summaryrefslogtreecommitdiffstats
path: root/lib
Commit message (Collapse)AuthorAgeFilesLines
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2020-08-011-19/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Encap offset calculation is incorrect in esp6, from Sabrina Dubroca. 2) Better parameter validation in pfkey_dump(), from Mark Salyzyn. 3) Fix several clang issues on powerpc in selftests, from Tanner Love. 4) cmsghdr_from_user_compat_to_kern() uses the wrong length, from Al Viro. 5) Out of bounds access in mlx5e driver, from Raed Salem. 6) Fix transfer buffer memleak in lan78xx, from Johan Havold. 7) RCU fixups in rhashtable, from Herbert Xu. 8) Fix ipv6 nexthop refcnt leak, from Xiyu Yang. 9) vxlan FDB dump must be done under RCU, from Ido Schimmel. 10) Fix use after free in mlxsw, from Ido Schimmel. 11) Fix map leak in HASH_OF_MAPS bpf code, from Andrii Nakryiko. 12) Fix bug in mac80211 Tx ack status reporting, from Vasanthakumar Thiagarajan. 13) Fix memory leaks in IPV6_ADDRFORM code, from Cong Wang. 14) Fix bpf program reference count leaks in mlx5 during mlx5e_alloc_rq(), from Xin Xiong. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (86 commits) vxlan: fix memleak of fdb rds: Prevent kernel-infoleak in rds_notify_queue_get() net/sched: The error lable position is corrected in ct_init_module net/mlx5e: fix bpf_prog reference count leaks in mlx5e_alloc_rq net/mlx5e: E-Switch, Specify flow_source for rule with no in_port net/mlx5e: E-Switch, Add misc bit when misc fields changed for mirroring net/mlx5e: CT: Support restore ipv6 tunnel net: gemini: Fix missing clk_disable_unprepare() in error path of gemini_ethernet_port_probe() ionic: unlock queue mutex in error path atm: fix atm_dev refcnt leaks in atmtcp_remove_persistent net: ethernet: mtk_eth_soc: fix MTU warnings net: nixge: fix potential memory leak in nixge_probe() devlink: ignore -EOPNOTSUPP errors on dumpit rxrpc: Fix race between recvmsg and sendmsg on immediate call failure MAINTAINERS: Replace Thor Thayer as Altera Triple Speed Ethernet maintainer selftests/bpf: fix netdevsim trap_flow_action_cookie read ipv6: fix memory leaks on IPV6_ADDRFORM path net/bpfilter: Initialize pos in __bpfilter_process_sockopt igb: reinit_locked() should be called with rtnl_lock e1000e: continue to init PHY even when failed to disable ULP ...
| * rhashtable: Restore RCU marking on rhash_lock_headHerbert Xu2020-07-281-19/+16
| | | | | | | | | | | | | | | | | | This patch restores the RCU marking on bucket_table->buckets as it really does need RCU protection. Its removal had led to a fatal bug. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* | random32: remove net_rand_state from the latent entropy gcc pluginLinus Torvalds2020-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It turns out that the plugin right now ends up being really unhappy about the change from 'static' to 'extern' storage that happened in commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity"). This is probably a trivial fix for the latent_entropy plugin, but for now, just remove net_rand_state from the list of things the plugin worries about. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Emese Revfy <re.emese@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | random32: update the net random state on interrupt and activityWilly Tarreau2020-07-291-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This modifies the first 32 bits out of the 128 bits of a random CPU's net_rand_state on interrupt or CPU activity to complicate remote observations that could lead to guessing the network RNG's internal state. Note that depending on some network devices' interrupt rate moderation or binding, this re-seeding might happen on every packet or even almost never. In addition, with NOHZ some CPUs might not even get timer interrupts, leaving their local state rarely updated, while they are running networked processes making use of the random state. For this reason, we also perform this update in update_process_times() in order to at least update the state when there is user or system activity, since it's the only case we care about. Reported-by: Amit Klein <aksecurity@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <edumazet@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'riscv-for-linus-5.8-rc5' of ↵Linus Torvalds2020-07-111-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: "I have a few KGDB-related fixes. They're mostly fixes for build warnings, but there's also: - Support for the qSupported and qXfer packets, which are necessary to pass around GDB XML information which we need for the RISC-V GDB port to fully function. - Users can now select STRICT_KERNEL_RWX instead of forcing it on" * tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Avoid kgdb.h including gdb_xml.h to solve unused-const-variable warning kgdb: Move the extern declaration kgdb_has_hit_break() to generic kgdb.h riscv: Fix "no previous prototype" compile warning in kgdb.c file riscv: enable the Kconfig prompt of STRICT_KERNEL_RWX kgdb: enable arch to support XML packet.
