# git rev-parse -q --verify 5f0bc0b042fc77ff70e14c790abdec960cde4ec1^{commit} # git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/linus master # git rev-parse -q --verify 5f0bc0b042fc77ff70e14c790abdec960cde4ec1^{commit} 5f0bc0b042fc77ff70e14c790abdec960cde4ec1 # git checkout -q -f -B kisskb 5f0bc0b042fc77ff70e14c790abdec960cde4ec1 # git clean -qxdf # < git log -1 # commit 5f0bc0b042fc77ff70e14c790abdec960cde4ec1 # Author: Linus Torvalds # Date: Tue Jul 25 09:38:32 2023 -0700 # # mm: suppress mm fault logging if fatal signal already pending # # Commit eda0047296a1 ("mm: make the page fault mmap locking killable") # intentionally made it much easier to trigger the "page fault fails # because a fatal signal is pending" situation, by having the mmap locking # fail early in that case. # # We have long aborted page faults in other fatal cases when the actual IO # for a page is interrupted by SIGKILL - which is particularly useful for # the traditional case of NFS hanging due to network issues, but local # filesystems could cause it too if you happened to get the SIGKILL while # waiting for a page to be faulted in (eg lock_folio_maybe_drop_mmap()). # # So aborting the page fault wasn't a new condition - but it now triggers # earlier, before we even get to 'handle_mm_fault()'. And as a result the # error doesn't go through our 'fault_signal_pending()' logic, and doesn't # get filtered away there. # # Normally you'd never even notice, because if a fatal signal is pending, # the new SIGSEGV we send ends up being ignored anyway. # # But it turns out that there is one very noticeable exception: if you # enable 'show_unhandled_signals', the aborted page fault will be logged # in the kernel messages, and you'll get a scary line looking something # like this in your logs: # # pverados[2183248]: segfault at 55e5a00f9ae0 ip 000055e5a00f9ae0 sp 00007ffc0720bea8 error 14 in perl[55e5a00d4000+195000] likely on CPU 10 (core 4, socket 0) # # which is rather misleading. It's not really a segfault at all, it's # just "the thread was killed before the page fault completed, so we # aborted the page fault". # # Fix this by just making it clear that a pending fatal signal means that # any new signal coming in after that is implicitly handled. This will # avoid the misleading logging, since now the signal isn't 'unhandled' any # more. # # Reported-and-tested-by: Fiona Ebner # Tested-by: Thomas Lamprecht # Link: https://lore.kernel.org/lkml/8d063a26-43f5-0bb7-3203-c6a04dc159f8@proxmox.com/ # Acked-by: Oleg Nesterov # Fixes: eda0047296a1 ("mm: make the page fault mmap locking killable") # 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 5f0bc0b042fc77ff70e14c790abdec960cde4ec1 # 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[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[4]: *** Waiting for unfinished jobs.... 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: 0:19:33.641541