June 2023 - Linux-kselftest-mirror

[PATCH bpf v5 0/2] bpf: fix NULL dereference during extable search

by Krister Johansen

Hi, Enclosed are a pair of patches for an oops that can occur if an exception is generated while a bpf subprogram is running. One of the bpf_prog_aux entries for the subprograms are missing an extable. This can lead to an exception that would otherwise be handled turning into a NULL pointer bug. These changes were tested via the verifier and progs selftests and no regressions were observed. Changes from v4: - Ensure that num_exentries is copied to prog->aux from func[0] (Feedback from Ilya Leoshkevich) Changes from v3: - Selftest style fixups (Feedback from Yonghong Song) - Selftest needs to assert that test bpf program executed (Feedback from Yonghong Song) - Selftest should combine open and load using open_and_load (Feedback from Yonghong Song) Changes from v2: - Insert only the main program's kallsyms (Feedback from Yonghong Song and Alexei Starovoitov) - Selftest should use ASSERT instead of CHECK (Feedback from Yonghong Song) - Selftest needs some cleanup (Feedback from Yonghong Song) - Switch patch order (Feedback from Alexei Starovoitov) Changes from v1: - Add a selftest (Feedback From Alexei Starovoitov) - Move to a 1-line verifier change instead of searching multiple extables Krister Johansen (2): bpf: ensure main program has an extable selftests/bpf: add a test for subprogram extables kernel/bpf/verifier.c | 7 ++- .../bpf/prog_tests/subprogs_extable.c | 29 +++++++++++ .../bpf/progs/test_subprogs_extable.c | 51 +++++++++++++++++++ 3 files changed, 85 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/subprogs_extable.c create mode 100644 tools/testing/selftests/bpf/progs/test_subprogs_extable.c -- 2.25.1

1 year, 6 months

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[linux-next:master] BUILD REGRESSION 1f6ce8392d6ff486af5ca96df9ded5882c4b6977

