/* * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Derived from "arch/m68k/kernel/ptrace.c" * Copyright (C) 1994 by Hamish Macdonald * Taken from linux/kernel/ptrace.c and modified for M680x0. * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds * * Modified by Cort Dougan (cort@hq.fsmlabs.com) * and Paul Mackerras (paulus@samba.org). * * This file is subject to the terms and conditions of the GNU General * Public License. See the file README.legal in the main directory of * this archive for more details. */ #include #include #include #include #include #include #include #include #define CREATE_TRACE_POINTS #include #include "ptrace-decl.h" /* * Called by kernel/ptrace.c when detaching.. * * Make sure single step bits etc are not set. */ void ptrace_disable(struct task_struct *child) { /* make sure the single step bit is not set. */ user_disable_single_step(child); } long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { int ret = -EPERM; void __user *datavp = (void __user *) data; unsigned long __user *datalp = datavp; switch (request) { /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long index, tmp; ret = -EIO; /* convert to index and check */ index = addr / sizeof(long); if ((addr & (sizeof(long) - 1)) || !child->thread.regs) break; if (index < PT_FPR0) ret = ptrace_get_reg(child, (int) index, &tmp); else ret = ptrace_get_fpr(child, index, &tmp); if (ret) break; ret = put_user(tmp, datalp); break; } /* write the word at location addr in the USER area */ case PTRACE_POKEUSR: { unsigned long index; ret = -EIO; /* convert to index and check */ index = addr / sizeof(long); if ((addr & (sizeof(long) - 1)) || !child->thread.regs) break; if (index < PT_FPR0) ret = ptrace_put_reg(child, index, data); else ret = ptrace_put_fpr(child, index, data); break; } case PPC_PTRACE_GETHWDBGINFO: { struct ppc_debug_info dbginfo; ppc_gethwdinfo(&dbginfo); if (copy_to_user(datavp, &dbginfo, sizeof(struct ppc_debug_info))) return -EFAULT; return 0; } case PPC_PTRACE_SETHWDEBUG: { struct ppc_hw_breakpoint bp_info; if (copy_from_user(&bp_info, datavp, sizeof(struct ppc_hw_breakpoint))) return -EFAULT; return ppc_set_hwdebug(child, &bp_info); } case PPC_PTRACE_DELHWDEBUG: { ret = ppc_del_hwdebug(child, data); break; } case PTRACE_GET_DEBUGREG: ret = ptrace_get_debugreg(child, addr, datalp); break; case PTRACE_SET_DEBUGREG: ret = ptrace_set_debugreg(child, addr, data); break; #ifdef CONFIG_PPC64 case PTRACE_GETREGS64: #endif case PTRACE_GETREGS: /* Get all pt_regs from the child. */ return copy_regset_to_user(child, &user_ppc_native_view, REGSET_GPR, 0, sizeof(struct user_pt_regs), datavp); #ifdef CONFIG_PPC64 case PTRACE_SETREGS64: #endif case PTRACE_SETREGS: /* Set all gp regs in the child. */ return copy_regset_from_user(child, &user_ppc_native_view, REGSET_GPR, 0, sizeof(struct user_pt_regs), datavp); case PTRACE_GETFPREGS: /* Get the child FPU state (FPR0...31 + FPSCR) */ return copy_regset_to_user(child, &user_ppc_native_view, REGSET_FPR, 0, sizeof(elf_fpregset_t), datavp); case PTRACE_SETFPREGS: /* Set the child FPU state (FPR0...31 + FPSCR) */ return copy_regset_from_user(child, &user_ppc_native_view, REGSET_FPR, 0, sizeof(elf_fpregset_t), datavp); #ifdef CONFIG_ALTIVEC case PTRACE_GETVRREGS: return copy_regset_to_user(child, &user_ppc_native_view, REGSET_VMX, 0, (33 * sizeof(vector128) + sizeof(u32)), datavp); case PTRACE_SETVRREGS: return copy_regset_from_user(child, &user_ppc_native_view, REGSET_VMX, 0, (33 * sizeof(vector128) + sizeof(u32)), datavp); #endif #ifdef CONFIG_VSX case PTRACE_GETVSRREGS: return copy_regset_to_user(child, &user_ppc_native_view, REGSET_VSX, 0, 32 * sizeof(double), datavp); case