Buildresult: powerpc-next/mmu_defconfig/microblaze-gcc5 built on Mar 2 2019, 21:41

kisskb

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Status:	OK
Date/Time:	Mar 2 2019, 21:41
Duration:	0:00:47.152696
Builder:	ka3
Revision:	powerpc/64s: Implement KUAP for Radix MMU (`dc8b1290efbbe974d9968106a03077823d0863d6)`
Target:	powerpc-next/mmu_defconfig/microblaze-gcc5
Branch:	powerpc-next
Compiler:	microblaze-gcc5 (microblazeel-linux-gcc.br_real (Buildroot 2016.11-git-00613-ge98b4dd) 5.4.0 / GNU ld (GNU Binutils) 2.26.1)
Config:	mmu_defconfig (download)
Log:	Download original Possible warnings (1) drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] Full Log # git rev-parse -q --verify dc8b1290efbbe974d9968106a03077823d0863d6^{commit} dc8b1290efbbe974d9968106a03077823d0863d6 already have revision, skipping fetch # git checkout -q -f -B kisskb dc8b1290efbbe974d9968106a03077823d0863d6 # git clean -qxdf # < git log -1 # commit dc8b1290efbbe974d9968106a03077823d0863d6 # Author: Russell Currey <ruscur@russell.cc> # Date: Fri Mar 1 01:49:17 2019 +1100 # # powerpc/64s: Implement KUAP for Radix MMU # # Kernel Userspace Access Prevention utilises a feature of the Radix MMU # which disallows read and write access to userspace addresses. By # utilising this, the kernel is prevented from accessing user data from # outside of trusted paths that perform proper safety checks, such as # copy_{to/from}_user() and friends. # # Userspace access is disabled from early boot and is only enabled when # performing an operation like copy_{to/from}_user(). The register that # controls this (AMR) does not prevent userspace from accessing itself, # so there is no need to save and restore when entering and exiting # userspace. # # This feature has a slight performance impact which I roughly measured # to be 3% slower in the worst case (performing 1GB of 1 byte # read()/write() syscalls), and is gated behind the CONFIG_PPC_KUAP # option for performance-critical builds. # # This feature can be tested by using the lkdtm driver (CONFIG_LKDTM=y) # and performing the following: # # # (echo ACCESS_USERSPACE) > [debugfs]/provoke-crash/DIRECT # # If enabled, this should send SIGSEGV to the thread. # # mpe: # - Drop the unused paca flags. # - Zero the UAMOR to be safe. # - Save the AMR when we enter the kernel from the kernel and then # block user access again if it's not already blocked. # - Restore on the way back to the kernel. # - This means we handle nesting of interrupts properly, ie. we are # protected inside the page fault handler caused by a user access. # - Add paranoid checking of AMR in switch and syscall return. # - Add isync()'s around AMR writes as per the ISA. # - Support selectively disabling read or write, with no support for # nesting. # # Co-authored-by: Michael Ellerman <mpe@ellerman.id.au> # Signed-off-by: Russell Currey <ruscur@russell.cc> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # --- # # v5: # - On kernel entry check if the AMR is already blocking user access # and if so don't do the mtspr again (pointed out by Nick). # - Rework the constants to make the asm a bit cleaner and avoid any # hard coded shifts. # - Selectively disable read or write, we don't support nesting and # shouldn't need to (famous last words). # < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-gcc --version # < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-ld --version # < git log --format=%s --max-count=1 dc8b1290efbbe974d9968106a03077823d0863d6 # < make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- mmu_defconfig # make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] if (ret == -EOPNOTSUPP) ^ Kernel: arch/microblaze/boot/linux.bin is ready (#1) Completed OK # rm -rf /kisskb/build/powerpc-next_mmu_defconfig_microblaze # Build took: 0:00:47.152696

© Michael Ellerman 2006-2018.