October 2020 - Linux-kselftest-mirror

[PATCH net-next v2 0/3] net: introduce rps_default_mask

by Paolo Abeni

Real-time setups try hard to ensure proper isolation between time critical applications and e.g. network processing performed by the network stack in softirq and RPS is used to move the softirq activity away from the isolated core. If the network configuration is dynamic, with netns and devices routinely created at run-time, enforcing the correct RPS setting on each newly created device allowing to transient bad configuration became complex. These series try to address the above, introducing a new sysctl knob: rps_default_mask. The new sysctl entry allows configuring a systemwide RPS mask, to be enforced since receive queue creation time without any fourther per device configuration required. Additionally, a simple self-test is introduced to check the rps_default_mask behavior. v1 -> v2: - fix sparse warning in patch 2/3 Paolo Abeni (3): net/sysctl: factor-out netdev_rx_queue_set_rps_mask() helper net/core: introduce default_rps_mask netns attribute self-tests: introduce self-tests for RPS default mask Documentation/admin-guide/sysctl/net.rst | 6 ++ include/linux/netdevice.h | 1 + net/core/net-sysfs.c | 73 +++++++++++-------- net/core/sysctl_net_core.c | 58 +++++++++++++++ tools/testing/selftests/net/Makefile | 1 + tools/testing/selftests/net/config | 3 + .../testing/selftests/net/rps_default_mask.sh | 57 +++++++++++++++ 7 files changed, 169 insertions(+), 30 deletions(-) create mode 100755 tools/testing/selftests/net/rps_default_mask.sh -- 2.26.2

1 year, 2 months

4
12
0 0

[PATCH v2 net-next 0/3] ptp: Add adjust phase to support phase offset.

by vincent.cheng.xh＠renesas.com

From: Vincent Cheng <vincent.cheng.xh(a)renesas.com> This series adds adjust phase to the PTP Hardware Clock device interface. Some PTP hardware clocks have a write phase mode that has a built-in hardware filtering capability. The write phase mode utilizes a phase offset control word instead of a frequency offset control word. Add adjust phase function to take advantage of this capability. Changes since v1: - As suggested by Richard Cochran: 1. ops->adjphase is new so need to check for non-null function pointer. 2. Kernel coding style uses lower_case_underscores. 3. Use existing PTP clock API for delayed worker. Vincent Cheng (3): ptp: Add adjphase function to support phase offset control. ptp: Add adjust_phase to ptp_clock_caps capability. ptp: ptp_clockmatrix: Add adjphase() to support PHC write phase mode. drivers/ptp/ptp_chardev.c | 1 + drivers/ptp/ptp_clock.c | 3 ++ drivers/ptp/ptp_clockmatrix.c | 92 +++++++++++++++++++++++++++++++++++ drivers/ptp/ptp_clockmatrix.h | 8 ++- include/linux/ptp_clock_kernel.h | 6 ++- include/uapi/linux/ptp_clock.h | 4 +- tools/testing/selftests/ptp/testptp.c | 6 ++- 7 files changed, 114 insertions(+), 6 deletions(-) -- 2.7.4

1 year, 8 months

5
8
0 0

[PATCH V2 0/3] riscv: add support for restartable sequence

by Vincent Chen

Add RSEQ, restartable sequence, support and related selftest to RISCV. The Kconfig option HAVE_REGS_AND_STACK_ACCESS_API is also required by RSEQ because RSEQ will modify the content of pt_regs.sepc through instruction_pointer_set() during the fixup procedure. In order to select the config HAVE_REGS_AND_STACK_ACCESS_API, the missing APIs for accessing pt_regs are also added in this patch set. The relevant RSEQ tests in kselftest require the Binutils patch "RISC-V: Fix linker problems with TLS copy relocs" to avoid placing PREINIT_ARRAY and TLS variable of librseq.so at the same address. https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=3e7bd7f… A segmental fault will happen if binutils misses this patch. Patrick Stählin (1): riscv: add required functions to enable HAVE_REGS_AND_STACK_ACCESS_API Vincent Chen (2): riscv: Add support for restartable sequence rseq/selftests: Add support for riscv Changes since v1: 1. Use the correct register name to access pt_regs arch/riscv/Kconfig | 2 + arch/riscv/include/asm/ptrace.h | 29 +- arch/riscv/kernel/entry.S | 4 + arch/riscv/kernel/ptrace.c | 99 +++++ arch/riscv/kernel/signal.c | 2 + tools/testing/selftests/rseq/param_test.c | 23 ++ tools/testing/selftests/rseq/rseq-riscv.h | 622 ++++++++++++++++++++++++++++++ tools/testing/selftests/rseq/rseq.h | 2 + 8 files changed, 782 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/rseq/rseq-riscv.h -- 2.7.4

