| Message ID | 1401485884-25500-1-git-send-email-pl@kamp.de |
|---|---|
| State | New |
| Headers | show |
* Peter Lieven (pl@kamp.de) wrote: > if a saved vm has unknown flags in the memory data qemu > currently simply ignores this flag and continues which > yields in an unpredictable result. > > this patch catches all unknown flags and > aborts the loading of the vm. Yes, I think that's quite nice - the only thing I'd add which would help a little is an error_report() in the case where you have invalid flags to let you know that's the reason for the EINVAL. (Having spent the day tracking down migration bugs...) Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > CC: qemu-stable@nongnu.org > Signed-off-by: Peter Lieven <pl@kamp.de> > Reviewed-by: Eric Blake <eblake@redhat.com> > --- > arch_init.c | 35 ++++++++++++++++------------------- > 1 file changed, 16 insertions(+), 19 deletions(-) > > diff --git a/arch_init.c b/arch_init.c > index 995f56d..322d129 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -1030,17 +1030,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > { > ram_addr_t addr; > int flags, ret = 0; > - int error; > static uint64_t seq_iter; > > seq_iter++; > > if (version_id != 4) { > ret = -EINVAL; > - goto done; > } > > - do { > + while (!ret) { > addr = qemu_get_be64(f); > > flags = addr & ~TARGET_PAGE_MASK; > @@ -1069,7 +1067,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > " in != " RAM_ADDR_FMT "\n", id, length, > block->length); > ret = -EINVAL; > - goto done; > } > break; > } > @@ -1079,21 +1076,21 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > fprintf(stderr, "Unknown ramblock \"%s\", cannot " > "accept migration\n", id); > ret = -EINVAL; > - goto done; > + } > + if (ret) { > + break; > } > > total_ram_bytes -= length; > } > - } > - > - if (flags & RAM_SAVE_FLAG_COMPRESS) { > + } else if (flags & RAM_SAVE_FLAG_COMPRESS) { > void *host; > uint8_t ch; > > host = host_from_stream_offset(f, addr, flags); > if (!host) { > ret = -EINVAL; > - goto done; > + break; > } > > ch = qemu_get_byte(f); > @@ -1104,7 +1101,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > host = host_from_stream_offset(f, addr, flags); > if (!host) { > ret = -EINVAL; > - goto done; > + break; > } > > qemu_get_buffer(f, host, TARGET_PAGE_SIZE); > @@ -1112,24 +1109,24 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) > void *host = host_from_stream_offset(f, addr, flags); > if (!host) { > ret = -EINVAL; > - goto done; > + break; > } > > if (load_xbzrle(f, addr, host) < 0) { > ret = -EINVAL; > - goto done; > + break; > } > } else if (flags & RAM_SAVE_FLAG_HOOK) { > ram_control_load_hook(f, flags); > + } else if (flags & RAM_SAVE_FLAG_EOS) { > + break; > + } else { > + ret = -EINVAL; > + break; > } > - error = qemu_file_get_error(f); > - if (error) { > - ret = error; > - goto done; > - } > - } while (!(flags & RAM_SAVE_FLAG_EOS)); > + ret = qemu_file_get_error(f); > + } > > -done: > DPRINTF("Completed load of VM with exit code %d seq iteration " > "%" PRIu64 "\n", ret, seq_iter); > return ret; > -- > 1.7.9.5 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On (Tue) 03 Jun 2014 [18:27:15], Dr. David Alan Gilbert wrote: > * Peter Lieven (pl@kamp.de) wrote: > > if a saved vm has unknown flags in the memory data qemu > > currently simply ignores this flag and continues which > > yields in an unpredictable result. > > > > this patch catches all unknown flags and > > aborts the loading of the vm. > > Yes, I think that's quite nice - the only thing I'd add which would help > a little is an error_report() in the case where you have invalid flags > to let you know that's the reason for the EINVAL. Agreed. Amit
On (Tue) 03 Jun 2014 [18:27:15], Dr. David Alan Gilbert wrote: > * Peter Lieven (pl@kamp.de) wrote: > > if a saved vm has unknown flags in the memory data qemu > > currently simply ignores this flag and continues which > > yields in an unpredictable result. > > > > this patch catches all unknown flags and > > aborts the loading of the vm. > > Yes, I think that's quite nice - the only thing I'd add which would help > a little is an error_report() in the case where you have invalid flags > to let you know that's the reason for the EINVAL. > > (Having spent the day tracking down migration bugs...) Peter, can you please add these before we pick the patch up? Thanks, Amit
On 10.06.2014 09:31, Amit Shah wrote: > On (Tue) 03 Jun 2014 [18:27:15], Dr. David Alan Gilbert wrote: >> * Peter Lieven (pl@kamp.de) wrote: >>> if a saved vm has unknown flags in the memory data qemu >>> currently simply ignores this flag and continues which >>> yields in an unpredictable result. >>> >>> this patch catches all unknown flags and >>> aborts the loading of the vm. >> Yes, I think that's quite nice - the only thing I'd add which would help >> a little is an error_report() in the case where you have invalid flags >> to let you know that's the reason for the EINVAL. >> >> (Having spent the day tracking down migration bugs...) > Peter, can you please add these before we pick the patch up? On its way. Peter
diff --git a/arch_init.c b/arch_init.c index 995f56d..322d129 100644 --- a/arch_init.c +++ b/arch_init.c @@ -1030,17 +1030,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) { ram_addr_t addr; int flags, ret = 0; - int error; static uint64_t seq_iter; seq_iter++; if (version_id != 4) { ret = -EINVAL; - goto done; } - do { + while (!ret) { addr = qemu_get_be64(f); flags = addr & ~TARGET_PAGE_MASK; @@ -1069,7 +1067,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) " in != " RAM_ADDR_FMT "\n", id, length, block->length); ret = -EINVAL; - goto done; } break; } @@ -1079,21 +1076,21 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) fprintf(stderr, "Unknown ramblock \"%s\", cannot " "accept migration\n", id); ret = -EINVAL; - goto done; + } + if (ret) { + break; } total_ram_bytes -= length; } - } - - if (flags & RAM_SAVE_FLAG_COMPRESS) { + } else if (flags & RAM_SAVE_FLAG_COMPRESS) { void *host; uint8_t ch; host = host_from_stream_offset(f, addr, flags); if (!host) { ret = -EINVAL; - goto done; + break; } ch = qemu_get_byte(f); @@ -1104,7 +1101,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) host = host_from_stream_offset(f, addr, flags); if (!host) { ret = -EINVAL; - goto done; + break; } qemu_get_buffer(f, host, TARGET_PAGE_SIZE); @@ -1112,24 +1109,24 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) void *host = host_from_stream_offset(f, addr, flags); if (!host) { ret = -EINVAL; - goto done; + break; } if (load_xbzrle(f, addr, host) < 0) { ret = -EINVAL; - goto done; + break; } } else if (flags & RAM_SAVE_FLAG_HOOK) { ram_control_load_hook(f, flags); + } else if (flags & RAM_SAVE_FLAG_EOS) { + break; + } else { + ret = -EINVAL; + break; } - error = qemu_file_get_error(f); - if (error) { - ret = error; - goto done; - } - } while (!(flags & RAM_SAVE_FLAG_EOS)); + ret = qemu_file_get_error(f); + } -done: DPRINTF("Completed load of VM with exit code %d seq iteration " "%" PRIu64 "\n", ret, seq_iter); return ret;