| * kgdb: enable arch to support XML packet.Vincent Chen2020-07-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | The XML packet could be supported by required architecture if the architecture defines CONFIG_HAVE_ARCH_KGDB_QXFER_PKT and implement its own kgdb_arch_handle_qxfer_pkt(). Except for the kgdb_arch_handle_qxfer_pkt(), the architecture also needs to record the feature supported by gdb stub into the kgdb_arch_gdb_stub_feature, and these features will be reported to host gdb when gdb stub receives the qSupported packet. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2020-07-101-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking BPF programs, from Maciej Żenczykowski. 2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu Mariappan. 3) Slay memory leak in nl80211 bss color attribute parsing code, from Luca Coelho. 4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin. 5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric Dumazet. 6) xsk code dips too deeply into DMA mapping implementation internals. Add dma_need_sync and use it. From Christoph Hellwig 7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko. 8) Check for disallowed attributes when loading flow dissector BPF programs. From Lorenz Bauer. 9) Correct packet injection to L3 tunnel devices via AF_PACKET, from Jason A. Donenfeld. 10) Don't advertise checksum offload on ipa devices that don't support it. From Alex Elder. 11) Resolve several issues in TCP MD5 signature support. Missing memory barriers, bogus options emitted when using syncookies, and failure to allow md5 key changes in established states. All from Eric Dumazet. 12) Fix interface leak in hsr code, from Taehee Yoo. 13) VF reset fixes in hns3 driver, from Huazhong Tan. 14) Make loopback work again with ipv6 anycast, from David Ahern. 15) Fix TX starvation under high load in fec driver, from Tobias Waldekranz. 16) MLD2 payload lengths not checked properly in bridge multicast code, from Linus Lüssing. 17) Packet scheduler code that wants to find the inner protocol currently only works for one level of VLAN encapsulation. Allow Q-in-Q situations to work properly here, from Toke Høiland-Jørgensen. 18) Fix route leak in l2tp, from Xin Long. 19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport support and various protocols. From Martin KaFai Lau. 20) Fix socket cgroup v2 reference counting in some situations, from Cong Wang. 21) Cure memory leak in mlx5 connection tracking offload support, from Eli Britstein. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits) mlxsw: pci: Fix use-after-free in case of failed devlink reload mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON() net: macb: fix call to pm_runtime in the suspend/resume functions net: macb: fix macb_suspend() by removing call to netif_carrier_off() net: macb: fix macb_get/set_wol() when moving to phylink net: macb: mark device wake capable when "magic-packet" property present net: macb: fix wakeup test in runtime suspend/resume routines bnxt_en: fix NULL dereference in case SR-IOV configuration fails libbpf: Fix libbpf hashmap on (I)LP32 architectures net/mlx5e: CT: Fix memory leak in cleanup net/mlx5e: Fix port buffers cell size value net/mlx5e: Fix 50G per lane indication net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash net/mlx5e: Fix VXLAN configuration restore after function reload net/mlx5e: Fix usage of rcu-protected pointer net/mxl5e: Verify that rpriv is not NULL net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode net/mlx5: Fix eeprom support for SFP module cgroup: Fix sock_cgroup_data on big-endian. selftests: bpf: Fix detach from sockmap tests ...
