On Wed, Nov 04, 2015 at 11:04:33AM +0300, Antony Pavlov wrote: > Hi! > > Peter has reported on strange barebox memcpy command behaviour on his MIPS board: > > he copies a file to memory using memcpy and then copyies appropriate memory contents > back to another file. Next he checks files md5sum and the sums are differ. > > I have reproduced the problem on Qemu VersatilePB ARM board. > > Here is an instruction. > > Configure barebox: > > $ cd barebox.git > $ export ARCH=arm > $ export CROSS_COMPILE=<your cross compiler prefix> > $ make versatilepb_defconfig > $ sed -i "s/^# CONFIG_CMD_MD5SUM.*$/CONFIG_CMD_MD5SUM=y/" .config > > Prepare testfile on host and compile: > > $ dd if=/dev/zero bs=1 count=4414 | tr "\000" "\377" > defaultenv/defaultenv-2-base/testfile > $ make > ... > > Run barebox under qemu: > > $ qemu-system-arm -M versatilepb -nographic -monitor null -kernel arch/arm/pbl/zbarebox -serial stdio > ... > barebox# memcpy -s /env/testfile 0 0x01000000 > > barebox# memcpy -d _testfile 0x01000000 0 4414 > > barebox# md5sum /env/testfile _testfile > bf8278051ba8de868def083bcc209002 /env/testfile 0x00000000 ... 0xffffffffffffffff > e295c2bfe32498e03531017443120e89 _testfile 0x00000000 ... 0xffffffffffffffff > > barebox# memcmp -s /env/testfile -d _testfile 0 0 > files differ at offset 4408 > > barebox# md -s /env/testfile 4400 > 00001130: ffffffff ffffffff ffffffff ffffffff .............. > > barebox# md -s _testfile 4400 > 00001130: ffffffff ffffffff 00000000 ffff0000 .............. > > barebox# md -b 0x01001130+0xe > 01001130: ff ff ff ff ff ff ff ff 00 00 00 00 00 00 .............. > > barebox# md -b -s /env/testfile 0x1130+0xe > 00001130: ff ff ff ff ff ff ff ff ff ff ff ff ff ff .............. > > So you see that last 6 bytes have not been copied. > > Please comment this report! This is fixed by: http://www.spinics.net/lists/u-boot-v2/msg24850.html Which I forgot to apply, but did now. The problem is that the newly introduced O_RWSIZE_8 flag clashed with the O_CREAT flag. This means that when a file is created (it's always set in memcpy) then we also do 8byte reads/writes which of course leads to the last bytes missing when the length is not 8byte aligned. Fixed in current master. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
