From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:48086) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h2ERB-00037t-Ph for qemu-devel@nongnu.org; Fri, 08 Mar 2019 07:17:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h2ERA-0004Wu-97 for qemu-devel@nongnu.org; Fri, 08 Mar 2019 07:17:17 -0500 From: Markus Armbruster References: <20190308062455.29755-1-armbru@redhat.com> <87d0n1fzy0.fsf@zen.linaroharston> Date: Fri, 08 Mar 2019 13:16:58 +0100 In-Reply-To: <87d0n1fzy0.fsf@zen.linaroharston> ("Alex =?utf-8?Q?Benn?= =?utf-8?Q?=C3=A9e=22's?= message of "Fri, 08 Mar 2019 10:00:39 +0000") Message-ID: <87ef7hef2d.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v7] pflash: Require backend size to match device, improve errors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex =?utf-8?Q?Benn=C3=A9e?= Cc: kwolf@redhat.com, qemu-block@nongnu.org, lersek@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, philmd@redhat.com Alex Benn=C3=A9e writes: > Markus Armbruster writes: > >> From: Alex Benn=C3=A9e >> >> 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 Benn=C3=A9e >> Signed-off-by: Markus Armbruster >> --- >> 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 =3D sector_len_per_device * blocks_per_device; >> >> - /* XXX: to be fixed */ >> -#if 0 >> - if (total_len !=3D (8 * 1024 * 1024) && total_len !=3D (16 * 1024 *= 1024) && >> - total_len !=3D (32 * 1024 * 1024) && total_len !=3D (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 =3D 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 !=3D 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 =3D 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 =3D pfl->sector_len * pfl->nb_blocs; >> - /* XXX: to be fixed */ >> -#if 0 >> - if (total_len !=3D (8 * 1024 * 1024) && total_len !=3D (16 * 1024 *= 1024) && >> - total_len !=3D (32 * 1024 * 1024) && total_len !=3D (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 =3D 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 !=3D 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 =3D 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!