by kernel test robot

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master branch HEAD: 1f6ce8392d6ff486af5ca96df9ded5882c4b6977 Add linux-next specific files for 20230613 Error/Warning reports: https://lore.kernel.org/oe-kbuild-all/202306082341.UQtCM8PO-lkp@intel.com https://lore.kernel.org/oe-kbuild-all/202306122223.HHER4zOo-lkp@intel.com https://lore.kernel.org/oe-kbuild-all/202306132155.BFZc9arF-lkp@intel.com https://lore.kernel.org/oe-kbuild-all/202306132237.Z4LJE8bP-lkp@intel.com https://lore.kernel.org/oe-kbuild-all/202306140347.S9nJS3Al-lkp@intel.com Error/Warning: (recently discovered and may have been fixed) arch/microblaze/include/asm/page.h:34: warning: "ARCH_DMA_MINALIGN" redefined arch/parisc/kernel/pdt.c:65:6: warning: no previous prototype for 'arch_report_meminfo' [-Wmissing-prototypes] csky-linux-ld: drivers/net/ethernet/sfc/ef100_netdev.c:114: undefined reference to `efx_tc_netevent_event' drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c:76: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst drivers/gpu/drm/i915/display/intel_display_power.h:256:70: error: declaration of 'struct seq_file' will not be visible outside of this function [-Werror,-Wvisibility] drivers/leds/leds-cht-wcove.c:144:21: warning: no previous prototype for 'cht_wc_leds_brightness_get' [-Wmissing-prototypes] include/asm-generic/bitops/instrumented-non-atomic.h:141: undefined reference to `uv_info' lib/kunit/executor_test.c:138:4: warning: cast from 'void (*)(const void *)' to 'kunit_action_t *' (aka 'void (*)(void *)') converts to incompatible function type [-Wcast-function-type-strict] lib/kunit/test.c:775:38: warning: cast from 'void (*)(const void *)' to 'kunit_action_t *' (aka 'void (*)(void *)') converts to incompatible function type [-Wcast-function-type-strict] Unverified Error/Warning (likely false positive, please contact us if interested): arch/arm64/kvm/mmu.c:147:3-9: preceding lock on line 140 drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c:98 mlx5_devcom_register_device() error: uninitialized symbol 'tmp_dev'. drivers/usb/cdns3/cdns3-starfive.c:23: warning: expecting prototype for cdns3(). Prototype was for USB_STRAP_HOST() instead fs/btrfs/volumes.c:6404 btrfs_map_block() error: we previously assumed 'mirror_num_ret' could be null (see line 6242) fs/smb/client/cifsfs.c:982 cifs_smb3_do_mount() warn: possible memory leak of 'cifs_sb' fs/smb/client/cifssmb.c:4089 CIFSFindFirst() warn: missing error code? 'rc' fs/smb/client/cifssmb.c:4216 CIFSFindNext() warn: missing error code? 'rc' fs/smb/client/connect.c:2775 cifs_match_super() error: 'tlink' dereferencing possible ERR_PTR() fs/smb/client/connect.c:2974 generic_ip_connect() error: we previously assumed 'socket' could be null (see line 2962) lib/kunit/test.c:336 __kunit_abort() warn: ignoring unreachable code. Error/Warning ids grouped by kconfigs: gcc_recent_errors |-- alpha-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- arc-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- arm-allmodconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- arm-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- arm64-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- arm64-randconfig-c033-20230611 | `-- arch-arm64-kvm-mmu.c:preceding-lock-on-line |-- csky-randconfig-c044-20230612 | |-- csky-linux-ld:drivers-net-ethernet-sfc-ef100_netdev.c:undefined-reference-to-efx_tc_netevent_event | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- i386-allyesconfig | |-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst | `-- drivers-leds-leds-cht-wcove.c:warning:no-previous-prototype-for-cht_wc_leds_brightness_get |-- i386-randconfig-m021-20230612 | |-- fs-smb-client-cifsfs.c-cifs_smb3_do_mount()-warn:possible-memory-leak-of-cifs_sb | |-- fs-smb-client-cifssmb.c-CIFSFindFirst()-warn:missing-error-code-rc | |-- fs-smb-client-cifssmb.c-CIFSFindNext()-warn:missing-error-code-rc | |-- fs-smb-client-connect.c-cifs_match_super()-error:tlink-dereferencing-possible-ERR_PTR() | `-- fs-smb-client-connect.c-generic_ip_connect()-error:we-previously-assumed-socket-could-be-null-(see-line-) |-- m68k-randconfig-m031-20230612 | |-- fs-btrfs-volumes.c-btrfs_map_block()-error:we-previously-assumed-mirror_num_ret-could-be-null-(see-line-) | `-- lib-kunit-test.c-__kunit_abort()-warn:ignoring-unreachable-code. |-- microblaze-buildonly-randconfig-r002-20230612 | `-- arch-microblaze-include-asm-page.h:warning:ARCH_DMA_MINALIGN-redefined |-- mips-allmodconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- mips-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- openrisc-randconfig-r013-20230612 | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- parisc-allyesconfig | |-- arch-parisc-kernel-pdt.c:warning:no-previous-prototype-for-arch_report_meminfo | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- parisc-defconfig | `-- arch-parisc-kernel-pdt.c:warning:no-previous-prototype-for-arch_report_meminfo |-- parisc-randconfig-r004-20230612 | `-- arch-parisc-kernel-pdt.c:warning:no-previous-prototype-for-arch_report_meminfo |-- parisc-randconfig-s031-20230612 | `-- arch-parisc-kernel-pdt.c:warning:no-previous-prototype-for-arch_report_meminfo |-- parisc64-defconfig | `-- arch-parisc-kernel-pdt.c:warning:no-previous-prototype-for-arch_report_meminfo |-- powerpc-allmodconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- riscv-allmodconfig | |-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst | `-- drivers-usb-cdns3-cdns3-starfive.c:warning:expecting-prototype-for-cdns3().-Prototype-was-for-USB_STRAP_HOST()-instead |-- riscv-allyesconfig | |-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst | `-- drivers-usb-cdns3-cdns3-starfive.c:warning:expecting-prototype-for-cdns3().