linux-dev/tools/testing/selftests/x86/Makefile, branch master

selftests: x86: add 32bit build warnings for SUSE

2022-04-04T19:29:43Z

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

2022-03-22T22:57:04Z

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

2021-10-28T12:35:27Z

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

2021-06-09T12:46:30Z

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

2021-05-19T10:45:07Z

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

2020-10-27T23:58:33Z

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

Merge tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-05T04:16:22Z

Pull x86 fsgsbase from Thomas Gleixner: "Support for FSGSBASE. Almost 5 years after the first RFC to support it, this has been brought into a shape which is maintainable and actually works. This final version was done by Sasha Levin who took it up after Intel dropped the ball. Sasha discovered that the SGX (sic!) offerings out there ship rogue kernel modules enabling FSGSBASE behind the kernels back which opens an instantanious unpriviledged root hole. The FSGSBASE instructions provide a considerable speedup of the context switch path and enable user space to write GSBASE without kernel interaction. This enablement requires careful handling of the exception entries which go through the paranoid entry path as they can no longer rely on the assumption that user GSBASE is positive (as enforced via prctl() on non FSGSBASE enabled systemn). All other entries (syscalls, interrupts and exceptions) can still just utilize SWAPGS unconditionally when the entry comes from user space. Converting these entries to use FSGSBASE has no benefit as SWAPGS is only marginally slower than WRGSBASE and locating and retrieving the kernel GSBASE value is not a free operation either. The real benefit of RD/WRGSBASE is the avoidance of the MSR reads and writes. The changes come with appropriate selftests and have held up in field testing against the (sanitized) Graphene-SGX driver" * tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86/fsgsbase: Fix Xen PV support x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase selftests/x86/fsgsbase: Add a missing memory constraint selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test selftests/x86: Add a syscall_arg_fault_64 test for negative GSBASE selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write Documentation/x86/64: Add documentation for GS/FS addressing mode x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2 x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bit x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit x86/entry/64: Introduce the FIND_PERCPU_BASE macro x86/entry/64: Switch CR3 before SWAPGS in paranoid entry x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation x86/process/64: Use FSGSBASE instructions on thread copy and ptrace x86/process/64: Use FSBSBASE in switch_to() if available x86/process/64: Make save_fsgs_for_kvm() ready for FSGSBASE x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE ...

x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase

2020-07-01T13:27:20Z

Debuggers expect that doing PTRACE_GETREGS, then poking at a tracee and maybe letting it run for a while, then doing PTRACE_SETREGS will put the tracee back where it was. In the specific case of a 32-bit tracer and tracee, the PTRACE_GETREGS/SETREGS data structure doesn't have fs_base or gs_base fields, so FSBASE and GSBASE fields are never stored anywhere. Everything used to still work because nonzero FS or GS would result full reloads of the segment registers when the tracee resumes, and the bases associated with FS==0 or GS==0 are irrelevant to 32-bit code. Adding FSGSBASE support broke this: when FSGSBASE is enabled, FSBASE and GSBASE are now restored independently of FS and GS for all tasks when context-switched in. This means that, if a 32-bit tracer restores a previous state using PTRACE_SETREGS but the tracee's pre-restore and post-restore bases don't match, then the tracee is resumed with the wrong base. Fix it by explicitly loading the base when a 32-bit tracer pokes FS or GS on a 64-bit kernel. Also add a test case. Fixes: 673903495c85 ("x86/process/64: Use FSBSBASE in switch_to() if available") Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/229cc6a50ecbb701abd50fe4ddaf0eda888898cd.1593192140.git.luto@kernel.org

selftests/x86: Consolidate and fix get/set_eflags() helpers

2020-07-01T08:00:27Z

There are several copies of get_eflags() and set_eflags() and they all are buggy. Consolidate them and fix them. The fixes are: Add memory clobbers. These are probably unnecessary but they make sure that the compiler doesn't move something past one of these calls when it shouldn't. Respect the redzone on x86_64. There has no failure been observed related to this, but it's definitely a bug. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/982ce58ae8dea2f1e57093ee894760e35267e751.1593191971.git.luto@kernel.org

selftests/x86/pkeys: move selftests to arch-neutral directory

2020-06-05T02:06:26Z

Patch series "selftests, powerpc, x86: Memory Protection Keys", v19. Memory protection keys enables an application to protect its address space from inadvertent access by its own code. This feature is now enabled on powerpc and has been available since 4.16-rc1. The patches move the selftests to arch neutral directory and enhance their test coverage. Tested on powerpc64 and x86_64 (Skylake-SP). This patch (of 24): Move selftest files from tools/testing/selftests/x86/ to tools/testing/selftests/vm/. Signed-off-by: Ram Pai Signed-off-by: Thiago Jung Bauermann Signed-off-by: Sandipan Das Signed-off-by: Andrew Morton Acked-by: Ingo Molnar Acked-by: Dave Hansen Cc: Dave Hansen Cc: Florian Weimer Cc: "Desnes A. Nunes do Rosario" Cc: Michal Hocko Cc: "Aneesh Kumar K.V" Cc: Michal Suchanek Cc: Michael Ellerman Cc: Shuah Khan Link: http://lkml.kernel.org/r/14d25194c3e2e652e0047feec4487e269e76e8c9.1585646528.git.sandipan@linux.ibm.com Signed-off-by: Linus Torvalds