wireguard-linux/tools/testing/selftests/x86/Makefile, branch stable

selftests/x86: Check signal state for rejected software interrupts

2026-09-18T10:33:18Z

Add a test of the signal ABI for INT instructions in both 32-bit and 64-bit processes. Check the signal number, trap number, error code, si_code, si_addr, instruction pointer and RF/TF state against legacy IDT behavior. Include a 15-byte prefixed INT to check that IP uses the hardware instruction length. Exercise both INT3 encodings, INT4, UD2 and HLT to cover the unchanged trap and fault paths. Run each instruction with TF clear and set. Resume at a known NOP after handling the signal and check that single-stepping traps after the NOP. Also drive INT 0x2d under ptrace, which resumes through the fault frame rather than sigreturn and so exposes a stale FRED software event flag. Start from an INT3 stop, whose FRED frame has no software event flag, instead of the syscall frame of raise(SIGSTOP). Single-step into the INT and check that the fault reports its address. Then suppress SIGSEGV and resume at the NOP, once with PTRACE_SINGLESTEP and once with PTRACE_CONT and TF set. Section 6.2.3 of the Intel FRED specification [1] specifies the immediate single-step trap caused by returning with both that flag and TF set. Check that each trap occurs after the NOP, rather than at its address. Report whether the CPU supports FRED, since a pass looks the same on either entry path. INT 0x80 with IA32 emulation disabled and a 64-bit tracer of a 32-bit tracee are not covered. Both variants pass all 29 checks on a non-FRED AMD host and on Panther Lake with FRED enabled and the fix applied. With the same binaries on unpatched Panther Lake, 16 signal-context checks fail and the first ptrace check reports the IP after the INT. The two dependent ptrace resume checks are not reached. [1] Intel Flexible Return and Event Delivery (FRED) Specification, revision 9.0 (346446-009US), section 6.2.3. Signed-off-by: Matthew Schwartz Signed-off-by: Peter Zijlstra (Intel) Link: https://cdrdv2.intel.com/v1/dl/getContent/678938 # [1] Link: https://patch.msgid.link/20260917230907.2080792-3-matthew.schwartz@linux.dev

selftests/x86: Add selftests include path for kselftest.h after centralization

2026-01-17T11:22:27Z

The previous change centralizing kselftest.h include path in lib.mk caused x86 selftests to fail, as x86 Makefile overwrites CFLAGS using ":=", dropping the include path added in lib.mk. Therefore, helpers.h could not find kselftest.h during compilation. Fix this by adding the tools/testing/sefltest to CFLAGS in x86 Makefile. [ bp: Correct commit ID in Fixes: ] Fixes: e6fbd1759c9e ("selftests: complete kselftest include centralization") Closes: https://lore.kernel.org/lkml/CA+G9fYvKjQcCBMfXA-z2YuL2L+3Qd-pJjEUDX8PDdz2-EEQd=Q@mail.gmail.com/T/#m83fd330231287fc9d6c921155bee16c591db7360 Reported-by: Linux Kernel Functional Testing Signed-off-by: Bala-Vignesh-Reddy Signed-off-by: Borislav Petkov (AMD) Tested-by: Anders Roxell Tested-by: Brendan Jackman Link: https://patch.msgid.link/20251022062948.162852-1-reddybalavignesh9979@gmail.com

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

2025-06-09T15:52:06Z

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

selftests/x86/apx: Add APX test

2025-04-16T07:44:14Z

The extended general-purpose registers for APX may contain random data, which is currently assumed by the xstate testing framework. This allows the testing of the new userspace feature using the common test code. Invoke the test entry function from apx.c after enumerating the state component and adding it to the support list Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Link: https://lore.kernel.org/r/20250416021720.12305-6-chang.seok.bae@intel.com

selftests/x86/avx: Add AVX tests

2025-02-26T12:05:30Z

Add xstate testing specifically for those vector register states, validating kernel's context switching and ensuring ABI compliance. Use the established xstate testing framework. Alternatively, this invocation could be placed directly in xstate.c::main(). However, the current test file naming convention, which clearly specifies the tested area, seems reasonable. Adding avx.c considerably aligns with that convention. The test output should be like this for ZMM_Hi256 as an example: $ avx_64 ... [RUN] AVX-512 ZMM_Hi256: check context switches, 10 iterations, 5 threads. [OK] No incorrect case was found. [RUN] AVX-512 ZMM_Hi256: inject xstate via ptrace(). [OK] 'xfeatures' in SW reserved area was correctly written [OK] xstate was correctly updated. [RUN] AVX-512 ZMM_Hi256: load xstate and raise SIGUSR1 [OK] 'magic1' is valid [OK] 'xfeatures' in SW reserved area is valid [OK] 'xfeatures' in XSAVE header is valid [OK] xstate delivery was successful [OK] 'magic2' is valid [RUN] AVX-512 ZMM_Hi256: load new xstate from sighandler and check it after sigreturn [OK] xstate was restored correctly But systems without AVX-512 will look like: ... The kernel does not support feature number: 5 The kernel does not support feature number: 6 The kernel does not support feature number: 7 Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-10-chang.seok.bae@intel.com

selftests/x86/xstate: Refactor context switching test

2025-02-26T12:05:29Z

The existing context switching and ptrace tests in amx.c are not specific to dynamic states, making them reusable for general xstate testing. As a first step, move the context switching test to xstate.c. Refactor the test code to allow specifying which xstate component being tested. To decouple the test from dynamic states, remove the permission request code. In fact, The permission request inside the test wrapper was redundant. Additionally, replace fatal_error() with ksft_exit_fail_msg() for consistency in error handling. Expected output: $ amx_64 ... [RUN] AMX Tile data: check context switches, 10 iterations, 5 threads. [OK] No incorrect case was found. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-5-chang.seok.bae@intel.com

Documentation/srso: Document a method for checking safe RET operates properly

2024-08-27T07:16:35Z

Add a method to quickly verify whether safe RET operates properly on a given system using perf tool. Also, add a selftest which does the same thing. Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240731160531.28640-1-bp@kernel.org

selftests/x86: avoid -no-pie warnings from clang during compilation

2024-07-11T17:23:55Z

When building with clang, via: make LLVM=1 -C tools/testing/selftests ...clang warns that -no-pie is "unused during compilation". This occurs because clang only wants to see -no-pie during linking. Here, we don't have a separate linking stage, so a compiler warning is unavoidable without (wastefully) restructuring the Makefile. Avoid the warning by simply disabling that warning, for clang builds. Acked-by: Muhammad Usama Anjum Signed-off-by: John Hubbard Signed-off-by: Shuah Khan

selftests/x86: build sysret_rip.c with clang

2024-07-11T17:23:55Z

When building with clang, via: make LLVM=1 -C tools/testing/selftests ...the build fails because clang's inline asm doesn't support all of the features that are used in the asm() snippet in sysret_rip.c. Fix this by moving the asm code into the clang_helpers_64.S file, where it can be built with the assembler's full set of features. Acked-by: Muhammad Usama Anjum Signed-off-by: John Hubbard Signed-off-by: Shuah Khan

selftests/x86: build fsgsbase_restore.c with clang

2024-07-11T17:23:55Z

When building with clang, via: make LLVM=1 -C tools/testing/selftests Fix this by moving the inline asm to "pure" assembly, in two new files: clang_helpers_32.S, clang_helpers_64.S. As a bonus, the pure asm avoids the need for ifdefs, and is now very simple and easy on the eyes. Acked-by: Muhammad Usama Anjum Signed-off-by: John Hubbard Signed-off-by: Shuah Khan