-Prototype-was-for-USB_STRAP_HOST()-instead |-- s390-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- s390-randconfig-r026-20230612 | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- s390-randconfig-r044-20230612 | `-- include-asm-generic-bitops-instrumented-non-atomic.h:undefined-reference-to-uv_info |-- sparc-allyesconfig | `-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst |-- x86_64-allyesconfig | |-- drivers-gpu-drm-amd-amdgpu-amdgpu_ras_eeprom.c:warning:This-comment-starts-with-but-isn-t-a-kernel-doc-comment.-Refer-Documentation-doc-guide-kernel-doc.rst | `-- drivers-leds-leds-cht-wcove.c:warning:no-previous-prototype-for-cht_wc_leds_brightness_get `-- x86_64-randconfig-m001-20230612 |-- drivers-net-ethernet-mellanox-mlx5-core-lib-devcom.c-mlx5_devcom_register_device()-error:uninitialized-symbol-tmp_dev-. |-- fs-smb-client-cifsfs.c-cifs_smb3_do_mount()-warn:possible-memory-leak-of-cifs_sb |-- fs-smb-client-cifssmb.c-CIFSFindFirst()-warn:missing-error-code-rc |-- fs-smb-client-cifssmb.c-CIFSFindNext()-warn:missing-error-code-rc |-- fs-smb-client-connect.c-cifs_match_super()-error:tlink-dereferencing-possible-ERR_PTR() `-- fs-smb-client-connect.c-generic_ip_connect()-error:we-previously-assumed-socket-could-be-null-(see-line-) clang_recent_errors |-- hexagon-buildonly-randconfig-r006-20230612 | |-- lib-kunit-executor_test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type | `-- lib-kunit-test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type |-- hexagon-randconfig-r041-20230612 | |-- lib-kunit-executor_test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type | `-- lib-kunit-test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type |-- hexagon-randconfig-r045-20230612 | |-- lib-kunit-executor_test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type | `-- lib-kunit-test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type |-- riscv-randconfig-r003-20230612 | |-- lib-kunit-executor_test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type | `-- lib-kunit-test.c:warning:cast-from-void-(-)(const-void-)-to-kunit_action_t-(aka-void-(-)(void-)-)-converts-to-incompatible-function-type `-- x86_64-randconfig-r036-20230612 `-- drivers-gpu-drm-i915-display-intel_display_power.h:error:declaration-of-struct-seq_file-will-not-be-visible-outside-of-this-function-Werror-Wvisibility elapsed time: 816m configs tested: 126 configs skipped: 6 tested configs: alpha allyesconfig gcc alpha buildonly-randconfig-r001-20230612 gcc alpha defconfig gcc alpha randconfig-r031-20230612 gcc arc allyesconfig gcc arc defconfig gcc arc randconfig-r015-20230612 gcc arc randconfig-r025-20230612 gcc arc randconfig-r043-20230612 gcc arm alldefconfig clang arm allmodconfig gcc arm allyesconfig gcc arm axm55xx_defconfig gcc arm buildonly-randconfig-r005-20230612 clang arm davinci_all_defconfig clang arm defconfig gcc arm hisi_defconfig gcc arm mmp2_defconfig clang arm nhk8815_defconfig gcc arm randconfig-r046-20230612 clang arm spitz_defconfig clang arm u8500_defconfig gcc arm64 allyesconfig gcc arm64 defconfig gcc csky defconfig gcc hexagon buildonly-randconfig-r006-20230612 clang hexagon randconfig-r041-20230612 clang hexagon randconfig-r045-20230612 clang i386 allyesconfig gcc i386 debian-10.3 gcc i386 defconfig gcc i386 randconfig-i001-20230612 clang i386 randconfig-i002-20230612 clang i386 randconfig-i003-20230612 clang i386 randconfig-i004-20230612 clang i386 randconfig-i005-20230612 clang i386 randconfig-i006-20230612 clang i386 randconfig-i011-20230612 gcc i386 randconfig-i012-20230612 gcc i386 randconfig-i013-20230612 gcc i386 randconfig-i014-20230612 gcc i386 randconfig-i015-20230612 gcc i386 randconfig-i016-20230612 gcc i386 randconfig-r012-20230612 gcc i386 randconfig-r014-20230612 gcc loongarch allmodconfig gcc loongarch allnoconfig gcc loongarch defconfig gcc loongarch randconfig-r035-20230612 gcc m68k allmodconfig gcc m68k allyesconfig gcc m68k defconfig gcc m68k m5307c3_defconfig gcc m68k randconfig-r023-20230612 gcc mips allmodconfig gcc mips allyesconfig gcc mips maltaup_defconfig clang mips omega2p_defconfig clang mips randconfig-r001-20230612 gcc mips randconfig-r011-20230612 clang mips rbtx49xx_defconfig clang mips rt305x_defconfig gcc mips xway_defconfig gcc nios2 buildonly-randconfig-r003-20230612 gcc nios2 defconfig gcc nios2 randconfig-r022-20230612 gcc openrisc buildonly-randconfig-r004-20230612 gcc openrisc randconfig-r013-20230612 gcc openrisc randconfig-r024-20230612 gcc parisc allyesconfig gcc parisc defconfig gcc parisc randconfig-r004-20230612 gcc parisc64 defconfig gcc powerpc adder875_defconfig gcc powerpc allmodconfig gcc powerpc allnoconfig gcc powerpc mpc512x_defconfig clang powerpc mpc885_ads_defconfig clang powerpc mvme5100_defconfig clang powerpc rainier_defconfig gcc powerpc randconfig-r033-20230612 clang powerpc sam440ep_defconfig gcc powerpc walnut_defconfig clang riscv allmodconfig gcc riscv allnoconfig clang riscv allnoconfig gcc riscv allyesconfig gcc riscv defconfig gcc riscv randconfig-r003-20230612 clang riscv randconfig-r042-20230612 gcc riscv rv32_defconfig gcc s390 allmodconfig gcc s390 allyesconfig gcc s390 defconfig gcc s390 randconfig-r016-20230612 gcc s390 randconfig-r026-20230612 gcc s390 randconfig-r044-20230612 gcc sh allmodconfig gcc sh espt_defconfig gcc sh polaris_defconfig gcc sh randconfig-r002-20230612 gcc sparc allyesconfig gcc sparc defconfig gcc sparc64 randconfig-r021-20230612 gcc um i386_defconfig gcc um x86_64_defconfig clang um x86_64_defconfig gcc x86_64 allyesconfig gcc x86_64 buildonly-randconfig-r002-20230612 clang x86_64 defconfig gcc x86_64 kexec gcc x86_64 randconfig-a001-20230613 gcc x86_64 randconfig-a002-20230613 gcc x86_64 randconfig-a003-20230613 gcc x86_64 randconfig-a004-20230613 gcc x86_64 randconfig-a005-20230613 gcc x86_64 randconfig-a006-20230613 gcc x86_64 randconfig-a011-20230612 gcc x86_64 randconfig-a012-20230612 gcc x86_64 randconfig-a013-20230612 gcc x86_64 randconfig-a014-20230612 gcc x86_64 randconfig-a015-20230612 gcc x86_64 randconfig-a016-20230612 gcc x86_64 randconfig-r005-20230612 clang x86_64 randconfig-r036-20230612 clang x86_64 rhel-8.3-rust clang x86_64 rhel-8.3 gcc xtensa iss_defconfig gcc -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki

