kernel/linux.git/arch/loongarch/include/uapi/asm, branch v6.1.174

asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch

2025-12-06T21:12:34+00:00

[ Upstream commit 8386f58f8deda81110283798a387fb53ec21957c ] Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0 in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are usable, it is probably fine to unify the definition of __BITS_PER_LONG as (__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h. In order to keep safe and avoid regression, only unify uapi bitsperlong.h for some archs such as arm64, riscv and loongarch which are using newer toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__. Suggested-by: Xi Ruoyao Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/ Suggested-by: Arnd Bergmann Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/ Signed-off-by: Tiezhu Yang Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin

LoongArch: Define __ARCH_WANT_NEW_STAT in unistd.h

2024-08-19T04:00:03+00:00

commit 7697a0fe0154468f5df35c23ebd7aa48994c2cdc upstream. Chromium sandbox apparently wants to deny statx [1] so it could properly inspect arguments after the sandboxed process later falls back to fstat. Because there's currently not a "fd-only" version of statx, so that the sandbox has no way to ensure the path argument is empty without being able to peek into the sandboxed process's memory. For architectures able to do newfstatat though, glibc falls back to newfstatat after getting -ENOSYS for statx, then the respective SIGSYS handler [2] takes care of inspecting the path argument, transforming allowed newfstatat's into fstat instead which is allowed and has the same type of return value. But, as LoongArch is the first architecture to not have fstat nor newfstatat, the LoongArch glibc does not attempt falling back at all when it gets -ENOSYS for statx -- and you see the problem there! Actually, back when the LoongArch port was under review, people were aware of the same problem with sandboxing clone3 [3], so clone was eventually kept. Unfortunately it seemed at that time no one had noticed statx, so besides restoring fstat/newfstatat to LoongArch uapi (and postponing the problem further), it seems inevitable that we would need to tackle seccomp deep argument inspection. However, this is obviously a decision that shouldn't be taken lightly, so we just restore fstat/newfstatat by defining __ARCH_WANT_NEW_STAT in unistd.h. This is the simplest solution for now, and so we hope the community will tackle the long-standing problem of seccomp deep argument inspection in the future [4][5]. Also add "newstat" to syscall_abis_64 in Makefile.syscalls due to upstream asm-generic changes. More infomation please reading this thread [6]. [1] https://chromium-review.googlesource.com/c/chromium/src/+/2823150 [2] https://chromium.googlesource.com/chromium/src/sandbox/+/c085b51940bd/linux/seccomp-bpf-helpers/sigsys_handlers.cc#355 [3] https://lore.kernel.org/linux-arch/20220511211231.GG7074@brightrain.aerifal.cx/ [4] https://lwn.net/Articles/799557/ [5] https://lpc.events/event/4/contributions/560/attachments/397/640/deep-arg-inspection.pdf [6] https://lore.kernel.org/loongarch/20240226-granit-seilschaft-eccc2433014d@brauner/T/#t Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Add BPF JIT support

2022-10-12T08:36:20+00:00

BPF programs are normally handled by a BPF interpreter, add BPF JIT support for LoongArch to allow the kernel to generate native code when a program is loaded into the kernel. This will significantly speed-up processing of BPF programs. Co-developed-by: Youling Tang Signed-off-by: Youling Tang Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Add perf events support

2022-10-12T08:36:14+00:00

The perf events infrastructure of LoongArch is very similar to old MIPS- based Loongson, so most of the codes are derived from MIPS. Signed-off-by: Huacai Chen

LoongArch: Add ELF and module support

2022-06-03T12:09:28+00:00

Add ELF-related definition and module relocation code for basic LoongArch support. Cc: Jessica Yu Reviewed-by: WANG Xuerui Reviewed-by: Luis Chamberlain Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen

LoongArch: Add signal handling support

2022-06-03T12:09:28+00:00

Add ucontext/sigcontext definition and signal handling support for LoongArch. Cc: Eric Biederman Cc: Al Viro Reviewed-by: WANG Xuerui Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen

LoongArch: Add system call support

2022-06-03T12:09:28+00:00

Add system call support and related uaccess.h for LoongArch. Q: Why keep _ARCH_WANT_SYS_CLONE definition while there is clone3: A: The latest glibc release has some basic support for clone3 but it is not complete. E.g., pthread_create() and spawni() have converted to use clone3 but fork() will still use clone. Moreover, some seccomp related applications can still not work perfectly with clone3. E.g., Chromium sandbox cannot work at all and there is no solution for it, which is more terrible than the fork() story [1]. [1] https://chromium-review.googlesource.com/c/chromium/src/+/2936184 Reviewed-by: WANG Xuerui Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen

LoongArch: Add process management

2022-06-03T12:09:28+00:00

Add process management support for LoongArch, including: thread info definition, context switch and process tracing. Reviewed-by: WANG Xuerui Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen

LoongArch: Add exception/interrupt handling

2022-06-03T12:09:28+00:00

Add the exception and interrupt handling machanism for basic LoongArch support. Reviewed-by: WANG Xuerui Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen

LoongArch: Add other common headers

2022-06-03T12:09:28+00:00

Add some other common headers for basic LoongArch support. Reviewed-by: WANG Xuerui Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen