CAUSE_NONE); -mis->from_src_file = f; aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); Thanks Peter. I have a doubt on this change because I see there are several places referencing from_src_file e.g. loadvm_postcopy_ram_handle_discard, and it seems to get byte from the file and it's called by qemu_loadvm_state. Anyway, you remind me for the description that is "In load_snapshot" rather than "In load_vmstate". thanks Oh I didn't really notice that. :) It shouldn't affect imho since load snapshot won't trigger postcopy codes. But sure current fix is good enough for me at least. Ok, thanks! Thanks, -- Regards QingFeng Hao
Re: [Qemu-block] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file
On Tue, Jun 06, 2017 at 11:38:05AM +0800, QingFeng Hao wrote: > > > 在 2017/6/6 11:03, Peter Xu 写道: > >On Mon, Jun 05, 2017 at 12:48:51PM +0200, QingFeng Hao wrote: > >>In load_vmstate, mis->from_src_file is freed twice, the first free is by > >>qemu_fclose, the second is by migration_incoming_state_destroy and > >>it causes Illegal instruction exception. The fix is just to remove the > >>first free. > >> > >>This problem is found by qemu-iotests case 068 since commit > >>"660819b migration: shut src return path unconditionally". The error is: > >>068 1s ... - output mismatch (see 068.out.bad) > >> --- tests/qemu-iotests/068.out 2017-05-06 01:00:26.417270437 +0200 > >> +++ 068.out.bad2017-06-03 13:59:55.360274640 +0200 > >> @@ -6,6 +6,8 @@ > >> QEMU X.Y.Z monitor - type 'help' for more information > >> (qemu) savevm 0 > >> (qemu) quit > >> +./common.config: line 107: 242472 Illegal instruction (core > >> dumped) ( if [ -n "${QEMU_NEED_PID}" ]; then > >> +echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"; > >> +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" ) > >> QEMU X.Y.Z monitor - type 'help' for more information > >> -(qemu) quit > >> -*** done > >> +(qemu) *** done > >> > >>Signed-off-by: QingFeng Hao > >>--- > >> migration/savevm.c | 1 - > >> 1 file changed, 1 deletion(-) > >> > >>diff --git a/migration/savevm.c b/migration/savevm.c > >>index 9c320f59d0..853e14e34e 100644 > >>--- a/migration/savevm.c > >>+++ b/migration/savevm.c > >>@@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp) > >> aio_context_acquire(aio_context); > >> ret = qemu_loadvm_state(f); > >>-qemu_fclose(f); > >> aio_context_release(aio_context); > >> migration_incoming_state_destroy(); > >Thanks QingFeng for the fix! > > > >Reviewed-by: Peter Xu > > > >Though here instead of removing the fclose(), not sure whether this is > >nicer: > > > >diff --git a/migration/savevm.c b/migration/savevm.c > >index 9c320f5..1feb519 100644 > >--- a/migration/savevm.c > >+++ b/migration/savevm.c > >@@ -2233,7 +2233,6 @@ int load_snapshot(const char *name, Error **errp) > > QEMUFile *f; > > int ret; > > AioContext *aio_context; > >-MigrationIncomingState *mis = migration_incoming_get_current(); > > > > if (!bdrv_all_can_snapshot(&bs)) { > > error_setg(errp, > >@@ -2286,7 +2285,6 @@ int load_snapshot(const char *name, Error **errp) > > } > > > > qemu_system_reset(SHUTDOWN_CAUSE_NONE); > >-mis->from_src_file = f; > > > > aio_context_acquire(aio_context); > > ret = qemu_loadvm_state(f); > Thanks Peter. I have a doubt on this change because I see there are several > places > referencing from_src_file e.g. loadvm_postcopy_ram_handle_discard, and it > seems to > get byte from the file and it's called by qemu_loadvm_state. > Anyway, you remind me for the description that is "In load_snapshot" rather > than > "In load_vmstate". thanks Oh I didn't really notice that. :) It shouldn't affect imho since load snapshot won't trigger postcopy codes. But sure current fix is good enough for me at least. Thanks, -- Peter Xu
Re: [Qemu-block] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file
在 2017/6/6 11:03, Peter Xu 写道: On Mon, Jun 05, 2017 at 12:48:51PM +0200, QingFeng Hao wrote: In load_vmstate, mis->from_src_file is freed twice, the first free is by qemu_fclose, the second is by migration_incoming_state_destroy and it causes Illegal instruction exception. The fix is just to remove the first free. This problem is found by qemu-iotests case 068 since commit "660819b migration: shut src return path unconditionally". The error is: 068 1s ... - output mismatch (see 068.out.bad) --- tests/qemu-iotests/068.out 2017-05-06 01:00:26.417270437 +0200 +++ 068.out.bad2017-06-03 13:59:55.360274640 +0200 @@ -6,6 +6,8 @@ QEMU X.Y.Z monitor - type 'help' for more information (qemu) savevm 0 (qemu) quit +./common.config: line 107: 242472 Illegal instruction (core dumped) ( if [ -n "${QEMU_NEED_PID}" ]; then +echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"; +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" ) QEMU X.Y.Z monitor - type 'help' for more information -(qemu) quit -*** done +(qemu) *** done Signed-off-by: QingFeng Hao --- migration/savevm.c | 1 - 1 file changed, 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f59d0..853e14e34e 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp) aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); -qemu_fclose(f); aio_context_release(aio_context); migration_incoming_state_destroy(); Thanks