在2022年6月1日六月 上午10:59，Huacai Chen写道： > 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 <git@xxxxxxxxxx> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > --- > arch/loongarch/include/asm/seccomp.h | 20 ++ > arch/loongarch/include/asm/syscall.h | 74 +++++++ > arch/loongarch/include/asm/uaccess.h | 269 +++++++++++++++++++++++ > arch/loongarch/include/asm/unistd.h | 11 + > arch/loongarch/include/uapi/asm/unistd.h | 5 + > arch/loongarch/kernel/entry.S | 89 ++++++++ > arch/loongarch/kernel/syscall.c | 63 ++++++ > 7 files changed, 531 insertions(+) > create mode 100644 arch/loongarch/include/asm/seccomp.h > create mode 100644 arch/loongarch/include/asm/syscall.h > create mode 100644 arch/loongarch/include/asm/uaccess.h > create mode 100644 arch/loongarch/include/asm/unistd.h > create mode 100644 arch/loongarch/include/uapi/asm/unistd.h > create mode 100644 arch/loongarch/kernel/entry.S > create mode 100644 arch/loongarch/kernel/syscall.c > > diff --git a/arch/loongarch/include/asm/seccomp.h > b/arch/loongarch/include/asm/seccomp.h > new file mode 100644 > index 000000000000..31d6ab42e43e > --- /dev/null > +++ b/arch/loongarch/include/asm/seccomp.h > @@ -0,0 +1,20 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef _ASM_SECCOMP_H > +#define _ASM_SECCOMP_H > + > +#include <asm/unistd.h> > + > +#include <asm-generic/seccomp.h> > + > +#ifdef CONFIG_32BIT > +# define SECCOMP_ARCH_NATIVE AUDIT_ARCH_LOONGARCH32 > +# define SECCOMP_ARCH_NATIVE_NR NR_syscalls > +# define SECCOMP_ARCH_NATIVE_NAME "loongarch32" > +#else > +# define SECCOMP_ARCH_NATIVE AUDIT_ARCH_LOONGARCH64 > +# define SECCOMP_ARCH_NATIVE_NR NR_syscalls > +# define SECCOMP_ARCH_NATIVE_NAME "loongarch64" > +#endif > + > +#endif /* _ASM_SECCOMP_H */ > diff --git a/arch/loongarch/include/asm/syscall.h > b/arch/loongarch/include/asm/syscall.h > new file mode 100644 > index 000000000000..e286dc58476e > --- /dev/null > +++ b/arch/loongarch/include/asm/syscall.h > @@ -0,0 +1,74 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +/* > + * Author: Hanlu Li <lihanlu@xxxxxxxxxxx> > + * Huacai Chen <chenhuacai@xxxxxxxxxxx> > + * > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited > + */ > + > +#ifndef __ASM_LOONGARCH_SYSCALL_H > +#define __ASM_LOONGARCH_SYSCALL_H > + > +#include <linux/compiler.h> > +#include <uapi/linux/audit.h> > +#include <linux/elf-em.h> > +#include <linux/kernel.h> > +#include <linux/sched.h> > +#include <linux/uaccess.h> > +#include <asm/ptrace.h> > +#include <asm/unistd.h> > + > +extern void *sys_call_table[]; > + > +static inline long syscall_get_nr(struct task_struct *task, > + struct pt_regs *regs) > +{ > + return regs->regs[11]; > +} > + > +static inline void syscall_rollback(struct task_struct *task, > + struct pt_regs *regs) > +{ > + regs->regs[4] = regs->orig_a0; > +} > + > +static inline long syscall_get_error(struct task_struct *task, > + struct pt_regs *regs) > +{ > + unsigned long error = regs->regs[4]; > + > + return IS_ERR_VALUE(error) ? error : 0; > +} > + > +static inline long syscall_get_return_value(struct task_struct *task, > + struct pt_regs *regs) > +{ > + return regs->regs[4]; > +} > + > +static inline void syscall_set_return_value(struct task_struct *task, > + struct pt_regs *regs, > + int error, long val) > +{ > + regs->regs[4] = (long) error ? error : val; > +} > + > +static inline void syscall_get_arguments(struct task_struct *task, > + struct pt_regs *regs, > + unsigned long *args) > +{ > + args[0] = regs->orig_a0; > + memcpy(&args[1], ®s->regs[5], 