| * lib: packing: add documentation for pbuflen argumentVladimir Oltean2020-06-281-0/+1
| | | | | | | | | | | | | | | | | | | | Fixes sparse warning: Function parameter or member 'pbuflen' not described in 'packing' Fixes: 554aae35007e ("lib: Add support for generic packing operations") Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge tag 'x86_entry_for_5.8' of ↵Linus Torvalds2020-06-281-0/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 entry fixes from Borislav Petkov: "This is the x86/entry urgent pile which has accumulated since the merge window. It is not the smallest but considering the almost complete entry core rewrite, the amount of fixes to follow is somewhat higher than usual, which is to be expected. Peter Zijlstra says: 'These patches address a number of instrumentation issues that were found after the x86/entry overhaul. When combined with rcu/urgent and objtool/urgent, these patches make UBSAN/KASAN/KCSAN happy again. Part of making this all work is bumping the minimum GCC version for KASAN builds to gcc-8.3, the reason for this is that the __no_sanitize_address function attribute is broken in GCC releases before that. No known GCC version has a working __no_sanitize_undefined, however because the only noinstr violation that results from this happens when an UB is found, we treat it like WARN. That is, we allow it to violate the noinstr rules in order to get the warning out'" * tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry: Fix #UD vs WARN more x86/entry: Increase entry_stack size to a full page x86/entry: Fixup bad_iret vs noinstr objtool: Don't consider vmlinux a C-file kasan: Fix required compiler version compiler_attributes.h: Support no_sanitize_undefined check with GCC 4 x86/entry, bug: Comment the instrumentation_begin() usage for WARN() x86/entry, ubsan, objtool: Whitelist __ubsan_handle_*() x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline() compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr kasan: Bump required compiler version x86, kcsan: Add __no_kcsan to noinstr kcsan: Remove __no_kcsan_or_inline x86, kcsan: Remove __no_kcsan_or_inline usage
| * | Merge branch 'linus' into x86/entry, to resolve conflictsIngo Molnar2020-06-264-6/+6
| |\| | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/traps.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | kasan: Fix required compiler versionMarco Elver2020-06-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first working GCC version to satisfy CC_HAS_WORKING_NOSANITIZE_ADDRESS is GCC 8.3.0. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89124 Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200623112448.GA208112@elver.google.com
| * | kasan: Bump required compiler versionMarco Elver2020-06-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds config variable CC_HAS_WORKING_NOSANITIZE_ADDRESS, which will be true if we have a compiler that does not fail builds due to no_sanitize_address functions. This does not yet mean they work as intended, but for automated build-tests, this is the minimum requirement. For example, we require that __always_inline functions used from no_sanitize_address functions do not generate instrumentation. On GCC <= 7 this fails to build entirely, therefore we make the minimum version GCC 8. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Andrey Konovalov <andreyknvl@google.com> Link: https://lkml.kernel.org/r/20200602175859.GC2604@hirez.programming.kicks-ass.net
* | | lib: fix test_hmm.c reference after freeRandy Dunlap2020-06-261-2/+1
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Coccinelle scripts report the following errors: lib/test_hmm.c:523:20-26: ERROR: reference preceded by free on line 521 lib/test_hmm.c:524:21-27: ERROR: reference preceded by free on line 521 lib/test_hmm.c:523:28-35: ERROR: devmem is NULL but dereferenced. lib/test_hmm.c:524:29-36: ERROR: devmem is NULL but dereferenced. Fix these by using the local variable 'res' instead of devmem. Link: http://lkml.kernel.org/r/c845c158-9c65-9665-0d0b-00342846dd07@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'kbuild-fixes-v5.8' of ↵Linus Torvalds2020-06-211-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - fix -gz=zlib compiler option test for CONFIG_DEBUG_INFO_COMPRESSED - improve cc-option in scripts/Kbuild.include to clean up temp files - improve cc-option in scripts/Kconfig.include for more reliable compile option test - do not copy modules.builtin by 'make install' because it would break existing systems - use 'userprogs' syntax for watch_queue sample * tag 'kbuild-fixes-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: samples: watch_queue: build sample program for target architecture Revert "Makefile: install modules.builtin even if CONFIG_MODULES=n" scripts: Fix typo in headers_install.sh kconfig: unify cc-option and as-option kbuild: improve cc-option to clean up all temporary files Makefile: Improve compressed debug info support detection