2 years, 9 months

3
8
0 0

[PATCH v4 0/5] Speed up mremap on large regions

by Kalesh Singh

This is a repost of the mremap speed up patches, adding Kirill's Acked-by's (from a separate discussion). The previous versions are posted at: v1 - https://lore.kernel.org/r/20200930222130.4175584-1-kaleshsingh@google.com v2 - https://lore.kernel.org/r/20201002162101.665549-1-kaleshsingh@google.com v3 - http://lore.kernel.org/r/20201005154017.474722-1-kaleshsingh@google.com mremap time can be optimized by moving entries at the PMD/PUD level if the source and destination addresses are PMD/PUD-aligned and PMD/PUD-sized. Enable moving at the PMD and PUD levels on arm64 and x86. Other architectures where this type of move is supported and known to be safe can also opt-in to these optimizations by enabling HAVE_MOVE_PMD and HAVE_MOVE_PUD. Observed Performance Improvements for remapping a PUD-aligned 1GB-sized region on x86 and arm64: - HAVE_MOVE_PMD is already enabled on x86 : N/A - Enabling HAVE_MOVE_PUD on x86 : ~13x speed up - Enabling HAVE_MOVE_PMD on arm64 : ~ 8x speed up - Enabling HAVE_MOVE_PUD on arm64 : ~19x speed up Altogether, HAVE_MOVE_PMD and HAVE_MOVE_PUD give a total of ~150x speed up on arm64. Changes in v2: - Reduce mremap_test time by only validating a configurable threshold of the remapped region, as per John. - Use a random pattern for mremap validation. Provide pattern seed in test output, as per John. - Moved set_pud_at() to separate patch, per Kirill. - Use switch() instead of ifs in move_pgt_entry(), per Kirill. - Update commit message with description of Android garbage collector use case for HAVE_MOVE_PUD, as per Joel. - Fix build test error reported by kernel test robot in [1]. Changes in v3: - Make lines 80 cols or less where they don’t need to be longer, per John. - Removed unused PATTERN_SIZE in mremap_test - Added Reviewed-by tag for patch 1/5 (mremap kselftest patch). - Use switch() instead of ifs in get_extent(), per Kirill - Add BUILD_BUG() is get_extent() default case. - Move get_old_pud() and alloc_new_pud() out of #ifdef CONFIG_HAVE_MOVE_PUD, per Kirill. - Have get_old_pmd() and alloc_new_pmd() use get_old_pud() and alloc_old_pud(), per Kirill. - Replace #ifdef CONFIG_HAVE_MOVE_PMD / PUD in move_page_tables() with IS_ENABLED(CONFIG_HAVE_MOVE_PMD / PUD), per Kirill. - Fold Add set_pud_at() patch into patch 4/5, per Kirill. [1] https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/CKPGL4F… Kalesh Singh (5): kselftests: vm: Add mremap tests arm64: mremap speedup - Enable HAVE_MOVE_PMD mm: Speedup mremap on 1GB or larger regions arm64: mremap speedup - Enable HAVE_MOVE_PUD x86: mremap speedup - Enable HAVE_MOVE_PUD arch/Kconfig | 7 + arch/arm64/Kconfig | 2 + arch/arm64/include/asm/pgtable.h | 1 + arch/x86/Kconfig | 1 + mm/mremap.c | 230 ++++++++++++--- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 1 + tools/testing/selftests/vm/mremap_test.c | 344 +++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 11 + 9 files changed, 558 insertions(+), 40 deletions(-) create mode 100644 tools/testing/selftests/vm/mremap_test.c -- 2.28.0.1011.ga647a8990f-goog

3 years, 4 months

4
11
0 0

[PATCHv2] selftests/powerpc/eeh: disable kselftest timeout setting for eeh-basic

by Po-Hsu Lin

The eeh-basic test got its own 60 seconds timeout (defined in commit 414f50434aa2 "selftests/eeh: Bump EEH wait time to 60s") per breakable device. And we have discovered that the number of breakable devices varies on different hardware. The device recovery time ranges from 0 to 35 seconds. In our test pool it will take about 30 seconds to run on a Power8 system that with 5 breakable devices, 60 seconds to run on a Power9 system that with 4 breakable devices. Extend the timeout setting in the kselftest framework to 5 minutes to give it a chance to finish. Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/powerpc/eeh/Makefile | 2 +- tools/testing/selftests/powerpc/eeh/settings | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/eeh/settings diff --git a/tools/testing/selftests/powerpc/eeh/Makefile b/tools/testing/selftests/powerpc/eeh/Makefile index b397bab..ae963eb 100644 --- a/tools/testing/selftests/powerpc/eeh/Makefile +++ b/tools/testing/selftests/powerpc/eeh/Makefile @@ -3,7 +3,7 @@ noarg: $(MAKE) -C ../ TEST_PROGS := eeh-basic.sh -TEST_FILES := eeh-functions.sh +TEST_FILES := eeh-functions.sh settings top_srcdir = ../../../../.. include ../../lib.mk diff --git a/tools/testing/selftests/powerpc/eeh/settings b/tools/testing/selftests/powerpc/eeh/settings new file mode 100644 index 0000000..694d707 --- /dev/null +++ b/tools/testing/selftests/powerpc/eeh/settings @@ -0,0 +1 @@ +timeout=300 -- 2.7.4

3 years, 5 months

2
2
0 0

[PATCH v6 0/6] mm: introduce memfd_secret system call to create "secret" memory areas

