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2025-06-25selftests/mm: fix validate_addr() helperDev Jain
validate_addr() checks whether the address returned by mmap() lies in the low or high VA space, according to whether a high addr hint was passed or not. The fix commit mentioned below changed the code in such a way that this function will always return failure when passed high_addr == 1; addr will be >= HIGH_ADDR_MARK always, we will fall down to "if (addr > HIGH_ADDR_MARK)" and return failure. Fix this. Link: https://lkml.kernel.org/r/20250620111150.50344-1-dev.jain@arm.com Fixes: d1d86ce28d0f ("selftests/mm: virtual_address_range: conform to TAP format output") Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Donet Tom <donettom@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25selftests/mm: virtual_address_range: avoid reading from VM_IO mappingsThomas Weißschuh
The virtual_address_range selftest reads from the start of each mapping listed in /proc/self/maps. However not all mappings are valid to be arbitrarily accessed. For example the vvar data used for virtual clocks on x86 [vvar_vclock] can only be accessed if 1) the kernel configuration enables virtual clocks and 2) the hypervisor provided the data for it. Only the VDSO itself has the necessary information to know this. Since commit e93d2521b27f ("x86/vdso: Split virtual clock pages into dedicated mapping") the virtual clock data was split out into its own mapping, leading to EFAULT from read() during the validation. Check for the VM_IO flag as a proxy. It is present for the VVAR mappings and MMIO ranges can be dangerous to access arbitrarily. Link: https://lkml.kernel.org/r/20250114-virtual_address_range-tests-v4-4-6fd7269934a5@linutronix.de Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202412271148.2656e485-lkp@intel.com Fixes: e93d2521b27f ("x86/vdso: Split virtual clock pages into dedicated mapping") Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Suggested-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/lkml/e97c2a5d-c815-4936-a767-ac42a3220a90@redhat.com/ Acked-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25selftests/mm: virtual_address_range: unmap chunks after validationThomas Weißschuh
For each accessed chunk a PTE is created. More than 1GiB of PTEs is used in this way. Remove each PTE after validating a chunk to reduce peak memory usage. It is important to only unmap memory that previously mmap()ed, as unmapping other mappings like the stack, heap or executable mappings will crash the process. The mappings read from /proc/self/maps and the return values from mmap() don't allow a simple correlation due to merging and no guaranteed order. To correlate the pointers and mappings use prctl(PR_SET_VMA_ANON_NAME). While it introduces a test dependency, other alternatives would introduce runtime or development overhead. Link: https://lkml.kernel.org/r/20250114-virtual_address_range-tests-v4-2-6fd7269934a5@linutronix.de Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: kernel test robot <oliver.sang@intel.com> Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25selftests/mm: virtual_address_range: mmap() without PROT_WRITEThomas Weißschuh
Patch series "selftests/mm: virtual_address_range: Reduce memory", v4. The selftest started failing since commit e93d2521b27f ("x86/vdso: Split virtual clock pages into dedicated mapping") was merged. While debugging I stumbled upon some memory usage optimizations. With these test now runs on a VM with only 60MiB of memory. This patch (of 4): When mapping a larger chunk than physical memory is available with PROT_WRITE and overcommit is disabled, the mapping will fail. This will prevent the test from running on systems with less then ~1GiB of memory and triggering an inscrutinable test failure. As the mappings are never written to anyways, the flag can be removed. Link: https://lkml.kernel.org/r/20250114-virtual_address_range-tests-v4-0-6fd7269934a5@linutronix.de Link: https://lkml.kernel.org/r/20250114-virtual_address_range-tests-v4-1-6fd7269934a5@linutronix.de Fixes: 4e5ce33ceb32 ("selftests/vm: add a test for virtual address range mapping") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Dev Jain <dev.jain@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org> Cc: kernel test robot <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-11selftest/mm: fix typo in virtual_address_rangeChunyan Zhang
The function name should be *hint* address, so correct it. Link: https://lkml.kernel.org/r/20241008094141.549248-4-zhangchunyan@iscas.ac.cn Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()Dev Jain
Currently, VA exhaustion is being checked by passing a hint to mmap() and expecting it to fail. While populating the lower VA space, mmap() fails because we have exhausted the space. Then, in validate_lower_address_hint(), because mmap() fails, we confirm that we have indeed exhausted the space. There is a circular logic involved here. Assume that there is a bug in mmap(), also assume that it exists independent of whether you pass a hint address or not; that for some reason it is not able to find a 1GB chunk. My idea is to assert the exhaustion against some other method. This patch makes a stricter test by successful write() calls from /proc/self/maps to a dump file, confirming that a free chunk is indeed not available. [dev.jain@arm.com: replace SZ_1GB with MAP_CHUNK_SIZE, tidy-up] Link: https://lkml.kernel.org/r/20240325042653.867055-1-dev.jain@arm.com Link: https://lkml.kernel.org/r/20240321103522.516097-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25selftests/mm: virtual_address_range: Switch to ksft_exit_fail_msgDev Jain
mmap() must not succeed in validate_lower_address_hint(), for if it does, it is a bug in mmap() itself. Reflect this behaviour with ksft_exit_fail_msg(). While at it, do some formatting changes. Link: https://lkml.kernel.org/r/20240314122250.68534-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22selftests/mm: virtual_address_range: conform to TAP format outputMuhammad Usama Anjum
Conform the layout, informational and status messages to TAP. No functional change is intended other than the layout of output messages. Link: https://lkml.kernel.org/r/20240202113119.2047740-13-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05selftests/mm: change NR_CHUNKS_HIGH for aarch64Chaitanya S Prakash
Although there is a provision for 52 bit VA on arm64 platform, it remains unutilised and higher addresses are not allocated. In order to accommodate 4PB [2^52] virtual address space where supported, NR_CHUNKS_HIGH is changed accordingly. Array holding addresses is changed from static allocation to dynamic allocation to accommodate its voluminous nature which otherwise might overflow the stack. Link: https://lkml.kernel.org/r/20230323060121.1175830-3-chaitanyas.prakash@arm.com Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05selftests/mm: change MAP_CHUNK_SIZEChaitanya S Prakash
Patch series "selftests: Fix virtual address range for arm64", v2. When the virtual address range selftest is run on arm64 and x86 platforms, it is observed that both the low and high VA range iterations are skipped when the MAP_CHUNK_SIZE is set to 16GB. The MAP_CHUNK_SIZE is changed to 1GB to resolve this issue, following which support for arm64 platform is added by changing the NR_CHUNKS_HIGH for aarch64 to accommodate up to 4PB of virtual address space allocation requests. Dynamic memory allocation of array holding addresses is introduced to prevent overflow of the stack. Finally, the overcommit_policy is set as OVERCOMMIT_ALWAYS to prevent the kernel from denying a memory allocation request based on a platform's physical memory availability. This patch (of 3): mmap() fails to allocate 16GB virtual space chunk, skipping both low and high VA range iterations. Hence, reduce MAP_CHUNK_SIZE to 1GB and update relevant macros as required. Link: https://lkml.kernel.org/r/20230323060121.1175830-1-chaitanyas.prakash@arm.com Link: https://lkml.kernel.org/r/20230323060121.1175830-2-chaitanyas.prakash@arm.com Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18selftests/vm: rename selftests/vm to selftests/mmSeongJae Park
Rename selftets/vm to selftests/mm for being more consistent with the code, documentation, and tools directories, and won't be confused with virtual machines. [sj@kernel.org: convert missing vm->mm changes] Link: https://lkml.kernel.org/r/20230107230643.252273-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230103180754.129637-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>