| * | kconfig: unify cc-option and as-optionMasahiro Yamada2020-06-171-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cc-option and as-option are almost the same; both pass the flag to $(CC). The main difference is the cc-option stops before the assemble stage (-S option) whereas as-option stops after (-c option). I chose -S because it is slightly faster, but $(cc-option,-gz=zlib) returns a wrong result (https://lkml.org/lkml/2020/6/9/1529). It has been fixed by commit 7b16994437c7 ("Makefile: Improve compressed debug info support detection"), but the assembler should always be invoked for more reliable compiler option tests. However, you cannot simply replace -S with -c because the following code in lib/Kconfig.debug would break: depends on $(cc-option,-gsplit-dwarf) The combination of -c and -gsplit-dwarf does not accept /dev/null as output. $ cat /dev/null | gcc -gsplit-dwarf -S -x c - -o /dev/null $ echo $? 0 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o /dev/null objcopy: Warning: '/dev/null' is not an ordinary file $ echo $? 1 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o tmp.o $ echo $? 0 There is another flag that creates an separate file based on the object file path: $ cat /dev/null | gcc -ftest-coverage -c -x c - -o /dev/null <stdin>:1: error: cannot open /dev/null.gcno So, we cannot use /dev/null to sink the output. Align the cc-option implementation with scripts/Kbuild.include. With -c option used in cc-option, as-option is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org>
| * | Makefile: Improve compressed debug info support detectionArvind Sankar2020-06-151-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 10e68b02c861 ("Makefile: support compressed debug info") added support for compressed debug sections. Support is detected by checking - does the compiler support -gz=zlib - does the assembler support --compressed-debug-sections=zlib - does the linker support --compressed-debug-sections=zlib However, the gcc driver's support for this option is somewhat convoluted. The driver's builtin specs are set based on the version of binutils that it was configured with. It reports an error if the configure-time linker/assembler (i.e., not necessarily the actual assembler that will be run) do not support the option, but only if the assembler (or linker) is actually invoked when -gz=zlib is passed. The cc-option check in scripts/Kconfig.include does not invoke the assembler, so the gcc driver reports success even if it does not support the option being passed to the assembler. Because the as-option check passes the option directly to the assembler via -Wa,--compressed-debug-sections=zlib, the gcc driver does not see this option and will never report an error. Combined with an installed version of binutils that is more recent than the one the compiler was built with, it is possible for all three tests to succeed, yet an actual compilation with -gz=zlib to fail. Moreover, it is unnecessary to explicitly pass --compressed-debug-sections=zlib to the assembler via -Wa, since the driver will do that automatically when it supports -gz=zlib. Convert the as-option to just -gz=zlib, simplifying it as well as performing a better test of the gcc driver's capabilities. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | Merge tag 'libnvdimm-for-5.8-rc2' of ↵Linus Torvalds2020-06-201-0/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "A feature (papr_scm health retrieval) and a fix (sysfs attribute visibility) for v5.8. Vaibhav explains in the merge commit below why missing v5.8 would be painful and I agreed to try a -rc2 pull because only cosmetics kept this out of -rc1 and his initial versions were posted in more than enough time for v5.8 consideration: 'These patches are tied to specific features that were committed to customers in upcoming distros releases (RHEL and SLES) whose time-lines are tied to 5.8 kernel release. Being able to track the health of an nvdimm is critical for our customers that are running workloads leveraging papr-scm nvdimms. Missing the 5.8 kernel would mean missing the distro timelines and shifting forward the availability of this feature in distro kernels by at least 6 months' Summary: - Fix the visibility of the region 'align' attribute. The new unit tests for region alignment handling caught a corner case where the alignment cannot be specified if the region is converted from static to dynamic provisioning at runtime. - Add support for device health retrieval for the persistent memory supported by the papr_scm driver. This includes both the standard sysfs "health flags" that the nfit persistent memory driver publishes and a mechanism for the ndctl tool to retrieve a health-command payload" * tag 'libnvdimm-for-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: nvdimm/region: always show the 'align' attribute powerpc/papr_scm: Implement support for PAPR_PDSM_HEALTH ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods powerpc/papr_scm: Improve error logging and handling papr_scm_ndctl() powerpc/papr_scm: Fetch nvdimm health information from PHYP seq_buf: Export seq_buf_printf powerpc: Document details on H_SCM_HEALTH hcall
| * | seq_buf: Export seq_buf_printfVaibhav Jain2020-06-151-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'seq_buf' provides a very useful abstraction for writing to a string buffer without needing to worry about it over-flowing. However even though the API has been stable for couple of years now its still not exported to kernel loadable modules limiting its usage. Hence this patch proposes update to 'seq_buf.c' to mark seq_buf_printf() which is part of the seq_buf API to be exported to kernel loadable GPL modules. This symbol will be used in later parts of this patch-set to simplify content creation for a sysfs attribute. Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Piotr Maziarz <piotrx.maziarz@linux.intel.com> Cc: Cezary Rojewski <cezary.rojewski@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lore.kernel.org/r/20200615124407.32596-3-vaibhav@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'hch' (maccess patches from Christoph Hellwig)Linus Torvalds2020-06-181-3/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge non-faulting memory access cleanups from Christoph Hellwig: "Andrew and I decided to drop the patches implementing your suggested rename of the probe_kernel_* and probe_user_* helpers from -mm as there were way to many conflicts. After -rc1 might be a good time for this as all the conflicts are resolved now" This also adds a type safety checking patch on top of the renaming series to make the subtle behavioral difference between 'get_user()' and 'get_kernel_nofault()' less potentially dangerous and surprising. * emailed patches from Christoph Hellwig <hch@lst.de>: maccess: make get_kernel_nofault() check for minimal type compatibility maccess: rename probe_kernel_address to get_kernel_nofault maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
| * | maccess: rename probe_kernel_address to get_kernel_nofaultChristoph Hellwig2020-06-181-3/+3
| |/ | | | | | | | | | | | | | | | | | | | | Better describe what this helper does, and match the naming of copy_from_kernel_nofault. Also switch the argument order around, so that it acts and looks like get_user(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / test_objagg: Fix potential memory leak in error handlingAditya Pakki2020-06-151-2/+2
|/ | | | | | | | | In case of failure of check_expect_hints_stats(), the resources allocated by objagg_hints_get should be freed. The patch fixes this issue. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge tag 'kbuild-v5.8-2' of ↵Linus Torvalds2020-06-131-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix build rules in binderfs sample - fix build errors when Kbuild recurses to the top Makefile - covert '---help---' in Kconfig to 'help' * tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: treewide: replace '---help---' in Kconfig files with 'help' kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables samples: binderfs: really compile this sample and fix build issues
| * treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada2020-06-141-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | Merge tag 'x86-entry-2020-06-12' of ↵Linus Torvalds2020-06-132-25/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 entry updates from Thomas Gleixner: "The x86 entry, exception and interrupt code rework This all started about 6 month ago with the attempt to move the Posix CPU timer heavy lifting out of the timer interrupt code and just have lockless quick checks in that code path. Trivial 5 patches. This unearthed an inconsistency in the KVM handling of task work and the review requested to move all of this into generic code so other architectures can share. Valid request and solved with another 25 patches but those unearthed inconsistencies vs. RCU and instrumentation. Digging into this made it obvious that there are quite some inconsistencies vs. instrumentation in general. The int3 text poke handling in particular was completely unprotected and with the batched update of trace events even more likely to expose to endless int3 recursion. In parallel the RCU implications of instrumenting fragile entry code came up in several discussions. The conclusion of the x86 maintainer team was to go all the way and make the protection against any form of instrumentation of fragile and dangerous code pathes enforcable and verifiable by tooling. A first batch of preparatory work hit mainline with commit d5f744f9a2ac ("Pull x86 entry code updates from Thomas Gleixner") That (almost) full solution introduced a new code section '.noinstr.text' into which all code which needs to be protected from instrumentation of all sorts goes into. Any call into instrumentable code out of this section has to be annotated. objtool has support to validate this. Kprobes now excludes this section fully which also prevents BPF from fiddling with it and all 'noinstr' annotated functions also keep ftrace off. The section, kprobes and objtool changes are already merged. The major changes coming with this are: - Preparatory cleanups - Annotating of relevant functions to move them into the noinstr.text section or enforcing inlining by marking them __always_inline so the compiler cannot misplace or instrument them. - Splitting and simplifying the idtentry macro maze so that it is now clearly separated into simple exception entries and the more interesting ones which use interrupt stacks and have the paranoid handling vs. CR3 and GS. - Move quite some of the low level ASM functionality into C code: - enter_from and exit to user space handling. The ASM code now calls into C after doing the really necessary ASM handling and the return path goes back out without bells and whistels in ASM. - exception entry/exit got the equivivalent treatment - move all IRQ tracepoints from ASM to C so they can be placed as appropriate which is especially important for the int3 recursion issue. - Consolidate the declaration and definition of entry points between 32 and 64 bit. They share a common header and macros now. - Remove the extra device interrupt entry maze and just use the regular exception entry code. - All ASM entry points except NMI are now generated from the shared header file and the corresponding macros in the 32 and 64 bit entry ASM. - The C code entry points are consolidated as well with the help of DEFINE_IDTENTRY*() macros. This allows to ensure at one central point that all corresponding entry points share the same semantics. The actual function body for most entry points is in an