June 2019 - Linux-kselftest-mirror

[PATCH v7 00/25] Unify vDSOs across more architectures

by Vincenzo Frascino

vDSO (virtual dynamic shared object) is a mechanism that the Linux kernel provides as an alternative to system calls to reduce where possible the costs in terms of cycles. This is possible because certain syscalls like gettimeofday() do not write any data and return one or more values that are stored in the kernel, which makes relatively safe calling them directly as a library function. Even if the mechanism is pretty much standard, every architecture in the last few years ended up implementing their own vDSO library in the architectural code. The purpose of this patch-set is to identify the commonalities in between the architectures and try to consolidate the common code paths, starting with gettimeofday(). This implementation contains the following design choices: * Every architecture defines the arch specific code in an header in "asm/vdso/". * The generic implementation includes the arch specific one and lives in "lib/vdso". * The arch specific code for gettimeofday lives in "<arch path>/vdso/gettimeofday.c" and includes the generic code only. * The generic implementation of update_vsyscall and update_vsyscall_tz lives in kernel/vdso and provide the bindings that can be implemented by each architecture. * Each architecture provides its implementation of the bindings in "asm/vdso/vsyscall.h". * This approach allows to consolidate the common code in a single place with the benefit of avoiding code duplication. This implementation contains the portings to the common library for: arm64, compat mode for arm64, arm, mips, x86_64, x32, compat mode for x86_64 and i386. The mips porting has been tested on qemu for mips32el. A configuration to repeat the tests can be found at [4]. The x86_64 porting has been tested on an Intel Xeon 5120T based machine running Ubuntu 18.04 and using the Ubuntu provided defconfig. The i386 porting has been tested on qemu using the i386_defconfig configuration. Last but not least from this porting arm64, compat arm64, arm and mips gain the support for: * CLOCK_BOOTTIME that can be useful in certain scenarios since it keeps track of the time during sleep as well. * CLOCK_TAI that is like CLOCK_REALTIME, but uses the International Atomic Time (TAI) reference instead of UTC to avoid jumping on leap second updates. for both clock_gettime and clock_getres. The porting has been validated using the vdsotest test-suite [1] extended to cover all the clock ids [2]. A new test has been added to the linux kselftest in order to validate the newly added library. The porting has been benchmarked and the performance results are provided as part of this cover letter. To simplify the testing, a copy of the patchset on top of a recent linux tree can be found at [3] and [4]. The v7 of this patchseries has been rebased on [5]. [1] https://github.com/nathanlynch/vdsotest [2] https://github.com/fvincenzo/vdsotest [3] git://linux-arm.org/linux-vf.git vdso/v7 [4] git://linux-arm.org/linux-vf.git vdso-mips/v7 [5] git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git hyperv-next Changes: -------- v7: - Rebased on [5] (5.2-rc3). - Added performance numbers for arm64 provided by Shijith Thotton. - Aimed at 1:1 replacement for pre-exisiting vDSO libraries. - Provided separate patches for newly added API. - Addressed review comments. v6: - Rebased on 5.2-rc2. - Added performance numbers. - Removed vdso_types.h. - Unified update_vsyscall and update_vsyscall_tz. - Reworked the kselftest included in this patchset. - Addressed review comments. v5: - Rebased on 5.0-rc7. - Added x86_64, compat mode for x86_64 and i386 portings. - Extended vDSO kselftest. - Addressed review comments. v4: - Rebased on 5.0-rc2. - Addressed review comments. - Disabled compat vdso on arm64 when the kernel is compiled with clang. v3: - Ported the latest fixes and optimizations done on the x86 architecture to the generic library. - Addressed review comments. - Improved the documentation of the interfaces. - Changed the HAVE_ARCH_TIMER config option to a more generic HAVE_HW_COUNTER. v2: - Added -ffixed-x18 to arm64 - Repleced occurrences of timeval and timespec - Modified datapage.h to be compliant with y2038 on all the architectures - Removed __u_vdso type Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Will Deacon <will.deacon(a)arm.com> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: Russell King <linux(a)armlinux.org.uk> Cc: Ralf Baechle <ralf(a)linux-mips.org> Cc: Paul Burton <paul.burton(a)mips.com> Cc: Daniel Lezcano <daniel.lezcano(a)linaro.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Mark Salyzyn <salyzyn(a)android.com> Cc: Peter Collingbourne <pcc(a)google.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Dmitry Safonov <0x7f454c46(a)gmail.com> Cc: Rasmus Villemoes <linux(a)rasmusvillemoes.dk> Cc: Huw Davies <huw(a)codeweavers.com> Cc: Shijith Thotton <sthotton(a)marvell.com> Cc: Andre Przywara <andre.przywara(a)arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Tested-by: Shijith Thotton <sthotton(a)marvell.com> Tested-by: Andre Przywara <andre.przywara(a)arm.com> Performance Numbers: Linux 5.2.0-rc2 - Xeon Gold 5120T ====================================================== Unified vDSO: ------------- clock-gettime-monotonic: syscall: 342 nsec/call clock-gettime-monotonic: libc: 25 nsec/call clock-gettime-monotonic: vdso: 24 nsec/call clock-getres-monotonic: syscall: 296 nsec/call clock-getres-monotonic: libc: 296 nsec/call clock-getres-monotonic: vdso: 3 nsec/call clock-gettime-monotonic-coarse: syscall: 294 nsec/call clock-gettime-monotonic-coarse: libc: 5 nsec/call clock-gettime-monotonic-coarse: vdso: 5 nsec/call clock-getres-monotonic-coarse: syscall: 295 nsec/call clock-getres-monotonic-coarse: libc: 292 nsec/call clock-getres-monotonic-coarse: vdso: 5 nsec/call clock-gettime-monotonic-raw: syscall: 343 nsec/call clock-gettime-monotonic-raw: libc: 25 nsec/call clock-gettime-monotonic-raw: vdso: 23 nsec/call clock-getres-monotonic-raw: syscall: 290 nsec/call clock-getres-monotonic-raw: libc: 290 nsec/call clock-getres-monotonic-raw: vdso: 4 nsec/call clock-gettime-tai: syscall: 332 nsec/call clock-gettime-tai: libc: 24 nsec/call clock-gettime-tai: vdso: 23 nsec/call clock-getres-tai: syscall: 288 nsec/call clock-getres-tai: libc: 288 nsec/call clock-getres-tai: vdso: 3 nsec/call clock-gettime-boottime: syscall: 342 nsec/call clock-gettime-boottime: libc: 24 nsec/call clock-gettime-boottime: vdso: 23 nsec/call clock-getres-boottime: syscall: 284 nsec/call clock-getres-boottime: libc: 291 nsec/call clock-getres-boottime: vdso: 3 nsec/call clock-gettime-realtime: syscall: 337 nsec/call clock-gettime-realtime: libc: 24 nsec/call clock-gettime-realtime: vdso: 23 nsec/call clock-getres-realtime: syscall: 287 nsec/call clock-getres-realtime: libc: 284 nsec/call clock-getres-realtime: vdso: 3 nsec/call clock-gettime-realtime-coarse: syscall: 307 nsec/call clock-gettime-realtime-coarse: libc: 4 nsec/call clock-gettime-realtime-coarse: vdso: 4 nsec/call clock-getres-realtime-coarse: syscall: 294 nsec/call clock-getres-realtime-coarse: libc: 291 nsec/call clock-getres-realtime-coarse: vdso: 4 nsec/call getcpu: syscall: 246 nsec/call getcpu: libc: 14 nsec/call getcpu: vdso: 11 nsec/call gettimeofday: syscall: 293 nsec/call gettimeofday: libc: 26 nsec/call gettimeofday: vdso: 25 nsec/call Stock Kernel: ------------- clock-gettime-monotonic: syscall: 338 nsec/call clock-gettime-monotonic: libc: 24 nsec/call clock-gettime-monotonic: vdso: 23 nsec/call clock-getres-monotonic: syscall: 291 nsec/call clock-getres-monotonic: libc: 304 nsec/call clock-getres-monotonic: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-monotonic-coarse: syscall: 297 nsec/call clock-gettime-monotonic-coarse: libc: 5 nsec/call clock-gettime-monotonic-coarse: vdso: 4 nsec/call clock-getres-monotonic-coarse: syscall: 281 nsec/call clock-getres-monotonic-coarse: libc: 286 nsec/call clock-getres-monotonic-coarse: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-monotonic-raw: syscall: 336 nsec/call clock-gettime-monotonic-raw: libc: 340 nsec/call clock-gettime-monotonic-raw: vdso: 346 nsec/call clock-getres-monotonic-raw: syscall: 297 nsec/call clock-getres-monotonic-raw: libc: 301 nsec/call clock-getres-monotonic-raw: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-tai: syscall: 351 nsec/call clock-gettime-tai: libc: 24 nsec/call clock-gettime-tai: vdso: 23 nsec/call clock-getres-tai: syscall: 298 nsec/call clock-getres-tai: libc: 290 nsec/call clock-getres-tai: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-boottime: syscall: 342 nsec/call clock-gettime-boottime: libc: 347 nsec/call clock-gettime-boottime: vdso: 355 nsec/call clock-getres-boottime: syscall: 296 nsec/call clock-getres-boottime: libc: 295 nsec/call clock-getres-boottime: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-realtime: syscall: 346 nsec/call clock-gettime-realtime: libc: 24 nsec/call clock-gettime-realtime: vdso: 22 nsec/call clock-getres-realtime: syscall: 295 nsec/call clock-getres-realtime: libc: 291 nsec/call clock-getres-realtime: vdso: not tested Note: vDSO version of clock_getres not found clock-gettime-realtime-coarse: syscall: 292 nsec/call clock-gettime-realtime-coarse: libc: 5 nsec/call clock-gettime-realtime-coarse: vdso: 4 nsec/call clock-getres-realtime-coarse: syscall: 300 nsec/call clock-getres-realtime-coarse: libc: 301 nsec/call clock-getres-realtime-coarse: vdso: not tested Note: vDSO version of clock_getres not found getcpu: syscall: 252 nsec/call getcpu: libc: 14 nsec/call getcpu: vdso: 11 nsec/call gettimeofday: syscall: 293 nsec/call gettimeofday: libc: 24 nsec/call gettimeofday: vdso: 25 nsec/call Performance Numbers: Linux 5.2.0-rc2 - ThunderX2 (arm64) ======================================================== Provided by: Shijith Thotton <sthotton(a)marvell.com> Unified vDSO: ------------- clock-gettime-monotonic: syscall: 346 nsec/call clock-gettime-monotonic: libc: 38 nsec/call clock-gettime-monotonic: vdso: 36 nsec/call clock-getres-monotonic: syscall: 262 nsec/call