kernel/tools/testing/selftests/x86/fsgsbase.c, branch linux-rolling-stable

selftests/x86: Consolidate redundant signal helper functions

2025-02-26T12:05:28Z

The x86 selftests frequently register and clean up signal handlers, but the sethandler() and clearhandler() functions have been redundantly copied across multiple .c files. Move these functions to helpers.h to enable reuse across tests, eliminating around 250 lines of duplicate code. Converge the error handling by using ksft_exit_fail_msg(), which is functionally equivalent with err() within the selftest framework. This change is a prerequisite for the upcoming xstate selftest, which requires signal handling for registering and cleaning up handlers. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-2-chang.seok.bae@intel.com

selftests/x86: remove (or use) unused variables and functions

2024-07-11T17:23:55Z

When building with clang, via: make LLVM=1 -C tools/testing/selftests ...quite a few functions are variables are generating "unused" warnings. Fix the warnings by deleting the unused items. One item, the "nerrs" variable in vsdo_restorer.c's main(), is unused but probably wants to be returned from main(), as a non-zero result. That result is also unused right now, so another option would be to delete it entirely, but this way, main() also gets fixed. It was missing a return value. Acked-by: Muhammad Usama Anjum Signed-off-by: John Hubbard Signed-off-by: Shuah Khan

selftests/x86/fsgsbase: Fix GS == 1, 2, and 3 tests

2020-11-24T12:46:16Z

Setting GS to 1, 2, or 3 causes a nonsensical part of the IRET microcode to change GS back to zero on a return from kernel mode to user mode. The result is that these tests fail randomly depending on when interrupts happen. Detect when this happens and let the test pass. Signed-off-by: Andy Lutomirski Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/7567fd44a1d60a9424f25b19a998f12149993b0d.1604346596.git.luto@kernel.org

selftests/x86/fsgsbase: Test PTRACE_PEEKUSER for GSBASE with invalid LDT GS

2020-08-26T18:54:18Z

This tests commit: 8ab49526b53d ("x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task") Unpatched kernels will OOPS. Signed-off-by: Andy Lutomirski Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/c618ae86d1f757e01b1a8e79869f553cb88acf9a.1598461151.git.luto@kernel.org

selftests/x86/fsgsbase: Reap a forgotten child

2020-08-26T18:54:17Z

The ptrace() test forgot to reap its child. Reap it. Signed-off-by: Andy Lutomirski Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/e7700a503f30e79ab35a63103938a19893dbeff2.1598461151.git.luto@kernel.org

selftests/x86/fsgsbase: Add a missing memory constraint

2020-07-01T13:27:20Z

The manual call to set_thread_area() via int $0x80 was missing any indication that the descriptor was a pointer, causing gcc to occasionally generate wrong code. Add the missing constraint. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/432968af67259ca92d68b774a731aff468eae610.1593192140.git.luto@kernel.org

selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test

2020-07-01T13:27:20Z

A comment was unclear. Fix it. Fixes: 5e7ec8578fa3 ("selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE") Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/901034a91a40169ec84f1f699ea86704dff762e4.1593192140.git.luto@kernel.org

selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE

2020-06-18T13:47:07Z

This validates that GS selector and base are independently preserved in ptrace commands. Suggested-by: Andy Lutomirski Signed-off-by: Chang S. Bae Signed-off-by: Sasha Levin Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Link: https://lkml.kernel.org/r/20200528201402.1708239-17-sashal@kernel.org

selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write

2020-06-18T13:47:06Z

The test validates that the selector is not changed when a ptracer writes the ptracee's GS base. Originally-by: Andy Lutomirski Signed-off-by: Chang S. Bae Signed-off-by: Sasha Levin Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Link: https://lkml.kernel.org/r/20200528201402.1708239-16-sashal@kernel.org

Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test

2019-07-15T15:12:31Z

This reverts commit 48f5e52e916b55fb73754833efbacc7f8081a159. The ptrace ABI change was a prerequisite to the proposed design for FSGSBASE. Since FSGSBASE support has been reverted, and since I'm not convinced that the ABI was ever adequately tested, revert the ABI change as well. This also modifies the test case so that it tests the preexisting behavior. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/fca39c478ea7fb15bc76fe8a36bd180810a067f6.1563200250.git.luto@kernel.org