Buildresult: powerpc-fixes/s390-defconfig/s390x-gcc8 built on Feb 25 2021, 01:47

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Status:	OK
Date/Time:	Feb 25 2021, 01:47
Duration:	0:04:56.265614
Builder:	ka1
Revision:	powerpc/603: Fix protection of user pages mapped with PROT_NONE (`51d92826594c3ac1f9b7179a3ab246394a11ecd8)`
Target:	powerpc-fixes/s390-defconfig/s390x-gcc8
Branch:	powerpc-fixes
Compiler:	s390x-gcc8 (s390-linux-gcc (GCC) 8.1.0 / GNU ld (GNU Binutils) 2.30)
Config:	defconfig (download)
Log:	Download original No warnings found in log. Full Log # git rev-parse -q --verify 51d92826594c3ac1f9b7179a3ab246394a11ecd8^{commit} 51d92826594c3ac1f9b7179a3ab246394a11ecd8 already have revision, skipping fetch # git checkout -q -f -B kisskb 51d92826594c3ac1f9b7179a3ab246394a11ecd8 # git clean -qxdf # < git log -1 # commit 51d92826594c3ac1f9b7179a3ab246394a11ecd8 # Author: Christophe Leroy <christophe.leroy@csgroup.eu> # Date: Mon Feb 1 06:29:50 2021 +0000 # # powerpc/603: Fix protection of user pages mapped with PROT_NONE # # On book3s/32, page protection is defined by the PP bits in the PTE # which provide the following protection depending on the access # keys defined in the matching segment register: # - PP 00 means RW with key 0 and N/A with key 1. # - PP 01 means RW with key 0 and RO with key 1. # - PP 10 means RW with both key 0 and key 1. # - PP 11 means RO with both key 0 and key 1. # # Since the implementation of kernel userspace access protection, # PP bits have been set as follows: # - PP00 for pages without _PAGE_USER # - PP01 for pages with _PAGE_USER and _PAGE_RW # - PP11 for pages with _PAGE_USER and without _PAGE_RW # # For kernelspace segments, kernel accesses are performed with key 0 # and user accesses are performed with key 1. As PP00 is used for # non _PAGE_USER pages, user can't access kernel pages not flagged # _PAGE_USER while kernel can. # # For userspace segments, both kernel and user accesses are performed # with key 0, therefore pages not flagged _PAGE_USER are still # accessible to the user. # # This shouldn't be an issue, because userspace is expected to be # accessible to the user. But unlike most other architectures, powerpc # implements PROT_NONE protection by removing _PAGE_USER flag instead of # flagging the page as not valid. This means that pages in userspace # that are not flagged _PAGE_USER shall remain inaccessible. # # To get the expected behaviour, just mimic other architectures in the # TLB miss handler by checking _PAGE_USER permission on userspace # accesses as if it was the _PAGE_PRESENT bit. # # Note that this problem only is only for 603 cores. The 604+ have # an hash table, and hash_page() function already implement the # verification of _PAGE_USER permission on userspace pages. # # Fixes: f342adca3afc ("powerpc/32s: Prepare Kernel Userspace Access Protection") # Cc: stable@vger.kernel.org # v5.2+ # Reported-by: Christoph Plattner <christoph.plattner@thalesgroup.com> # Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.1612160907.git.christophe.leroy@csgroup.eu # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-ld --version # < git log --format=%s --max-count=1 51d92826594c3ac1f9b7179a3ab246394a11ecd8 # < make -s -j 48 ARCH=s390 O=/kisskb/build/powerpc-fixes_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux- defconfig # < make -s -j 48 ARCH=s390 O=/kisskb/build/powerpc-fixes_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux- help # make -s -j 48 ARCH=s390 O=/kisskb/build/powerpc-fixes_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux- olddefconfig # make -s -j 48 ARCH=s390 O=/kisskb/build/powerpc-fixes_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_s390-defconfig_s390x-gcc8 # Build took: 0:04:56.265614

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