clock-getres-monotonic: libc: 6 nsec/call clock-getres-monotonic: vdso: 5 nsec/call clock-gettime-monotonic-coarse: syscall: 296 nsec/call clock-gettime-monotonic-coarse: libc: 39 nsec/call clock-gettime-monotonic-coarse: vdso: 38 nsec/call clock-getres-monotonic-coarse: syscall: 260 nsec/call clock-getres-monotonic-coarse: libc: 8 nsec/call clock-getres-monotonic-coarse: vdso: 5 nsec/call clock-gettime-monotonic-raw: syscall: 345 nsec/call clock-gettime-monotonic-raw: libc: 35 nsec/call clock-gettime-monotonic-raw: vdso: 34 nsec/call clock-getres-monotonic-raw: syscall: 261 nsec/call clock-getres-monotonic-raw: libc: 7 nsec/call clock-getres-monotonic-raw: vdso: 5 nsec/call clock-gettime-tai: syscall: 357 nsec/call clock-gettime-tai: libc: 38 nsec/call clock-gettime-tai: vdso: 36 nsec/call clock-getres-tai: syscall: 257 nsec/call clock-getres-tai: libc: 7 nsec/call clock-getres-tai: vdso: 5 nsec/call clock-gettime-boottime: syscall: 356 nsec/call clock-gettime-boottime: libc: 38 nsec/call clock-gettime-boottime: vdso: 36 nsec/call clock-getres-boottime: syscall: 257 nsec/call clock-getres-boottime: libc: 6 nsec/call clock-getres-boottime: vdso: 5 nsec/call clock-gettime-realtime: syscall: 345 nsec/call clock-gettime-realtime: libc: 38 nsec/call clock-gettime-realtime: vdso: 36 nsec/call clock-getres-realtime: syscall: 257 nsec/call clock-getres-realtime: libc: 7 nsec/call clock-getres-realtime: vdso: 5 nsec/call clock-gettime-realtime-coarse: syscall: 295 nsec/call clock-gettime-realtime-coarse: libc: 39 nsec/call clock-gettime-realtime-coarse: vdso: 38 nsec/call clock-getres-realtime-coarse: syscall: 260 nsec/call clock-getres-realtime-coarse: libc: 8 nsec/call clock-getres-realtime-coarse: vdso: 5 nsec/call getcpu: syscall: 244 nsec/call getcpu: libc: 247 nsec/call getcpu: vdso: not tested Note: vDSO version of getcpu not found gettimeofday: syscall: 383 nsec/call gettimeofday: libc: 39 nsec/call gettimeofday: vdso: 35 nsec/call Stock Kernel: ------------- clock-gettime-monotonic: syscall: 344 nsec/call clock-gettime-monotonic: libc: 74 nsec/call clock-gettime-monotonic: vdso: 73 nsec/call clock-getres-monotonic: syscall: 258 nsec/call clock-getres-monotonic: libc: 6 nsec/call clock-getres-monotonic: vdso: 4 nsec/call clock-gettime-monotonic-coarse: syscall: 300 nsec/call clock-gettime-monotonic-coarse: libc: 36 nsec/call clock-gettime-monotonic-coarse: vdso: 34 nsec/call clock-getres-monotonic-coarse: syscall: 261 nsec/call clock-getres-monotonic-coarse: libc: 6 nsec/call clock-getres-monotonic-coarse: vdso: 4 nsec/call clock-gettime-monotonic-raw: syscall: 346 nsec/call clock-gettime-monotonic-raw: libc: 74 nsec/call clock-gettime-monotonic-raw: vdso: 72 nsec/call clock-getres-monotonic-raw: syscall: 254 nsec/call clock-getres-monotonic-raw: libc: 6 nsec/call clock-getres-monotonic-raw: vdso: 4 nsec/call clock-gettime-tai: syscall: 345 nsec/call clock-gettime-tai: libc: 361 nsec/call clock-gettime-tai: vdso: 359 nsec/call clock-getres-tai: syscall: 259 nsec/call clock-getres-tai: libc: 262 nsec/call clock-getres-tai: vdso: 258 nsec/call clock-gettime-boottime: syscall: 353 nsec/call clock-gettime-boottime: libc: 365 nsec/call clock-gettime-boottime: vdso: 362 nsec/call clock-getres-boottime: syscall: 260 nsec/call clock-getres-boottime: libc: 267 nsec/call clock-getres-boottime: vdso: 259 nsec/call clock-gettime-realtime: syscall: 344 nsec/call clock-gettime-realtime: libc: 73 nsec/call clock-gettime-realtime: vdso: 72 nsec/call clock-getres-realtime: syscall: 255 nsec/call clock-getres-realtime: libc: 7 nsec/call clock-getres-realtime: vdso: 4 nsec/call clock-gettime-realtime-coarse: syscall: 296 nsec/call clock-gettime-realtime-coarse: libc: 35 nsec/call clock-gettime-realtime-coarse: vdso: 33 nsec/call clock-getres-realtime-coarse: syscall: 258 nsec/call clock-getres-realtime-coarse: libc: 6 nsec/call clock-getres-realtime-coarse: vdso: 4 nsec/call getcpu: syscall: 237 nsec/call getcpu: libc: 242 nsec/call getcpu: vdso: not tested Note: vDSO version of getcpu not found gettimeofday: syscall: 378 nsec/call gettimeofday: libc: 73 nsec/call gettimeofday: vdso: 70 nsec/call Peter Collingbourne (1): arm64: Build vDSO with -ffixed-x18 Vincenzo Frascino (24): kernel: Standardize vdso_datapage kernel: Define gettimeofday vdso common code kernel: Unify update_vsyscall implementation arm64: Substitute gettimeofday with C implementation arm64: compat: Add missing syscall numbers arm64: compat: Expose signal related structures arm64: compat: Generate asm offsets for signals lib: vdso: Add compat support arm64: compat: Add vDSO arm64: Refactor vDSO code arm64: compat: vDSO setup for compat layer arm64: elf: vDSO code page discovery arm64: compat: Get sigreturn trampolines from vDSO arm64: Add vDSO compat support arm: Add support for generic vDSO arm: Add clock_getres entry point arm: Add clock_gettime64 entry point mips: Add support for generic vDSO mips: Add clock_getres entry point mips: Add clock_gettime64 entry point x86: Add support for generic vDSO x86: Add clock_getres entry point x86: Add clock_gettime64 entry point kselftest: Extend vDSO selftest arch/arm/Kconfig | 3 + arch/arm/include/asm/vdso/gettimeofday.h | 94 +++++ arch/arm/include/asm/vdso/vsyscall.h | 71 ++++ arch/arm/include/asm/vdso_datapage.h | 29 +- arch/arm/kernel/vdso.c | 87 +---- arch/arm/vdso/Makefile | 13 +- arch/arm/vdso/note.c | 15 + arch/arm/vdso/vdso.lds.S | 2 + arch/arm/vdso/vgettimeofday.c | 256 +------------ arch/arm64/Kconfig | 3 + arch/arm64/Makefile | 23 +- arch/arm64/include/asm/elf.h | 14 + arch/arm64/include/asm/signal32.h | 46 +++ arch/arm64/include/asm/unistd.h | 5 + arch/arm64/include/asm/vdso.h | 3 + arch/arm64/include/asm/vdso/compat_barrier.h | 51 +++ .../include/asm/vdso/compat_gettimeofday.h | 110 ++++++ arch/arm64/include/asm/vdso/gettimeofday.h | 86 +++++ arch/arm64/include/asm/vdso/vsyscall.h | 53 +++ arch/arm64/include/asm/vdso_datapage.h | 48 --- arch/arm64/kernel/Makefile | 6 +- arch/arm64/kernel/asm-offsets.c | 39 +- arch/arm64/kernel/signal32.c | 72 ++-- arch/arm64/kernel/vdso.c | 356 ++++++++++++------ arch/arm64/kernel/vdso/Makefile | 34 +- arch/arm64/kernel/vdso/gettimeofday.S | 334 ---------------- arch/arm64/kernel/vdso/vgettimeofday.c | 28 ++ arch/arm64/kernel/vdso32/.gitignore | 2 + arch/arm64/kernel/vdso32/Makefile | 186 +++++++++ arch/arm64/kernel/vdso32/note.c | 15 + arch/arm64/kernel/vdso32/sigreturn.S | 62 +++ arch/arm64/kernel/vdso32/vdso.S | 19 + arch/arm64/kernel/vdso32/vdso.lds.S | 82 ++++ arch/arm64/kernel/vdso32/vgettimeofday.c | 59 +++ arch/mips/Kconfig | 2 + arch/mips/include/asm/vdso.h | 78 +--- arch/mips/include/asm/vdso/gettimeofday.h | 177 +++++++++ arch/mips/{ => include/asm}/vdso/vdso.h | 6 +- arch/mips/include/asm/vdso/vsyscall.h | 43 +++ arch/mips/kernel/vdso.c | 37 +- arch/mips/vdso/Makefile | 27 +- arch/mips/vdso/elf.S | 2 +- arch/mips/vdso/sigreturn.S | 2 +- arch/mips/vdso/vdso.lds.S | 4 + arch/mips/vdso/vgettimeofday.c | 58 +++ arch/x86/Kconfig | 3 + arch/x86/entry/vdso/Makefile | 9 + arch/x86/entry/vdso/vclock_gettime.c | 249 +++--------- arch/x86/entry/vdso/vdso.lds.S | 2 + arch/x86/entry/vdso/vdso32/vdso32.lds.S | 2 + arch/x86/entry/vdso/vdsox32.lds.S | 1 + arch/x86/entry/vsyscall/Makefile | 2 - arch/x86/entry/vsyscall/vsyscall_gtod.c | 83 ---- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/include/asm/vdso/gettimeofday.h | 205 ++++++++++ arch/x86/include/asm/vdso/vsyscall.h | 44 +++ arch/x86/include/asm/vgtod.h | 75 +--- arch/x86/include/asm/vvar.h | 7 +- arch/x86/kernel/pvclock.c | 1 + include/asm-generic/vdso/vsyscall.h | 56 +++ include/linux/hrtimer.h | 15 +- include/linux/hrtimer_defs.h | 25 ++ include/linux/timekeeper_internal.h | 9 + include/vdso/datapage.h | 93 +++++ include/vdso/helpers.h | 56 +++ include/vdso/vsyscall.h | 11 + kernel/Makefile | 1 + kernel/vdso/Makefile | 2 + kernel/vdso/vsyscall.c | 131 +++++++ lib/Kconfig | 5 + lib/vdso/Kconfig | 36 ++ lib/vdso/Makefile | 22 ++ lib/vdso/gettimeofday.c | 231 ++++++++++++ tools/testing/selftests/vDSO/Makefile | 2 + tools/testing/selftests/vDSO/vdso_config.h | 90 +++++ tools/testing/selftests/vDSO/vdso_full_test.c | 244 ++++++++++++ 76 files changed, 3044 insertions(+), 1412 deletions(-) create mode 100644 arch/arm/include/asm/vdso/gettimeofday.h create mode 100644 arch/arm/include/asm/vdso/vsyscall.h create mode 100644 arch/arm/vdso/note.c create mode 100644 arch/arm64/include/asm/vdso/compat_barrier.h create mode 100644 arch/arm64/include/asm/vdso/compat_gettimeofday.h create mode 100644 arch/arm64/include/asm/vdso/gettimeofday.h create mode 100644 arch/arm64/include/asm/vdso/vsyscall.h delete mode 100644 arch/arm64/include/asm/vdso_datapage.h delete mode 100644 arch/arm64/kernel/vdso/gettimeofday.S create mode 100644 arch/arm64/kernel/vdso/vgettimeofday.c create mode 100644 arch/arm64/kernel/vdso32/.gitignore create mode 100644 arch/arm64/kernel/vdso32/Makefile create mode 100644 arch/arm64/kernel/vdso32/note.c create mode 100644 arch/arm64/kernel/vdso32/sigreturn.S create mode 100644 arch/arm64/kernel/vdso32/vdso.S create mode 100644 arch/arm64/kernel/vdso32/vdso.lds.S create mode 100644 arch/arm64/kernel/vdso32/vgettimeofday.c create mode 100644 arch/mips/include/asm/vdso/gettimeofday.h rename arch/mips/{ => include/asm}/vdso/vdso.h (89%) create mode 100644 arch/mips/include/asm/vdso/vsyscall.h create mode 100644 arch/mips/vdso/vgettimeofday.c delete mode 100644 arch/x86/entry/vsyscall/vsyscall_gtod.c create mode 100644 arch/x86/include/asm/vdso/gettimeofday.h create mode 100644 arch/x86/include/asm/vdso/vsyscall.h create mode 100644 include/asm-generic/vdso/vsyscall.h create mode 100644 include/linux/hrtimer_defs.h create mode 100644 include/vdso/datapage.h create mode 100644 include/vdso/helpers.h create mode 100644 include/vdso/vsyscall.h create mode 100644 kernel/vdso/Makefile create mode 100644 kernel/vdso/vsyscall.c create mode 100644 lib/vdso/Kconfig create mode 100644 lib/vdso/Makefile create mode 100644 lib/vdso/gettimeofday.c create mode 100644 tools/testing/selftests/vDSO/vdso_config.h create mode 100644 tools/testing/selftests/vDSO/vdso_full_test.c -- 2.21.0

