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2023-09-06LoongArch: Add KASAN (Kernel Address Sanitizer) supportQing Zhang1-1/+7
1/8 of kernel addresses reserved for shadow memory. But for LoongArch, There are a lot of holes between different segments and valid address space (256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core, saying (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET So LoongArch has a arch-specific mapping formula, different segments are mapped individually, and only limited space lengths of these specific segments are mapped to shadow. At early boot stage the whole shadow region populated with just one physical page (kasan_early_shadow_page). Later, this page is reused as readonly zero shadow for some memory that kasan currently don't track. After mapping the physical memory, pages for shadow memory are allocated and mapped. Functions like memset()/memcpy()/memmove() do a lot of memory accesses. If bad pointer passed to one of these function it is important to be caught. Compiler's instrumentation cannot do this since these functions are written in assembly. KASan replaces memory functions with manually instrumented variants. Original functions declared as weak symbols so strong definitions in mm/kasan/kasan.c could replace them. Original functions have aliases with '__' prefix in names, so we could call non-instrumented variant if needed. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-08-25LoongArch: Replace #include <asm/export.h> with #include <linux/export.h>Masahiro Yamada1-1/+1
Commit ddb5cdbafaaad ("kbuild: generate KSYMTAB entries by modpost") deprecated <asm/export.h>, which is now a wrapper of <linux/export.h>. Replace #include <asm/export.h> with #include <linux/export.h>. After all the <asm/export.h> lines are converted, <asm/export.h> and <asm-generic/export.h> will be removed. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-05-01LoongArch: Optimize memory ops (memset/memcpy/memmove)WANG Rui1-26/+121
To optimize memset()/memcpy()/memmove() and so on, we use a jump table to dispatch cases for short data lengths; and for long data lengths, we split the destination into head part (first 8 bytes), tail part (last 8 bytes) and middle part. The head part and tail part may be at unaligned addresses, while the middle part is always aligned (the middle part is allowed to overlap the head/tail part). In this way, the first and last 8 bytes may be unaligned accesses, but we can make sure the data in the middle is processed at an aligned destination address. We have tested micro-bench[1] on a Loongson-3C5000 16-core machine (2.2GHz): 1. memset | length | src offset | dst offset | speed before | speed after | % | |--------|------------|------------|--------------|-------------|---------| | 8 | 0 | 0 | 696.191 | 1518.785 | 118.16% | | 8 | 0 | 1 | 696.325 | 1518.937 | 118.14% | | 50 | 0 | 0 | 969.976 | 8053.902 | 730.32% | | 50 | 0 | 1 | 970.034 | 8058.475 | 730.74% | | 300 | 0 | 0 | 5876.612 | 16544.703 | 181.53% | | 300 | 0 | 1 | 5030.849 | 16549.011 | 228.95% | | 1200 | 0 | 0 | 11797.077 | 16752.137 | 42.00% | | 1200 | 0 | 1 | 5687.141 | 16645.233 | 192.68% | | 4000 | 0 | 0 | 15723.27 | 16761.557 | 6.60% | | 4000 | 0 | 1 | 5906.114 | 16732.316 | 183.30% | | 8000 | 0 | 0 | 16751.403 | 16770.002 | 0.11% | | 8000 | 0 | 1 | 5995.449 | 16754.07 | 179.45% | 2. memcpy | length | src offset | dst offset | speed before | speed after | % | |--------|------------|------------|--------------|-------------|---------| | 8 | 0 | 0 | 696.2 | 1670.605 | 139.96% | | 8 | 0 | 1 | 696.325 | 1671.138 | 139.99% | | 50 | 0 | 0 | 969.974 | 8724.999 | 799.51% | | 50 | 0 | 1 | 970.032 | 8730.138 | 799.98% | | 300 | 0 | 0 | 5564.662 | 16272.652 | 192.43% | | 300 | 0 | 1 | 4670.436 | 14972.842 | 220.59% | | 1200 | 0 | 0 | 10740.23 | 16751.728 | 55.97% | | 1200 | 0 | 1 | 5027.741 | 14874.564 | 195.85% | | 4000 | 0 | 0 | 15122.367 | 16737.642 | 10.68% | | 4000 | 0 | 1 | 5536.918 | 14890.397 | 168.93% | | 8000 | 0 | 0 | 16505.453 | 16553.543 | 0.29% | | 8000 | 0 | 1 | 5821.619 | 14841.804 | 154.94% | 3. memmove | length | src offset | dst offset | speed before | speed after | % | |--------|------------|------------|--------------|-------------|---------| | 8 | 0 | 0 | 982.693 | 