1 year, 6 months

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[RFC v1 0/6] kunit: Add test attributes API

by Rae Moar

Hello everyone, This is an RFC patch series to propose the addition of a test attributes framework to KUnit. There has been interest in filtering out "slow" KUnit tests. Most notably, a new config, CONFIG_MEMCPY_SLOW_KUNIT_TEST, has been added to exclude particularly slow memcpy tests (https://lore.kernel.org/all/20230118200653.give.574-kees@kernel.org/). This proposed attributes framework would be used to save and access test associated data, including whether a test is slow. These attributes would be reportable (via KTAP and command line output) and some will be filterable. This framework is designed to allow for the addition of other attributes in the future. These attributes could include whether the test is flaky, associated test files, etc. Note that this could intersect with the discussions on how to format test-associated data in KTAP v2 that I am also involved in (https://lore.kernel.org/all/20230420205734.1288498-1-rmoar@google.com/). If the overall idea seems good, I'll make sure to add tests/documentation, and more patches marking existing tests as slow to the patch series. Thanks! Rae Rae Moar (6): kunit: Add test attributes API structure kunit: Add speed attribute kunit: Add ability to filter attributes kunit: tool: Add command line interface to filter and report attributes kunit: memcpy: Mark tests as slow using test attributes kunit: time: Mark test as slow using test attributes include/kunit/attributes.h | 41 ++++ include/kunit/test.h | 62 ++++++ kernel/time/time_test.c | 2 +- lib/kunit/Makefile | 3 +- lib/kunit/attributes.c | 280 +++++++++++++++++++++++++ lib/kunit/executor.c | 89 ++++++-- lib/kunit/executor_test.c | 8 +- lib/kunit/kunit-example-test.c | 9 + lib/kunit/test.c | 17 +- lib/memcpy_kunit.c | 8 +- tools/testing/kunit/kunit.py | 34 ++- tools/testing/kunit/kunit_kernel.py | 6 +- tools/testing/kunit/kunit_tool_test.py | 41 ++-- 13 files changed, 536 insertions(+), 64 deletions(-) create mode 100644 include/kunit/attributes.h create mode 100644 lib/kunit/attributes.c base-commit: fefdb43943c1a0d87e1b43ae4d03e5f9a1d058f4 -- 2.41.0.162.gfafddb0af9-goog

1 year, 6 months

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Re: [PATCH] selftests/bpf: Remove unneeded variable "ret"

by Yonghong Song

On 6/13/23 1:50 AM, baomingtong001(a)208suo.com wrote: > Fix the following coccicheck warning: > > tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c:28:14-17: Unneeded > variable: "ret". > > Return "1". > > Signed-off-by: Mingtong Bao <baomingtong001(a)208suo.com> > --- > tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c > b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c > index 4a9f63bea66c..7f0146682577 100644 > --- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c > +++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c > @@ -25,10 +25,9 @@ static __noinline > int subprog_tail(struct __sk_buff *skb) > { > /* Don't propagate the constant to the caller */ > - volatile int ret = 1; > > bpf_tail_call_static(skb, &jmp_table, 0); > - return ret; > + return 1; Please pay attention to the comment: /* Don't propagate the constant to the caller */ which clearly says 'constant' is not preferred. The patch introduced this change is: 5e0b0a4c52d30 selftests/bpf: Test tail call counting with bpf2bpf and data on stack The test intentionally want to: 'Specifically when the size of data allocated on BPF stack is not a multiple on 8.' Note that with volatile and without volatile, the generated code will be different and it will result in different verification path. cc Jakub for further clarification. > } > > SEC("tc")

1 year, 6 months

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Re: [PATCH v2 1/2] tty: tty_io: update timestamps on all device nodes

by Greg KH

On Thu, Jun 08, 2023 at 07:52:54PM +0200, Michal Sekletar wrote: > On Thu, Jun 8, 2023 at 1:51 PM Greg KH <gregkh(a)linuxfoundation.org> wrote: > > > So how are you protecting this from being an information leak like we > > have had in the past where you could monitor how many characters were > > being sent to the tty through a proc file? Seems like now you can just > > monitor any tty node in the system and get the same information, while > > today you can only do it for the tty devices you have permissions for, > > right? > > Hi Greg, > > I am not protecting against it in any way, but proposed changes are only > about timestamp updates which still happen in at least 8 seconds intervals > so exact timing of read/writes to tty can't be inferred. Frankly, I may > have misunderstood something. It would be great if you could mention a bit > more details about CVE you had in mind. Ah, I missed that this is in 8 second increments, nevermind then! thanks, greg k-h