4 years, 7 months

18
107
0 0

[PATCH v4 0/6] lib/string: Add strscpy_pad() function

by Tobin C. Harding

Hi Shua, Here is the set with cleanup as suggested by Kees on v3. Configured, built, and tested all modules loaded by tools/testing/selftests/lib/*.sh >From previous cover letters ... While doing the testing for strscpy_pad() it was noticed that there is duplication in how test modules are being fed to kselftest and also in the test modules themselves. This set makes an attempt at adding a framework to kselftest for writing kernel test modules. It also adds a script for use in creating script test runners for kselftest. My macro-foo is not great, all criticism and suggestions very much appreciated. The design is based on test modules lib/test_printf.c, lib/test_bitmap.c, lib/test_xarray.c. Changes since last version: - Remove dependency on Bash (thanks Kees) - Use oneliner to implement kselftest test runners (thanks Kees) - Squash patch that adds kselftest script creator script with patch that uses it. - Fix typos (thanks Randy) - Add Kees' Acked-by tags to all patches thanks, Tobin. Tobin C. Harding (6): lib/test_printf: Add empty module_exit function kselftest: Add test runner creation script kselftest: Add test module framework header lib: Use new kselftest header lib/string: Add strscpy_pad() function lib: Add test module for strscpy_pad Documentation/dev-tools/kselftest.rst | 94 +++++++++++- include/linux/string.h | 4 + lib/Kconfig.debug | 3 + lib/Makefile | 1 + lib/string.c | 47 +++++- lib/test_bitmap.c | 20 +-- lib/test_printf.c | 17 +-- lib/test_strscpy.c | 150 +++++++++++++++++++ tools/testing/selftests/kselftest_module.h | 48 ++++++ tools/testing/selftests/kselftest_module.sh | 84 +++++++++++ tools/testing/selftests/lib/Makefile | 2 +- tools/testing/selftests/lib/bitmap.sh | 18 +-- tools/testing/selftests/lib/config | 1 + tools/testing/selftests/lib/prime_numbers.sh | 17 +-- tools/testing/selftests/lib/printf.sh | 19 +-- tools/testing/selftests/lib/strscpy.sh | 3 + 16 files changed, 440 insertions(+), 88 deletions(-) create mode 100644 lib/test_strscpy.c create mode 100644 tools/testing/selftests/kselftest_module.h create mode 100755 tools/testing/selftests/kselftest_module.sh create mode 100755 tools/testing/selftests/lib/strscpy.sh -- 2.21.0

4 years, 8 months

5
11
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[RFC v3 00/19] kunit: introduce KUnit, the Linux kernel unit testing framework

by Brendan Higgins

This patch set proposes KUnit, a lightweight unit testing and mocking framework for the Linux kernel. Unlike Autotest and kselftest, KUnit is a true unit testing framework; it does not require installing the kernel on a test machine or in a VM and does not require tests to be written in userspace running on a host kernel. Additionally, KUnit is fast: From invocation to completion KUnit can run several dozen tests in under a second. Currently, the entire KUnit test suite for KUnit runs in under a second from the initial invocation (build time excluded). KUnit is heavily inspired by JUnit, Python's unittest.mock, and Googletest/Googlemock for C++. KUnit provides facilities for defining unit test cases, grouping related test cases into test suites, providing common infrastructure for running tests, mocking, spying, and much more. ## What's so special about unit testing? A unit test is supposed to test a single unit of code in isolation, hence the name. There should be no dependencies outside the control of the test; this means no external dependencies, which makes tests orders of magnitudes faster. Likewise, since there are no external dependencies, there are no hoops to jump through to run the tests. Additionally, this makes unit tests deterministic: a failing unit test always indicates a problem. Finally, because unit tests necessarily have finer granularity, they are able to test all code paths easily solving the classic problem of difficulty in exercising error handling code. ## Is KUnit trying to replace other testing frameworks for the kernel? No. Most existing tests for the Linux kernel are end-to-end tests, which have their place. A well tested system has lots of unit tests, a reasonable number of integration tests, and some end-to-end tests. KUnit is just trying to address the unit test space which is currently not being addressed. ## More information on KUnit There is a bunch of documentation near the end of this patch set that describes how to use KUnit and best practices for writing unit tests. For convenience I am hosting the compiled docs here: https://google.github.io/kunit-docs/third_party/kernel/docs/ Additionally for convenience, I have applied these patches to a branch: https://kunit.googlesource.com/linux/+/kunit/rfc/4.19/v3 The repo may be cloned with: git clone https://kunit.googlesource.com/linux This patchset is on the kunit/rfc/4.19/v3 branch. ## Changes Since Last Version - Changed namespace prefix from `test_*` to `kunit_*` as requested by Shuah. - Started converting/cleaning up the device tree unittest to use KUnit. - Started adding KUnit expectations with custom messages. -- 2.20.0.rc0.387.gc7a69e6b6c-goog

