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2025-02-17selftests/mm: Use PKEY_UNRESTRICTED macroYury Khrustalev
Replace literal 0 with macro PKEY_UNRESTRICTED where pkey_*() functions are used in mm selftests for memory protection keys. Signed-off-by: Yury Khrustalev <yury.khrustalev@arm.com> Suggested-by: Joey Gouly <joey.gouly@arm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20250113170619.484698-3-yury.khrustalev@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-01-13selftests/mm: remove X permission from sigaltstack mappingKevin Brodsky
There is no reason why the alternate signal stack should be mapped as RWX. Map it as RW instead. Link: https://lkml.kernel.org/r/20241209095019.1732120-15-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13selftests/mm: skip pkey_sighandler_tests if support is missingKevin Brodsky
The pkey_sighandler_tests are bound to fail if either the kernel or CPU doesn't support pkeys. Skip the tests if pkeys support is missing. Link: https://lkml.kernel.org/r/20241209095019.1732120-14-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13selftests/mm: use sys_pkey helpers consistentlyKevin Brodsky
sys_pkey_alloc, sys_pkey_free and sys_mprotect_pkey are currently used in protections_keys.c, while pkey_sighandler_tests.c calls the libc wrappers directly (e.g. pkey_mprotect()). This is probably ok when using glibc (those symbols appeared a while ago), but Musl does not currently provide them. The logging in the helpers from pkey-helpers.h can also come in handy. Make things more consistent by using the sys_pkey helpers in pkey_sighandler_tests.c too. To that end their implementation is moved to a common .c file (pkey_util.c). This also enables calling is_pkeys_supported() outside of protections_keys.c, since it relies on sys_pkey_{alloc,free}. [kevin.brodsky@arm.com: fix dependency on pkey_util.c] Link: https://lkml.kernel.org/r/20241216092849.2140850-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20241209095019.1732120-12-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13selftests/mm: ensure non-global pkey symbols are marked staticKevin Brodsky
The pkey tests define a whole lot of functions and some global variables. A few are truly global (declared in pkey-helpers.h), but the majority are file-scoped. Make sure those are labelled static. Some of the pkey_{access,write}_{allow,deny} helpers are not called, or only called when building for some architectures. Mark them __maybe_unused to suppress compiler warnings. Link: https://lkml.kernel.org/r/20241209095019.1732120-11-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13selftests/mm: remove empty pkey helper definitionKevin Brodsky
Some of the functions declared in pkey-helpers.h are actually defined in protections_keys.c, meaning they can only be called from protections_keys.c. This is less than ideal, but it is hard to avoid as these helpers are themselves called from inline functions in pkey-<arch>.h. Let's at least add a comment clarifying that. We can also remove the empty definition in pkey_sighandler_tests.c: expected_pkey_fault() is not meant to be called from there. Link: https://lkml.kernel.org/r/20241209095019.1732120-10-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13selftests/mm: fix -Warray-bounds warnings in pkey_sighandler_testsKevin Brodsky
GCC doesn't like dereferencing a pointer set to 0x1 (when building at -O2): pkey_sighandler_tests.c:166:9: warning: array subscript 0 is outside array bounds of 'int[0]' [-Warray-bounds=] 166 | *(int *) (0x1) = 1; | ^~~~~~~~~~~~~~ cc1: note: source object is likely at address zero Using NULL instead seems to make it happy. This should make no difference in practice (SIGSEGV with SEGV_MAPERR will be the outcome regardless), we just need to update the expected si_addr. [kevin.brodsky@arm.com: fix clang dereferencing-null issue] Link: https://lkml.kernel.org/r/20241218153615.2267571-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20241209095019.1732120-5-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Keith Lucas <keith.lucas@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-04selftests/mm: Enable pkey_sighandler_tests on arm64Kevin Brodsky
pkey_sighandler_tests.c makes raw syscalls using its own helper, syscall_raw(). One of those syscalls is clone, which is problematic as every architecture has a different opinion on the order of its arguments. To complete arm64 support, we therefore add an appropriate implementation in syscall_raw(), and introduce a clone_raw() helper that shuffles arguments as needed for each arch. Having done this, we enable building pkey_sighandler_tests for arm64 in the Makefile. Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Link: https://lore.kernel.org/r/20241029144539.111155-6-kevin.brodsky@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-04selftests/mm: Use generic pkey register manipulationKevin Brodsky
pkey_sighandler_tests.c currently hardcodes x86 PKRU encodings. The first step towards running those tests on arm64 is to abstract away the pkey register values. Since those tests want to deny access to all keys except a few, we have each arch define PKEY_REG_ALLOW_NONE, the pkey register value denying access to all keys. We then use the existing set_pkey_bits() helper to grant access to specific keys. Because pkeys may also remove the execute permission on arm64, we need to be a little careful: all code is mapped with pkey 0, and we need it to remain executable. pkey_reg_restrictive_default() is introduced for that purpose: the value it returns prevents RW access to all pkeys, but retains X permission for pkey 0. test_pkru_preserved_after_sigusr1() only checks that the pkey register value remains unchanged after a signal is delivered, so the particular value is irrelevant. We enable pkey 0 and a few more arbitrary keys in the smallest range available on all architectures (8 keys on arm64). Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20241029144539.111155-5-kevin.brodsky@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-08-02selftests/mm: Add new testcases for pkeysKeith Lucas
Add a few new tests to exercise the signal handler flow, especially with PKEY 0 disabled: - Verify that the SIGSEGV handler is invoked when pkey 0 is disabled. - Verify that a thread which disables PKEY 0 segfaults with PKUERR when accessing the stack. - Verify that the SIGSEGV handler that uses an alternate signal stack is correctly invoked when the thread disabled PKEY 0 - Verify that the PKRU value set by the application is correctly restored upon return from signal handling. - Verify that sigreturn() is able to restore the altstack even if the thread had PKEY 0 disabled [ Aruna: Adapted to upstream ] [ tglx: Made it actually compile. Restored protection_keys compile. Added useful info to the changelog instead of bare function names. ] Signed-off-by: Keith Lucas <keith.lucas@oracle.com> Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240802061318.2140081-6-aruna.ramakrishna@oracle.com