// SPDX-License-Identifier: GPL-2.0-or-later /* * OpenRISC ptrace.c * * Linux architectural port borrowing liberally from similar works of * others. All original copyrights apply as per the original source * declaration. * * Modifications for the OpenRISC architecture: * Copyright (C) 2003 Matjaz Breskvar * Copyright (C) 2005 Gyorgy Jeney * Copyright (C) 2010-2011 Jonas Bonn */ #include #include #include #include #include #include #include #include #include #include #include #include asmlinkage long do_syscall_trace_enter(struct pt_regs *regs); asmlinkage void do_syscall_trace_leave(struct pt_regs *regs); /* * Copy the thread state to a regset that can be interpreted by userspace. * * It doesn't matter what our internal pt_regs structure looks like. The * important thing is that we export a consistent view of the thread state * to userspace. As such, we need to make sure that the regset remains * ABI compatible as defined by the struct user_regs_struct: * * (Each item is a 32-bit word) * r0 = 0 (exported for clarity) * 31 GPRS r1-r31 * PC (Program counter) * SR (Supervision register) */ static int genregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { const struct pt_regs *regs = task_pt_regs(target); /* r0 */ membuf_zero(&to, 4); membuf_write(&to, regs->gpr + 1, 31 * 4); membuf_store(&to, regs->pc); return membuf_store(&to, regs->sr); } /* * Set the thread state from a regset passed in via ptrace */ static int genregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user * ubuf) { struct pt_regs *regs = task_pt_regs(target); int ret; /* ignore r0 */ user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); /* r1 - r31 */ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs->gpr+1, 4, 4*32); /* PC */ if (!ret) ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, ®s->pc, 4*32, 4*33); /* * Skip SR and padding... userspace isn't allowed to changes bits in * the Supervision register */ if (!ret) user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 4*33, -1); return ret; } #ifdef CONFIG_FPU /* * As OpenRISC shares GPRs and floating point registers we don't need to export * the floating point registers again. So here we only export the fpcsr special * purpose register. */ static int fpregs_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) { return membuf_store(&to, target->thread.fpcsr); } static int fpregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { /* FPCSR */ return user_regset_copyin(&pos, &count, &kbuf, &ubuf, &target->thread.fpcsr, 0, 4); } #endif /* * Define the register sets available on OpenRISC under Linux */ enum or1k_regset { REGSET_GENERAL, #ifdef CONFIG_FPU REGSET_FPU, #endif }; static const struct user_regset or1k_regsets[] = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = ELF_NGREG, .size = sizeof(long), .align = sizeof(long), .regset_get = genregs_get, .set = genregs_set, }, #ifdef CONFIG_FPU [REGSET_FPU] = { .core_note_type = NT_PRFPREG, .n = sizeof(struct __or1k_fpu_state) / sizeof(long), .size = sizeof(long), .align = sizeof(long), .regset_get = fpregs_get, .set = fpregs_set, }, #endif }; static const struct user_regset_view user_or1k_native_view = { .name = "or1k", .e_machine = EM_OPENRISC, .regsets = or1k_regsets, .n = ARRAY_SIZE(or1k_regsets), }; const struct user_regset_view *task_user_regset_view(struct task_struct *task) { return &user_or1k_native_view; } /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ struct pt_regs_offset { const char *name; int offset; }; #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} #define REG_OFFSET_END {.name = NULL, .offset = 0} static const struct pt_regs_offset regoffset_table[] = { REG_OFFSET_NAME(sr), REG_OFFSET_NAME(sp), REG_OFFSET_NAME(gpr2), REG_OFFSET_NAME(gpr3), REG_OFFSET_NAME(gpr4), REG_OFFSET_NAME(gpr5), REG_OFFSET_NAME(gpr6), REG_OFFSET_NAME(gpr7), REG_OFFSET_NAME(gpr8), REG_OFFSET_NAME(gpr9), REG_OFFSET_NAME(gpr10), REG_OFFSET_NAME(gpr11), REG_OFFSET_NAME(gpr12), REG_OFFSET_NAME(gpr13), REG_OFFSET_NAME(gpr14), REG_OFFSET_NAME(gpr15), REG_OFFSET_NAME(gpr16), REG_OFFSET_NAME(gpr17), REG_OFFSET_NAME(gpr18), REG_OFFSET_NAME(gpr19), REG_OFFSET_NAME(gpr20), REG_OFFSET_NAME(gpr21), REG_OFFSET_NAME(gpr22), REG_OFFSET_NAME(gpr23), REG_OFFSET_NAME(gpr24), REG_OFFSET_NAME(gpr25), REG_OFFSET_NAME(gpr26), REG_OFFSET_NAME(gpr27), REG_OFFSET_NAME(gpr28), REG_OFFSET_NAME(gpr29), REG_OFFSET_NAME(gpr30), REG_OFFSET_NAME(gpr31), REG_OFFSET_NAME(pc), REG_OFFSET_NAME(orig_gpr11), REG_OFFSET_END, }; /** * regs_query_register_offset() - query register offset from its name * @name: the name of a register * * regs_query_register_offset() returns the offset of a register in struct * pt_regs from its name. If the name is invalid, this returns -EINVAL; */ int regs_query_register_offset(const char *name) { const struct pt_regs_offset *roff; for (roff = regoffset_table; roff->name != NULL; roff++) if (!strcmp(roff->name, name)) return roff->offset; return -EINVAL; } /** * regs_within_kernel_stack() - check the address in the stack * @regs: pt_regs which contains kernel stack pointer. * @addr: address which is checked. * * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). * If @addr is within the kernel stack, it returns true. If not, returns false. */ static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) { return (addr & ~(THREAD_SIZE - 1)) == (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)); } /** * regs_get_kernel_stack_nth() - get Nth entry of the stack * @regs: pt_regs which contains kernel stack pointer. * @n: stack entry number. * * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which * is specified by @regs. If the @n th entry is NOT in the kernel stack, * this returns 0. */ unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) { unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); addr += n; if (regs_within_kernel_stack(regs, (unsigned long)addr)) return *addr; else return 0; } /* * Called by kernel/ptrace.c when detaching.. * * Make sure the single step bit is not set. */ void ptrace_disable(struct task_struct *child) { pr_debug("ptrace_disable(): TODO\n"); user_disable_single_step(child); clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); } long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { int ret; switch (request) { default: ret = ptrace_request(child, request, addr, data); break; } return ret; } /* * Notification of system call entry/exit * - triggered by current->work.syscall_trace */ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) { long ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE) && ptrace_report_syscall_entry(regs)) /* * Tracing decided this syscall should not happen. * We'll return a bogus call number to get an ENOSYS * error, but leave the original number in . */ ret = -1L; audit_syscall_entry(regs->gpr[11], regs->gpr[3], regs->gpr[4], regs->gpr[5], regs->gpr[6]); return ret ? : regs->gpr[11]; } asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) { int step; audit_syscall_exit(regs); step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) ptrace_report_syscall_exit(regs, step); }