QingFeng for the fix! Reviewed-by: Peter Xu Though here instead of removing the fclose(), not sure whether this is nicer: diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f5..1feb519 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2233,7 +2233,6 @@ int load_snapshot(const char *name, Error **errp) QEMUFile *f; int ret; AioContext *aio_context; -MigrationIncomingState *mis = migration_incoming_get_current(); if (!bdrv_all_can_snapshot(&bs)) { error_setg(errp, @@ -2286,7 +2285,6 @@ int load_snapshot(const char *name, Error **errp) } qemu_system_reset(SHUTDOWN_CAUSE_NONE); -mis->from_src_file = f; aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); Thanks Peter. I have a doubt on this change because I see there are several places referencing from_src_file e.g. loadvm_postcopy_ram_handle_discard, and it seems to get byte from the file and it's called by qemu_loadvm_state. Anyway, you remind me for the description that is "In load_snapshot" rather than "In load_vmstate". thanks Since I see we setup from_src_file but we don't really use it. If we remove that line, we can also remove the migration_incoming_get_current() call altogether. Either way work for me. So my r-b stands always. :-) -- Regards QingFeng Hao
Re: [Qemu-block] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file
On Mon, Jun 05, 2017 at 12:48:51PM +0200, QingFeng Hao wrote: > In load_vmstate, mis->from_src_file is freed twice, the first free is by > qemu_fclose, the second is by migration_incoming_state_destroy and > it causes Illegal instruction exception. The fix is just to remove the > first free. > > This problem is found by qemu-iotests case 068 since commit > "660819b migration: shut src return path unconditionally". The error is: > 068 1s ... - output mismatch (see 068.out.bad) > --- tests/qemu-iotests/068.out2017-05-06 01:00:26.417270437 +0200 > +++ 068.out.bad 2017-06-03 13:59:55.360274640 +0200 > @@ -6,6 +6,8 @@ > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm 0 > (qemu) quit > +./common.config: line 107: 242472 Illegal instruction (core dumped) > ( if [ -n "${QEMU_NEED_PID}" ]; then > +echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"; > +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" ) > QEMU X.Y.Z monitor - type 'help' for more information > -(qemu) quit > -*** done > +(qemu) *** done > > Signed-off-by: QingFeng Hao > --- > migration/savevm.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/migration/savevm.c b/migration/savevm.c > index 9c320f59d0..853e14e34e 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp) > > aio_context_acquire(aio_context); > ret = qemu_loadvm_state(f); > -qemu_fclose(f); > aio_context_release(aio_context); > > migration_incoming_state_destroy(); Thanks QingFeng for the fix! Reviewed-by: Peter Xu Though here instead of removing the fclose(), not sure whether this is nicer: diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f5..1feb519 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2233,7 +2233,6 @@ int load_snapshot(const char *name, Error **errp) QEMUFile *f; int ret; AioContext *aio_context; -MigrationIncomingState *mis = migration_incoming_get_current(); if (!bdrv_all_can_snapshot(&bs)) { error_setg(errp, @@ -2286,7 +2285,6 @@ int load_snapshot(const char *name, Error **errp) } qemu_system_reset(SHUTDOWN_CAUSE_NONE); -mis->from_src_file = f; aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); Since I see we setup from_src_file but we don't really use it. If we remove that line, we can also remove the migration_incoming_get_current() call altogether. Either way work for me. So my r-b stands always. :-) -- Peter Xu
[Qemu-block] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file
In load_vmstate, mis->from_src_file is freed twice, the first free is by qemu_fclose, the second is by migration_incoming_state_destroy and it causes Illegal instruction exception. The fix is just to remove the first free. This problem is found by qemu-iotests case 068 since commit "660819b migration: shut src return path unconditionally". The error is: 068 1s ... - output mismatch (see 068.out.bad) --- tests/qemu-iotests/068.out 2017-05-06 01:00:26.417270437 +0200 +++ 068.out.bad 2017-06-03 13:59:55.360274640 +0200 @@ -6,6 +6,8 @@ QEMU X.Y.Z monitor - type 'help' for more information (qemu) savevm 0 (qemu) quit +./common.config: line 107: 242472 Illegal instruction (core dumped) ( if [ -n "${QEMU_NEED_PID}" ]; then +echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid"; +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" ) QEMU X.Y.Z monitor - type 'help' for more information -(qemu) quit -*** done +(qemu) *** done Signed-off-by: QingFeng Hao --- migration/savevm.c | 1 - 1 file changed, 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index 9c320f59d0..853e14e34e 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp) aio_context_acquire(aio_context); ret = qemu_loadvm_state(f); -qemu_fclose(f); aio_context_release(aio_context); migration_incoming_state_destroy(); -- 2.11.2