kernel/linux.git/drivers/iommu/intel/debugfs.c, branch v5.15.208

iommu/vt-d: Replace snprintf with scnprintf in dmar_latency_snapshot()

2025-12-06T21:09:23+00:00

[ Upstream commit 75c02a037609f34db17e91be195cedb33b61bae0 ] snprintf() returns the number of bytes that would have been written, not the number actually written. Using this for offset tracking can cause buffer overruns if truncation occurs. Replace snprintf() with scnprintf() to ensure the offset stays within bounds. Since scnprintf() never returns a negative value, and zero is not possible in this context because 'bytes' starts at 0 and 'size - bytes' is DEBUG_BUFFER_SIZE in the first call, which is large enough to hold the string literals used, the return value is always positive. An integer overflow is also completely out of reach here due to the small and fixed buffer size. The error check in latency_show_one() is therefore unnecessary. Remove it and make dmar_latency_snapshot() return void. Signed-off-by: Seyediman Seyedarab Link: https://lore.kernel.org/r/20250731225048.131364-1-ImanDevel@gmail.com Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/vt-d: Expose latency monitor data through debugfs

2021-06-10T07:06:13+00:00

A debugfs interface /sys/kernel/debug/iommu/intel/dmar_perf_latency is created to control and show counts of execution time ranges for various types per DMAR. The interface may help debug any potential performance issue. By default, the interface is disabled. Possible write value of /sys/kernel/debug/iommu/intel/dmar_perf_latency 0 - disable sampling all latency data 1 - enable sampling IOTLB invalidation latency data 2 - enable sampling devTLB invalidation latency data 3 - enable sampling intr entry cache invalidation latency data 4 - enable sampling prq handling latency data Read /sys/kernel/debug/iommu/intel/dmar_perf_latency gives a snapshot of sampling result of all enabled monitors. Signed-off-by: Fenghua Yu Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20210610020115.1637656-15-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Rename intel-pasid.h to pasid.h

2020-07-24T08:51:21+00:00

As Intel VT-d files have been moved to its own subdirectory, the prefix makes no sense. No functional changes. Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20200724014925.15523-13-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Move Intel IOMMU driver into subdirectory

2020-06-10T15:46:43+00:00

Move all files related to the Intel IOMMU driver into its own subdirectory. Signed-off-by: Joerg Roedel Reviewed-by: Jerry Snitselaar Reviewed-by: Lu Baolu Link: https://lore.kernel.org/r/20200609130303.26974-3-joro@8bytes.org