1670.568 | 70.00% | | 8 | 0 | 1 | 983.023 | 1671.174 | 70.00% | | 50 | 0 | 0 | 1230.87 | 8727.625 | 609.06% | | 50 | 0 | 1 | 1232.515 | 8730.138 | 608.32% | | 300 | 0 | 0 | 6490.375 | 16296.993 | 151.09% | | 300 | 0 | 1 | 4282.687 | 14972.842 | 249.61% | | 1200 | 0 | 0 | 11742.755 | 16752.546 | 42.66% | | 1200 | 0 | 1 | 5039.338 | 14872.951 | 195.14% | | 4000 | 0 | 0 | 15467.786 | 16737.09 | 8.21% | | 4000 | 0 | 1 | 5009.905 | 14890.542 | 197.22% | | 8000 | 0 | 0 | 16489.664 | 16553.273 | 0.39% | | 8000 | 0 | 1 | 5823.786 | 14858.646 | 155.14% | * speed: MB/s * length: byte [1] https://github.com/heiher/mem-bench Signed-off-by: WANG Rui <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: Mark some assembler symbols as non-kprobe-ableTiezhu Yang1-0/+3
Some assembler symbols are not kprobe safe, such as handle_syscall (used as syscall exception handler), *memset*/*memcpy*/*memmove* (may cause recursive exceptions), they can not be instrumented, just blacklist them for kprobing. Here is a related problem and discussion: Link: https://lore.kernel.org/lkml/20230114143859.7ccc45c1c5d9ce302113ab0a@kernel.org/ Tested-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: Use alternative to optimize librariesHuacai Chen1-0/+95
Use the alternative to optimize common libraries according whether CPU has UAL (hardware unaligned access support) feature, including memset(), memcopy(), memmove(), copy_user() and clear_user(). We have tested UnixBench on a Loongson-3A5000 quad-core machine (1.6GHz): 1, One copy, before patch: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 9566582.0 819.8 Double-Precision Whetstone 55.0 2805.3 510.1 Execl Throughput 43.0 2120.0 493.0 File Copy 1024 bufsize 2000 maxblocks 3960.0 209833.0 529.9 File Copy 256 bufsize 500 maxblocks 1655.0 89400.0 540.2 File Copy 4096 bufsize 8000 maxblocks 5800.0 320036.0 551.8 Pipe Throughput 12440.0 340624.0 273.8 Pipe-based Context Switching 4000.0 109939.1 274.8 Process Creation 126.0 4728.7 375.3 Shell Scripts (1 concurrent) 42.4 2223.1 524.3 Shell Scripts (8 concurrent) 6.0 883.1 1471.9 System Call Overhead 15000.0 518639.1 345.8 ======== System Benchmarks Index Score 500.2 2, One copy, after patch: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 9567674.7 819.9 Double-Precision Whetstone 55.0 2805.5 510.1 Execl Throughput 43.0 2392.7 556.4 File Copy 1024 bufsize 2000 maxblocks 3960.0 417804.0 1055.1 File Copy 256 bufsize 500 maxblocks 1655.0 112909.5 682.2 File Copy 4096 bufsize 8000 maxblocks 5800.0 1255207.4 2164.2 Pipe Throughput 12440.0 555712.0 446.7 Pipe-based Context Switching 4000.0 99964.5 249.9 Process Creation 126.0 5192.5 412.1 Shell Scripts (1 concurrent) 42.4 2302.4 543.0 Shell Scripts (8 concurrent) 6.0 919.6 1532.6 System Call Overhead 15000.0 511159.3 340.8 ======== System Benchmarks Index Score 640.1 3, Four copies, before patch: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 38268610.5 3279.2 Double-Precision Whetstone 55.0 11222.2 2040.4 Execl Throughput 43.0 7892.0 1835.3 File Copy 1024 bufsize 2000 maxblocks 3960.0 235149.6 593.8 File Copy 256 bufsize 500 maxblocks 1655.0 74959.6 452.9 File Copy 4096 bufsize 8000 maxblocks 5800.0 545048.5 939.7 Pipe Throughput 12440.0 1337359.0 1075.0 Pipe-based Context Switching 4000.0 473663.9 1184.2 Process Creation 126.0 17491.2 1388.2 Shell Scripts (1 concurrent) 42.4 6865.7 1619.3 Shell Scripts (8 concurrent) 6.0 1015.9 1693.1 System Call Overhead 15000.0 1899535.2 1266.4 ======== System Benchmarks Index Score 1278.3 4, Four copies, after patch: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 38272815.5 3279.6 Double-Precision Whetstone 55.0 11222.8 2040.5 Execl Throughput 43.0 8839.2 2055.6 File Copy 1024 bufsize 2000 maxblocks 3960.0 313912.9 792.7 File Copy 256 bufsize 500 maxblocks 1655.0 80976.1 489.3 File Copy 4096 bufsize 8000 maxblocks 5800.0 1176594.3 2028.6 Pipe Throughput 12440.0 2100941.9 1688.9 Pipe-based Context Switching 4000.0 476696.4 1191.7 Process Creation 126.0 18394.7 1459.9 Shell Scripts (1 concurrent) 42.4 7172.2 1691.6 Shell Scripts (8 concurrent) 6.0 1058.3 1763.9 System Call Overhead 15000.0 1874714.7 1249.8 ======== System Benchmarks Index Score 1488.8 Signed-off-by: Jun Yi <yijun@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>