4 years, 10 months

11
105
0 0

[PATCH v18 00/15] arm64: untag user pointers passed to the kernel

by Andrey Konovalov

=== Overview arm64 has a feature called Top Byte Ignore, which allows to embed pointer tags into the top byte of each pointer. Userspace programs (such as HWASan, a memory debugging tool [1]) might use this feature and pass tagged user pointers to the kernel through syscalls or other interfaces. Right now the kernel is already able to handle user faults with tagged pointers, due to these patches: 1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a tagged pointer") 2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged pointers") 3. 276e9327 ("arm64: entry: improve data abort handling of tagged pointers") This patchset extends tagged pointer support to syscall arguments. As per the proposed ABI change [3], tagged pointers are only allowed to be passed to syscalls when they point to memory ranges obtained by anonymous mmap() or sbrk() (see the patchset [3] for more details). For non-memory syscalls this is done by untaging user pointers when the kernel performs pointer checking to find out whether the pointer comes from userspace (most notably in access_ok). The untagging is done only when the pointer is being checked, the tag is preserved as the pointer makes its way through the kernel and stays tagged when the kernel dereferences the pointer when perfoming user memory accesses. The mmap and mremap (only new_addr) syscalls do not currently accept tagged addresses. Architectures may interpret the tag as a background colour for the corresponding vma. Other memory syscalls (mprotect, etc.) don't do user memory accesses but rather deal with memory ranges, and untagged pointers are better suited to describe memory ranges internally. Thus for memory syscalls we untag pointers completely when they enter the kernel. === Other approaches One of the alternative approaches to untagging that was considered is to completely strip the pointer tag as the pointer enters the kernel with some kind of a syscall wrapper, but that won't work with the countless number of different ioctl calls. With this approach we would need a custom wrapper for each ioctl variation, which doesn't seem practical. An alternative approach to untagging pointers in memory syscalls prologues is to inspead allow tagged pointers to be passed to find_vma() (and other vma related functions) and untag them there. Unfortunately, a lot of find_vma() callers then compare or subtract the returned vma start and end fields against the pointer that was being searched. Thus this approach would still require changing all find_vma() callers. === Testing The following testing approaches has been taken to find potential issues with user pointer untagging: 1. Static testing (with sparse [2] and separately with a custom static analyzer based on Clang) to track casts of __user pointers to integer types to find places where untagging needs to be done. 2. Static testing with grep to find parts of the kernel that call find_vma() (and other similar functions) or directly compare against vm_start/vm_end fields of vma. 3. Static testing with grep to find parts of the kernel that compare user pointers with TASK_SIZE or other similar consts and macros. 4. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running a modified syzkaller version that passes tagged pointers to the kernel. Based on the results of the testing the requried patches have been added to the patchset. === Notes This patchset is meant to be merged together with "arm64 relaxed ABI" [3]. This patchset is a prerequisite for ARM's memory tagging hardware feature support [4]. This patchset has been merged into the Pixel 2 & 3 kernel trees and is now being used to enable testing of Pixel phones with HWASan. Thanks! [1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html [2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060… [3] https://lkml.org/lkml/2019/6/12/745 [4] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architectur… === History Changes in v18: - Reverted the selftest back to not using the LD_PRELOAD approach. - Added prctl(PR_SET_TAGGED_ADDR_CTRL) call to the selftest. - Reworded the patch descriptions to make them less oriented on arm64 only. - Catalin's patch: "I added a Kconfig option and dropped the prctl args zero check. There is some minor clean-up as well". Changes in v17: - The "uaccess: add noop untagged_addr definition" patch is dropped, as it was merged into upstream named as "uaccess: add noop untagged_addr definition". - Merged "mm, arm64: untag user pointers in do_pages_move" into "mm, arm64: untag user pointers passed to memory syscalls". - Added "arm64: Introduce prctl() options to control the tagged user addresses ABI" patch from Catalin. - Add tags_lib.so to tools/testing/selftests/arm64/.gitignore. - Added a comment clarifying untagged in mremap. - Moved untagging back into mlx4_get_umem_mr() for the IB patch. Changes in v16: - Moved untagging for memory syscalls from arm64 wrappers back to generic code. - Dropped untagging for the following memory syscalls: brk, mmap, munmap; mremap (only dropped for new_address); mmap_pgoff (not used on arm64); remap_file_pages (deprecated); shmat, shmdt (work on shared memory). - Changed kselftest to LD_PRELOAD a shared library that overrides malloc to return tagged pointers. - Rebased onto 5.2-rc3. Changes in v15: - Removed unnecessary untagging from radeon_ttm_tt_set_userptr(). - Removed unnecessary untagging from amdgpu_ttm_tt_set_userptr(). - Moved untagging to validate_range() in userfaultfd code. - Moved untagging to ib_uverbs_(re)reg_mr() from mlx4_get_umem_mr(). - Rebased onto 5.1. Changes in v14: - Moved untagging for most memory syscalls to an arm64 specific implementation, instead of doing that in the common code. - Dropped "net, arm64: untag user pointers in tcp_zerocopy_receive", since the provided user pointers don't come from an anonymous map and thus are not covered by this ABI relaxation. - Dropped "kernel, arm64: untag user pointers in prctl_set_mm*". - Moved untagging from __check_mem_type() to tee_shm_register(). - Updated untagging for the amdgpu and radeon drivers to cover the MMU notifier, as suggested by Felix. - Since this ABI relaxation doesn't actually allow tagged instruction pointers, dropped the following patches: - Dropped "tracing, arm64: untag user pointers in seq_print_user_ip". - Dropped "uprobes, arm64: untag user pointers in find_active_uprobe". - Dropped "bpf, arm64: untag user pointers in stack_map_get_build_id_offset". - Rebased onto 5.1-rc7 (37624b58). Changes in v13: - Simplified untagging in tcp_zerocopy_receive(). - Looked at find_vma() callers in drivers/, which allowed to identify a few other places where untagging is needed. - Added patch "mm, arm64: untag user pointers in get_vaddr_frames". - Added patch "drm/amdgpu, arm64: untag user pointers in amdgpu_ttm_tt_get_user_pages". - Added patch "drm/radeon, arm64: untag user pointers in radeon_ttm_tt_pin_userptr". - Added patch "IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr". - Added patch "media/v4l2-core, arm64: untag user pointers in videobuf_dma_contig_user_get". - Added patch "tee/optee, arm64: untag user pointers in check_mem_type". - Added patch "vfio/type1, arm64: untag user pointers". Changes in v12: - Changed untagging in tcp_zerocopy_receive() to also untag zc->address. - Fixed untagging in prctl_set_mm* to only untag pointers for vma lookups and validity checks, but leave them as is for actual user space accesses. - Updated the link to the v2 of the "arm64 relaxed ABI" patchset [3]. - Dropped the documentation patch, as the "arm64 relaxed ABI" patchset [3] handles that. Changes in v11: - Added "uprobes, arm64: untag user pointers in find_active_uprobe" patch. - Added "bpf, arm64: untag user pointers in stack_map_get_build_id_offset" patch. - Fixed "tracing, arm64: untag user pointers in seq_print_user_ip" to correctly perform subtration with a tagged addr. - Moved untagged_addr() from SYSCALL_DEFINE3(mprotect) and SYSCALL_DEFINE4(pkey_mprotect) to do_mprotect_pkey(). - Moved untagged_addr() definition for other arches from include/linux/memory.h to include/linux/mm.h. - Changed untagging in strn*_user() to perform userspace accesses through tagged pointers. - Updated the documentation to mention that passing tagged pointers to memory syscalls is allowed. - Updated the test to use malloc'ed memory instead of stack memory. Changes in v10: - Added "mm, arm64: untag user pointers passed to memory syscalls" back. - New patch "fs, arm64: untag user pointers in fs/userfaultfd.c". - New patch "net, arm64: untag user pointers in tcp_zerocopy_receive". - New patch "kernel, arm64: untag user pointers in prctl_set_mm*". - New patch "tracing, arm64: untag user pointers in seq_print_user_ip". Changes in v9: - Rebased onto 4.20-rc6. - Used u64 instead of __u64 in type casts in the untagged_addr macro for arm64. - Added braces around (addr) in the untagged_addr macro for other arches. Changes in v8: - Rebased onto 65102238 (4.20-rc1). - Added a note to the cover letter on why syscall wrappers/shims that untag user pointers won't work. - Added a note to the cover letter that this patchset has been merged into the Pixel 2 kernel tree. - Documentation fixes, in particular added a list of syscalls that don't support tagged user pointers. Changes in v7: - Rebased onto 17b57b18 (4.19-rc6). - Dropped the "arm64: untag user address in __do_user_fault" patch, since the existing patches already handle user faults properly. - Dropped the "usb, arm64: untag user addresses in devio" patch, since the passed pointer must come from a vma and therefore be untagged. - Dropped the "arm64: annotate user pointers casts detected by sparse" patch (see the discussion to the replies of the v6 of this patchset). - Added more context to the cover letter. - Updated Documentation/arm64/tagged-pointers.txt. Changes in v6: - Added annotations for user pointer casts found by sparse. - Rebased onto 050cdc6c (4.19-rc1+). Changes in v5: - Added 3 new patches that add untagging to places found with static analysis. - Rebased onto 44c929e1 (4.18-rc8). Changes in v4: - Added a selftest for checking that passing tagged pointers to the kernel succeeds. - Rebased onto 81e97f013 (4.18-rc1+). Changes in v3: - Rebased onto e5c51f30 (4.17-rc6+). - Added linux-arch@ to the list of recipients. Changes in v2: - Rebased onto 2d618bdf (4.17-rc3+). - Removed excessive untagging in gup.c. - Removed untagging pointers returned from __uaccess_mask_ptr. Changes in v1: - Rebased onto 4.17-rc1. Changes in RFC v2: - Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of defining it for each arch individually. - Updated Documentation/arm64/tagged-pointers.txt. - Dropped "mm, arm64: untag user addresses in memory syscalls". - Rebased onto 3eb2ce82 (4.16-rc7). Signed-off-by: Andrey Konovalov <andreyknvl(a)google.com> Andrey Konovalov (14): arm64: untag user pointers in access_ok and __uaccess_mask_ptr lib: untag user pointers in strn*_user mm: untag user pointers passed to memory syscalls mm: untag user pointers in mm/gup.c mm: untag user pointers in get_vaddr_frames fs/namespace: untag user pointers in copy_mount_options userfaultfd: untag user pointers drm/amdgpu: untag user pointers drm/radeon: untag user pointers in radeon_gem_userptr_ioctl IB/mlx4: untag user pointers in mlx4_get_umem_mr media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get tee/shm: untag user pointers in tee_shm_register vfio/type1: untag user pointers in vaddr_get_pfn selftests, arm64: add a selftest for passing tagged pointers to kernel Catalin Marinas (1): arm64: Introduce prctl() options to control the tagged user addresses ABI arch/arm64/Kconfig | 9 +++ arch/arm64/include/asm/processor.h | 8 +++ arch/arm64/include/asm/thread_info.h | 1 + arch/arm64/include/asm/uaccess.h | 12 +++- arch/arm64/kernel/process.c | 72 +++++++++++++++++++ .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 2 + drivers/gpu/drm/radeon/radeon_gem.c | 2 + drivers/infiniband/hw/mlx4/mr.c | 7 +- drivers/media/v4l2-core/videobuf-dma-contig.c | 9 +-- drivers/tee/tee_shm.c | 1 + drivers/vfio/vfio_iommu_type1.c | 2 + fs/namespace.c | 2 +- fs/userfaultfd.c | 22 +++--- include/uapi/linux/prctl.h | 5 ++ kernel/sys.c | 12 ++++ lib/strncpy_from_user.c | 3 +- lib/strnlen_user.c | 3 +- mm/frame_vector.c | 2 + mm/gup.c | 4 ++ mm/madvise.c | 2 + mm/mempolicy.c | 3 + mm/migrate.c | 2 +- mm/mincore.c | 2 + mm/mlock.c | 4 ++ mm/mprotect.c | 2 + mm/mremap.c | 7 ++ mm/msync.c | 2 + tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 11 +++ .../testing/selftests/arm64/run_tags_test.sh | 12 ++++ tools/testing/selftests/arm64/tags_test.c | 29 ++++++++ 32 files changed, 232 insertions(+), 25 deletions(-) create mode 100644 tools/testing/selftests/arm64/.gitignore create mode 100644 tools/testing/selftests/arm64/Makefile create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh create mode 100644 tools/testing/selftests/arm64/tags_test.c -- 2.22.0.410.gd8fdbe21b5-goog

