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linux/tools/testing/selftests/arm64/fp/fp-ptrace.h

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kselftest/arm64: Test that ptrace takes effect in the target process While we have test coverage for the ptrace interface in our selftests the current programs have a number of gaps. The testing is done per regset so does not cover interactions and at no point do any of the tests actually run the traced processes meaning that there is no validation that anything we read or write corresponds to register values the process actually sees. Let's add a new program which attempts to cover these gaps. Each test we do performs a single ptrace write. For each test we generate some random initial register data in memory and then fork() and trace a child. The child will load the generated data into the registers then trigger a breakpoint. The parent waits for the breakpoint then reads the entire child register state via ptrace, verifying that the values expected were actually loaded by the child. It then does the write being tested and resumes the child. Once resumed the child saves the register state it sees to memory and executes another breakpoint. The parent uses process_vm_readv() to get these values from the child and verifies that the values were as expected before cleaning up the child. We generate configurations with combinations of vector lengths and SVCR values and then try every ptrace write which will implement the transition we generated. In order to control execution time (especially in emulation) we only cover the minimum and maximum VL for each of SVE and SME, this will ensure we generate both increasing and decreasing changes in vector length. In order to provide a baseline test we also check the case where we resume the child without doing a ptrace write. In order to simplify the generation of the test count for kselftest we will report but skip a substantial number of tests that can't actually be expressed via a single ptrace write, several times more than we actually run. This is noisy and will add some overhead but is very much simpler so is probably worth the tradeoff. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240122-arm64-test-ptrace-regs-v1-1-0897f822d73e@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-01-22 21:05:03 +00:00
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (C) 2021-3 ARM Limited.
#ifndef FP_PTRACE_H
#define FP_PTRACE_H
#define SVCR_SM_SHIFT 0
#define SVCR_ZA_SHIFT 1
#define SVCR_SM (1 << SVCR_SM_SHIFT)
#define SVCR_ZA (1 << SVCR_ZA_SHIFT)
kselftets/arm64: Use flag bits for features in fp-ptrace assembler code The assembler portions of fp-ptrace are passed feature flags by the C code indicating which architectural features are supported. Currently these use an entire register for each flag which is wasteful and gets cumbersome as new flags are added. Switch to using flag bits in a single register to make things easier to maintain. No functional change. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241112-arm64-fp-ptrace-fpmr-v2-1-250b57c61254@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 13:08:14 +00:00
#define HAVE_SVE_SHIFT 0
#define HAVE_SME_SHIFT 1
#define HAVE_SME2_SHIFT 2
#define HAVE_FA64_SHIFT 3
kselftest/arm64: Add FPMR coverage to fp-ptrace Add coverage for FPMR to fp-ptrace. FPMR can be available independently of SVE and SME, if SME is supported then FPMR is cleared by entering and exiting streaming mode. As with other registers we generate random values to load into the register, we restrict these to bitfields which are always defined. We also leave bitfields where the valid values are affected by the set of supported FP8 formats zero to reduce complexity, it is unlikely that specific bitfields will be affected by ptrace issues. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241112-arm64-fp-ptrace-fpmr-v2-3-250b57c61254@kernel.org [catalin.marinas@arm.com: use REG_FPMR instead of FPMR] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 13:08:16 +00:00
#define HAVE_FPMR_SHIFT 4
kselftets/arm64: Use flag bits for features in fp-ptrace assembler code The assembler portions of fp-ptrace are passed feature flags by the C code indicating which architectural features are supported. Currently these use an entire register for each flag which is wasteful and gets cumbersome as new flags are added. Switch to using flag bits in a single register to make things easier to maintain. No functional change. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241112-arm64-fp-ptrace-fpmr-v2-1-250b57c61254@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 13:08:14 +00:00
#define HAVE_SVE (1 << HAVE_SVE_SHIFT)
#define HAVE_SME (1 << HAVE_SME_SHIFT)
#define HAVE_SME2 (1 << HAVE_SME2_SHIFT)
#define HAVE_FA64 (1 << HAVE_FA64_SHIFT)
kselftest/arm64: Add FPMR coverage to fp-ptrace Add coverage for FPMR to fp-ptrace. FPMR can be available independently of SVE and SME, if SME is supported then FPMR is cleared by entering and exiting streaming mode. As with other registers we generate random values to load into the register, we restrict these to bitfields which are always defined. We also leave bitfields where the valid values are affected by the set of supported FP8 formats zero to reduce complexity, it is unlikely that specific bitfields will be affected by ptrace issues. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241112-arm64-fp-ptrace-fpmr-v2-3-250b57c61254@kernel.org [catalin.marinas@arm.com: use REG_FPMR instead of FPMR] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 13:08:16 +00:00
#define HAVE_FPMR (1 << HAVE_FPMR_SHIFT)
kselftets/arm64: Use flag bits for features in fp-ptrace assembler code The assembler portions of fp-ptrace are passed feature flags by the C code indicating which architectural features are supported. Currently these use an entire register for each flag which is wasteful and gets cumbersome as new flags are added. Switch to using flag bits in a single register to make things easier to maintain. No functional change. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241112-arm64-fp-ptrace-fpmr-v2-1-250b57c61254@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 13:08:14 +00:00
kselftest/arm64: Test that ptrace takes effect in the target process While we have test coverage for the ptrace interface in our selftests the current programs have a number of gaps. The testing is done per regset so does not cover interactions and at no point do any of the tests actually run the traced processes meaning that there is no validation that anything we read or write corresponds to register values the process actually sees. Let's add a new program which attempts to cover these gaps. Each test we do performs a single ptrace write. For each test we generate some random initial register data in memory and then fork() and trace a child. The child will load the generated data into the registers then trigger a breakpoint. The parent waits for the breakpoint then reads the entire child register state via ptrace, verifying that the values expected were actually loaded by the child. It then does the write being tested and resumes the child. Once resumed the child saves the register state it sees to memory and executes another breakpoint. The parent uses process_vm_readv() to get these values from the child and verifies that the values were as expected before cleaning up the child. We generate configurations with combinations of vector lengths and SVCR values and then try every ptrace write which will implement the transition we generated. In order to control execution time (especially in emulation) we only cover the minimum and maximum VL for each of SVE and SME, this will ensure we generate both increasing and decreasing changes in vector length. In order to provide a baseline test we also check the case where we resume the child without doing a ptrace write. In order to simplify the generation of the test count for kselftest we will report but skip a substantial number of tests that can't actually be expressed via a single ptrace write, several times more than we actually run. This is noisy and will add some overhead but is very much simpler so is probably worth the tradeoff. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240122-arm64-test-ptrace-regs-v1-1-0897f822d73e@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-01-22 21:05:03 +00:00
#endif
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