Alex Bennée <alex.ben...@linaro.org> writes:
> Markus Armbruster <arm...@redhat.com> writes:
>
>> From: Alex Bennée <alex.ben...@linaro.org>
>>
>> We reject undersized backends with a rather enigmatic "failed to read
>> the initial flash content" error.
>>
>> We happily accept oversized images, ignoring their tail. Throwing
>> away parts of firmware that way is pretty much certain to end in an
>> even more enigmatic failure to boot.
>>
>> Require the backend's size to match the device's size exactly. Report
>> mismatch as "device requires N bytes, block backend 'NAME' provides M
>> bytes".
>>
>> Improve the error for actual read failures to "can't read initial
>> flash content from block backend 'NAME'.
>>
>> We disabled code to limit device sizes to 8, 16, 32 or 64MiB more than
>> a decade ago in commit 95d1f3edd5e and c8b153d7949, v0.9.1. Bury.
>>
>> Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
>> Signed-off-by: Markus Armbruster <arm...@redhat.com>
>> ---
>> hw/block/pflash_cfi01.c | 31 ++++++++++++++++++++++---------
>> hw/block/pflash_cfi02.c | 31 +++++++++++++++++++++++--------
>> 2 files changed, 45 insertions(+), 17 deletions(-)
>>
>> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
>> index 9d1c356eb6..2e3a05c0b3 100644
>> --- a/hw/block/pflash_cfi01.c
>> +++ b/hw/block/pflash_cfi01.c
>> @@ -730,13 +730,6 @@ static void pflash_cfi01_realize(DeviceState *dev,
>> Error **errp)
>> }
>> device_len = sector_len_per_device * blocks_per_device;
>>
>> - /* XXX: to be fixed */
>> -#if 0
>> - if (total_len != (8 * 1024 * 1024) && total_len != (16 * 1024 * 1024) &&
>> - total_len != (32 * 1024 * 1024) && total_len != (64 * 1024 * 1024))
>> - return NULL;
>> -#endif
>> -
>> memory_region_init_rom_device(
>> &pfl->mem, OBJECT(dev),
>> &pflash_cfi01_ops,
>> @@ -763,12 +756,32 @@ static void pflash_cfi01_realize(DeviceState *dev,
>> Error **errp)
>> }
>>
>> if (pfl->blk) {
>> + /*
>> + * Validate the backing store is the right size for pflash
>> + * devices. If the user supplies a larger file we ignore the
>> + * tail.
>> + */
>
> We need to drop the last sentence...
D'oh!
>> + int64_t backing_len = blk_getlength(pfl->blk);
>> +
>> + if (backing_len < 0) {
>> + error_setg(errp, "can't get size of block backend '%s'",
>> + blk_name(pfl->blk));
>> + return;
>> + }
>> + if (backing_len != total_len) {
>> + error_setg(errp, "device requires %" PRIu64 " bytes, "
>> + "block backend '%s' provides %" PRIu64 " bytes",
>> + total_len, blk_name(pfl->blk), backing_len);
>> + return;
>> + }
>> +
>> /* read the initial flash content */
>> ret = blk_pread(pfl->blk, 0, pfl->storage, total_len);
>> -
>> if (ret < 0) {
>> vmstate_unregister_ram(&pfl->mem, DEVICE(pfl));
>> - error_setg(errp, "failed to read the initial flash content");
>> + error_setg(errp, "can't read initial flash content"
>> + " from block backend '%s'",
>> + blk_name(pfl->blk));
>> return;
>> }
>> }
>> diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
>> index 33779ce807..45b88d65d8 100644
>> --- a/hw/block/pflash_cfi02.c
>> +++ b/hw/block/pflash_cfi02.c
>> @@ -550,12 +550,6 @@ static void pflash_cfi02_realize(DeviceState *dev,
>> Error **errp)
>> }
>>
>> chip_len = pfl->sector_len * pfl->nb_blocs;
>> - /* XXX: to be fixed */
>> -#if 0
>> - if (total_len != (8 * 1024 * 1024) && total_len != (16 * 1024 * 1024) &&
>> - total_len != (32 * 1024 * 1024) && total_len != (64 * 1024 * 1024))
>> - return NULL;
>> -#endif
>>
>> memory_region_init_rom_device(&pfl->orig_mem, OBJECT(pfl), pfl->be ?
>> &pflash_cfi02_ops_be :
>> &pflash_cfi02_ops_le,
>> @@ -581,11 +575,32 @@ static void pflash_cfi02_realize(DeviceState *dev,
>> Error **errp)
>> }
>>
>> if (pfl->blk) {
>> + /*
>> + * Validate the backing store is the right size for pflash
>> + * devices. If the user supplies a larger file we ignore the
>> + * tail.
>> + */
>
> And here.
>
>> + int64_t backing_len = blk_getlength(pfl->blk);
>> +
>> + if (backing_len < 0) {
>> + error_setg(errp, "can't get size of block backend '%s'",
>> + blk_name(pfl->blk));
>> + return;
>> + }
>> + if (backing_len != chip_len) {
>> + error_setg(errp, "device requires %" PRIu32 " bytes, "
>> + "block backend '%s' provides %" PRIu64 " bytes",
>> + chip_len, blk_name(pfl->blk), backing_len);
>> + return;
>> + }
>> +
>> /* read the initial flash content */
>> ret = blk_pread(pfl->blk, 0, pfl->storage, chip_len);
>> if (ret < 0) {
>> - vmstate_unregister_ram(&pfl->orig_mem, DEVICE(pfl));
>> - error_setg(errp, "failed to read the initial flash content");
>> + vmstate_unregister_ram(&pfl->mem, DEVICE(pfl));
>> + error_setg(errp, "can't read initial flash content"
>> + " from block backend '%s'",
>> + blk_name(pfl->blk));
>> return;
>> }
>> }
>
> Otherwise all good... not that a r-b means anything from me ;-)
v8 coming up... thanks!
