Buildresult: linus-rand/arm64-randconfig/arm64-gcc5 built on Jan 7 2019, 09:40

kisskb

Revisions | Branches | Compilers | Configs | Build Results | Build Failures |

Status:	OK
Date/Time:	Jan 7 2019, 09:40
Duration:	0:16:19.329131
Builder:	ka1
Revision:	Fix 'acccess_ok()' on alpha and SH (`94bd8a05cd4de344a9a57e52ef7d99550251984f)`
Target:	linus-rand/arm64-randconfig/arm64-gcc5
Branch:	linus-rand
Compiler:	arm64-gcc5 (aarch64-linux-gcc.br_real (Buildroot 2016.11-git-00613-ge98b4dd) 5.4.0 / GNU ld (GNU Binutils) 2.25.1)
Config:	randconfig (download)
Log:	Download original Possible warnings (4) warning: There are too many unreachable loose objects; run 'git prune' to remove them. arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts:25.9-29.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts:46.9-50.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts:94.9-98.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' Full Log # git rev-parse -q --verify 94bd8a05cd4de344a9a57e52ef7d99550251984f^{commit} # git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/linus master error: The last gc run reported the following. Please correct the root cause and remove .git/gc.log. Automatic cleanup will not be performed until the file is removed. warning: There are too many unreachable loose objects; run 'git prune' to remove them. # git rev-parse -q --verify 94bd8a05cd4de344a9a57e52ef7d99550251984f^{commit} 94bd8a05cd4de344a9a57e52ef7d99550251984f # git checkout -q -f -B kisskb 94bd8a05cd4de344a9a57e52ef7d99550251984f # git clean -qxdf # < git log -1 # commit 94bd8a05cd4de344a9a57e52ef7d99550251984f # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Sun Jan 6 11:15:04 2019 -0800 # # Fix 'acccess_ok()' on alpha and SH # # Commit 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'") # broke both alpha and SH booting in qemu, as noticed by Guenter Roeck. # # It turns out that the bug wasn't actually in that commit itself (which # would have been surprising: it was mostly a no-op), but in how the # addition of access_ok() to the strncpy_from_user() and strnlen_user() # functions now triggered the case where those functions would test the # access of the very last byte of the user address space. # # The string functions actually did that user range test before too, but # they did it manually by just comparing against user_addr_max(). But # with user_access_begin() doing the check (using "access_ok()"), it now # exposed problems in the architecture implementations of that function. # # For example, on alpha, the access_ok() helper macro looked like this: # # #define __access_ok(addr, size) \ # ((get_fs().seg & (addr \| size \| (addr+size))) == 0) # # and what it basically tests is of any of the high bits get set (the # USER_DS masking value is 0xfffffc0000000000). # # And that's completely wrong for the "addr+size" check. Because it's # off-by-one for the case where we check to the very end of the user # address space, which is exactly what the strn*_user() functions do. # # Why? Because "addr+size" will be exactly the size of the address space, # so trying to access the last byte of the user address space will fail # the __access_ok() check, even though it shouldn't. As a result, the # user string accessor functions failed consistently - because they # literally don't know how long the string is going to be, and the max # access is going to be that last byte of the user address space. # # Side note: that alpha macro is buggy for another reason too - it re-uses # the arguments twice. # # And SH has another version of almost the exact same bug: # # #define __addr_ok(addr) \ # ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg) # # so far so good: yes, a user address must be below the limit. But then: # # #define __access_ok(addr, size) \ # (__addr_ok((addr) + (size))) # # is wrong with the exact same off-by-one case: the case when "addr+size" # is exactly _equal_ to the limit is actually perfectly fine (think "one # byte access at the last address of the user address space") # # The SH version is actually seriously buggy in another way: it doesn't # actually check for overflow, even though it did copy the _comment_ that # talks about overflow. # # So it turns out that both SH and alpha actually have completely buggy # implementations of access_ok(), but they happened to work in practice # (although the SH overflow one is a serious serious security bug, not # that anybody likely cares about SH security). # # This fixes the problems by using a similar macro on both alpha and SH. # It isn't trying to be clever, the end address is based on this logic: # # unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; # # which basically says "add start and length, and then subtract one unless # the length was zero". We can't subtract one for a zero length, or we'd # just hit an underflow instead. # # For a lot of access_ok() users the length is a constant, so this isn't # actually as expensive as it initially looks. # # Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> # Cc: Matt Turner <mattst88@gmail.com> # Cc: Yoshinori Sato <ysato@users.sourceforge.jp> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version # < git log --format=%s --max-count=1 94bd8a05cd4de344a9a57e52ef7d99550251984f # < make -s -j 8 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- randconfig KCONFIG_SEED=0xF665BBEE # Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y # yes \n \| make -s -j 8 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- oldconfig yes: standard output: Broken pipe # make -s -j 8 ARCH=arm64 O=/kisskb/build/linus-rand_arm64-randconfig_arm64 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts:25.9-29.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts:46.9-50.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts:94.9-98.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port' arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum Completed OK # rm -rf /kisskb/build/linus-rand_arm64-randconfig_arm64 # Build took: 0:16:19.329131

© Michael Ellerman 2006-2018.