4 years, 10 months

7
46
0 0

[PATCH v10 6/9] kselftests: cgroup: add freezer controller self-tests

by Roman Gushchin

This patch implements 9 tests for the freezer controller for cgroup v2: 1) a simple test, which aims to freeze and unfreeze a cgroup with 100 processes 2) a more complicated tree test, which creates a hierarchy of cgroups, puts some processes in some cgroups, and tries to freeze and unfreeze different parts of the subtree 3) a forkbomb test: the test aims to freeze a forkbomb running in a cgroup, kill all tasks in the cgroup and remove the cgroup without the unfreezing. 4) rmdir test: the test creates two nested cgroups, freezes the parent one, checks that the child can be successfully removed, and a new child can be created 5) migration tests: the test checks migration of a task between frozen cgroups: from a frozen to a running, from a running to a frozen, and from a frozen to a frozen. 6) ptrace test: the test checks that it's possible to attach to a process in a frozen cgroup, get some information and detach, and the cgroup will remain frozen. 7) stopped test: the test checks that it's possible to freeze a cgroup with a stopped task 8) ptraced test: the test checks that it's possible to freeze a cgroup with a ptraced task 9) vfork test: the test checks that it's possible to freeze a cgroup with a parent process waiting for the child process in vfork() Expected output: $ ./test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb ok 4 test_cgrreezer_rmdir ok 5 test_cgfreezer_migrate ok 6 test_cgfreezer_ptrace ok 7 test_cgfreezer_stopped ok 8 test_cgfreezer_ptraced ok 9 test_cgfreezer_vfork Signed-off-by: Roman Gushchin <guro(a)fb.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Tejun Heo <tj(a)kernel.org> Cc: kernel-team(a)fb.com Cc: linux-kselftest(a)vger.kernel.org --- tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/cgroup_util.c | 54 +- tools/testing/selftests/cgroup/cgroup_util.h | 5 + tools/testing/selftests/cgroup/test_freezer.c | 851 ++++++++++++++++++ 5 files changed, 912 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/cgroup/test_freezer.c diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore index adacda50a4b2..7f9835624793 100644 --- a/tools/testing/selftests/cgroup/.gitignore +++ b/tools/testing/selftests/cgroup/.gitignore @@ -1,2 +1,3 @@ test_memcontrol test_core +test_freezer diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index 23fbaa4a9630..8d369b6a2069 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -5,8 +5,10 @@ all: TEST_GEN_PROGS = test_memcontrol TEST_GEN_PROGS += test_core +TEST_GEN_PROGS += test_freezer include ../lib.mk $(OUTPUT)/test_memcontrol: cgroup_util.c $(OUTPUT)/test_core: cgroup_util.c +$(OUTPUT)/test_freezer: cgroup_util.c diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index eba06f94433b..4c223266299a 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -74,6 +74,16 @@ char *cg_name_indexed(const char *root, const char *name, int index) return ret; } +char *cg_control(const char *cgroup, const char *control) +{ + size_t len = strlen(cgroup) + strlen(control) + 2; + char *ret = malloc(len); + + snprintf(ret, len, "%s/%s", cgroup, control); + + return ret; +} + int cg_read(const char *cgroup, const char *control, char *buf, size_t len) { char path[PATH_MAX]; @@ -196,7 +206,32 @@ int cg_create(const char *cgroup) return mkdir(cgroup, 0644); } -static int cg_killall(const char *cgroup) +int cg_wait_for_proc_count(const char *cgroup, int count) +{ + char buf[10 * PAGE_SIZE] = {0}; + int attempts; + char *ptr; + + for (attempts = 10; attempts >= 0; attempts--) { + int nr = 0; + + if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf))) + break; + + for (ptr = buf; *ptr; ptr++) + if (*ptr == '\n') + nr++; + + if (nr >= count) + return 0; + + usleep(100000); + } + + return -1; +} + +int cg_killall(const char *cgroup) { char buf[PAGE_SIZE]; char *ptr = buf; @@ -238,6 +273,14 @@ int cg_destroy(const char *cgroup) return ret; } +int cg_enter(const char *cgroup, int pid) +{ + char pidbuf[64]; + + snprintf(pidbuf, sizeof(pidbuf), "%d", pid); + return cg_write(cgroup, "cgroup.procs", pidbuf); +} + int cg_enter_current(const char *cgroup) { char pidbuf[64]; @@ -367,3 +410,12 @@ int set_oom_adj_score(int pid, int score) close(fd); return 0; } + +char proc_read_text(int pid, const char *item, char *buf, size_t size) +{ + char path[PATH_MAX]; + + snprintf(path, sizeof(path), "/proc/%d/%s", pid, item); + + return read_text(path, buf, size); +} diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h index 9ac8b7958f83..c72f28046bfa 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.h +++ b/tools/testing/selftests/cgroup/cgroup_util.h @@ -18,6 +18,7 @@ static inline int values_close(long a, long b, int err) extern int cg_find_unified_root(char *root, size_t len); extern char *cg_name(const char *root, const char *name); extern char *cg_name_indexed(const char *root, const char *name, int index); +extern char *cg_control(const char *cgroup, const char *control); extern int cg_create(const char *cgroup); extern int cg_destroy(const char *cgroup); extern int cg_read(const char *cgroup, const char *control, @@ -32,6 +33,7 @@ extern int cg_write(const char *cgroup, const char *control, char *buf); extern int cg_run(const char *cgroup, int (*fn)(const char *cgroup, void *arg), void *arg); +extern int cg_enter(const char *cgroup, int pid); extern int cg_enter_current(const char *cgroup); extern int cg_run_nowait(const char *cgroup, int (*fn)(const char *cgroup, void *arg), @@ -41,3 +43,6 @@ extern int alloc_pagecache(int fd, size_t size); extern int alloc_anon(const char *cgroup, void *arg); extern int is_swap_enabled(void); extern int set_oom_adj_score(int pid, int score); +extern int cg_wait_for_proc_count(const char *cgroup, int count); +extern int cg_killall(const char *cgroup); +extern char proc_read_text(int pid, const char *item, char *buf, size_t size); diff --git a/tools/testing/selftests/cgroup/test_freezer.c b/tools/testing/selftests/cgroup/test_freezer.c new file mode 100644 index 000000000000..2bfddb6d6d3b --- /dev/null +++ b/tools/testing/selftests/cgroup/test_freezer.c @@ -0,0 +1,851 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <stdbool.h> +#include <linux/limits.h> +#include <sys/ptrace.h> +#include <sys/types.h> +#include <sys/mman.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> +#include <poll.h> +#include <stdlib.h> +#include <sys/inotify.h> +#include <string.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include "../kselftest.h" +#include "cgroup_util.h" + +#define DEBUG +#ifdef DEBUG +#define debug(args...) fprintf(stderr, args) +#else +#define debug(args...) +#endif + +/* + * Check if the cgroup is frozen by looking at the cgroup.events::frozen value. + */ +static int cg_check_frozen(const char *cgroup, bool frozen) +{ + if (frozen) { + if (cg_read_strstr(cgroup, "cgroup.events", "frozen 1") != 0) { + debug("Cgroup %s isn't frozen\n", cgroup); + return -1; + } + } else { + /* + * Check the cgroup.events::frozen value. + */ + if (cg_read_strstr(cgroup, "cgroup.events", "frozen 0") != 0) { + debug("Cgroup %s is frozen\n", cgroup); + return -1; + } + } + + return 0; +} + +/* + * Freeze the given cgroup. + */ +static int cg_freeze_nowait(const char *cgroup, bool freeze) +{ + return cg_write(cgroup, "cgroup.freeze", freeze ? "1" : "0"); +} + +/* + * Prepare for waiting on cgroup.events file. + */ +static int cg_prepare_for_wait(const char *cgroup) +{ + int fd, ret = -1; + + fd = inotify_init1(0); + if (fd == -1) { + debug("Error: inotify_init1() failed\n"); + return fd; + } + + ret = inotify_add_watch(fd, cg_control(cgroup, "cgroup.events"), + IN_MODIFY); + if (ret == -1) { + debug("Error: inotify_add_watch() failed\n"); + close(fd); + } + + return fd; +} + +/* + * Wait for an event. If there are no events for 10 seconds, + * treat this an error. + */ +static int cg_wait_for(int fd) +{ + int ret = -1; + struct pollfd fds = { + .fd = fd, + .events = POLLIN, + }; + + while (true) { + ret = poll(&fds, 1, 10000); + + if (ret == -1) { + if (errno == EINTR) + continue; + debug("Error: poll() failed\n"); + break; + } + + if (ret > 0 && fds.revents & POLLIN) { + ret = 0; + break; + } + } + + return ret; +} + +/* + * Attach a task to the given cgroup and wait for a cgroup frozen event. + * All transient events (e.g. populated) are ignored. + */ +static int cg_enter_and_wait_for_frozen(const char *cgroup, int pid, + bool frozen) +{ + int fd, ret = -1; + int attempts; + + fd = cg_prepare_for_wait(cgroup); + if (fd < 0) + return fd; + + ret = cg_enter(cgroup, pid); + if (ret) + goto out; + + for (attempts = 0; attempts < 10; attempts++) { + ret = cg_wait_for(fd); + if (ret) + break; + + ret = cg_check_frozen(cgroup, frozen); + if (ret) + continue; + } + +out: + close(fd); + return ret; +} + +/* + * Freeze the given cgroup and wait for the inotify signal. + * If there are no events in 10 seconds, treat this as an error. + * Then check that the cgroup is in the desired state. + */ +static int cg_freeze_wait(const char *cgroup, bool freeze) +{ + int fd, ret = -1; + + fd = cg_prepare_for_wait(cgroup); + if (fd < 0) + return fd; + + ret = cg_freeze_nowait(cgroup, freeze); + if (ret) { + debug("Error: cg_freeze_nowait() failed\n"); + goto out; + } + + ret = cg_wait_for(fd); + if (ret) + goto out; + + ret = cg_check_frozen(cgroup, freeze); +out: + close(fd); + return ret; +} + +/* + * A simple process running in a sleep loop until being + * re-parented. + */ +static int child_fn(const char *cgroup, void *arg) +{ + int ppid = getppid(); + + while (getppid() == ppid) + usleep(1000); + + return getppid() == ppid; +} + +/* + * A simple test for the cgroup freezer: populated the cgroup with 100 + * running processes and freeze it. Then unfreeze it. Then it kills all + * processes and destroys the cgroup. + */ +static int test_cgfreezer_simple(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + int i; + + cgroup = cg_name(root, "cg_test_simple"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + for (i = 0; i < 100; i++) + cg_run_nowait(cgroup, child_fn, NULL); + + if (cg_wait_for_proc_count(cgroup, 100)) + goto cleanup; + + if (cg_check_frozen(cgroup, false)) + goto cleanup; + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + if (cg_freeze_wait(cgroup, false)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * The test creates the following hierarchy: + * A + * / / \ \ + * B E I K + * /\ | + * C D F + * | + * G + * | + * H + * + * with a process in C, H and 3 processes in K. + * Then it tries to freeze and unfreeze the whole tree. + */ +static int test_cgfreezer_tree(const char *root) +{ + char *cgroup[10] = {0}; + int ret = KSFT_FAIL; + int i; + + cgroup[0] = cg_name(root, "cg_test_tree_A"); + if (!cgroup[0]) + goto cleanup; + + cgroup[1] = cg_name(cgroup[0], "B"); + if (!cgroup[1]) + goto cleanup; + + cgroup[2] = cg_name(cgroup[1], "C"); + if (!cgroup[2]) + goto cleanup; + + cgroup[3] = cg_name(cgroup[1], "D"); + if (!cgroup[3]) + goto cleanup; + + cgroup[4] = cg_name(cgroup[0], "E"); + if (!cgroup[4]) + goto cleanup; + + cgroup[5] = cg_name(cgroup[4], "F"); + if (!cgroup[5]) + goto cleanup; + + cgroup[6] = cg_name(cgroup[5], "G"); + if (!cgroup[6]) + goto cleanup; + + cgroup[7] = cg_name(cgroup[6], "H"); + if (!cgroup[7]) + goto cleanup; + + cgroup[8] = cg_name(cgroup[0], "I"); + if (!cgroup[8]) + goto cleanup; + + cgroup[9] = cg_name(cgroup[0], "K"); + if (!cgroup[9]) + goto cleanup; + + for (i = 0; i < 10; i++) + if (cg_create(cgroup[i])) + goto cleanup; + + cg_run_nowait(cgroup[2], child_fn, NULL); + cg_run_nowait(cgroup[7], child_fn, NULL); + cg_run_nowait(cgroup[9], child_fn, NULL); + cg_run_nowait(cgroup[9], child_fn, NULL); + cg_run_nowait(cgroup[9], child_fn, NULL); + + /* + * Wait until all child processes will enter + * corresponding cgroups. + */ + + if (cg_wait_for_proc_count(cgroup[2], 1) || + cg_wait_for_proc_count(cgroup[7], 1) || + cg_wait_for_proc_count(cgroup[9], 3)) + goto cleanup; + + /* + * Freeze B. + */ + if (cg_freeze_wait(cgroup[1], true)) + goto cleanup; + + /* + * Freeze F. + */ + if (cg_freeze_wait(cgroup[5], true)) + goto cleanup; + + /* + * Freeze G. + */ + if (cg_freeze_wait(cgroup[6], true)) + goto cleanup; + + /* + * Check that A and E are not frozen. + */ + if (cg_check_frozen(cgroup[0], false)) + goto cleanup; + + if (cg_check_frozen(cgroup[4], false)) + goto cleanup; + + /* + * Freeze A. Check that A, B and E are frozen. + */ + if (cg_freeze_wait(cgroup[0], true)) + goto cleanup; + + if (cg_check_frozen(cgroup[1], true)) + goto cleanup; + + if (cg_check_frozen(cgroup[4], true)) + goto cleanup; + + /* + * Unfreeze B, F and G + */ + if (cg_freeze_nowait(cgroup[1], false)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[5], false)) + goto cleanup; + + if (cg_freeze_nowait(cgroup[6], false)) + goto cleanup; + + /* + * Check that C and H are still frozen. + */ + if (cg_check_frozen(cgroup[2], true)) + goto cleanup; + + if (cg_check_frozen(cgroup[7], true)) + goto cleanup; + + /* + * Unfreeze A. Check that A, C and K are not frozen. + */ + if (cg_freeze_wait(cgroup[0], false)) + goto cleanup; + + if (cg_check_frozen(cgroup[2], false)) + goto cleanup; + + if (cg_check_frozen(cgroup[9], false)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + for (i = 9; i >= 0 && cgroup[i]; i--) { + cg_destroy(cgroup[i]); + free(cgroup[i]); + } + + return ret; +} + +/* + * A fork bomb emulator. + */ +static int forkbomb_fn(const char *cgroup, void *arg) +{ + int ppid; + + fork(); + fork(); + + ppid = getppid(); + + while (getppid() == ppid) + usleep(1000); + + return getppid() == ppid; +} + +/* + * The test runs a fork bomb in a cgroup and tries to freeze it. + * Then it kills all processes and checks that cgroup isn't populated + * anymore. + */ +static int test_cgfreezer_forkbomb(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + + cgroup = cg_name(root, "cg_forkbomb_test"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + cg_run_nowait(cgroup, forkbomb_fn, NULL); + + usleep(100000); + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + if (cg_killall(cgroup)) + goto cleanup; + + if (cg_wait_for_proc_count(cgroup, 0)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * The test creates two nested cgroups, freezes the parent + * and removes the child. Then it checks that the parent cgroup + * remains frozen and it's possible to create a new child + * without unfreezing. The new child is frozen too. + */ +static int test_cgfreezer_rmdir(const char *root) +{ + int ret = KSFT_FAIL; + char *parent, *child = NULL; + + parent = cg_name(root, "cg_test_rmdir_A"); + if (!parent) + goto cleanup; + + child = cg_name(parent, "cg_test_rmdir_B"); + if (!child) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_freeze_wait(parent, true)) + goto cleanup; + + if (cg_destroy(child)) + goto cleanup; + + if (cg_check_frozen(parent, true)) + goto cleanup; + + if (cg_create(child)) + goto cleanup; + + if (cg_check_frozen(child, true)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (child) + cg_destroy(child); + free(child); + if (parent) + cg_destroy(parent); + free(parent); + return ret; +} + +/* + * The test creates two cgroups: A and B, runs a process in A + * and performs several migrations: + * 1) A (running) -> B (frozen) + * 2) B (frozen) -> A (running) + * 3) A (frozen) -> B (frozen) + * + * On each step it checks the actual state of both cgroups. + */ +static int test_cgfreezer_migrate(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup[2] = {0}; + int pid; + + cgroup[0] = cg_name(root, "cg_test_migrate_A"); + if (!cgroup[0]) + goto cleanup; + + cgroup[1] = cg_name(root, "cg_test_migrate_B"); + if (!cgroup[1]) + goto cleanup; + + if (cg_create(cgroup[0])) + goto cleanup; + + if (cg_create(cgroup[1])) + goto cleanup; + + pid = cg_run_nowait(cgroup[0], child_fn, NULL); + if (pid < 0) + goto cleanup; + + if (cg_wait_for_proc_count(cgroup[0], 1)) + goto cleanup; + + /* + * Migrate from A (running) to B (frozen) + */ + if (cg_freeze_wait(cgroup[1], true)) + goto cleanup; + + if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true)) + goto cleanup; + + if (cg_check_frozen(cgroup[0], false)) + goto cleanup; + + /* + * Migrate from B (frozen) to A (running) + */ + if (cg_enter_and_wait_for_frozen(cgroup[0], pid, false)) + goto cleanup; + + if (cg_check_frozen(cgroup[1], true)) + goto cleanup; + + /* + * Migrate from A (frozen) to B (frozen) + */ + if (cg_freeze_wait(cgroup[0], true)) + goto cleanup; + + if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true)) + goto cleanup; + + if (cg_check_frozen(cgroup[0], true)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup[0]) + cg_destroy(cgroup[0]); + free(cgroup[0]); + if (cgroup[1]) + cg_destroy(cgroup[1]); + free(cgroup[1]); + return ret; +} + +/* + * The test checks that ptrace works with a tracing process in a frozen cgroup. + */ +static int test_cgfreezer_ptrace(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + siginfo_t siginfo; + int pid; + + cgroup = cg_name(root, "cg_test_ptrace"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + pid = cg_run_nowait(cgroup, child_fn, NULL); + if (pid < 0) + goto cleanup; + + if (cg_wait_for_proc_count(cgroup, 1)) + goto cleanup; + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + if (ptrace(PTRACE_SEIZE, pid, NULL, NULL)) + goto cleanup; + + if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL)) + goto cleanup; + + waitpid(pid, NULL, 0); + + /* + * Cgroup has to remain frozen, however the test task + * is in traced state. + */ + if (cg_check_frozen(cgroup, true)) + goto cleanup; + + if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo)) + goto cleanup; + + if (ptrace(PTRACE_DETACH, pid, NULL, NULL)) + goto cleanup; + + if (cg_check_frozen(cgroup, true)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * Check if the process is stopped. + */ +static int proc_check_stopped(int pid) +{ + char buf[PAGE_SIZE]; + int len; + + len = proc_read_text(pid, "stat", buf, sizeof(buf)); + if (len == -1) { + debug("Can't get %d stat\n", pid); + return -1; + } + + if (strstr(buf, "(test_freezer) T ") == NULL) { + debug("Process %d in the unexpected state: %s\n", pid, buf); + return -1; + } + + return 0; +} + +/* + * Test that it's possible to freeze a cgroup with a stopped process. + */ +static int test_cgfreezer_stopped(const char *root) +{ + int pid, ret = KSFT_FAIL; + char *cgroup = NULL; + + cgroup = cg_name(root, "cg_test_stopped"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + pid = cg_run_nowait(cgroup, child_fn, NULL); + + if (cg_wait_for_proc_count(cgroup, 1)) + goto cleanup; + + if (kill(pid, SIGSTOP)) + goto cleanup; + + if (cg_check_frozen(cgroup, false)) + goto cleanup; + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + if (cg_freeze_wait(cgroup, false)) + goto cleanup; + + if (proc_check_stopped(pid)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +/* + * Test that it's possible to freeze a cgroup with a ptraced process. + */ +static int test_cgfreezer_ptraced(const char *root) +{ + int pid, ret = KSFT_FAIL; + char *cgroup = NULL; + siginfo_t siginfo; + + cgroup = cg_name(root, "cg_test_ptraced"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + pid = cg_run_nowait(cgroup, child_fn, NULL); + + if (cg_wait_for_proc_count(cgroup, 1)) + goto cleanup; + + if (ptrace(PTRACE_SEIZE, pid, NULL, NULL)) + goto cleanup; + + if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL)) + goto cleanup; + + waitpid(pid, NULL, 0); + + if (cg_check_frozen(cgroup, false)) + goto cleanup; + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + /* + * cg_check_frozen(cgroup, true) will fail here, + * because the task in in the TRACEd state. + */ + if (cg_freeze_wait(cgroup, false)) + goto cleanup; + + if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo)) + goto cleanup; + + if (ptrace(PTRACE_DETACH, pid, NULL, NULL)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +static int vfork_fn(const char *cgroup, void *arg) +{ + int pid = vfork(); + + if (pid == 0) + while (true) + sleep(1); + + return pid; +} + +/* + * Test that it's possible to freeze a cgroup with a process, + * which called vfork() and is waiting for a child. + */ +static int test_cgfreezer_vfork(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup = NULL; + + cgroup = cg_name(root, "cg_test_vfork"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + cg_run_nowait(cgroup, vfork_fn, NULL); + + if (cg_wait_for_proc_count(cgroup, 2)) + goto cleanup; + + if (cg_freeze_wait(cgroup, true)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + +#define T(x) { x, #x } +struct cgfreezer_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_cgfreezer_simple), + T(test_cgfreezer_tree), + T(test_cgfreezer_forkbomb), + T(test_cgfreezer_rmdir), + T(test_cgfreezer_migrate), + T(test_cgfreezer_ptrace), + T(test_cgfreezer_stopped), + T(test_cgfreezer_ptraced), + T(test_cgfreezer_vfork), +}; +#undef T + +int main(int argc, char *argv[]) +{ + char root[PATH_MAX]; + int i, ret = EXIT_SUCCESS; + + if (cg_find_unified_root(root, sizeof(root))) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + for (i = 0; i < ARRAY_SIZE(tests); i++) { + switch (tests[i].fn(root)) { + case KSFT_PASS: + ksft_test_result_pass("%s\n", tests[i].name); + break; + case KSFT_SKIP: + ksft_test_result_skip("%s\n", tests[i].name); + break; + default: + ret = EXIT_FAILURE; + ksft_test_result_fail("%s\n", tests[i].name); + break; + } + } + + return ret; +} -- 2.20.1