by Mike Rapoport

From: Mike Rapoport <rppt(a)linux.ibm.com> Hi, This is an implementation of "secret" mappings backed by a file descriptor. I've dropped the boot time reservation patch for now as it is not strictly required for the basic usage and can be easily added later either with or without CMA. v6 changes: * Silence the warning about missing syscall, thanks to Qian Cai * Replace spaces with tabs in Kconfig additions, per Randy * Add a selftest. v5 changes: * rebase on v5.9-rc5 * drop boot time memory reservation patch v4 changes: * rebase on v5.9-rc1 * Do not redefine PMD_PAGE_ORDER in fs/dax.c, thanks Kirill * Make secret mappings exclusive by default and only require flags to memfd_secret() system call for uncached mappings, thanks again Kirill :) v3 changes: * Squash kernel-parameters.txt update into the commit that added the command line option. * Make uncached mode explicitly selectable by architectures. For now enable it only on x86. v2 changes: * Follow Michael's suggestion and name the new system call 'memfd_secret' * Add kernel-parameters documentation about the boot option * Fix i386-tinyconfig regression reported by the kbuild bot. CONFIG_SECRETMEM now depends on !EMBEDDED to disable it on small systems from one side and still make it available unconditionally on architectures that support SET_DIRECT_MAP. The file descriptor backing secret memory mappings is created using a dedicated memfd_secret system call The desired protection mode for the memory is configured using flags parameter of the system call. The mmap() of the file descriptor created with memfd_secret() will create a "secret" memory mapping. The pages in that mapping will be marked as not present in the direct map and will have desired protection bits set in the user page table. For instance, current implementation allows uncached mappings. Although normally Linux userspace mappings are protected from other users, such secret mappings are useful for environments where a hostile tenant is trying to trick the kernel into giving them access to other tenants mappings. Additionally, the secret mappings may be used as a mean to protect guest memory in a virtual machine host. For demonstration of secret memory usage we've created a userspace library [1] that does two things: the first is act as a preloader for openssl to redirect all the OPENSSL_malloc calls to secret memory meaning any secret keys get automatically protected this way and the other thing it does is expose the API to the user who needs it. We anticipate that a lot of the use cases would be like the openssl one: many toolkits that deal with secret keys already have special handling for the memory to try to give them greater protection, so this would simply be pluggable into the toolkits without any need for user application modification. I've hesitated whether to continue to use new flags to memfd_create() or to add a new system call and I've decided to use a new system call after I've started to look into man pages update. There would have been two completely independent descriptions and I think it would have been very confusing. Hiding secret memory mappings behind an anonymous file allows (ab)use of the page cache for tracking pages allocated for the "secret" mappings as well as using address_space_operations for e.g. page migration callbacks. The anonymous file may be also used implicitly, like hugetlb files, to implement mmap(MAP_SECRET) and use the secret memory areas with "native" mm ABIs in the future. As the fragmentation of the direct map was one of the major concerns raised during the previous postings, I've added an amortizing cache of PMD-size pages to each file descriptor that is used as an allocation pool for the secret memory areas. v5: https://lore.kernel.org/lkml/20200916073539.3552-1-rppt@kernel.org v4: https://lore.kernel.org/lkml/20200818141554.13945-1-rppt@kernel.org v3: https://lore.kernel.org/lkml/20200804095035.18778-1-rppt@kernel.org v2: https://lore.kernel.org/lkml/20200727162935.31714-1-rppt@kernel.org v1: https://lore.kernel.org/lkml/20200720092435.17469-1-rppt@kernel.org Mike Rapoport (6): mm: add definition of PMD_PAGE_ORDER mmap: make mlock_future_check() global mm: introduce memfd_secret system call to create "secret" memory areas arch, mm: wire up memfd_secret system call were relevant mm: secretmem: use PMD-size pages to amortize direct map fragmentation secretmem: test: add basic selftest for memfd_secret(2) arch/Kconfig | 7 + arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 2 + arch/arm64/include/uapi/asm/unistd.h | 1 + arch/riscv/include/asm/unistd.h | 1 + arch/x86/Kconfig | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + fs/dax.c | 11 +- include/linux/pgtable.h | 3 + include/linux/syscalls.h | 1 + include/uapi/asm-generic/unistd.h | 7 +- include/uapi/linux/magic.h | 1 + include/uapi/linux/secretmem.h | 8 + kernel/sys_ni.c | 2 + mm/Kconfig | 4 + mm/Makefile | 1 + mm/internal.h | 3 + mm/mmap.c | 5 +- mm/secretmem.c | 333 ++++++++++++++++++++++ scripts/checksyscalls.sh | 4 + tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 3 +- tools/testing/selftests/vm/memfd_secret.c | 296 +++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 17 ++ 25 files changed, 703 insertions(+), 13 deletions(-) create mode 100644 include/uapi/linux/secretmem.h create mode 100644 mm/secretmem.c create mode 100644 tools/testing/selftests/vm/memfd_secret.c -- 2.28.0

