Buildresult: powerpc-fixes/mmu_defconfig/microblaze-gcc5 built on Mar 4 2020, 00:31

kisskb

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Status:	OK
Date/Time:	Mar 4 2020, 00:31
Duration:	0:00:51.001220
Builder:	ka2
Revision:	powerpc/mm: Fix missing KUAP disable in flush_coherent_icache() (`b1ad106c02e19d81927b5a522167780525569490)`
Target:	powerpc-fixes/mmu_defconfig/microblaze-gcc5
Branch:	powerpc-fixes
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 No warnings found in log. Full Log # git rev-parse -q --verify b1ad106c02e19d81927b5a522167780525569490^{commit} b1ad106c02e19d81927b5a522167780525569490 already have revision, skipping fetch # git checkout -q -f -B kisskb b1ad106c02e19d81927b5a522167780525569490 # git clean -qxdf # < git log -1 # commit b1ad106c02e19d81927b5a522167780525569490 # Author: Michael Ellerman <mpe@ellerman.id.au> # Date: Tue Mar 3 23:28:47 2020 +1100 # # powerpc/mm: Fix missing KUAP disable in flush_coherent_icache() # # We received a report of strange kernel faults which turned out to be # due to a missing KUAP disable in flush_coherent_icache() called # from flush_icache_range(). # # The fault looks like: # # Kernel attempted to access user page (7fffc30d9c00) - exploit attempt? (uid: 1009) # BUG: Unable to handle kernel data access on read at 0x7fffc30d9c00 # Faulting instruction address: 0xc00000000007232c # Oops: Kernel access of bad area, sig: 11 [#1] # LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV # CPU: 35 PID: 5886 Comm: sigtramp Not tainted 5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40 #79 # NIP: c00000000007232c LR: c00000000003b7fc CTR: 0000000000000000 # REGS: c000001e11093940 TRAP: 0300 Not tainted (5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40) # MSR: 900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28000884 XER: 00000000 # CFAR: c0000000000722fc DAR: 00007fffc30d9c00 DSISR: 08000000 IRQMASK: 0 # GPR00: c00000000003b7fc c000001e11093bd0 c0000000023ac200 00007fffc30d9c00 # GPR04: 00007fffc30d9c18 0000000000000000 c000001e11093bd4 0000000000000000 # GPR08: 0000000000000000 0000000000000001 0000000000000000 c000001e1104ed80 # GPR12: 0000000000000000 c000001fff6ab380 c0000000016be2d0 4000000000000000 # GPR16: c000000000000000 bfffffffffffffff 0000000000000000 0000000000000000 # GPR20: 00007fffc30d9c00 00007fffc30d8f58 00007fffc30d9c18 00007fffc30d9c20 # GPR24: 00007fffc30d9c18 0000000000000000 c000001e11093d90 c000001e1104ed80 # GPR28: c000001e11093e90 0000000000000000 c0000000023d9d18 00007fffc30d9c00 # NIP flush_icache_range+0x5c/0x80 # LR handle_rt_signal64+0x95c/0xc2c # Call Trace: # 0xc000001e11093d90 (unreliable) # handle_rt_signal64+0x93c/0xc2c # do_notify_resume+0x310/0x430 # ret_from_except_lite+0x70/0x74 # Instruction dump: # 409e002c 7c0802a6 3c62ff31 3863f6a0 f8010080 48195fed 60000000 48fe4c8d # 60000000 e8010080 7c0803a6 7c0004ac <7c00ffac> 7c0004ac 4c00012c 38210070 # # This path through handle_rt_signal64() to setup_trampoline() and # flush_icache_range() is only triggered by 64-bit processes that have # unmapped their VDSO, which is rare. # # flush_icache_range() takes a range of addresses to flush. In # flush_coherent_icache() we implement an optimisation for CPUs where we # know we don't actually have to flush the whole range, we just need to # do a single icbi. # # However we still execute the icbi on the user address of the start of # the range we're flushing. On CPUs that also implement KUAP (Power9) # that leads to the spurious fault above. # # We should be able to pass any address, including a kernel address, to # the icbi on these CPUs, which would avoid any interaction with KUAP. # But I don't want to make that change in a bug fix, just in case it # surfaces some strange behaviour on some CPU. # # So for now just disable KUAP around the icbi. Note the icbi is treated # as a load, so we allow read access, not write as you'd expect. # # Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU") # Cc: stable@vger.kernel.org # v5.2+ # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /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 b1ad106c02e19d81927b5a522167780525569490 # < make -s -j 48 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- mmu_defconfig # < make -s -j 48 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- help # make -s -j 48 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- olddefconfig # make -s -j 48 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- Kernel: arch/microblaze/boot/linux.bin is ready (#1) Completed OK # rm -rf /kisskb/build/powerpc-fixes_mmu_defconfig_microblaze # Build took: 0:00:51.001220

© Michael Ellerman 2006-2018.