On Fri, 6 Aug 2021, Christophe Leroy wrote: > > > > > > > > > > Can you check if they DO NOT happen at preceding commit c16728835~ > > > > > > > > > > > $ git checkout c16728835~ > > > Previous HEAD position was c16728835eec powerpc/32: Manage KUAP in C > > > HEAD is now at 0b45359aa2df powerpc/8xx: Create C version of kuap > > > save/restore/check helpers > > > $ git am ../message.mbox > > > warning: Patch sent with format=flowed; space at the end of lines might be > > > lost. > > > Applying: powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE > > > $ cp ../dot-config-powermac-5.13 .config > > > $ make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- -j4 clean > > > olddefconfig vmlinux > > > > > > Linux version 5.12.0-rc3-pmac-00077-gc9f6e8dd045 > > > > > > 3) PB 3400c > > > Hangs at boot (Mac OS screen) > > > > > > 4) Wallstreet > > > X fails, errors in console log (different than test 2), see > > > Wallstreet_console-2.txt. > > > > > > > This log shows that the errors "xfce4-session[1775]: bus error (7)" and > > "kernel BUG at arch/powerpc/kernel/interrupt.c:49!" happen prior to commit > > c16728835eec ("powerpc/32: Manage KUAP in C"). > > As mentionned by Nic, this is due to r11 being cloberred. For the time being > the only r11 clobber identified is the one I have provided a fix for. I'm > wondering whether it was applied for all further tests or not. >
Your fix was applied to this build with "git am ../message.mbox". > ... > > > > > > > > > > > > Could you test with CONFIG_PPC_KUAP and CONFIG_PPC_KUAP_DEBUG > > > ... > > > > > > $scripts/config -e CONFIG_PPC_KUAP > > > $ scripts/config -e CONFIG_PPC_KUAP_DEBUG > > > $ make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- -j4 clean > > > olddefconfig vmlinux > > > $ grep CONFIG_PPC_KUAP .config > > > CONFIG_PPC_KUAP=y > > > CONFIG_PPC_KUAP_DEBUG=y > > > > > > Linux version 5.12.0-rc3-pmac-00078-g5cac2bc3752 > > > > > > 9) PB 3400c > > > Hangs at boot (Mac OS screen) > > > > > > 10) Wallstreet > > > X failed at first login, worked at second login, one error in console > > > log ("BUG: Unable to handle kernel instruction fetch"), see > > > Wallstreet_console-5.txt. > > > > > > > One might expect to see "Kernel attempted to write user page (b3399774) - > > exploit attempt?" again here (see c16728835eec build above) but instead > > this log says "Oops: Kernel access of bad area, sig: 11". > > Maybe the test should be done a second time. As r11 is garbage it may or > may not be a user address. If it is a user address the we get "Kernel > attempted to write user page". If it is a random kernel address, we > likely get "Kernel access of bad area" instead. > Your fix was applied here also.