3 years, 5 months

14
56
0 0

[PATCH v22 00/12] Landlock LSM

by Mickaël Salaün

Hi, Can you please consider to merge this into the tree? This new patch series improves documentation, cleans up comments, renames ARCH_EPHEMERAL_STATES to ARCH_EPHEMERAL_INODES and removes LANDLOCK_ACCESS_FS_CHROOT. The SLOC count is 1183 for security/landlock/ and 1657 for tools/testing/selftest/landlock/ . Test coverage for security/landlock/ is 95.2% of lines. The code not covered only deals with internal kernel errors (e.g. memory allocation) and race conditions. The compiled documentation is available here: https://landlock.io/linux-doc/landlock-v22/userspace-api/landlock.html This series can be applied on top of v5.10-rc1 . This can be tested with CONFIG_SECURITY_LANDLOCK and CONFIG_SAMPLE_LANDLOCK. This patch series can be found in a Git repository here: https://github.com/landlock-lsm/linux/commits/landlock-v22 I would really appreciate constructive comments on this patch series. # Landlock LSM The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]. Previous version: https://lore.kernel.org/lkml/20201008153103.1155388-1-mic@digikod.net/ [1] https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler… [2] https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.n… Casey Schaufler (1): LSM: Infrastructure management of the superblock Mickaël Salaün (11): landlock: Add object management landlock: Add ruleset and domain management landlock: Set up the security framework and manage credentials landlock: Add ptrace restrictions fs,security: Add sb_delete hook landlock: Support filesystem access-control landlock: Add syscall implementations arch: Wire up Landlock syscalls selftests/landlock: Add user space tests samples/landlock: Add a sandbox manager example landlock: Add user and kernel documentation Documentation/security/index.rst | 1 + Documentation/security/landlock.rst | 79 + Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/landlock.rst | 259 +++ MAINTAINERS | 13 + arch/Kconfig | 7 + arch/alpha/kernel/syscalls/syscall.tbl | 3 + arch/arm/tools/syscall.tbl | 3 + arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 6 + arch/ia64/kernel/syscalls/syscall.tbl | 3 + arch/m68k/kernel/syscalls/syscall.tbl | 3 + arch/microblaze/kernel/syscalls/syscall.tbl | 3 + arch/mips/kernel/syscalls/syscall_n32.tbl | 3 + arch/mips/kernel/syscalls/syscall_n64.tbl | 3 + arch/mips/kernel/syscalls/syscall_o32.tbl | 3 + arch/parisc/kernel/syscalls/syscall.tbl | 3 + arch/powerpc/kernel/syscalls/syscall.tbl | 3 + arch/s390/kernel/syscalls/syscall.tbl | 3 + arch/sh/kernel/syscalls/syscall.tbl | 3 + arch/sparc/kernel/syscalls/syscall.tbl | 3 + arch/um/Kconfig | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 3 + arch/x86/entry/syscalls/syscall_64.tbl | 3 + arch/xtensa/kernel/syscalls/syscall.tbl | 3 + fs/super.c | 1 + include/linux/lsm_hook_defs.h | 1 + include/linux/lsm_hooks.h | 3 + include/linux/security.h | 4 + include/linux/syscalls.h | 7 + include/uapi/asm-generic/unistd.h | 8 +- include/uapi/linux/landlock.h | 128 ++ kernel/sys_ni.c | 5 + samples/Kconfig | 7 + samples/Makefile | 1 + samples/landlock/.gitignore | 1 + samples/landlock/Makefile | 15 + samples/landlock/sandboxer.c | 219 +++ security/Kconfig | 11 +- security/Makefile | 2 + security/landlock/Kconfig | 19 + security/landlock/Makefile | 4 + security/landlock/common.h | 20 + security/landlock/cred.c | 46 + security/landlock/cred.h | 58 + security/landlock/fs.c | 604 ++++++ security/landlock/fs.h | 60 + security/landlock/object.c | 66 + security/landlock/object.h | 91 + security/landlock/ptrace.c | 120 ++ security/landlock/ptrace.h | 14 + security/landlock/ruleset.c | 350 ++++ security/landlock/ruleset.h | 157 ++ security/landlock/setup.c | 40 + security/landlock/setup.h | 18 + security/landlock/syscall.c | 427 +++++ security/security.c | 51 +- security/selinux/hooks.c | 58 +- security/selinux/include/objsec.h | 6 + security/selinux/ss/services.c | 3 +- security/smack/smack.h | 6 + security/smack/smack_lsm.c | 35 +- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/landlock/.gitignore | 2 + tools/testing/selftests/landlock/Makefile | 24 + tools/testing/selftests/landlock/base_test.c | 117 ++ tools/testing/selftests/landlock/common.h | 113 ++ tools/testing/selftests/landlock/config | 5 + tools/testing/selftests/landlock/fs_test.c | 1675 +++++++++++++++++ .../testing/selftests/landlock/ptrace_test.c | 307 +++ tools/testing/selftests/landlock/true.c | 5 + 71 files changed, 5255 insertions(+), 77 deletions(-) create mode 100644 Documentation/security/landlock.rst create mode 100644 Documentation/userspace-api/landlock.rst create mode 100644 include/uapi/linux/landlock.h create mode 100644 samples/landlock/.gitignore create mode 100644 samples/landlock/Makefile create mode 100644 samples/landlock/sandboxer.c create mode 100644 security/landlock/Kconfig create mode 100644 security/landlock/Makefile create mode 100644 security/landlock/common.h create mode 100644 security/landlock/cred.c create mode 100644 security/landlock/cred.h create mode 100644 security/landlock/fs.c create mode 100644 security/landlock/fs.h create mode 100644 security/landlock/object.c create mode 100644 security/landlock/object.h create mode 100644 security/landlock/ptrace.c create mode 100644 security/landlock/ptrace.h create mode 100644 security/landlock/ruleset.c create mode 100644 security/landlock/ruleset.h create mode 100644 security/landlock/setup.c create mode 100644 security/landlock/setup.h create mode 100644 security/landlock/syscall.c create mode 100644 tools/testing/selftests/landlock/.gitignore create mode 100644 tools/testing/selftests/landlock/Makefile create mode 100644 tools/testing/selftests/landlock/base_test.c create mode 100644 tools/testing/selftests/landlock/common.h create mode 100644 tools/testing/selftests/landlock/config create mode 100644 tools/testing/selftests/landlock/fs_test.c create mode 100644 tools/testing/selftests/landlock/ptrace_test.c create mode 100644 tools/testing/selftests/landlock/true.c base-commit: 3650b228f83adda7e5ee532e2b90429c03f7b9ec -- 2.28.0

