kernel/linux.git/tools/testing/selftests/x86, branch v6.6.131

selftests/x86: Add a test to detect infinite SIGTRAP handler loop

2025-06-27T10:08:59+00:00

commit f287822688eeb44ae1cf6ac45701d965efc33218 upstream. When FRED is enabled, if the Trap Flag (TF) is set without an external debugger attached, it can lead to an infinite loop in the SIGTRAP handler. To avoid this, the software event flag in the augmented SS must be cleared, ensuring that no single-step trap remains pending when ERETU completes. This test checks for that specific scenario—verifying whether the kernel correctly prevents an infinite SIGTRAP loop in this edge case when FRED is enabled. The test should _always_ pass with IDT event delivery, thus no need to disable the test even when FRED is not enabled. Signed-off-by: Xin Li (Intel) Signed-off-by: Dave Hansen Tested-by: Sohil Mehta Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250609084054.2083189-3-xin%40zytor.com Signed-off-by: Greg Kroah-Hartman

selftests/x86/lam: Zero out buffer for readlink()

2023-11-20T10:58:54+00:00

[ Upstream commit 29060633411a02f6f2dd9d5245919385d69d81f0 ] Zero out the buffer for readlink() since readlink() does not append a terminating null byte to the buffer. Also change the buffer length passed to readlink() to 'PATH_MAX - 1' to ensure the resulting string is always null terminated. Fixes: 833c12ce0f430 ("selftests/x86/lam: Add inherit test cases for linear-address masking") Signed-off-by: Binbin Wu Signed-off-by: Ingo Molnar Reviewed-by: Kirill A. Shutemov Link: https://lore.kernel.org/r/20231016062446.695-1-binbin.wu@linux.intel.com Signed-off-by: Sasha Levin

selftests/x86: Update map_shadow_stack syscall nr

2023-09-01T21:34:13+00:00

Shadow stack's selftest utilizes the map_shadow_stack syscall. The syscall is new with the feature, but the selftests cannot automatically find the headers for the kernel source tree they are located in. This resulted in the shadow stack test failing to build until the brand new headers were installed. To avoid this, a copy of the new uapi defines needed by the test were included in the selftest (see link for discussion). When shadow stack was merged the syscall number was changed, but the copy in the selftest was not updated. So update the copy of the syscall number define used when the required headers are not installed, to have the final syscall number from the merge. Signed-off-by: Rick Edgecombe Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/lkml/Y%2FijdXoTAATt0+Ct@zn.tnic/ Link: https://lore.kernel.org/r/20230901181652.2583861-1-rick.p.edgecombe@intel.com Reviewed-by: Sohil Mehta Fixes: df57721f9a63 ("Merge tag 'x86_shstk_for_6.6-rc1' of [...]")

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

Merge tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-04-28T16:43:49+00:00

Pull x86 LAM (Linear Address Masking) support from Dave Hansen: "Add support for the new Linear Address Masking CPU feature. This is similar to ARM's Top Byte Ignore and allows userspace to store metadata in some bits of pointers without masking it out before use" * tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/iommu/sva: Do not allow to set FORCE_TAGGED_SVA bit from outside x86/mm/iommu/sva: Fix error code for LAM enabling failure due to SVA selftests/x86/lam: Add test cases for LAM vs thread creation selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking selftests/x86/lam: Add inherit test cases for linear-address masking selftests/x86/lam: Add io_uring test cases for linear-address masking selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking x86/mm/iommu/sva: Make LAM and SVA mutually exclusive iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() mm: Expose untagging mask in /proc/$PID/status x86/mm: Provide arch_prctl() interface for LAM x86/mm: Reduce untagged_addr() overhead for systems without LAM x86/uaccess: Provide untagged_addr() and remove tags before address check mm: Introduce untagged_addr_remote() x86/mm: Handle LAM on context switch x86: CPUID and CR3/CR4 flags for Linear Address Masking x86: Allow atomic MM_CONTEXT flags setting x86/mm: Rework address range check in get_user() and put_user()

selftests/x86/amx: Add a ptrace test

2023-03-22T18:00:49+00:00

Include a test case to validate the XTILEDATA injection to the target. Also, it ensures the kernel's ability to copy states between different XSAVE formats. Refactor the memcmp() code to be usable for the state validation. Signed-off-by: Chang S. Bae Signed-off-by: Dave Hansen Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20230227210504.18520-3-chang.seok.bae%40intel.com

selftests/x86/lam: Add test cases for LAM vs thread creation

2023-03-16T20:08:41+00:00

LAM enabling is only allowed when the process has single thread. LAM mode is inherited into child thread. Trying to enable LAM after spawning a thread has to fail. Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20230312112612.31869-18-kirill.shutemov%40linux.intel.com

selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking

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

By default do not allow to enable both LAM and use SVA in the same process. The new ARCH_FORCE_TAGGED_SVA arch_prctl() overrides the limitation. Add new test cases for the new arch_prctl: Before using ARCH_FORCE_TAGGED_SVA, should not allow to enable LAM/SVA coexisting. the test cases should be negative. The test depands on idxd driver and iommu. before test, need add "intel_iommu=on,sm_on" in kernel command line and insmod idxd driver. 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/20230312112612.31869-17-kirill.shutemov%40linux.intel.com

selftests/x86/lam: Add inherit test cases for linear-address masking

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

LAM is enabled per-thread and gets inherited on fork(2)/clone(2). exec() reverts LAM status to the default disabled state. There are two test scenarios: - Fork test cases: These cases were used to test the inheritance of LAM for per-thread, Child process generated by fork() should inherit LAM feature from parent process, Child process can get the LAM mode same as parent process. - Execve test cases: Processes generated by execve() are different from processes generated by fork(), these processes revert LAM status to disabled status. 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/20230312112612.31869-16-kirill.shutemov%40linux.intel.com

selftests/x86/lam: Add io_uring test cases for linear-address masking

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

LAM should be supported in kernel thread, using io_uring to verify LAM feature. The test cases implement read a file through io_uring, the test cases choose an iovec array as receiving buffer, which used to receive data, according to LAM mode, set metadata in high bits of these buffer. io_uring can deal with these buffers that pointed to pointers with the metadata in high bits. 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/20230312112612.31869-15-kirill.shutemov%40linux.intel.com