1 year, 6 months

2
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[PATCH v12 0/5] Implement IOCTL to get and optionally clear info about PTEs

by Muhammad Usama Anjum

*Changes in v12* - Update and other memory types to UFFD_FEATURE_WP_ASYNC - Rebaase on top of next-20230406 - Review updates *Changes in v11* - Rebase on top of next-20230307 - Base patches on UFFD_FEATURE_WP_UNPOPULATED - Do a lot of cosmetic changes and review updates - Remove ENGAGE_WP + !GET operation as it can be performed with UFFDIO_WRITEPROTECT *Changes in v10* - Add specific condition to return error if hugetlb is used with wp async - Move changes in tools/include/uapi/linux/fs.h to separate patch - Add documentation *Changes in v9:* - Correct fault resolution for userfaultfd wp async - Fix build warnings and errors which were happening on some configs - Simplify pagemap ioctl's code *Changes in v8:* - Update uffd async wp implementation - Improve PAGEMAP_IOCTL implementation *Changes in v7:* - Add uffd wp async - Update the IOCTL to use uffd under the hood instead of soft-dirty flags *Motivation* The real motivation for adding PAGEMAP_SCAN IOCTL is to emulate Windows GetWriteWatch() syscall [1]. The GetWriteWatch{} retrieves the addresses of the pages that are written to in a region of virtual memory. This syscall is used in Windows applications and games etc. This syscall is being emulated in pretty slow manner in userspace. Our purpose is to enhance the kernel such that we translate it efficiently in a better way. Currently some out of tree hack patches are being used to efficiently emulate it in some kernels. We intend to replace those with these patches. So the whole gaming on Linux can effectively get benefit from this. It means there would be tons of users of this code. CRIU use case [2] was mentioned by Andrei and Danylo: > Use cases for migrating sparse VMAs are binaries sanitized with ASAN, > MSAN or TSAN [3]. All of these sanitizers produce sparse mappings of > shadow memory [4]. Being able to migrate such binaries allows to highly > reduce the amount of work needed to identify and fix post-migration > crashes, which happen constantly. Andrei's defines the following uses of this code: * it is more granular and allows us to track changed pages more effectively. The current interface can clear dirty bits for the entire process only. In addition, reading info about pages is a separate operation. It means we must freeze the process to read information about all its pages, reset dirty bits, only then we can start dumping pages. The information about pages becomes more and more outdated, while we are processing pages. The new interface solves both these downsides. First, it allows us to read pte bits and clear the soft-dirty bit atomically. It means that CRIU will not need to freeze processes to pre-dump their memory. Second, it clears soft-dirty bits for a specified region of memory. It means CRIU will have actual info about pages to the moment of dumping them. * The new interface has to be much faster because basic page filtering is happening in the kernel. With the old interface, we have to read pagemap for each page. *Implementation Evolution (Short Summary)* From the definition of GetWriteWatch(), we feel like kernel's soft-dirty feature can be used under the hood with some additions like: * reset soft-dirty flag for only a specific region of memory instead of clearing the flag for the entire process * get and clear soft-dirty flag for a specific region atomically So we decided to use ioctl on pagemap file to read or/and reset soft-dirty flag. But using soft-dirty flag, sometimes we get extra pages which weren't even written. They had become soft-dirty because of VMA merging and VM_SOFTDIRTY flag. This breaks the definition of GetWriteWatch(). We were able to by-pass this short coming by ignoring VM_SOFTDIRTY until David reported that mprotect etc messes up the soft-dirty flag while ignoring VM_SOFTDIRTY [5]. This wasn't happening until [6] got introduced. We discussed if we can revert these patches. But we could not reach to any conclusion. So at this point, I made couple of tries to solve this whole VM_SOFTDIRTY issue by correcting the soft-dirty implementation: * [7] Correct the bug fixed wrongly back in 2014. It had potential to cause regression. We left it behind. * [8] Keep a list of soft-dirty part of a VMA across splits and merges. I got the reply don't increase the size of the VMA by 8 bytes. At this point, we left soft-dirty considering it is too much delicate and userfaultfd [9] seemed like the only way forward. From there onward, we have been basing soft-dirty emulation on userfaultfd wp feature where kernel resolves the faults itself when WP_ASYNC feature is used. It was straight forward to add WP_ASYNC feature in userfautlfd. Now we get only those pages dirty or written-to which are really written in reality. (PS There is another WP_UNPOPULATED userfautfd feature is required which is needed to avoid pre-faulting memory before write-protecting [9].) All the different masks were added on the request of CRIU devs to create interface more generic and better. [1] https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-… [2] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com [3] https://github.com/google/sanitizers [4] https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm#64-bit [5] https://lore.kernel.org/all/bfcae708-db21-04b4-0bbe-712badd03071@redhat.com [6] https://lore.kernel.org/all/20220725142048.30450-1-peterx@redhat.com/ [7] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [8] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [9] https://lore.kernel.org/all/20230306213925.617814-1-peterx@redhat.com [10] https://lore.kernel.org/all/20230125144529.1630917-1-mdanylo@google.com * Original Cover letter from v8* Hello, Note: Soft-dirty pages and pages which have been written-to are synonyms. As kernel already has soft-dirty feature inside which we have given up to use, we are using written-to terminology while using UFFD async WP under the hood. This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear the info about page table entries. The following operations are supported in this ioctl: - Get the information if the pages have been written-to (PAGE_IS_WRITTEN), file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT) or swapped (PAGE_IS_SWAPPED). - Write-protect the pages (PAGEMAP_WP_ENGAGE) to start finding which pages have been written-to. - Find pages which have been written-to and write protect the pages (atomic PAGE_IS_WRITTEN + PAGEMAP_WP_ENGAGE) It is possible to find and clear soft-dirty pages entirely in userspace. But it isn't efficient: - The mprotect and SIGSEGV handler for bookkeeping - The userfaultfd wp (synchronous) with the handler for bookkeeping Some benchmarks can be seen here[1]. This series adds features that weren't present earlier: - There is no atomic get soft-dirty/Written-to status and clear present in the kernel. - The pages which have been written-to can not be found in accurate way. (Kernel's soft-dirty PTE bit + sof_dirty VMA bit shows more soft-dirty pages than there actually are.) Historically, soft-dirty PTE bit tracking has been used in the CRIU project. The procfs interface is enough for finding the soft-dirty bit status and clearing the soft-dirty bit of all the pages of a process. We have the use case where we need to track the soft-dirty PTE bit for only specific pages on-demand. We need this tracking and clear mechanism of a region of memory while the process is running to emulate the getWriteWatch() syscall of Windows. *(Moved to using UFFD instead of soft-dirtyi feature to find pages which have been written-to from v7 patch series)*: Stop using the soft-dirty flags for finding which pages have been written to. It is too delicate and wrong as it shows more soft-dirty pages than the actual soft-dirty pages. There is no interest in correcting it [2][3] as this is how the feature was written years ago. It shouldn't be updated to changed behaviour. Peter Xu has suggested using the async version of the UFFD WP [4] as it is based inherently on the PTEs. So in this patch series, I've added a new mode to the UFFD which is asynchronous version of the write protect. When this variant of the UFFD WP is used, the page faults are resolved automatically by the kernel. The pages which have been written-to can be found by reading pagemap file (!PM_UFFD_WP). This feature can be used successfully to find which pages have been written to from the time the pages were write protected. This works just like the soft-dirty flag without showing any extra pages which aren't soft-dirty in reality. The information related to pages if the page is file mapped, present and swapped is required for the CRIU project [5][6]. The addition of the required mask, any mask, excluded mask and return masks are also required for the CRIU project [5]. The IOCTL returns the addresses of the pages which match the specific masks. The page addresses are returned in struct page_region in a compact form. The max_pages is needed to support a use case where user only wants to get a specific number of pages. So there is no need to find all the pages of interest in the range when max_pages is specified. The IOCTL returns when the maximum number of the pages are found. The max_pages is optional. If max_pages is specified, it must be equal or greater than the vec_size. This restriction is needed to handle worse case when one page_region only contains info of one page and it cannot be compacted. This is needed to emulate the Windows getWriteWatch() syscall. The patch series include the detailed selftest which can be used as an example for the uffd async wp test and PAGEMAP_IOCTL. It shows the interface usages as well. [1] https://lore.kernel.org/lkml/54d4c322-cd6e-eefd-b161-2af2b56aae24@collabora… [2] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [3] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [4] https://lore.kernel.org/all/Y6Hc2d+7eTKs7AiH@x1n [5] https://lore.kernel.org/all/YyiDg79flhWoMDZB@gmail.com/ [6] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com/ Regards, Muhammad Usama Anjum Muhammad Usama Anjum (4): fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs tools headers UAPI: Update linux/fs.h with the kernel sources mm/pagemap: add documentation of PAGEMAP_SCAN IOCTL selftests: mm: add pagemap ioctl tests Peter Xu (1): userfaultfd: UFFD_FEATURE_WP_ASYNC Documentation/admin-guide/mm/pagemap.rst | 56 + Documentation/admin-guide/mm/userfaultfd.rst | 35 + fs/proc/task_mmu.c | 426 ++++++ fs/userfaultfd.c | 26 +- include/linux/userfaultfd_k.h | 29 +- include/uapi/linux/fs.h | 53 + include/uapi/linux/userfaultfd.h | 9 +- mm/hugetlb.c | 32 +- mm/memory.c | 27 +- tools/include/uapi/linux/fs.h | 53 + tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 4 +- tools/testing/selftests/mm/config | 1 + tools/testing/selftests/mm/pagemap_ioctl.c | 1301 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 4 + 15 files changed, 2034 insertions(+), 23 deletions(-) create mode 100644 tools/testing/selftests/mm/pagemap_ioctl.c mode change 100644 => 100755 tools/testing/selftests/mm/run_vmtests.sh -- 2.39.2