3 years, 5 months

4
36
0 0

[PATCH] selftests/seccomp: Update kernel config

by Mickaël Salaün

seccomp_bpf.c uses unshare(CLONE_NEWPID), which requires CONFIG_PID_NS to be set. Cc: Kees Cook <keescook(a)chromium.org> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Tycho Andersen <tycho(a)tycho.pizza> Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace") Signed-off-by: Mickaël Salaün <mic(a)linux.microsoft.com> --- tools/testing/selftests/seccomp/config | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/seccomp/config b/tools/testing/selftests/seccomp/config index 64c19d8eba79..ad431a5178fb 100644 --- a/tools/testing/selftests/seccomp/config +++ b/tools/testing/selftests/seccomp/config @@ -1,3 +1,4 @@ +CONFIG_PID_NS=y CONFIG_SECCOMP=y CONFIG_SECCOMP_FILTER=y CONFIG_USER_NS=y base-commit: 3650b228f83adda7e5ee532e2b90429c03f7b9ec -- 2.28.0

3 years, 5 months

2
1
0 0

[PATCH v3 00/11] Introduce Simple atomic counters

by Shuah Khan

This patch series is a result of discussion at the refcount_t BOF the Linux Plumbers Conference. In this discussion, we identified a need for looking closely and investigating atomic_t usages in the kernel when it is used strictly as a counter without it controlling object lifetimes and state changes. There are a number of atomic_t usages in the kernel where atomic_t api is used strictly for counting and not for managing object lifetime. In some cases, atomic_t might not even be needed. The purpose of these counters is to clearly differentiate atomic_t counters from atomic_t usages that guard object lifetimes, hence prone to overflow and underflow errors. It allows tools that scan for underflow and overflow on atomic_t usages to detect overflow and underflows to scan just the cases that are prone to errors. Simple atomic counters api provides interfaces for simple atomic counters that just count, and don't guard resource lifetimes. The interfaces are built on top of atomic_t api, providing a smaller subset of atomic_t interfaces necessary to support simple counters. Counter wraps around to INT_MIN when it overflows and should not be used to guard resource lifetimes, device usage and open counts that control state changes, and pm states. Overflowing to INT_MIN is consistent with the atomic_t api, which it is built on top of. Using counter_atomic* to guard lifetimes could lead to use-after free when it overflows and undefined behavior when used to manage state changes and device usage/open states. This patch series introduces Simple atomic counters. Counter atomic ops leverage atomic_t and provide a sub-set of atomic_t ops. In addition this patch series converts a few drivers to use the new api. The following criteria is used for select variables for conversion: 1. Variable doesn't guard object lifetimes, manage state changes e.g: device usage counts, device open counts, and pm states. 2. Variable is used for stats and counters. 3. The conversion doesn't change the overflow behavior. Note: Would like to get this into Linux 5.10-rc1 so we can continue updating drivers that can be updated to use this API. If this all looks good, Kees, would you like to take this through your tree or would you like to take this through mine. Changes since Patch v2: -- Thanks for reviews and reviewed-by, and Acked-by tags. Updated the patches with the tags. -- Minor changes to address Greg's comment to remove default from Kconfig -- Added Copyrights to new files Updates to address comments on v2 from Kees Cook -- Updated Patch 1/11 to make clear that the counter wraps around to INT_MIN and that this behavior is consistent with the atomic_t api, on which this counter built api built on top of. -- Other patch change logs updated with the correct wrap around behavior. -- Patch 1/11 is updated to add tests with constants for overflow and underflow. -- Patch 8/11 - added inits for the stat counters -- Patch 10/11 - fixes the vmci_num_guest_devices != 0 to >0 which is safer than checking for !=0. Changes since Patch v1 -- Thanks for reviews and reviewed-by, and Acked-by tags. Updated the patches with the tags. -- Addressed Kees's and Joel's comments: 1. Removed dec_return interfaces 2. Removed counter_simple interfaces to be added later with changes to drivers that use them (if any). Changes since RFC: -- Thanks for reviews and reviewed-by, and Acked-by tags. Updated the patches with the tags. -- Addressed Kees's comments: 1. Non-atomic counters renamed to counter_simple32 and counter_simple64 to clearly indicate size. 2. Added warning for counter_simple* usage and it should be used only when there is no need for atomicity. 3. Renamed counter_atomic to counter_atomic32 to clearly indicate size. 4. Renamed counter_atomic_long to counter_atomic64 and it now uses atomic64_t ops and indicates size. 5. Test updated for the API renames. 6. Added helper functions for test results printing 7. Verified that the test module compiles in kunit env. and test module can be loaded to run the test. 8. Updated Documentation to reflect the intent to make the API restricted so it can never be used to guard object lifetimes and state management. I left _return ops for now, inc_return is necessary for now as per the discussion we had on this topic. -- Updated driver patches with API name changes. -- We discussed if binder counters can be non-atomic. For now I left them the same as the RFC patch - using counter_atomic32 -- Unrelated to this patch series: The patch series review uncovered improvements could be made to test_async_driver_probe and vmw_vmci/vmci_guest. I will track these for fixing later. Shuah Khan (11): counters: Introduce counter_atomic* counters selftests:lib:test_counters: add new test for counters drivers/base: convert deferred_trigger_count and probe_count to counter_atomic32 drivers/base/devcoredump: convert devcd_count to counter_atomic32 drivers/acpi: convert seqno counter_atomic32 drivers/acpi/apei: convert seqno counter_atomic32 drivers/android/binder: convert stats, transaction_log to counter_atomic32 drivers/base/test/test_async_driver_probe: convert to use counter_atomic32 drivers/char/ipmi: convert stats to use counter_atomic32 drivers/misc/vmw_vmci: convert num guest devices counter to counter_atomic32 drivers/edac: convert pci counters to counter_atomic32 Documentation/core-api/counters.rst | 109 ++++++++++++ MAINTAINERS | 8 + drivers/acpi/acpi_extlog.c | 5 +- drivers/acpi/apei/ghes.c | 5 +- drivers/android/binder.c | 41 ++--- drivers/android/binder_internal.h | 3 +- drivers/base/dd.c | 19 +- drivers/base/devcoredump.c | 5 +- drivers/base/test/test_async_driver_probe.c | 26 +-- drivers/char/ipmi/ipmi_msghandler.c | 9 +- drivers/char/ipmi/ipmi_si_intf.c | 9 +- drivers/edac/edac_pci.h | 5 +- drivers/edac/edac_pci_sysfs.c | 28 +-- drivers/misc/vmw_vmci/vmci_guest.c | 9 +- include/linux/counters.h | 176 +++++++++++++++++++ lib/Kconfig | 9 + lib/Makefile | 1 + lib/test_counters.c | 162 +++++++++++++++++ tools/testing/selftests/lib/Makefile | 1 + tools/testing/selftests/lib/config | 1 + tools/testing/selftests/lib/test_counters.sh | 10 ++ 21 files changed, 567 insertions(+), 74 deletions(-) create mode 100644 Documentation/core-api/counters.rst create mode 100644 include/linux/counters.h create mode 100644 lib/test_counters.c create mode 100755 tools/testing/selftests/lib/test_counters.sh -- 2.25.1