5 years

3
4
0 0

[PATCH for 5.2] rseq/selftests: Fix Thumb mode build failure on arm32

by Mathieu Desnoyers

Using ".arm .inst" for the arm signature introduces build issues for programs compiled in Thumb mode because the assembler stays in the arm mode for the rest of the inline assembly. Revert to using a ".word" to express the signature as data instead. The choice of signature is a valid trap instruction on arm32 little endian, where both code and data are little endian. ARMv6+ big endian (BE8) generates mixed endianness code vs data: little-endian code and big-endian data. The data value of the signature needs to have its byte order reversed to generate the trap instruction. Prior to ARMv6, -mbig-endian generates big-endian code and data (which match), so the endianness of the data representation of the signature should not be reversed. However, the choice between BE32 and BE8 is done by the linker, so we cannot know whether code and data endianness will be mixed before the linker is invoked. So rather than try to play tricks with the linker, the rseq signature is simply data (not a trap instruction) prior to ARMv6 on big endian. This is why the signature is expressed as data (.word) rather than as instruction (.inst) in assembler. Because a ".word" is used to emit the signature, it will be interpreted as a literal pool by a disassembler, not as an actual instruction. Considering that the signature is not meant to be executed except in scenarios where the program execution is completely bogus, this should not be an issue. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Acked-by: Will Deacon <will.deacon(a)arm.com> CC: Peter Zijlstra <peterz(a)infradead.org> CC: Thomas Gleixner <tglx(a)linutronix.de> CC: Joel Fernandes <joelaf(a)google.com> CC: Catalin Marinas <catalin.marinas(a)arm.com> CC: Dave Watson <davejwatson(a)fb.com> CC: Will Deacon <will.deacon(a)arm.com> CC: Shuah Khan <shuah(a)kernel.org> CC: Andi Kleen <andi(a)firstfloor.org> CC: linux-kselftest(a)vger.kernel.org CC: "H . Peter Anvin" <hpa(a)zytor.com> CC: Chris Lameter <cl(a)linux.com> CC: Russell King <linux(a)arm.linux.org.uk> CC: Michael Kerrisk <mtk.manpages(a)gmail.com> CC: "Paul E . McKenney" <paulmck(a)linux.vnet.ibm.com> CC: Paul Turner <pjt(a)google.com> CC: Boqun Feng <boqun.feng(a)gmail.com> CC: Josh Triplett <josh(a)joshtriplett.org> CC: Steven Rostedt <rostedt(a)goodmis.org> CC: Ben Maurer <bmaurer(a)fb.com> CC: linux-api(a)vger.kernel.org CC: Andy Lutomirski <luto(a)amacapital.net> CC: Andrew Morton <akpm(a)linux-foundation.org> CC: Linus Torvalds <torvalds(a)linux-foundation.org> CC: Carlos O'Donell <carlos(a)redhat.com> CC: Florian Weimer <fweimer(a)redhat.com> --- tools/testing/selftests/rseq/rseq-arm.h | 61 ++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 28 deletions(-) diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h index 84f28f147fb6..5943c816c07c 100644 --- a/tools/testing/selftests/rseq/rseq-arm.h +++ b/tools/testing/selftests/rseq/rseq-arm.h @@ -6,6 +6,8 @@ */ /* + * - ARM little endian + * * RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand * value 0x5de3. This traps if user-space reaches this instruction by mistake, * and the uncommon operand ensures the kernel does not move the instruction @@ -22,36 +24,40 @@ * def3 udf #243 ; 0xf3 * e7f5 b.n <7f5> * - * pre-ARMv6 big endian code: - * e7f5 b.n <7f5> - * def3 udf #243 ; 0xf3 + * - ARMv6+ big endian (BE8): * * ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian - * code and big-endian data. Ensure the RSEQ_SIG data signature matches code - * endianness. Prior to ARMv6, -mbig-endian generates big-endian code and data - * (which match), so there is no need to reverse the endianness of the data - * representation of the signature. However, the choice between BE32 and BE8 - * is done by the linker, so we cannot know whether code and data endianness - * will be mixed before the linker is invoked. + * code and big-endian data. The data value of the signature needs to have its + * byte order reversed to generate the trap instruction: + * + * Data: 0xf3def5e7 + * + * Translates to this A32 instruction pattern: + * + * e7f5def3 udf #24035 ; 0x5de3 + * + * Translates to this T16 instruction pattern: + * + * def3 udf #243 ; 0xf3 + * e7f5 b.n <7f5> + * + * - Prior to ARMv6 big endian (BE32): + * + * Prior to ARMv6, -mbig-endian generates big-endian code and data + * (which match), so the endianness of the data representation of the + * signature should not be reversed. However, the choice between BE32 + * and BE8 is done by the linker, so we cannot know whether code and + * data endianness will be mixed before the linker is invoked. So rather + * than try to play tricks with the linker, the rseq signature is simply + * data (not a trap instruction) prior to ARMv6 on big endian. This is + * why the signature is expressed as data (.word) rather than as + * instruction (.inst) in assembler. */ -#define RSEQ_SIG_CODE 0xe7f5def3 - -#ifndef __ASSEMBLER__ - -#define RSEQ_SIG_DATA \ - ({ \ - int sig; \ - asm volatile ("b 2f\n\t" \ - "1: .inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \ - "2:\n\t" \ - "ldr %[sig], 1b\n\t" \ - : [sig] "=r" (sig)); \ - sig; \ - }) - -#define RSEQ_SIG RSEQ_SIG_DATA - +#ifdef __ARMEB__ +#define RSEQ_SIG 0xf3def5e7 /* udf #24035 ; 0x5de3 (ARMv6+) */ +#else +#define RSEQ_SIG 0xe7f5def3 /* udf #24035 ; 0x5de3 */ #endif #define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") @@ -125,8 +131,7 @@ do { \ __rseq_str(table_label) ":\n\t" \ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ - ".arm\n\t" \ - ".inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \ + ".word " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ "b %l[" __rseq_str(abort_label) "]\n\t" -- 2.11.0