1 year, 6 months

3
28
0 0

Re: [PATCH v3 09/10] eventfs: moving tracing/events to eventfs

by Ajay Kaher

> Hello, > > kernel test robot noticed "WARNING:possible_circular_locking_dependency_detected" on: > > commit: a3bb763435d444023d3bca5479da632c57724619 ("[PATCH v3 09/10] eventfs: moving tracing/events to eventfs") > url: https://github.com/intel-lab-lkp/linux/commits/Ajay-Kaher/tracing-Require-a… > base: https://git.kernel.org/cgit/linux/kernel/git/shuah/linux-kselftest.git next > patch link: 1685610013-33478-10-git-send-email-akaher(a)vmware.com/">https://lore.kernel.org/all/1685610013-33478-10-git-send-email-akaher@vmwar… > patch subject: [PATCH v3 09/10] eventfs: moving tracing/events to eventfs > > in testcase: kernel-selftests > version: kernel-selftests-x86_64-60acb023-1_20230329 > with following parameters: > > group: ftrace > > test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel. > test-url: https://www.kernel.org/doc/Documentation/kselftest.txt > > > compiler: gcc-12 > test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 32G memory > > (please refer to attached dmesg/kmsg for entire log/backtrace) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <oliver.sang(a)intel.com> > | Closes: 202306102230.b5aa258d-oliver.sang(a)intel.com">https://lore.kernel.org/oe-lkp/202306102230.b5aa258d-oliver.sang@intel.com > > > kern :warn : [ 173.884312] WARNING: possible circular locking dependency detected > kern :warn : [ 173.884947] 6.4.0-rc1-00014-ga3bb763435d4 #1 Not tainted > kern :warn : [ 173.885501] ------------------------------------------------------ > kern :warn : [ 173.886125] ftracetest/2186 is trying to acquire lock: > kern :warn : [ 173.886665] ffff88810045d368 (&sb->s_type->i_mutex_key#5){++++}-{3:3}, at: dcache_dir_open_wrapper (fs/tracefs/event_inode.c:373) > kern :warn : [ 173.887638] > but task is already holding lock: > kern :warn : [ 173.888299] ffffffff84e6d640 (eventfs_rwsem/1){.+.+}-{3:3}, at: dcache_dir_open_wrapper (fs/tracefs/event_inode.c:364) > kern :warn : [ 173.889183] > which lock already depends on the new lock. > > kern :warn : [ 173.890101] > the existing dependency chain (in reverse order) is: > kern :warn : [ 173.890898] > -> #1 (eventfs_rwsem/1){.+.+}-{3:3}: > kern :warn : [ 173.891600] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5693 kernel/locking/lockdep.c:5656) > kern :warn : [ 173.892066] down_read_nested (kernel/locking/rwsem.c:1263 kernel/locking/rwsem.c:1646) > kern :warn : [ 173.892553] eventfs_root_lookup (fs/tracefs/event_inode.c:283) > kern :warn : [ 173.893058] __lookup_slow (include/linux/dcache.h:359 include/linux/dcache.h:364 fs/namei.c:1691) > kern :warn : [ 173.893529] walk_component (include/linux/fs.h:790 fs/namei.c:1708 fs/namei.c:1998) > kern :warn : [ 173.894006] path_lookupat (fs/namei.c:2455 fs/namei.c:2479) > kern :warn : [ 173.894476] filename_lookup (fs/namei.c:2508) > kern :warn : [ 173.894974] vfs_statx (fs/stat.c:239) > kern :warn : [ 173.895410] vfs_fstatat (fs/stat.c:277) > kern :warn : [ 173.895851] __do_sys_newfstatat (fs/stat.c:447) > kern :warn : [ 173.896350] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > kern :warn : [ 173.896815] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) > kern :warn : [ 173.897392] > -> #0 (&sb->s_type->i_mutex_key#5){++++}-{3:3}: > kern :warn : [ 173.898158] check_prev_add (kernel/locking/lockdep.c:3109) > kern :warn : [ 173.898643] __lock_acquire (kernel/locking/lockdep.c:3228 kernel/locking/lockdep.c:3842 kernel/locking/lockdep.c:5074) > kern :warn : [ 173.899133] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5693 kernel/locking/lockdep.c:5656) > kern :warn : [ 173.899610] down_write (arch/x86/include/asm/preempt.h:80 kernel/locking/rwsem.c:1304 kernel/locking/rwsem.c:1315 kernel/locking/rwsem.c:1574) > kern :warn : [ 173.900054] dcache_dir_open_wrapper (fs/tracefs/event_inode.c:373) > kern :warn : [ 173.900603] do_dentry_open (fs/open.c:920) > kern :warn : [ 173.901081] do_open (fs/namei.c:3636) > kern :warn : [ 173.901508] path_openat (fs/namei.c:3792) > kern :warn : [ 173.901963] do_filp_open (fs/namei.c:3818) > kern :warn : [ 173.902425] do_sys_openat2 (fs/open.c:1356) > kern :warn : [ 173.902902] __x64_sys_openat (fs/open.c:1383) > kern :warn : [ 173.903408] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > kern :warn : [ 173.903864] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) > kern :warn : [ 173.904451] > other info that might help us debug this: > > kern :warn : [ 173.905372] Possible unsafe locking scenario: > > kern :warn : [ 173.906049] CPU0 CPU1 > kern :warn : [ 173.906538] ---- ---- > kern :warn : [ 173.907027] rlock(eventfs_rwsem/1); > kern :warn : [ 173.907464] lock(&sb->s_type->i_mutex_key#5); > kern :warn : [ 173.908171] lock(eventfs_rwsem/1); > kern :warn : [ 173.908800] lock(&sb->s_type->i_mutex_key#5); > kern :warn : [ 173.909291] > *** DEADLOCK *** Steve, this seems not to be a problem here as dcache_dir_open_wrapper() and eventfs_root_lookup() both lock eventfs_rwsem as read lock, however it’s known problem in Lockdep for rwlock: https://lpc.events/event/2/contributions/74/ And available patchset on Lockdep not upstreamed: https://lore.kernel.org/all/20190829083132.22394-1-duyuyang@gmail.com/ -Ajay

