# git rev-parse -q --verify 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f^{commit} # git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/linus master warning: 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 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f^{commit} 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f # git checkout -q -f -B kisskb 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f # git clean -qxdf # < git log -1 # commit 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f # Author: Christian Brauner # Date: Mon Jul 24 17:00:49 2023 +0200 # # file: always lock position for FMODE_ATOMIC_POS # # The pidfd_getfd() system call allows a caller with ptrace_may_access() # abilities on another process to steal a file descriptor from this # process. This system call is used by debuggers, container runtimes, # system call supervisors, networking proxies etc. So while it is a # special interest system call it is used in common tools. # # That ability ends up breaking our long-time optimization in fdget_pos(), # which "knew" that if we had exclusive access to the file descriptor # nobody else could access it, and we didn't need the lock for the file # position. # # That check for file_count(file) was always fairly subtle - it depended # on __fdget() not incrementing the file count for single-threaded # processes and thus included that as part of the rule - but it did mean # that we didn't need to take the lock in all those traditional unix # process contexts. # # So it's sad to see this go, and I'd love to have some way to re-instate # the optimization. At the same time, the lock obviously isn't ever # contended in the case we optimized, so all we were optimizing away is # the atomics and the cacheline dirtying. Let's see if anybody even # notices that the optimization is gone. # # Link: https://lore.kernel.org/linux-fsdevel/20230724-vfs-fdget_pos-v1-1-a4abfd7103f3@kernel.org/ # Fixes: 8649c322f75c ("pid: Implement pidfd_getfd syscall") # Cc: stable@kernel.org # Signed-off-by: Christian Brauner # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux-ld --version # < git log --format=%s --max-count=1 20ea1e7d13c1b544fe67c4a8dc3943bb1ab33e6f # make -s -j 32 ARCH=mips O=/kisskb/build/linus-rand_allmodconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux- allmodconfig # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_SAMPLES=n # Added to kconfig CONFIG_MIPS_CPS_NS16550_BASE=0x1b0003f8 # Added to kconfig CONFIG_MIPS_CPS_NS16550_SHIFT=0 # Added to kconfig CONFIG_GCC_PLUGINS=n # Added to kconfig # < make -s -j 32 ARCH=mips O=/kisskb/build/linus-rand_allmodconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux- help # make -s -j 32 ARCH=mips O=/kisskb/build/linus-rand_allmodconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux- olddefconfig .config:14504:warning: override: reassigning to symbol MIPS_CPS_NS16550_SHIFT # make -s -j 32 ARCH=mips O=/kisskb/build/linus-rand_allmodconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux- In file included from /kisskb/src/include/linux/string.h:254, from /kisskb/src/include/linux/bitmap.h:11, from /kisskb/src/include/linux/cpumask.h:12, from /kisskb/src/include/linux/smp.h:13, from /kisskb/src/arch/mips/include/asm/cpu-type.h:12, from /kisskb/src/arch/mips/include/asm/timex.h:19, from /kisskb/src/include/linux/timex.h:67, from /kisskb/src/include/linux/time32.h:13, from /kisskb/src/include/linux/time.h:60, from /kisskb/src/include/linux/stat.h:19, from /kisskb/src/include/linux/module.h:13, from /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:20: In function 'fortify_memset_chk', inlined from 'memset_io' at /kisskb/src/arch/mips/include/asm/io.h:486:2, inlined from 'build_auth_frame' at /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:2697:2: /kisskb/src/include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 493 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In function 'fortify_memcpy_chk', inlined from 'memcpy_toio' at /kisskb/src/arch/mips/include/asm/io.h:494:2, inlined from 'translate_frame' at /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:955:3, inlined from 'ray_hw_xmit.constprop' at /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:912:12: /kisskb/src/include/linux/fortify-string.h:583:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 583 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors make[7]: *** [/kisskb/src/scripts/Makefile.build:243: drivers/net/wireless/legacy/ray_cs.o] Error 1 make[7]: *** Waiting for unfinished jobs.... make[6]: *** [/kisskb/src/scripts/Makefile.build:480: drivers/net/wireless/legacy] Error 2 make[6]: *** Waiting for unfinished jobs.... make[5]: *** [/kisskb/src/scripts/Makefile.build:480: drivers/net/wireless] Error 2 make[5]: *** Waiting for unfinished jobs.... make[4]: *** [/kisskb/src/scripts/Makefile.build:480: drivers/net] Error 2 make[3]: *** [/kisskb/src/scripts/Makefile.build:480: drivers] Error 2 make[2]: *** [/kisskb/src/Makefile:2032: .] Error 2 make[1]: *** [/kisskb/src/Makefile:234: __sub-make] Error 2 make: *** [Makefile:234: __sub-make] Error 2 Command 'make -s -j 32 ARCH=mips O=/kisskb/build/linus-rand_allmodconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux- ' returned non-zero exit status 2. # rm -rf /kisskb/build/linus-rand_allmodconfig_mips-gcc13 # Build took: 0:27:01.775974