5 * sizeof(long)); > +} > + > +static inline int syscall_get_arch(struct task_struct *task) > +{ > + return AUDIT_ARCH_LOONGARCH64; > +} > + > +static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs) > +{ > + return false; > +} > + > +#endif /* __ASM_LOONGARCH_SYSCALL_H */ > diff --git a/arch/loongarch/include/asm/uaccess.h > b/arch/loongarch/include/asm/uaccess.h > new file mode 100644 > index 000000000000..217c6a3727b1 > --- /dev/null > +++ b/arch/loongarch/include/asm/uaccess.h > @@ -0,0 +1,269 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited > + * > + * Derived from MIPS: > + * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle > + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. > + * Copyright (C) 2007 Maciej W. Rozycki > + * Copyright (C) 2014, Imagination Technologies Ltd. > + */ > +#ifndef _ASM_UACCESS_H > +#define _ASM_UACCESS_H > + > +#include <linux/kernel.h> > +#include <linux/string.h> > +#include <linux/extable.h> > +#include <asm/pgtable.h> > +#include <asm-generic/extable.h> > +#include <asm-generic/access_ok.h> > + > +extern u64 __ua_limit; > + > +#define __UA_ADDR ".dword" > +#define __UA_LA "la.abs" > +#define __UA_LIMIT __ua_limit > + > +/* > + * get_user: - Get a simple variable from user space. > + * @x: Variable to store result. > + * @ptr: Source address, in user space. > + * > + * Context: User context only. This function may sleep if pagefaults > are > + * enabled. > + * > + * This macro copies a single simple variable from user space to kernel > + * space. It supports simple types like char and int, but not larger > + * data types like structures or arrays. > + * > + * @ptr must have pointer-to-simple-variable type, and the result of > + * dereferencing @ptr must be assignable to @x without a cast. > + * > + * Returns zero on success, or -EFAULT on error. > + * On error, the variable @x is set to zero. > + */ > +#define get_user(x, ptr) \ > +({ \ > + const __typeof__(*(ptr)) __user *__p = (ptr); \ > + \ > + might_fault(); \ > + access_ok(__p, sizeof(*__p)) ? __get_user((x), __p) : \ > + ((x) = 0, -EFAULT); \ > +}) > + > +/* > + * put_user: - Write a simple value into user space. > + * @x: Value to copy to user space. > + * @ptr: Destination address, in user space. > + * > + * Context: User context only. This function may sleep if pagefaults > are > + * enabled. > + * > + * This macro copies a single simple value from kernel space to user > + * space. It supports simple types like char and int, but not larger > + * data types like structures or arrays. > + * > + * @ptr must have pointer-to-simple-variable type, and @x must be > assignable > + * to the result of dereferencing @ptr. > + * > + * Returns zero on success, or -EFAULT on error. > + */ > +#define put_user(x, ptr) \ > +({ \ > + __typeof__(*(ptr)) __user *__p = (ptr); \ > + \ > + might_fault(); \ > + access_ok(__p, sizeof(*__p)) ? __put_user((x), __p) : -EFAULT; \ > +}) > + > +/* > + * __get_user: - Get a simple variable from user space, with less > checking. > + * @x: Variable to store result. > + * @ptr: Source address, in user space. > + * > + * Context: User context only. This function may sleep if pagefaults > are > + * enabled. > + * > + * This macro copies a single simple variable from user space to kernel > + * space. It supports simple types like char and int, but not larger > + * data types like structures or arrays. > + * > + * @ptr must have pointer-to-simple-variable type, and the result of > + * dereferencing @ptr must be assignable to @x without a cast. > + * > + * Caller must check the pointer with access_ok() before calling this > + * function. > + * > + * Returns zero on success, or -EFAULT on error. > + * On error, the variable @x is set to zero. > + */ > +#define __get_user(x, ptr) \ > +({ \ > + int __gu_err = 0; \ > + \ > + __chk_user_ptr(ptr); \ > + __get_user_common((x), sizeof(*(ptr)), ptr); \ > + __gu_err; \ > +}) > + > +/* > + * __put_user: - Write a simple value into user space, with less > checking. > + * @x: Value to copy to user space. > + * @ptr: Destination address, in user space. > + * > + * Context: User context only. This function may sleep if pagefaults > are > + * enabled. > + * > + * This macro copies a single simple value from kernel space to user > + * space. It supports simple types like char and int, but not larger > + * data types like structures or arrays. > + * > + * @ptr must have pointer-to-simple-variable type, and @x must be > assignable > + * to the result of dereferencing @ptr. > + * > + * Caller must check the pointer with access_ok() before calling this > + * function. > + * > + * Returns zero on success, or -EFAULT on error. > + */ > +#define __put_user(x, ptr) \ > +({ \ > + int __pu_err = 0; \ > + __typeof__(*(ptr)) __pu_val; \ > + \ > + __pu_val = (x); \ > + __chk_user_ptr(ptr); \ > + __put_user_common(ptr, sizeof(*(ptr))); \ > + __pu_err; \ > +}) > + > +struct __large_struct { unsigned long buf[100]; }; > +#define __m(x) (*(struct __large_struct __user *)(x)) > + > +#define __get_user_common(val, size, ptr) \ > +do { \ > + switch (size) { \ > + case 1: __get_data_asm(val, "ld.b", ptr); break; \ > + case 2: __get_data_asm(val, "ld.h", ptr); break; \ > + case 4: __get_data_asm(val, "ld.w", ptr); break; \ > + case 8: __get_data_asm(val, "ld.d", ptr); break; \ > + default: BUILD_BUG(); break; \ > + } \ > +} while (0) > + > +#define __get_kernel_common(val, size, ptr) __get_user_common(val, > size, ptr) > + > +#define __get_data_asm(val, insn, ptr) \ > +{ \ > + long __gu_tmp; \ > + \ > + __asm__ __volatile__( \ > + "1: " insn " %1, %2 \n" \ > + "2: \n" \ > + " .section .fixup,\"ax\" \n" \ > + "3: li.w %0, %3 \n" \ > + " or %1, $r0, $r0 \n" \ > + " b 2b \n" \ > + " .previous \n" \ > + " .section __ex_table,\"a\" \n" \ > + " "__UA_ADDR "\t1b, 3b \n" \ > + " .previous \n" \ > + : "+r" (__gu_err), "=r" (__gu_tmp) \ > + : "m" (__m(ptr)), "i" (-EFAULT)); \ > + \ > + (val) = (__typeof__(*(ptr))) __gu_tmp; \ > +} > + > +#define __put_user_common(ptr, size) \ > +do { \ > + switch (size) { \ > + case 1: __put_data_asm("st.b", ptr); break; \ > + case 2: __put_data_asm("st.h", ptr); break; \ > + case 4: __put_data_asm("st.w", ptr); break; \ > + case 8: __put_data_asm("st.d", ptr); break; \ > + default: BUILD_BUG(); break; \ > + } \ > +} while (0) > + > +#define __put_kernel_common(ptr, size) __put_user_common(ptr, size) > + > +#define __put_data_asm(insn, ptr) \ > +{ \ > + __asm__ __volatile__( \ > + "1: " insn " %z2, %1 # __put_user_asm\n" \ > + "2: \n" \ > + " .section .fixup,\"ax\" \n" \ > + "3: li.w %0, %3 \n" \ > + " b 2b \n" \ > + " .previous \n" \ > + " .section __ex_table,\"a\" \n" \ > + " " __UA_ADDR " 1b, 3b \n" \ > + " .previous \n" \ > + : "+r" (__pu_err), "=m" (__m(ptr)) \ > + : "Jr" (__pu_val), "i" (-EFAULT)); \ > +} > + > +#define __get_kernel_nofault(dst, src, type, err_label) \ > +do { \ > + int __gu_err = 0; \ > + \ > + __get_kernel_common(*((type *)(dst)), sizeof(type), \ > + (__force type *)(src)); \ > + if (unlikely(__gu_err)) \ > + goto err_label; \ > +} while (0) > + > +#define __put_kernel_nofault(dst, src, type, err_label) \ > +do { \ > + type __pu_val; \ > + int __pu_err = 0; \ > + \ > + __pu_val = *(__force type *)(src); \ > + __put_kernel_common(((type *)(dst)), sizeof(type)); \ > + if (unlikely(__pu_err)) \ > + goto err_label; \ > +} while (0) > + > +extern unsigned long __copy_user(void *to, const void *from, > __kernel_size_t n); > + > +static inline unsigned long __must_check > +raw_copy_from_user(void *to, const void __user *from, unsigned long n) > +{ > + return __copy_user(to, from, n); > +} > + > +static inline unsigned long __must_check > +raw_copy_to_user(void __user *to, const void *from, unsigned long n) > +{ > + return __copy_user(to, from, n); > +} > + > +#define INLINE_COPY_FROM_USER > +#define INLINE_COPY_TO_USER > + > +/* > + * __clear_user: - Zero a block of memory in user space, with less > checking. > + * @addr: Destination address, in user space. > + * @size: Number of bytes to zero. > + * > + * Zero a block of memory in user space. Caller must check > + * the specified block with access_ok() before calling this function. > + * > + * Returns number of bytes that could not be cleared. > + * On success, this will be zero. > + */ > +extern unsigned long __clear_user(void __user *addr, __kernel_size_t > size); > + > +#define clear_user(addr, n) \ > +({ \ > + void __user *__cl_addr = (addr); \ > + unsigned long __cl_size = (n); \ > + if (__cl_size && access_ok(__cl_addr, __cl_size)) \ > + __cl_size = __clear_user(__cl_addr, __cl_size); \ > + __cl_size; \ > +}) > + > +extern long strncpy_from_user(char *to, const char __user *from, long > n); > +extern long strnlen_user(const char __user *str, long n); > + > +#endif /* _ASM_UACCESS_H */ > diff --git a/arch/loongarch/include/asm/unistd.h > b/arch/loongarch/include/asm/unistd.h > new file mode 100644 > index 000000000000..cfddb0116a8c > --- /dev/null > +++ b/arch/loongarch/include/asm/unistd.h > @@ -0,0 +1,11 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +/* > + * Author: Hanlu Li <lihanlu@xxxxxxxxxxx> > + * Huacai Chen <chenhuacai@xxxxxxxxxxx> > + * > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited > + */ > + > +#include <uapi/asm/unistd.h> > + > +#define NR_syscalls (__NR_syscalls) > diff --git a/arch/loongarch/include/uapi/asm/unistd.h > b/arch/loongarch/include/uapi/asm/unistd.h > new file mode 100644 > index 000000000000..fcb668984f03 > --- /dev/null > +++ b/arch/loongarch/include/uapi/asm/unistd.h > @@ -0,0 +1,5 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +#define __ARCH_WANT_SYS_CLONE > +#define __ARCH_WANT_SYS_CLONE3 > + > +#include <asm-generic/unistd.h> > diff --git a/arch/loongarch/kernel/entry.S > b/arch/loongarch/kernel/entry.S > new file mode 100644 > index 000000000000..d5b3dbcf5425 > --- /dev/null > +++ b/arch/loongarch/kernel/entry.S > @@ -0,0 +1,89 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited > + * > + * Derived from MIPS: > + * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle > + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. > + * Copyright (C) 2001 MIPS Technologies, Inc. > + */ > + > +#include <asm/asm.h> > +#include <asm/asmmacro.h> > +#include <asm/loongarch.h> > +#include <asm/regdef.h> > +#include <asm/stackframe.h> > +#include <asm/thread_info.h> > + > + .text > + .cfi_sections .debug_frame > + .align 5 > +SYM_FUNC_START(handle_syscall) > + csrrd t0, PERCPU_BASE_KS > + la.abs