kernel/linux.git/tools/testing/selftests/x86/Makefile, branch v6.7

selftests/x86/mm: Add new test that userspace stack is in fact NX

2023-10-03T19:00:45+00:00

Here is how it works: * fault and fill the stack from RSP with INT3 down until rlimit allows, * fill upwards with INT3 too, overwrite libc stuff, argv, envp, * try to exec INT3 on each page and catch it in either SIGSEGV or SIGTRAP handler. Note: trying to execute _every_ INT3 on a 8 MiB stack takes 30-40 seconds even on fast machine which is too much for kernel selftesting (not for LTP!) so only 1 INT3 per page is tried. Tested on F37 kernel and on a custom kernel which does: vm_flags |= VM_EXEC; to stack VMA. Report from the buggy kernel: $ ./nx_stack_32 stack min ff007000 stack max ff807000 FAIL executable page on the stack: eip ff806001 $ ./nx_stack_64 stack min 7ffe65bb0000 stack max 7ffe663b0000 FAIL executable page on the stack: rip 7ffe663af001 Signed-off-by: Alexey Dobriyan Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/4cef8266-ad6d-48af-a5f1-fc2b6a8eb422@p183

selftests/x86: Add shadow stack test

2023-08-02T22:01:51+00:00

Add a simple selftest for exercising some shadow stack behavior: - map_shadow_stack syscall and pivot - Faulting in shadow stack memory - Handling shadow stack violations - GUP of shadow stack memory - mprotect() of shadow stack memory - Userfaultfd on shadow stack memory - 32 bit segmentation - Guard gap test - Ptrace test Co-developed-by: Yu-cheng Yu Signed-off-by: Yu-cheng Yu Signed-off-by: Rick Edgecombe Signed-off-by: Dave Hansen Acked-by: Mike Rapoport (IBM) Tested-by: Pengfei Xu Tested-by: John Allen Tested-by: Kees Cook Link: https://lore.kernel.org/all/20230613001108.3040476-40-rick.p.edgecombe%40intel.com

selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking

2023-03-16T20:08:40+00:00

LAM is supported only in 64-bit mode and applies only addresses used for data accesses. In 64-bit mode, linear address have 64 bits. LAM is applied to 64-bit linear address and allow software to use high bits for metadata. LAM supports configurations that differ regarding which pointer bits are masked and can be used for metadata. LAM includes following mode: - LAM_U57, pointer bits in positions 62:57 are masked (LAM width 6), allows bits 62:57 of a user pointer to be used as metadata. There are some arch_prctls: ARCH_ENABLE_TAGGED_ADDR: enable LAM mode, mask high bits of a user pointer. ARCH_GET_UNTAG_MASK: get current untagged mask. ARCH_GET_MAX_TAG_BITS: the maximum tag bits user can request. zero if LAM is not supported. The LAM mode is for pre-process, a process has only one chance to set LAM mode. But there is no API to disable LAM mode. So all of test cases are run under child process. Functions of this test: MALLOC - LAM_U57 masks bits 57:62 of a user pointer. Process on user space can dereference such pointers. - Disable LAM, dereference a pointer with metadata above 48 bit or 57 bit lead to trigger SIGSEGV. TAG_BITS - Max tag bits of LAM_U57 is 6. Signed-off-by: Weihong Zhang Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20230312112612.31869-13-kirill.shutemov%40linux.intel.com

selftests: x86: Fix incorrect kernel headers search path

2023-02-13T16:09:46+00:00

Use $(KHDR_INCLUDES) as lookup path for kernel headers. This prevents building against kernel headers from the build environment in scenarios where kernel headers are installed into a specific output directory (O=...). Signed-off-by: Mathieu Desnoyers Cc: Shuah Khan Cc: linux-kselftest@vger.kernel.org Cc: Ingo Molnar Cc: # 5.18+ Signed-off-by: Shuah Khan

selftests: x86: add 32bit build warnings for SUSE

2022-04-04T19:29:43+00:00

In order to successfully build all these 32bit tests, these 32bit gcc and glibc packages, named gcc-32bit and glibc-devel-static-32bit on SUSE, need to be installed. This patch added this information in warn_32bit_failure. Signed-off-by: Geliang Tang Signed-off-by: Shuah Khan

selftests, x86: fix how check_cc.sh is being invoked

2022-03-22T22:57:04+00:00

The $(CC) variable used in Makefiles could contain several arguments such as "ccache gcc". These need to be passed as a single string to check_cc.sh, otherwise only the first argument will be used as the compiler command. Without quotes, the $(CC) variable is passed as distinct arguments which causes the script to fail to build trivial programs. Fix this by adding quotes around $(CC) when calling check_cc.sh to pass the whole string as a single argument to the script even if it has several words such as "ccache gcc". Link: https://lkml.kernel.org/r/d0d460d7be0107a69e3c52477761a6fe694c1840.1646991629.git.guillaume.tucker@collabora.com Fixes: e9886ace222e ("selftests, x86: Rework x86 target architecture detection") Signed-off-by: Guillaume Tucker Tested-by: "kernelci.org bot" Reviewed-by: Guenter Roeck Cc: Shuah Khan Cc: Borislav Petkov Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests/x86/amx: Add test cases for AMX state management

2021-10-28T12:35:27+00:00

AMX TILEDATA is a very large XSAVE feature. It could have caused nasty XSAVE buffer space waste in two places: * Signal stacks * Kernel task_struct->fpu buffers To avoid this waste, neither of these buffers have AMX state by default. The non-default features are called "dynamic" features. There is an arch_prctl(ARCH_REQ_XCOMP_PERM) which allows a task to declare that it wants to use AMX or other "dynamic" XSAVE features. This arch_prctl() ensures that sufficient sigaltstack space is available before it will succeed. It also expands the task_struct buffer. Functions of this test: * Test arch_prctl(ARCH_REQ_XCOMP_PERM). Ensure that it checks for proper sigaltstack sizing and that the sizing is enforced for future sigaltstack calls. * Ensure that ARCH_REQ_XCOMP_PERM is inherited across fork() * Ensure that TILEDATA use before the prctl() is fatal * Ensure that TILEDATA is cleared across fork() Note: Generally, compiler support is needed to do something with AMX. Instead, directly load AMX state from userspace with a plain XSAVE. Do not depend on the compiler. [ dhansen: bunches of cleanups ] Signed-off-by: Chang S. Bae Signed-off-by: Dave Hansen Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211026122524.7BEDAA95@davehans-spike.ostc.intel.com

selftests/x86: Test signal frame XSTATE header corruption handling

2021-06-09T12:46:30+00:00

This is very heavily based on some code from Thomas Gleixner. On a system without XSAVES, it triggers the WARN_ON(): Bad FPU state detected at copy_kernel_to_fpregs+0x2f/0x40, reinitializing FPU registers. [ bp: Massage in nitpicks. ] Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Acked-by: Dave Hansen Acked-by: Rik van Riel Link: https://lkml.kernel.org/r/20210608144346.234764986@linutronix.de

selftest/x86/signal: Include test cases for validating sigaltstack

2021-05-19T10:45:07+00:00

The test measures the kernel's signal delivery with different (enough vs. insufficient) stack sizes. Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov Reviewed-by: Len Brown Acked-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20210518200320.17239-7-chang.seok.bae@intel.com

kselftest: Move test_vdso to the vDSO test suite

2020-10-27T23:58:33+00:00

Move test_vdso from x86 to the vDSO test suite. Suggested-by: Andy Lutomirski Cc: Shuah Khan Signed-off-by: Vincenzo Frascino Acked-by: Thomas Gleixner Signed-off-by: Shuah Khan