On Fri, Aug 28, 2020 at 12:03:38PM +0200, Bodo Stroesser wrote: > Hi, > I'm adding stable@xxxxxxxxxxxxxxx > > Once again, this time really adding stable. > > On 2020-06-03 04:31, Martin K. Petersen wrote: > > On Thu, 28 May 2020 21:31:08 +0200, Bodo Stroesser wrote: > > > > > 1) If remaining ring space before the end of the ring is > > > smaller then the next cmd to write, tcmu writes a padding > > > entry which fills the remaining space at the end of the > > > ring. > > > Then tcmu calls tcmu_flush_dcache_range() with the size > > > of struct tcmu_cmd_entry as data length to flush. > > > If the space filled by the padding was smaller then > > > tcmu_cmd_entry, tcmu_flush_dcache_range() is called for > > > an address range reaching behind the end of the vmalloc'ed > > > ring. > > > tcmu_flush_dcache_range() in a loop calls > > > flush_dcache_page(virt_to_page(start)); > > > for every page being part of the range. On x86 the line is > > > optimized out by the compiler, as flush_dcache_page() is > > > empty on x86. > > > But I assume the above can cause trouble on other > > > architectures that really have a flush_dcache_page(). > > > For paddings only the header part of an entry is relevant > > > Due to alignment rules the header always fits in the > > > remaining space, if padding is needed. > > > So tcmu_flush_dcache_range() can safely be called with > > > sizeof(entry->hdr) as the length here. > > > > > > [...] > > > > Applied to 5.8/scsi-queue, thanks! > > > > [1/1] scsi: target: tcmu: Fix size in calls to tcmu_flush_dcache_range > > https://git.kernel.org/mkp/scsi/c/8c4e0f212398 > > > > The full commit of this patch is: > 8c4e0f212398cdd1eb4310a5981d06a723cdd24f > > This patch is the first of four patches that are necessary to run tcmu > on ARM without crash. For details please see > https://bugzilla.kernel.org/show_bug.cgi?id=208045 > Upsteam commits of patches 2,3, and 4 are: > 2: 3c58f737231e "scsi: target: tcmu: Optimize use of flush_dcache_page" > 3: 3145550a7f8b "scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range > on ARM" > 4: 5a0c256d96f0 "scsi: target: tcmu: Fix crash on ARM during cmd > completion" > > Since patches 3 and 4 already were accepted for 5.8, 5.4, and 4.19, and > I sent a request to add patch 2 about 1 hour ago, please consider adding > this patch to 5.4 and 4.19, because without it tcmu on ARM will still > crash. I don't see such a request, and am confused now. What exact commits do you want backported, and to what trees? thanks, greg k-h
