# git rev-parse -q --verify b791d1bdf9212d944d749a5c7ff6febdba241771^{commit} b791d1bdf9212d944d749a5c7ff6febdba241771 already have revision, skipping fetch # git checkout -q -f -B kisskb b791d1bdf9212d944d749a5c7ff6febdba241771 # git clean -qxdf # < git log -1 # commit b791d1bdf9212d944d749a5c7ff6febdba241771 # Merge: 9716e57a0195 1f44328ea24c # Author: Linus Torvalds # Date: Thu Jun 11 18:55:43 2020 -0700 # # Merge tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip # # Pull the Kernel Concurrency Sanitizer from Thomas Gleixner: # "The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector, # which relies on compile-time instrumentation, and uses a # watchpoint-based sampling approach to detect races. # # The feature was under development for quite some time and has already # found legitimate bugs. # # Unfortunately it comes with a limitation, which was only understood # late in the development cycle: # # It requires an up to date CLANG-11 compiler # # CLANG-11 is not yet released (scheduled for June), but it's the only # compiler today which handles the kernel requirements and especially # the annotations of functions to exclude them from KCSAN # instrumentation correctly. # # These annotations really need to work so that low level entry code and # especially int3 text poke handling can be completely isolated. # # A detailed discussion of the requirements and compiler issues can be # found here: # # https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/ # # We came to the conclusion that trying to work around compiler # limitations and bugs again would end up in a major trainwreck, so # requiring a working compiler seemed to be the best choice. # # For Continous Integration purposes the compiler restriction is # manageable and that's where most xxSAN reports come from. # # For a change this limitation might make GCC people actually look at # their bugs. Some issues with CSAN in GCC are 7 years old and one has # been 'fixed' 3 years ago with a half baken solution which 'solved' the # reported issue but not the underlying problem. # # The KCSAN developers also ponder to use a GCC plugin to become # independent, but that's not something which will show up in a few # days. # # Blocking KCSAN until wide spread compiler support is available is not # a really good alternative because the continuous growth of lockless # optimizations in the kernel demands proper tooling support" # # * tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits) # compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining # compiler.h: Move function attributes to compiler_types.h # compiler.h: Avoid nested statement expression in data_race() # compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE() # kcsan: Update Documentation to change supported compilers # kcsan: Remove 'noinline' from __no_kcsan_or_inline # kcsan: Pass option tsan-instrument-read-before-write to Clang # kcsan: Support distinguishing volatile accesses # kcsan: Restrict supported compilers # kcsan: Avoid inserting __tsan_func_entry/exit if possible # ubsan, kcsan: Don't combine sanitizer with kcov on clang # objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn() # kcsan: Add __kcsan_{enable,disable}_current() variants # checkpatch: Warn about data_race() without comment # kcsan: Use GFP_ATOMIC under spin lock # Improve KCSAN documentation a bit # kcsan: Make reporting aware of KCSAN tests # kcsan: Fix function matching in report # kcsan: Change data_race() to no longer require marking racing accesses # kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h # ... # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-ld --version # < git log --format=%s --max-count=1 b791d1bdf9212d944d749a5c7ff6febdba241771 # < make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux- se7619_defconfig # < make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux- help # make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux- olddefconfig # make -s -j 48 ARCH=sh O=/kisskb/build/linus_se7619_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux- Generating include/generated/machtypes.h :1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] /kisskb/src/arch/sh/kernel/cpu/sh2/../../entry-common.S: Assembler messages: /kisskb/src/arch/sh/kernel/cpu/sh2/../../entry-common.S:385: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/arch/sh/kernel/cpu/sh2/../../entry-common.S:388: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/drivers/sh/clk/cpg.c: In function 'r8': /kisskb/src/drivers/sh/clk/cpg.c:41:17: warning: passing argument 1 of 'ioread8' discards 'const' qualifier from pointer target type return ioread8(addr); ^ In file included from /kisskb/src/arch/sh/include/asm/io.h:21:0, from /kisskb/src/include/linux/io.h:13, from /kisskb/src/drivers/sh/clk/cpg.c:14: /kisskb/src/include/asm-generic/iomap.h:29:21: note: expected 'void *' but argument is of type 'const void *' extern unsigned int ioread8(void __iomem *); ^ /kisskb/src/drivers/sh/clk/cpg.c: In function 'r16': /kisskb/src/drivers/sh/clk/cpg.c:46:18: warning: passing argument 1 of 'ioread16' discards 'const' qualifier from pointer target type return ioread16(addr); ^ In file included from /kisskb/src/arch/sh/include/asm/io.h:21:0, from /kisskb/src/include/linux/io.h:13, from /kisskb/src/drivers/sh/clk/cpg.c:14: /kisskb/src/include/asm-generic/iomap.h:30:21: note: expected 'void *' but argument is of type 'const void *' extern unsigned int ioread16(void __iomem *); ^ /kisskb/src/drivers/sh/clk/cpg.c: In function 'r32': /kisskb/src/drivers/sh/clk/cpg.c:51:18: warning: passing argument 1 of 'ioread32' discards 'const' qualifier from pointer target type return ioread32(addr); ^ In file included from /kisskb/src/arch/sh/include/asm/io.h:21:0, from /kisskb/src/include/linux/io.h:13, from /kisskb/src/drivers/sh/clk/cpg.c:14: /kisskb/src/include/asm-generic/iomap.h:32:21: note: expected 'void *' but argument is of type 'const void *' extern unsigned int ioread32(void __iomem *); ^ Completed OK # rm -rf /kisskb/build/linus_se7619_defconfig_sh4-gcc4.9 # Build took: 0:00:21.127867