1 year, 6 months

1
0
0 0

[PATCH 0/3] tracing/user_events: Fix incorrect return value for

by sunliming

Now the writing operation return the count of writes whether events are enabled or disabled. Fix this by just return -EFAULT when events are disabled. sunliming (3): tracing/user_events: Fix incorrect return value for writing operation when events are disabled selftests/user_events: Enable the event before write_fault test in ftrace self-test selftests/user_events: Add test cases when event is disabled kernel/trace/trace_events_user.c | 3 ++- tools/testing/selftests/user_events/ftrace_test.c | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-) -- 2.25.1

1 year, 6 months

3
6
0 0

kselftest/next build: 3 builds: 0 failed, 3 passed, 3 warnings (v6.4-rc6-10-g8cd0d8633e2d)

by kernelci.org bot

kselftest/next build: 3 builds: 0 failed, 3 passed, 3 warnings (v6.4-rc6-10-g8cd0d8633e2d) Full Build Summary: https://kernelci.org/build/kselftest/branch/next/kernel/v6.4-rc6-10-g8cd0d8… Tree: kselftest Branch: next Git Describe: v6.4-rc6-10-g8cd0d8633e2d Git Commit: 8cd0d8633e2de4e6dd9ddae7980432e726220fdb Git URL: https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git Built: 3 unique architectures Warnings Detected: arm64: i386: x86_64: x86_64_defconfig+kselftest (gcc-10): 3 warnings Warnings summary: 1 vmlinux.o: warning: objtool: iovec_from_user+0x88: call to copy_iovec_from_user.part.0() with UACCESS enabled 1 vmlinux.o: warning: objtool: __import_iovec+0x147: call to copy_iovec_from_user.part.0() with UACCESS enabled 1 vmlinux.o: warning: objtool: .altinstr_replacement+0x1d1b: redundant UACCESS disable ================================================================================ Detailed per-defconfig build reports: -------------------------------------------------------------------------------- defconfig+kselftest (arm64, clang-16) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- i386_defconfig+kselftest (i386, gcc-10) — PASS, 0 errors, 0 warnings, 0 section mismatches -------------------------------------------------------------------------------- x86_64_defconfig+kselftest (x86_64, gcc-10) — PASS, 0 errors, 3 warnings, 0 section mismatches Warnings: vmlinux.o: warning: objtool: .altinstr_replacement+0x1d1b: redundant UACCESS disable vmlinux.o: warning: objtool: iovec_from_user+0x88: call to copy_iovec_from_user.part.0() with UACCESS enabled vmlinux.o: warning: objtool: __import_iovec+0x147: call to copy_iovec_from_user.part.0() with UACCESS enabled --- For more info write to <info(a)kernelci.org>

1 year, 6 months

1
0
0 0

[PATCH v3 0/4] Check if FIPS mode is enabled when running selftests

by Magali Lemes

Some test cases from net/tls, net/fcnal-test and net/vrf-xfrm-tests that rely on cryptographic functions to work and use non-compliant FIPS algorithms fail in FIPS mode. In order to allow these tests to pass in a wider set of kernels, - for net/tls, skip the test variants that use the ChaCha20-Poly1305 and SM4 algorithms, when FIPS mode is enabled; - for net/fcnal-test, skip the MD5 tests, when FIPS mode is enabled; - for net/vrf-xfrm-tests, replace the algorithms that are not FIPS-compliant with compliant ones. Changes in v3: - Add new commit to allow skipping test directly from test setup. - No need to initialize static variable to zero. - Skip tests during test setup only. - Use the constructor attribute to set fips_enabled before entering main(). Changes in v2: - Add R-b tags. - Put fips_non_compliant into the variants. - Turn fips_enabled into a static global variable. - Read /proc/sys/crypto/fips_enabled only once at main(). v1: https://lore.kernel.org/netdev/20230607174302.19542-1-magali.lemes@canonica… v2: https://lore.kernel.org/netdev/20230609164324.497813-1-magali.lemes@canonic… Magali Lemes (4): selftests/harness: allow tests to be skipped during setup selftests: net: tls: check if FIPS mode is enabled selftests: net: vrf-xfrm-tests: change authentication and encryption algos selftests: net: fcnal-test: check if FIPS mode is enabled tools/testing/selftests/kselftest_harness.h | 6 ++-- tools/testing/selftests/net/fcnal-test.sh | 27 +++++++++++----- tools/testing/selftests/net/tls.c | 25 ++++++++++++++- tools/testing/selftests/net/vrf-xfrm-tests.sh | 32 +++++++++---------- 4 files changed, 62 insertions(+), 28 deletions(-) -- 2.34.1

1 year, 6 months

2
5
0 0

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