instrumentable and sane state. There are special macros for the more sensitive entry points, e.g. INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF. They allow to put the whole entry instrumentation and RCU handling into safe places instead of the previous pray that it is correct approach. - The INT3 text poke handling is now completely isolated and the recursion issue banned. Aside of the entry rework this required other isolation work, e.g. the ability to force inline bsearch. - Prevent #DB on fragile entry code, entry relevant memory and disable it on NMI, #MC entry, which allowed to get rid of the nested #DB IST stack shifting hackery. - A few other cleanups and enhancements which have been made possible through this and already merged changes, e.g. consolidating and further restricting the IDT code so the IDT table becomes RO after init which removes yet another popular attack vector - About 680 lines of ASM maze are gone. There are a few open issues: - An escape out of the noinstr section in the MCE handler which needs some more thought but under the aspect that MCE is a complete trainwreck by design and the propability to survive it is low, this was not high on the priority list. - Paravirtualization When PV is enabled then objtool complains about a bunch of indirect calls out of the noinstr section. There are a few straight forward ways to fix this, but the other issues vs. general correctness were more pressing than parawitz. - KVM KVM is inconsistent as well. Patches have been posted, but they have not yet been commented on or picked up by the KVM folks. - IDLE Pretty much the same problems can be found in the low level idle code especially the parts where RCU stopped watching. This was beyond the scope of the more obvious and exposable problems and is on the todo list. The lesson learned from this brain melting exercise to morph the evolved code base into something which can be validated and understood is that once again the violation of the most important engineering principle "correctness first" has caused quite a few people to spend valuable time on problems which could have been avoided in the first place. The "features first" tinkering mindset really has to stop. With that I want to say thanks to everyone involved in contributing to this effort. Special thanks go to the following people (alphabetical order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra, Vitaly Kuznetsov, and Will Deacon" * tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits) x86/entry: Force rcu_irq_enter() when in idle task x86/entry: Make NMI use IDTENTRY_RAW x86/entry: Treat BUG/WARN as NMI-like entries x86/entry: Unbreak __irqentry_text_start/end magic x86/entry: __always_inline CR2 for noinstr lockdep: __always_inline more for noinstr x86/entry: Re-order #DB handler to avoid *SAN instrumentation x86/entry: __always_inline arch_atomic_* for noinstr x86/entry: __always_inline irqflags for noinstr x86/entry: __always_inline debugreg for noinstr x86/idt: Consolidate idt functionality x86/idt: Cleanup trap_init() x86/idt: Use proper constants for table size x86/idt: Add comments about early #PF handling x86/idt: Mark init only functions __init x86/entry: Rename trace_hardirqs_off_prepare() x86/entry: Clarify irq_{enter,exit}_rcu() x86/entry: Remove DBn stacks x86/entry: Remove debug IDT frobbing x86/entry: Optimize local_db_save() for virt ...
| * | lib/bsearch: Provide __always_inline variantPeter Zijlstra2020-06-111-20/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For code that needs the ultimate performance (it can inline the @cmp function too) or simply needs to avoid calling external functions for whatever reason, provide an __always_inline variant of bsearch(). [ tglx: Renamed to __inline_bsearch() as suggested by Andy ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135313.624443814@linutronix.de
| * | lib/smp_processor_id: Move it into noinstr sectionThomas Gleixner2020-06-111-5/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That code is already not traceable. Move it into the noinstr section so the objtool section validation does not trigger. Annotate the warning code as "safe". While it might be not under all circumstances, getting the information out is important enough. Should this ever trigger from the sensitive code which is shielded against instrumentation, e.g. low level entry, then the printk is the least of the worries. Addresses the objtool warnings: vmlinux.o: warning: objtool: context_tracking_recursion_enter()+0x7: call to __this_cpu_preempt_check() leaves .noinstr.text section vmlinux.o: warning: objtool: __context_tracking_exit()+0x17: call to __this_cpu_preempt_check() leaves .noinstr.text section vmlinux.o: warning: objtool: __context_tracking_enter()+0x2a: call to __this_cpu_preempt_check() leaves .noinstr.text section Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.902709267@linutronix.de
* | Merge tag 'locking-kcsan-2020-06-11' of ↵Linus Torvalds2020-06-116-6/+224