3 years, 5 months

4
14
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[PATCH RFC PKS/PMEM 00/58] PMEM: Introduce stray write protection for PMEM

by ira.weiny＠intel.com

From: Ira Weiny <ira.weiny(a)intel.com> Should a stray write in the kernel occur persistent memory is affected more than regular memory. A write to the wrong area of memory could result in latent data corruption which will will persist after a reboot. PKS provides a nice way to restrict access to persistent memory kernel mappings, while providing fast access when needed. Since the last RFC[1] this patch set has grown quite a bit. It now depends on the core patches submitted separately. https://lore.kernel.org/lkml/20201009194258.3207172-1-ira.weiny@intel.com/ And contained in the git tree here: https://github.com/weiny2/linux-kernel/tree/pks-rfc-v3 However, functionally there is only 1 major change from the last RFC. Specifically, kmap() is most often used within a single thread in a 'map/do something/unmap' pattern. In fact this is the pattern used in ~90% of the callers of kmap(). This pattern works very well for the pmem use case and the testing which was done. However, there were another ~20-30 kmap users which do not follow this pattern. Some of them seem to expect the mapping to be 'global' while others require a detailed audit to be sure.[2][3] While we don't anticipate global mappings to pmem there is a danger in changing the semantics of kmap(). Effectively, this would cause an unresolved page fault with little to no information about why. There were a number of options considered. 1) Attempt to change all the thread local kmap() calls to kmap_atomic() 2) Introduce a flags parameter to kmap() to indicate if the mapping should be global or not 3) Change ~20-30 call sites to 'kmap_global()' to indicate that they require a global mapping of the pages 4) Change ~209 call sites to 'kmap_thread()' to indicate that the mapping is to be used within that thread of execution only Option 1 is simply not feasible kmap_atomic() is not the same semantic as kmap() within a single tread. Option 2 would require all of the call sites of kmap() to change. Option 3 seems like a good minimal change but there is a danger that new code may miss the semantic change of kmap() and not get the behavior intended for future users. Therefore, option #4 was chosen. To handle the global PKRS state in the most efficient manner possible. We lazily override the thread specific PKRS key value only when needed because we anticipate PKS to not be needed will not be needed most of the time. And even when it is used 90% of the time it is a thread local call. [1] https://lore.kernel.org/lkml/20200717072056.73134-1-ira.weiny@intel.com/ [2] The following list of callers continue calling kmap() (utilizing the global PKRS). It would be nice if more of them could be converted to kmap_thread() drivers/firewire/net.c: ptr = kmap(dev->broadcast_rcv_buffer.pages[u]); drivers/gpu/drm/i915/gem/i915_gem_pages.c: return kmap(sg_page(sgt->sgl)); drivers/gpu/drm/ttm/ttm_bo_util.c: map->virtual = kmap(map->page); drivers/infiniband/hw/qib/qib_user_sdma.c: mpage = kmap(page); drivers/misc/vmw_vmci/vmci_host.c: context->notify = kmap(context->notify_page) + (uva & (PAGE_SIZE - 1)); drivers/misc/xilinx_sdfec.c: addr = kmap(pages[i]); drivers/mmc/host/usdhi6rol0.c: host->pg.mapped = kmap(host->pg.page); drivers/mmc/host/usdhi6rol0.c: host->pg.mapped = kmap(host->pg.page); drivers/mmc/host/usdhi6rol0.c: host->pg.mapped = kmap(host->pg.page); drivers/nvme/target/tcp.c: iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset; drivers/scsi/libiscsi_tcp.c: segment->sg_mapped = kmap(sg_page(sg)); drivers/target/iscsi/iscsi_target.c: iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off; drivers/target/target_core_transport.c: return kmap(sg_page(sg)) + sg->offset; fs/btrfs/check-integrity.c: block_ctx->datav[i] = kmap(block_ctx->pagev[i]); fs/ceph/dir.c: cache_ctl->dentries = kmap(cache_ctl->page); fs/ceph/inode.c: ctl->dentries = kmap(ctl->page); fs/erofs/zpvec.h: kmap_atomic(ctor->curr) : kmap(ctor->curr); lib/scatterlist.c: miter->addr = kmap(miter->page) + miter->__offset; net/ceph/pagelist.c: pl->mapped_tail = kmap(page); net/ceph/pagelist.c: pl->mapped_tail = kmap(page); virt/kvm/kvm_main.c: hva = kmap(page); [3] The following appear to follow the same pattern as ext2 which was converted after some code audit. So I _think_ they too could be converted to k[un]map_thread(). fs/freevxfs/vxfs_subr.c|75| kmap(pp); fs/jfs/jfs_metapage.c|102| kmap(page); fs/jfs/jfs_metapage.c|156| kmap(page); fs/minix/dir.c|72| kmap(page); fs/nilfs2/dir.c|195| kmap(page); fs/nilfs2/ifile.h|24| void *kaddr = kmap(ibh->b_page); fs/ntfs/aops.h|78| kmap(page); fs/ntfs/compress.c|574| kmap(page); fs/qnx6/dir.c|32| kmap(page); fs/qnx6/dir.c|58| kmap(*p = page); fs/qnx6/inode.c|190| kmap(page); fs/qnx6/inode.c|557| kmap(page); fs/reiserfs/inode.c|2397| kmap(bh_result->b_page); fs/reiserfs/xattr.c|444| kmap(page); fs/sysv/dir.c|60| kmap(page); fs/sysv/dir.c|262| kmap(page); fs/ufs/dir.c|194| kmap(page); fs/ufs/dir.c|562| kmap(page); Ira Weiny (58): x86/pks: Add a global pkrs option x86/pks/test: Add testing for global option memremap: Add zone device access protection kmap: Add stray access protection for device pages kmap: Introduce k[un]map_thread kmap: Introduce k[un]map_thread debugging drivers/drbd: Utilize new kmap_thread() drivers/firmware_loader: Utilize new kmap_thread() drivers/gpu: Utilize new kmap_thread() drivers/rdma: Utilize new kmap_thread() drivers/net: Utilize new kmap_thread() fs/afs: Utilize new kmap_thread() fs/btrfs: Utilize new kmap_thread() fs/cifs: Utilize new kmap_thread() fs/ecryptfs: Utilize new kmap_thread() fs/gfs2: Utilize new kmap_thread() fs/nilfs2: Utilize new kmap_thread() fs/hfs: Utilize new kmap_thread() fs/hfsplus: Utilize new kmap_thread() fs/jffs2: Utilize new kmap_thread() fs/nfs: Utilize new kmap_thread() fs/f2fs: Utilize new kmap_thread() fs/fuse: Utilize new kmap_thread() fs/freevxfs: Utilize new kmap_thread() fs/reiserfs: Utilize new kmap_thread() fs/zonefs: Utilize new kmap_thread() fs/ubifs: Utilize new kmap_thread() fs/cachefiles: Utilize new kmap_thread() fs/ntfs: Utilize new kmap_thread() fs/romfs: Utilize new kmap_thread() fs/vboxsf: Utilize new kmap_thread() fs/hostfs: Utilize new kmap_thread() fs/cramfs: Utilize new kmap_thread() fs/erofs: Utilize new kmap_thread() fs: Utilize new kmap_thread() fs/ext2: Use ext2_put_page fs/ext2: Utilize new kmap_thread() fs/isofs: Utilize new kmap_thread() fs/jffs2: Utilize new kmap_thread() net: Utilize new kmap_thread() drivers/target: Utilize new kmap_thread() drivers/scsi: Utilize new kmap_thread() drivers/mmc: Utilize new kmap_thread() drivers/xen: Utilize new kmap_thread() drivers/firmware: Utilize new kmap_thread() drives/staging: Utilize new kmap_thread() drivers/mtd: Utilize new kmap_thread() drivers/md: Utilize new kmap_thread() drivers/misc: Utilize new kmap_thread() drivers/android: Utilize new kmap_thread() kernel: Utilize new kmap_thread() mm: Utilize new kmap_thread() lib: Utilize new kmap_thread() powerpc: Utilize new kmap_thread() samples: Utilize new kmap_thread() dax: Stray access protection for dax_direct_access() nvdimm/pmem: Stray access protection for pmem->virt_addr [dax|pmem]: Enable stray access protection Documentation/core-api/protection-keys.rst | 11 +- arch/powerpc/mm/mem.c | 4 +- arch/x86/entry/common.c | 28 +++ arch/x86/include/asm/pkeys.h | 6 +- arch/x86/include/asm/pkeys_common.h | 8 +- arch/x86/kernel/process.c | 74 ++++++- arch/x86/mm/fault.c | 193 ++++++++++++++---- arch/x86/mm/pkeys.c | 88 ++++++-- drivers/android/binder_alloc.c | 4 +- drivers/base/firmware_loader/fallback.c | 4 +- drivers/base/firmware_loader/main.c | 4 +- drivers/block/drbd/drbd_main.c | 4 +- drivers/block/drbd/drbd_receiver.c | 12 +- drivers/dax/device.c | 2 + drivers/dax/super.c | 2 + drivers/firmware/efi/capsule-loader.c | 6 +- drivers/firmware/efi/capsule.c | 4 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 12 +- drivers/gpu/drm/gma500/gma_display.c | 4 +- drivers/gpu/drm/gma500/mmu.c | 10 +- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 4 +- .../drm/i915/gem/selftests/i915_gem_context.c | 4 +- .../drm/i915/gem/selftests/i915_gem_mman.c | 8 +- drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 4 +- drivers/gpu/drm/i915/gt/intel_gtt.c | 4 +- drivers/gpu/drm/i915/gt/shmem_utils.c | 4 +- drivers/gpu/drm/i915/i915_gem.c | 8 +- drivers/gpu/drm/i915/i915_gpu_error.c | 4 +- drivers/gpu/drm/i915/selftests/i915_perf.c | 4 +- drivers/gpu/drm/radeon/radeon_ttm.c | 4 +- drivers/infiniband/hw/hfi1/sdma.c | 4 +- drivers/infiniband/hw/i40iw/i40iw_cm.c | 10 +- drivers/infiniband/sw/siw/siw_qp_tx.c | 14 +- drivers/md/bcache/request.c | 4 +- drivers/misc/vmw_vmci/vmci_queue_pair.c | 12 +- drivers/mmc/host/mmc_spi.c | 4 +- drivers/mmc/host/sdricoh_cs.c | 4 +- drivers/mtd/mtd_blkdevs.c | 12 +- drivers/net/ethernet/intel/igb/igb_ethtool.c | 4 +- .../net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 4 +- drivers/nvdimm/pmem.c | 6 + drivers/scsi/ipr.c | 8 +- drivers/scsi/pmcraid.c | 8 +- drivers/staging/rts5208/rtsx_transport.c | 4 +- drivers/target/target_core_iblock.c | 4 +- drivers/target/target_core_rd.c | 4 +- drivers/target/target_core_transport.c | 4 +- drivers/xen/gntalloc.c | 4 +- fs/afs/dir.c | 16 +- fs/afs/dir_edit.c | 16 +- fs/afs/mntpt.c | 4 +- fs/afs/write.c | 4 +- fs/aio.c | 4 +- fs/binfmt_elf.c | 4 +- fs/binfmt_elf_fdpic.c | 4 +- fs/btrfs/check-integrity.c | 4 +- fs/btrfs/compression.c | 4 +- fs/btrfs/inode.c | 16 +- fs/btrfs/lzo.c | 24 +-- fs/btrfs/raid56.c | 34 +-- fs/btrfs/reflink.c | 8 +- fs/btrfs/send.c | 4 +- fs/btrfs/zlib.c | 32 +-- fs/btrfs/zstd.c | 20 +- fs/cachefiles/rdwr.c | 4 +- fs/cifs/cifsencrypt.c | 6 +- fs/cifs/file.c | 16 +- fs/cifs/smb2ops.c | 8 +- fs/cramfs/inode.c | 10 +- fs/ecryptfs/crypto.c | 8 +- fs/ecryptfs/read_write.c | 8 +- fs/erofs/super.c | 4 +- fs/erofs/xattr.c | 4 +- fs/exec.c | 10 +- fs/ext2/dir.c | 8 +- fs/ext2/ext2.h | 8 + fs/ext2/namei.c | 15 +- fs/f2fs/f2fs.h | 8 +- fs/freevxfs/vxfs_immed.c | 4 +- fs/fuse/readdir.c | 4 +- fs/gfs2/bmap.c | 4 +- fs/gfs2/ops_fstype.c | 4 +- fs/hfs/bnode.c | 14 +- fs/hfs/btree.c | 20 +- fs/hfsplus/bitmap.c | 20 +- fs/hfsplus/bnode.c | 102 ++++----- fs/hfsplus/btree.c | 18 +- fs/hostfs/hostfs_kern.c | 12 +- fs/io_uring.c | 4 +- fs/isofs/compress.c | 4 +- fs/jffs2/file.c | 8 +- fs/jffs2/gc.c | 4 +- fs/nfs/dir.c | 20 +- fs/nilfs2/alloc.c | 34 +-- fs/nilfs2/cpfile.c | 4 +- fs/ntfs/aops.c | 4 +- fs/reiserfs/journal.c | 4 +- fs/romfs/super.c | 4 +- fs/splice.c | 4 +- fs/ubifs/file.c | 16 +- fs/vboxsf/file.c | 12 +- fs/zonefs/super.c | 4 +- include/linux/entry-common.h | 3 + include/linux/highmem.h | 63 +++++- include/linux/memremap.h | 1 + include/linux/mm.h | 43 ++++ include/linux/pkeys.h | 6 +- include/linux/sched.h | 8 + include/trace/events/kmap_thread.h | 56 +++++ init/init_task.c | 6 + kernel/fork.c | 18 ++ kernel/kexec_core.c | 8 +- lib/Kconfig.debug | 8 + lib/iov_iter.c | 12 +- lib/pks/pks_test.c | 138 +++++++++++-- lib/test_bpf.c | 4 +- lib/test_hmm.c | 8 +- mm/Kconfig | 13 ++ mm/debug.c | 23 +++ mm/memory.c | 8 +- mm/memremap.c | 90 ++++++++ mm/swapfile.c | 4 +- mm/userfaultfd.c | 4 +- net/ceph/messenger.c | 4 +- net/core/datagram.c | 4 +- net/core/sock.c | 8 +- net/ipv4/ip_output.c | 4 +- net/sunrpc/cache.c | 4 +- net/sunrpc/xdr.c | 8 +- net/tls/tls_device.c | 4 +- samples/vfio-mdev/mbochs.c | 4 +- 131 files changed, 1284 insertions(+), 565 deletions(-) create mode 100644 include/trace/events/kmap_thread.h -- 2.28.0.rc0.12.gb6a658bd00c9

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17
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Linux-kselftest-mirror October 2020