t1, kernelsp > + add.d t1, t1, t0 > + move t2, sp > + ld.d sp, t1, 0 > + > + addi.d sp, sp, -PT_SIZE > + cfi_st t2, PT_R3 > + cfi_rel_offset sp, PT_R3 > + st.d zero, sp, PT_R0 > + csrrd t2, LOONGARCH_CSR_PRMD > + st.d t2, sp, PT_PRMD > + csrrd t2, LOONGARCH_CSR_CRMD > + st.d t2, sp, PT_CRMD > + csrrd t2, LOONGARCH_CSR_EUEN > + st.d t2, sp, PT_EUEN > + csrrd t2, LOONGARCH_CSR_ECFG > + st.d t2, sp, PT_ECFG > + csrrd t2, LOONGARCH_CSR_ESTAT > + st.d t2, sp, PT_ESTAT > + cfi_st ra, PT_R1 > + cfi_st a0, PT_R4 > + cfi_st a1, PT_R5 > + cfi_st a2, PT_R6 > + cfi_st a3, PT_R7 > + cfi_st a4, PT_R8 > + cfi_st a5, PT_R9 > + cfi_st a6, PT_R10 > + cfi_st a7, PT_R11 > + csrrd ra, LOONGARCH_CSR_ERA > + st.d ra, sp, PT_ERA > + cfi_rel_offset ra, PT_ERA > + > + cfi_st tp, PT_R2 > + cfi_st u0, PT_R21 > + cfi_st fp, PT_R22 > + > + SAVE_STATIC > + > + move u0, t0 > + li.d tp, ~_THREAD_MASK > + and tp, tp, sp > + > + move a0, sp > + bl do_syscall > + > + RESTORE_ALL_AND_RET > +SYM_FUNC_END(handle_syscall) > + > +SYM_CODE_START(ret_from_fork) > + bl schedule_tail # a0 = struct task_struct *prev > + move a0, sp > + bl syscall_exit_to_user_mode > + RESTORE_STATIC > + RESTORE_SOME > + RESTORE_SP_AND_RET > +SYM_CODE_END(ret_from_fork) > + > +SYM_CODE_START(ret_from_kernel_thread) > + bl schedule_tail # a0 = struct task_struct *prev > + move a0, s1 > + jirl ra, s0, 0 > + move a0, sp > + bl syscall_exit_to_user_mode > + RESTORE_STATIC > + RESTORE_SOME > + RESTORE_SP_AND_RET > +SYM_CODE_END(ret_from_kernel_thread) > diff --git a/arch/loongarch/kernel/syscall.c > b/arch/loongarch/kernel/syscall.c > new file mode 100644 > index 000000000000..3fc4211db989 > --- /dev/null > +++ b/arch/loongarch/kernel/syscall.c > @@ -0,0 +1,63 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Author: Hanlu Li <lihanlu@xxxxxxxxxxx> > + * Huacai Chen <chenhuacai@xxxxxxxxxxx> > + * > + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited > + */ > +#include <linux/capability.h> > +#include <linux/entry-common.h> > +#include <linux/errno.h> > +#include <linux/linkage.h> > +#include <linux/syscalls.h> > +#include <linux/unistd.h> > + > +#include <asm/asm.h> > +#include <asm/signal.h> > +#include <asm/switch_to.h> > +#include <asm-generic/syscalls.h> > + > +#undef __SYSCALL > +#define __SYSCALL(nr, call) [nr] = (call), > + > +SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, > unsigned long, > + prot, unsigned long, flags, unsigned long, fd, off_t, offset) > +{ > + if (offset & ~PAGE_MASK) > + return -EINVAL; > + > + return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> > PAGE_SHIFT); > +} > + > +void *sys_call_table[__NR_syscalls] = { > + [0 ... __NR_syscalls - 1] = sys_ni_syscall, > +#include <asm/unistd.h> > +}; > + > +typedef long (*sys_call_fn)(unsigned long, unsigned long, > + unsigned long, unsigned long, unsigned long, unsigned long); > + > +void noinstr do_syscall(struct pt_regs *regs) > +{ > + unsigned long nr; > + sys_call_fn syscall_fn; > + > + nr = regs->regs[11]; > + /* Set for syscall restarting */ > + if (nr < NR_syscalls) > + regs->regs[0] = nr + 1; > + > + regs->csr_era += 4; > + regs->orig_a0 = regs->regs[4]; > + regs->regs[4] = -ENOSYS; > + > + nr = syscall_enter_from_user_mode(regs, nr); > + > + if (nr < NR_syscalls) { > + syscall_fn = sys_call_table[nr]; > + regs->regs[4] = syscall_fn(regs->orig_a0, regs->regs[5], > regs->regs[6], > + regs->regs[7], regs->regs[8], regs->regs[9]); > + } > + > + syscall_exit_to_user_mode(regs); > +} > -- > 2.27.0 -- - Jiaxun