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * | kcsan: Restrict supported compilersMarco Elver2020-06-111-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first version of Clang that supports -tsan-distinguish-volatile will be able to support KCSAN. The first Clang release to do so, will be Clang 11. This is due to satisfying all the following requirements: 1. Never emit calls to __tsan_func_{entry,exit}. 2. __no_kcsan functions should not call anything, not even kcsan_{enable,disable}_current(), when using __{READ,WRITE}_ONCE => Requires leaving them plain! 3. Support atomic_{read,set}*() with KCSAN, which rely on arch_atomic_{read,set}*() using __{READ,WRITE}_ONCE() => Because of #2, rely on Clang 11's -tsan-distinguish-volatile support. We will double-instrument atomic_{read,set}*(), but that's reasonable given it's still lower cost than the data_race() variant due to avoiding 2 extra calls (kcsan_{en,dis}able_current() calls). 4. __always_inline functions inlined into __no_kcsan functions are never instrumented. 5. __always_inline functions inlined into instrumented functions are instrumented. 6. __no_kcsan_or_inline functions may be inlined into __no_kcsan functions => Implies leaving 'noinline' off of __no_kcsan_or_inline. 7. Because of #6, __no_kcsan and __no_kcsan_or_inline functions should never be spuriously inlined into instrumented functions, causing the accesses of the __no_kcsan function to be instrumented. Older versions of Clang do not satisfy #3. The latest GCC currently doesn't support at least #1, #3, and #7. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com Link: https://lkml.kernel.org/r/20200521142047.169334-7-elver@google.com
| * | ubsan, kcsan: Don't combine sanitizer with kcov on clangArnd Bergmann2020-06-112-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang does not allow -fsanitize-coverage=trace-{pc,cmp} together with -fsanitize=bounds or with ubsan: clang: error: argument unused during compilation: '-fsanitize-coverage=trace-pc' [-Werror,-Wunused-command-line-argument] clang: error: argument unused during compilation: '-fsanitize-coverage=trace-cmp' [-Werror,-Wunused-command-line-argument] To avoid the warning, check whether clang can handle this correctly or disallow ubsan and kcsan when kcov is enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marco Elver <elver@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://bugs.llvm.org/show_bug.cgi?id=45831 Link: https://lore.kernel.org/lkml/20200505142341.1096942-1-arnd@arndb.de Link: https://lkml.kernel.org/r/20200521142047.169334-2-elver@google.com
| * | Rebase locking/kcsan to locking/urgentThomas Gleixner2020-06-115-6/+195
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * Merge branch 'kcsan-for-tip' of ↵Thomas Gleixner2020-05-081-7/+32
| | |\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan Pull KCSAN updates from Paul McKenney.
| | | * Improve KCSAN documentation a bitIngo Molnar2020-04-271-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit simplifies and clarifies the highest level KCSAN Kconfig help text. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | * kcsan: Add option for verbose reportingMarco Elver2020-03-251-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds CONFIG_KCSAN_VERBOSE to optionally enable more verbose reports. Currently information about the reporting task's held locks and IRQ trace events are shown, if they are enabled. Signed-off-by: Marco Elver <elver@google.com> Suggested-by: Qian Cai <cai@lca.pw> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | | * kcsan: Add option to allow watcher interruptionsMarco Elver2020-03-251-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add option to allow interrupts while a watchpoint is set up. This can be enabled either via CONFIG_KCSAN_INTERRUPT_WATCHER or via the boot parameter 'kcsan.interrupt_watcher=1'. Note that, currently not all safe per-CPU access primitives and patterns are accounted for, which could result in false positives. For example, asm-generic/percpu.h uses plain operations, which by default are instrumented. On interrupts and subsequent accesses to the same variable, KCSAN would currently report a data race with this option. Therefore, this option should currently remain disabled by default, but may be enabled for specific test scenarios. To avoid new warnings, changes all uses of smp_processor_id() to use the raw version (as already done in kcsan_found_watchpoint()). The exact SMP processor id is for informational purposes in the report, and correctness is not affected. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | * | Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar2020-04-1346-264/+1695
| | |\ \ | | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | kcsan: Introduce KCSAN_ACCESS_ASSERT access typeMarco Elver2020-03-211-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The KCSAN_ACCESS_ASSERT access type may be used to introduce dummy reads and writes to assert certain properties of concurrent code, where bugs could not be detected as normal data races. For example, a variable that is only meant to be written by a single CPU, but may be read (without locking) by other CPUs must still be marked properly to avoid data races. However, concurrent writes, regardless if WRITE_ONCE() or not, would be a bug. Using kcsan_check_access(&x, sizeof(x), KCSAN_ACCESS_ASSERT) would allow catching such bugs. To support KCSAN_ACCESS_ASSERT the following notable changes were made: * If an access is of type KCSAN_ASSERT_ACCESS, disable various filters that only apply to data races, so that all races that KCSAN observes are reported. * Bug reports that involve an ASSERT access type will be reported as "KCSAN: assert: race in ..." instead of "data-race"; this will help more easily distinguish them. * Update a few comments to just mention 'races' where we do not always mean pure data races. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | kcsan: Clean up the main KCSAN Kconfig optionMarco Elver2020-03-211-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch cleans up the rules of the 'KCSAN' Kconfig option by: 1. implicitly selecting 'STACKTRACE' instead of depending on it; 2. depending on DEBUG_KERNEL, to avoid accidentally turning KCSAN on if the kernel is not meant to be a debug kernel; 3. updating the short and long summaries. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | kcsan: Clarify Kconfig option KCSAN_IGNORE_ATOMICSMarco Elver2020-03-211-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clarify difference between options KCSAN_IGNORE_ATOMICS and KCSAN_ASSUME_PLAIN_WRITES_ATOMIC in help text. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | kcsan: Add option to assume plain aligned writes up to word size are atomicMarco Elver2020-03-211-7/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds option KCSAN_ASSUME_PLAIN_WRITES_ATOMIC. If enabled, plain aligned writes up to word size are assumed to be atomic, and also not subject to other unsafe compiler optimizations resulting in data races. This option has been enabled by default to reflect current kernel-wide preferences. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | copy_to_user, copy_from_user: Use generic instrumented.hMarco Elver2020-03-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces the KASAN instrumentation with generic instrumentation, implicitly adding KCSAN instrumentation support. For KASAN no functional change is intended. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | iov_iter: Use generic instrumented.hMarco Elver2020-03-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces the kasan instrumentation with generic instrumentation, implicitly adding KCSAN instrumentation support. For KASAN no functional change is intended. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | kcsan: Rate-limit reporting per data racesMarco Elver2020-03-211-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KCSAN data-race reports can occur quite frequently, so much so as to render the system useless. This commit therefore adds support for time-based rate-limiting KCSAN reports, with the time interval specified by a new KCSAN_REPORT_ONCE_IN_MS Kconfig option. The default is 3000 milliseconds, also known as three seconds. Because KCSAN must detect data races in allocators and in other contexts where use of allocation is ill-advised, a fixed-size array is used to buffer reports during each reporting interval. To reduce the number of reports lost due to array overflow, this commit stores only one instance of duplicate reports, which has the benefit of further reducing KCSAN's console output rate. Reported-by: Qian Cai <cai@lca.pw> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | Merge branch 'linus' into locking/kcsan, to pick up fixesIngo Molnar2020-03-212-9/+30
| | |\ \ | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * \ \ Merge branch 'x86/kdump' into locking/kcsan, to resolve conflictsIngo Molnar2020-03-2161-712/+6199
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/purgatory/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * \ \ \ Merge branch 'kcsan.2020.01.07a' into locking/kcsanIngo Molnar2020-01-241-0/+1
| | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KCSAN updates from Paul E. McKenney: - UBSAN fixes - inlining updates - documentation updates Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | kcsan, ubsan: Make KCSAN+UBSAN work togetherMarco Elver2020-01-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Context: http://lkml.kernel.org/r/fb7e25d8-aba4-3dcf-7761-cb7ecb3ebb71@infradead.org Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Marco Elver <elver@google.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| | * | | | | Merge tag 'v5.5-rc7' into locking/kcsan, to refresh the treeIngo Molnar2020-01-201-0/+1
| | |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * \ \ \ \ \ Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar2019-12-3060-836/+14830
| | |\ \ \ \ \ \ | | | |_|/ / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | kcsan: Improve various small stylistic detailsIngo Molnar2019-11-201-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tidy up a few bits: - Fix typos and grammar, improve wording. - Remove spurious newlines that are col80 warning artifacts where the resulting line-break is worse than the disease it's curing. - Use core kernel coding style to improve readability and reduce spurious code pattern variations. - Use better vertical alignment for structure definitions and initialization sequences. - Misc other small details. No change in functionality intended. Cc: linux-kernel@vger.kernel.org Cc: Marco Elver <elver@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | Merge branch 'for-mingo' of ↵Ingo Molnar2019-11-193-0/+123
| | |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan Pull the KCSAN subsystem from Paul E. McKenney: "This pull request contains base kernel concurrency sanitizer (KCSAN) enablement for x86, courtesy of Marco Elver. KCSAN is a sampling watchpoint-based data-race detector, and is documented in Documentation/dev-tools/kcsan.rst. KCSAN was announced in September, and much feedback has since been incorporated: http://lkml.kernel.org/r/CANpmjNPJ_bHjfLZCAPV23AXFfiPiyXXqqu72n6TgWzb2Gnu1eA@mail.gmail.com The data races located thus far have resulted in a number of fixes: https://github.com/google/ktsan/wiki/KCSAN#upstream-fixes-of-data-races-found-by-kcsan Additional information may be found here: https://lore.kernel.org/lkml/20191114180303.66955-1-elver@google.com/ " Signed-off-by: Ingo Molnar <mingo@kernel.org>