kernel/linux.git/arch/loongarch/lib, branch v6.12.91

LoongArch: csum: Fix OoB access in IP checksum code for negative lengths

2025-02-21T13:01:17+00:00

[ Upstream commit 6287f1a8c16138c2ec750953e35039634018c84a ] Commit 69e3a6aa6be2 ("LoongArch: Add checksum optimization for 64-bit system") would cause an undefined shift and an out-of-bounds read. Commit 8bd795fedb84 ("arm64: csum: Fix OoB access in IP checksum code for negative lengths") fixes the same issue on ARM64. Fixes: 69e3a6aa6be2 ("LoongArch: Add checksum optimization for 64-bit system") Co-developed-by: Wentao Guan Signed-off-by: Wentao Guan Signed-off-by: Yuli Wang Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

LoongArch: Select ARCH_SUPPORTS_INT128 if CC_HAS_INT128

2024-05-14T04:24:18+00:00

This allows compiling a full 128-bit product of two 64-bit integers as a mul/mulh pair, instead of a nasty long sequence of 20+ instructions. However, after selecting ARCH_SUPPORTS_INT128, when optimizing for size the compiler generates calls to __ashlti3, __ashrti3, and __lshrti3 for shifting __int128 values, causing a link failure: loongarch64-unknown-linux-gnu-ld: kernel/sched/fair.o: in function `mul_u64_u32_shr': /include/linux/math64.h:161:(.text+0x5e4): undefined reference to `__lshrti3' So provide the implementation of these functions if ARCH_SUPPORTS_INT128. Closes: https://lore.kernel.org/loongarch/CAAhV-H5EZ=7OF7CSiYyZ8_+wWuenpo=K2WT8-6mAT4CvzUC_4g@mail.gmail.com/ Signed-off-by: Xi Ruoyao Signed-off-by: Huacai Chen

LoongArch: Add ORC stack unwinder support

2024-03-11T14:23:47+00:00

The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster. The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections. The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time. Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings. Co-developed-by: Jinyang He Signed-off-by: Jinyang He Co-developed-by: Youling Tang Signed-off-by: Youling Tang Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Add KASAN (Kernel Address Sanitizer) support

2023-09-06T14:54:16+00:00

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 Signed-off-by: Huacai Chen

LoongArch: Add SIMD-optimized XOR routines

2023-09-06T14:53:55+00:00

Add LSX and LASX implementations of xor operations, operating on 64 bytes (one L1 cache line) at a time, for a balance between memory utilization and instruction mix. Huacai confirmed that all future LoongArch implementations by Loongson (that we care) will likely also feature 64-byte cache lines, and experiments show no throughput improvement with further unrolling. Performance numbers measured during system boot on a 3A5000 @ 2.5GHz: > 8regs : 12702 MB/sec > 8regs_prefetch : 10920 MB/sec > 32regs : 12686 MB/sec > 32regs_prefetch : 10918 MB/sec > lsx : 17589 MB/sec > lasx : 26116 MB/sec Acked-by: Song Liu Signed-off-by: WANG Xuerui Signed-off-by: Huacai Chen

LoongArch: Adjust {copy, clear}_user exception handler behavior

2023-09-06T14:53:10+00:00

The {copy, clear}_user function should returns number of bytes that could not be {copied, cleared}. So, try to {copy, clear} byte by byte when ld.{d,w,h} and st.{d,w,h} trapped into an exception. Reviewed-by: WANG Rui Signed-off-by: Weihao Li Signed-off-by: Huacai Chen

LoongArch: Replace #include with #include

2023-08-25T15:40:26+00:00

Commit ddb5cdbafaaad ("kbuild: generate KSYMTAB entries by modpost") deprecated , which is now a wrapper of . Replace #include with #include . After all the lines are converted, and will be removed. Signed-off-by: Masahiro Yamada Signed-off-by: Huacai Chen

LoongArch: Remove unneeded #include

2023-08-25T15:40:26+00:00

There is no EXPORT_SYMBOL() line there, hence #include is unneeded. Signed-off-by: Masahiro Yamada Signed-off-by: Huacai Chen

LoongArch: Fix return value underflow in exception path

2023-07-28T02:30:42+00:00

This patch fixes an underflow issue in the return value within the exception path, specifically at .Llt8 when the remaining length is less than 8 bytes. Cc: stable@vger.kernel.org Fixes: 8941e93ca590 ("LoongArch: Optimize memory ops (memset/memcpy/memmove)") Reported-by: Weihao Li Signed-off-by: WANG Rui Signed-off-by: Huacai Chen

LoongArch: Make the CPUCFG&CSR ops simple aliases of compiler built-ins

2023-06-29T12:58:43+00:00

In addition to less visual clutter, this also makes Clang happy regarding the const-ness of arguments. In the original approach, all Clang gets to see is the incoming arguments whose const-ness cannot be proven without first being inlined; so Clang errors out here while GCC is fine. While at it, tweak several printk format strings because the return type of csr_read64 becomes effectively unsigned long, instead of unsigned long long. Signed-off-by: WANG Xuerui Signed-off-by: Huacai Chen