5 years

2
2
0 0

[PATCH] selftests/powerpc: Add missing newline at end of file

by Geert Uytterhoeven

"git diff" says: \ No newline at end of file after modifying the file. Signed-off-by: Geert Uytterhoeven <geert+renesas(a)glider.be> --- tools/testing/selftests/powerpc/mm/.gitignore | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore index ba919308fe3052f3..16861ab840f57e90 100644 --- a/tools/testing/selftests/powerpc/mm/.gitignore +++ b/tools/testing/selftests/powerpc/mm/.gitignore @@ -3,4 +3,4 @@ subpage_prot tempfile prot_sao segv_errors -wild_bctr \ No newline at end of file +wild_bctr -- 2.17.1

5 years

4
3
0 0

[PATCH v5 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework

by Brendan Higgins

## TL;DR A not so quick follow-up to Stephen's suggestions on PATCH v4. Nothing that really changes any functionality or usage with the minor exception of a couple public functions that Stephen asked me to rename. Nevertheless, a good deal of clean up and fixes. See changes below. As for our current status, right now we got Reviewed-bys on all patches except: - [PATCH v5 08/18] objtool: add kunit_try_catch_throw to the noreturn list However, it would probably be good to get reviews/acks from the subsystem maintainers on: - [PATCH v5 06/18] kbuild: enable building KUnit - [PATCH v5 08/18] objtool: add kunit_try_catch_throw to the noreturn list - [PATCH v5 15/18] Documentation: kunit: add documentation for KUnit - [PATCH v5 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() - [PATCH v5 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section Other than that, I think we should be good to go. One last thing, I updated the background to include my thoughts on KUnit vs. in kernel testing with kselftest in the background sections as suggested by Frank in the discussion on PATCH v2. ## Background This patch set proposes KUnit, a lightweight unit testing and mocking framework for the Linux kernel. Unlike Autotest and kselftest, KUnit is a true unit testing framework; it does not require installing the kernel on a test machine or in a VM (however, KUnit still allows you to run tests on test machines or in VMs if you want[1]) and does not require tests to be written in userspace running on a host kernel. Additionally, KUnit is fast: From invocation to completion KUnit can run several dozen tests in under a second. Currently, the entire KUnit test suite for KUnit runs in under a second from the initial invocation (build time excluded). KUnit is heavily inspired by JUnit, Python's unittest.mock, and Googletest/Googlemock for C++. KUnit provides facilities for defining unit test cases, grouping related test cases into test suites, providing common infrastructure for running tests, mocking, spying, and much more. ### But wait! Doesn't kselftest support in kernel testing?! In a previous version of this patchset Frank pointed out that kselftest already supports writing a test that resides in the kernel using the test module feature[2]. LWN did a really great summary on this discussion here[3]. Kselftest has a feature that allows a test module to be loaded into a kernel using the kselftest framework; this does allow someone to write tests against kernel code not directly exposed to userland; however, it does not provide much of a framework around how to structure the tests. The kselftest test module feature just provides a header which has a standardized way of reporting test failures, and then provides infrastructure to load and run the tests using the kselftest test harness. The kselftest test module does not seem to be opinionated at all in regards to how tests are structured, how they check for failures, how tests are organized. Even in the method it provides for reporting failures is pretty simple; it doesn't have any more advanced failure reporting or logging features. Given what's there, I think it is fair to say that it is not actually a framework, but a feature that makes it possible for someone to do some checks in kernel space. Furthermore, kselftest test module has very few users. I checked for all the tests that use it using the following grep command: grep -Hrn -e 'kselftest_module\.h' and only got three results: lib/test_strscpy.c, lib/test_printf.c, and lib/test_bitmap.c. So despite kselftest test module's existence, there really is no feature overlap between kselftest and KUnit, save one: that you can use either to write an in-kernel test, but this is a very small feature in comparison to everything that KUnit allows you to do. KUnit is a full x-unit style unit testing framework, whereas kselftest looks a lot more like an end-to-end/functional testing framework, with a feature that makes it possible to write in-kernel tests. ### What's so special about unit testing? A unit test is supposed to test a single unit of code in isolation, hence the name. There should be no dependencies outside the control of the test; this means no external dependencies, which makes tests orders of magnitudes faster. Likewise, since there are no external dependencies, there are no hoops to jump through to run the tests. Additionally, this makes unit tests deterministic: a failing unit test always indicates a problem. Finally, because unit tests necessarily have finer granularity, they are able to test all code paths easily solving the classic problem of difficulty in exercising error handling code. ### Is KUnit trying to replace other testing frameworks for the kernel? No. Most existing tests for the Linux kernel are end-to-end tests, which have their place. A well tested system has lots of unit tests, a reasonable number of integration tests, and some end-to-end tests. KUnit is just trying to address the unit test space which is currently not being addressed. ### More information on KUnit There is a bunch of documentation near the end of this patch set that describes how to use KUnit and best practices for writing unit tests. For convenience I am hosting the compiled docs here[4]. Additionally for convenience, I have applied these patches to a branch[5]. The repo may be cloned with: git clone https://kunit.googlesource.com/linux This patchset is on the kunit/rfc/v5.2-rc4/v5 branch. ## Changes Since Last Version Aside from a couple public function renames, there isn't really anything in here that changes any functionality. - Went through and fixed a couple of anti-patterns suggested by Stephen Boyd. Things like: - Dropping an else clause at the end of a function. - Dropping the comma on the closing sentinel, `{}`, of a list. - Inlines a bunch of functions in the test case running logic in patch 01/18 to make it more readable as suggested by Stephen Boyd - Found and fixed bug in resource deallocation logic in patch 02/18. Bug was discovered as a result of making a change suggested by Stephen Boyd. This does not substantially change how any of the code works conceptually. - Renamed new_string_stream() to alloc_string_stream() as suggested by Stephen Boyd. - Made string-stream a KUnit managed object - based on a suggestion made by Stephen Boyd. - Renamed kunit_new_stream() to alloc_kunit_stream() as suggested by Stephen Boyd. - Removed the ability to set log level after allocating a kunit_stream, as suggested by Stephen Boyd. [1] https://google.github.io/kunit-docs/third_party/kernel/docs/usage.html#kuni… [2] https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html#test-module [3] https://lwn.net/Articles/790235/ [4] https://google.github.io/kunit-docs/third_party/kernel/docs/ [5] https://kunit.googlesource.com/linux/+/kunit/rfc/v5.2-rc4/v5 -- 2.22.0.410.gd8fdbe21b5-goog

5 years

7
59
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[PATCH 00/13] Add arm64/signal initial kselftest support

by Cristian Marussi

Hi this patch aims to add the initial arch-specific arm64 support to kselftest starting with signals-related test-cases. A common internal test-case layout is proposed which then it is anyway wired-up to the toplevel kselftest Makefile, so that it should be possible at the end to run it on an arm64 target in the usual way with KSFT. ~/linux# make TARGETS=arm64 kselftest Notes: ----- - further details in the included READMEs - more tests still to be written (current strategy is going through the related Kernel signal-handling code and write a test for each possible and sensible code-path) - a bit of overlap around KSFT arm64/ Makefiles is expected with this recently proposed patch-series: http://lists.infradead.org/pipermail/linux-arm-kernel/2019-June/659432.html Cristian Marussi (13): kselftest: arm64: introduce new boilerplate code kselftest: arm64: adds arm64/signal support code kselftest: arm64: mangle_sp_misaligned kselftest: arm64: mangle_pc_invalid kselftest: arm64: mangle_pstate_invalid_daif_bits kselftest: arm64: mangle_pstate_invalid_state_toggle kselftest: arm64: mangle_pstate_invalid_mode_el? kselftest: arm64: mangle_pstate_ssbs_regs kselftest: arm64: fake_sigreturn_misaligned kselftest: arm64: fake_sigreturn_bad_magic kselftest: arm64: fake_sigreturn_bad_size kselftest: arm64: fake_sigreturn_bad_size_for_magic0 kselftest: arm64: fake_sigreturn_overflow_reserved tools/testing/selftests/Makefile | 1 + tools/testing/selftests/arm64/Makefile | 51 ++++ tools/testing/selftests/arm64/README | 44 +++ .../testing/selftests/arm64/signal/.gitignore | 5 + tools/testing/selftests/arm64/signal/Makefile | 86 ++++++ tools/testing/selftests/arm64/signal/README | 56 ++++ .../testing/selftests/arm64/signal/signals.S | 64 +++++ .../arm64/signal/test_arm64_signals.sh | 44 +++ .../selftests/arm64/signal/test_signals.c | 30 ++ .../selftests/arm64/signal/test_signals.h | 136 ++++++++++ .../arm64/signal/test_signals_utils.c | 256 ++++++++++++++++++ .../arm64/signal/test_signals_utils.h | 110 ++++++++ .../arm64/signal/testcases/.gitignore | 13 + .../testcases/fake_sigreturn_bad_magic.c | 42 +++ .../testcases/fake_sigreturn_bad_size.c | 40 +++ .../fake_sigreturn_bad_size_for_magic0.c | 44 +++ .../testcases/fake_sigreturn_misaligned.c | 30 ++ .../fake_sigreturn_overflow_reserved.c | 48 ++++ .../signal/testcases/mangle_pc_invalid.c | 24 ++ .../mangle_pstate_invalid_daif_bits.c | 25 ++ .../mangle_pstate_invalid_mode_el1.c | 25 ++ .../mangle_pstate_invalid_mode_el2.c | 25 ++ .../mangle_pstate_invalid_mode_el3.c | 25 ++ .../mangle_pstate_invalid_state_toggle.c | 25 ++ .../testcases/mangle_pstate_ssbs_regs.c | 41 +++ .../signal/testcases/mangle_sp_misaligned.c | 24 ++ .../arm64/signal/testcases/testcases.c | 123 +++++++++ .../arm64/signal/testcases/testcases.h | 85 ++++++ 28 files changed, 1522 insertions(+) create mode 100644 tools/testing/selftests/arm64/Makefile create mode 100644 tools/testing/selftests/arm64/README create mode 100644 tools/testing/selftests/arm64/signal/.gitignore create mode 100644 tools/testing/selftests/arm64/signal/Makefile create mode 100644 tools/testing/selftests/arm64/signal/README create mode 100644 tools/testing/selftests/arm64/signal/signals.S create mode 100755 tools/testing/selftests/arm64/signal/test_arm64_signals.sh create mode 100644 tools/testing/selftests/arm64/signal/test_signals.c create mode 100644 tools/testing/selftests/arm64/signal/test_signals.h create mode 100644 tools/testing/selftests/arm64/signal/test_signals_utils.c create mode 100644 tools/testing/selftests/arm64/signal/test_signals_utils.h create mode 100644 tools/testing/selftests/arm64/signal/testcases/.gitignore create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_overflow_reserved.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pc_invalid.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el2.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el3.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_ssbs_regs.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_sp_misaligned.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/testcases.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/testcases.h -- 2.17.1

5 years

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[PATCH bpf 1/3] bpf, x32: Fix bug with ALU64 {LSH, RSH, ARSH} BPF_X shift by 0

by Luke Nelson

The current x32 BPF JIT for shift operations is not correct when the shift amount in a register is 0. The expected behavior is a no-op, whereas the current implementation changes bits in the destination register. The following example demonstrates the bug. The expected result of this program is 1, but the current JITed code returns 2. r0 = 1 r1 = 1 r2 = 0 r1 <<= r2 if r1 == 1 goto end r0 = 2 end: exit The bug is caused by an incorrect assumption by the JIT that a shift by 32 clear the register. On x32 however, shifts use the lower 5 bits of the source, making a shift by 32 equivalent to a shift by 0. This patch fixes the bug using double-precision shifts, which also simplifies the code. Fixes: 03f5781be2c7 ("bpf, x86_32: add eBPF JIT compiler for ia32") Co-developed-by: Xi Wang <xi.wang(a)gmail.com> Signed-off-by: Xi Wang <xi.wang(a)gmail.com> Signed-off-by: Luke Nelson <luke.r.nels(a)gmail.com> --- arch/x86/net/bpf_jit_comp32.c | 221 ++++------------------------------ 1 file changed, 23 insertions(+), 198 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c index b29e82f190c7..f34ef513f4f9 100644 --- a/arch/x86/net/bpf_jit_comp32.c +++ b/arch/x86/net/bpf_jit_comp32.c @@ -724,9 +724,6 @@ static inline void emit_ia32_lsh_r64(const u8 dst[], const u8 src[], { u8 *prog = *pprog; int cnt = 0; - static int jmp_label1 = -1; - static int jmp_label2 = -1; - static int jmp_label3 = -1; u8 dreg_lo = dstk ? IA32_EAX : dst_lo; u8 dreg_hi = dstk ? IA32_EDX : dst_hi; @@ -745,79 +742,23 @@ static inline void emit_ia32_lsh_r64(const u8 dst[], const u8 src[], /* mov ecx,src_lo */ EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); - /* cmp ecx,32 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); - /* Jumps when >= 32 */ - if (is_imm8(jmp_label(jmp_label1, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); - - /* < 32 */ - /* shl dreg_hi,cl */ - EMIT2(0xD3, add_1reg(0xE0, dreg_hi)); - /* mov ebx,dreg_lo */ - EMIT2(0x8B, add_2reg(0xC0, dreg_lo, IA32_EBX)); + /* shld dreg_hi,dreg_lo,cl */ + EMIT3(0x0F, 0xA5, add_2reg(0xC0, dreg_hi, dreg_lo)); /* shl dreg_lo,cl */ EMIT2(0xD3, add_1reg(0xE0, dreg_lo)); - /* IA32_ECX = -IA32_ECX + 32 */ - /* neg ecx */ - EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); - /* add ecx,32 */ - EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); - - /* shr ebx,cl */ - EMIT2(0xD3, add_1reg(0xE8, IA32_EBX)); - /* or dreg_hi,ebx */ - EMIT2(0x09, add_2reg(0xC0, dreg_hi, IA32_EBX)); - - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 32 */ - if (jmp_label1 == -1) - jmp_label1 = cnt; + /* if ecx >= 32, mov dreg_lo into dreg_hi and clear dreg_lo */ - /* cmp ecx,64 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); - /* Jumps when >= 64 */ - if (is_imm8(jmp_label(jmp_label2, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* skip the next two instructions (4 bytes) when < 32 */ + EMIT2(IA32_JB, 4); - /* >= 32 && < 64 */ - /* sub ecx,32 */ - EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); - /* shl dreg_lo,cl */ - EMIT2(0xD3, add_1reg(0xE0, dreg_lo)); /* mov dreg_hi,dreg_lo */ EMIT2(0x89, add_2reg(0xC0, dreg_hi, dreg_lo)); - /* xor dreg_lo,dreg_lo */ EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 64 */ - if (jmp_label2 == -1) - jmp_label2 = cnt; - /* xor dreg_lo,dreg_lo */ - EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); - /* xor dreg_hi,dreg_hi */ - EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); - - if (jmp_label3 == -1) - jmp_label3 = cnt; - if (dstk) { /* mov dword ptr [ebp+off],dreg_lo */ EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), @@ -836,9 +777,6 @@ static inline void emit_ia32_arsh_r64(const u8 dst[], const u8 src[], { u8 *prog = *pprog; int cnt = 0; - static int jmp_label1 = -1; - static int jmp_label2 = -1; - static int jmp_label3 = -1; u8 dreg_lo = dstk ? IA32_EAX : dst_lo; u8 dreg_hi = dstk ? IA32_EDX : dst_hi; @@ -857,78 +795,22 @@ static inline void emit_ia32_arsh_r64(const u8 dst[], const u8 src[], /* mov ecx,src_lo */ EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); - /* cmp ecx,32 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); - /* Jumps when >= 32 */ - if (is_imm8(jmp_label(jmp_label1, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); - - /* < 32 */ - /* lshr dreg_lo,cl */ - EMIT2(0xD3, add_1reg(0xE8, dreg_lo)); - /* mov ebx,dreg_hi */ - EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); - /* ashr dreg_hi,cl */ + /* shrd dreg_lo,dreg_hi,cl */ + EMIT3(0x0F, 0xAD, add_2reg(0xC0, dreg_lo, dreg_hi)); + /* sar dreg_hi,cl */ EMIT2(0xD3, add_1reg(0xF8, dreg_hi)); - /* IA32_ECX = -IA32_ECX + 32 */ - /* neg ecx */ - EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); - /* add ecx,32 */ - EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); - - /* shl ebx,cl */ - EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); - /* or dreg_lo,ebx */ - EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); - - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 32 */ - if (jmp_label1 == -1) - jmp_label1 = cnt; + /* if ecx >= 32, mov dreg_hi to dreg_lo and set/clear dreg_hi depending on sign */ - /* cmp ecx,64 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); - /* Jumps when >= 64 */ - if (is_imm8(jmp_label(jmp_label2, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* skip the next two instructions (5 bytes) when < 32 */ + EMIT2(IA32_JB, 5); - /* >= 32 && < 64 */ - /* sub ecx,32 */ - EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); - /* ashr dreg_hi,cl */ - EMIT2(0xD3, add_1reg(0xF8, dreg_hi)); /* mov dreg_lo,dreg_hi */ EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); - - /* ashr dreg_hi,imm8 */ - EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); - - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 64 */ - if (jmp_label2 == -1) - jmp_label2 = cnt; - /* ashr dreg_hi,imm8 */ + /* sar dreg_hi,31 */ EMIT3(0xC1, add_1reg(0xF8, dreg_hi), 31); - /* mov dreg_lo,dreg_hi */ - EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); - - if (jmp_label3 == -1) - jmp_label3 = cnt; if (dstk) { /* mov dword ptr [ebp+off],dreg_lo */ @@ -948,9 +830,6 @@ static inline void emit_ia32_rsh_r64(const u8 dst[], const u8 src[], bool dstk, { u8 *prog = *pprog; int cnt = 0; - static int jmp_label1 = -1; - static int jmp_label2 = -1; - static int jmp_label3 = -1; u8 dreg_lo = dstk ? IA32_EAX : dst_lo; u8 dreg_hi = dstk ? IA32_EDX : dst_hi; @@ -969,77 +848,23 @@ static inline void emit_ia32_rsh_r64(const u8 dst[], const u8 src[], bool dstk, /* mov ecx,src_lo */ EMIT2(0x8B, add_2reg(0xC0, src_lo, IA32_ECX)); - /* cmp ecx,32 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); - /* Jumps when >= 32 */ - if (is_imm8(jmp_label(jmp_label1, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label1, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label1, 6)); - - /* < 32 */ - /* lshr dreg_lo,cl */ - EMIT2(0xD3, add_1reg(0xE8, dreg_lo)); - /* mov ebx,dreg_hi */ - EMIT2(0x8B, add_2reg(0xC0, dreg_hi, IA32_EBX)); + /* shrd dreg_lo,dreg_hi,cl */ + EMIT3(0x0F, 0xAD, add_2reg(0xC0, dreg_lo, dreg_hi)); /* shr dreg_hi,cl */ EMIT2(0xD3, add_1reg(0xE8, dreg_hi)); - /* IA32_ECX = -IA32_ECX + 32 */ - /* neg ecx */ - EMIT2(0xF7, add_1reg(0xD8, IA32_ECX)); - /* add ecx,32 */ - EMIT3(0x83, add_1reg(0xC0, IA32_ECX), 32); - - /* shl ebx,cl */ - EMIT2(0xD3, add_1reg(0xE0, IA32_EBX)); - /* or dreg_lo,ebx */ - EMIT2(0x09, add_2reg(0xC0, dreg_lo, IA32_EBX)); + /* if ecx >= 32, mov dreg_hi to dreg_lo and clear dreg_hi */ - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 32 */ - if (jmp_label1 == -1) - jmp_label1 = cnt; - /* cmp ecx,64 */ - EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 64); - /* Jumps when >= 64 */ - if (is_imm8(jmp_label(jmp_label2, 2))) - EMIT2(IA32_JAE, jmp_label(jmp_label2, 2)); - else - EMIT2_off32(0x0F, IA32_JAE + 0x10, jmp_label(jmp_label2, 6)); + /* cmp ecx,32 */ + EMIT3(0x83, add_1reg(0xF8, IA32_ECX), 32); + /* skip the next two instructions (4 bytes) when < 32 */ + EMIT2(IA32_JB, 4); - /* >= 32 && < 64 */ - /* sub ecx,32 */ - EMIT3(0x83, add_1reg(0xE8, IA32_ECX), 32); - /* shr dreg_hi,cl */ - EMIT2(0xD3, add_1reg(0xE8, dreg_hi)); /* mov dreg_lo,dreg_hi */ EMIT2(0x89, add_2reg(0xC0, dreg_lo, dreg_hi)); /* xor dreg_hi,dreg_hi */ EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); - /* goto out; */ - if (is_imm8(jmp_label(jmp_label3, 2))) - EMIT2(0xEB, jmp_label(jmp_label3, 2)); - else - EMIT1_off32(0xE9, jmp_label(jmp_label3, 5)); - - /* >= 64 */ - if (jmp_label2 == -1) - jmp_label2 = cnt; - /* xor dreg_lo,dreg_lo */ - EMIT2(0x33, add_2reg(0xC0, dreg_lo, dreg_lo)); - /* xor dreg_hi,dreg_hi */ - EMIT2(0x33, add_2reg(0xC0, dreg_hi, dreg_hi)); - - if (jmp_label3 == -1) - jmp_label3 = cnt; - if (dstk) { /* mov dword ptr [ebp+off],dreg_lo */ EMIT3(0x89, add_2reg(0x40, IA32_EBP, dreg_lo), -- 2.20.1

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Linux-kselftest-mirror June 2019