PTRACE_SETVSRREGS: return copy_regset_from_user(child, &user_ppc_native_view, REGSET_VSX, 0, 32 * sizeof(double), datavp); #endif #ifdef CONFIG_SPE case PTRACE_GETEVRREGS: /* Get the child spe register state. */ return copy_regset_to_user(child, &user_ppc_native_view, REGSET_SPE, 0, 35 * sizeof(u32), datavp); case PTRACE_SETEVRREGS: /* Set the child spe register state. */ return copy_regset_from_user(child, &user_ppc_native_view, REGSET_SPE, 0, 35 * sizeof(u32), datavp); #endif default: ret = ptrace_request(child, request, addr, data); break; } return ret; } #ifdef CONFIG_SECCOMP static int do_seccomp(struct pt_regs *regs) { if (!test_thread_flag(TIF_SECCOMP)) return 0; /* * The ABI we present to seccomp tracers is that r3 contains * the syscall return value and orig_gpr3 contains the first * syscall parameter. This is different to the ptrace ABI where * both r3 and orig_gpr3 contain the first syscall parameter. */ regs->gpr[3] = -ENOSYS; /* * We use the __ version here because we have already checked * TIF_SECCOMP. If this fails, there is nothing left to do, we * have already loaded -ENOSYS into r3, or seccomp has put * something else in r3 (via SECCOMP_RET_ERRNO/TRACE). */ if (__secure_computing(NULL)) return -1; /* * The syscall was allowed by seccomp, restore the register * state to what audit expects. * Note that we use orig_gpr3, which means a seccomp tracer can * modify the first syscall parameter (in orig_gpr3) and also * allow the syscall to proceed. */ regs->gpr[3] = regs->orig_gpr3; return 0; } #else static inline int do_seccomp(struct pt_regs *regs) { return 0; } #endif /* CONFIG_SECCOMP */ /** * do_syscall_trace_enter() - Do syscall tracing on kernel entry. * @regs: the pt_regs of the task to trace (current) * * Performs various types of tracing on syscall entry. This includes seccomp, * ptrace, syscall tracepoints and audit. * * The pt_regs are potentially visible to userspace via ptrace, so their * contents is ABI. * * One or more of the tracers may modify the contents of pt_regs, in particular * to modify arguments or even the syscall number itself. * * It's also possible that a tracer can choose to reject the system call. In * that case this function will return an illegal syscall number, and will put * an appropriate return value in regs->r3. * * Return: the (possibly changed) syscall number. */ long do_syscall_trace_enter(struct pt_regs *regs) { u32 flags; flags = READ_ONCE(current_thread_info()->flags) & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE); if (flags) { int rc = tracehook_report_syscall_entry(regs); if (unlikely(flags & _TIF_SYSCALL_EMU)) { /* * A nonzero return code from * tracehook_report_syscall_entry() tells us to prevent * the syscall execution, but we are not going to * execute it anyway. * * Returning -1 will skip the syscall execution. We want * to avoid clobbering any registers, so we don't goto * the skip label below. */ return -1; } if (rc) { /* * The tracer decided to abort the syscall. Note that * the tracer may also just change regs->gpr[0] to an * invalid syscall number, that is handled below on the * exit path. */ goto skip; } } /* Run seccomp after ptrace; allow it to set gpr[3]. */ if (do_seccomp(regs)) return -1; /* Avoid trace and audit when syscall is invalid. */ if (regs->gpr[0] >= NR_syscalls) goto skip; if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_enter(regs, regs->gpr[0]); if (!is_32bit_task()) audit_syscall_entry(regs->gpr[0], regs->gpr[3], regs->gpr[4], regs->gpr[5], regs->gpr[6]); else audit_syscall_entry(regs->gpr[0], regs->gpr[3] & 0xffffffff, regs->gpr[4] & 0xffffffff, regs->gpr[5] & 0xffffffff, regs->gpr[6] & 0xffffffff); /* Return the possibly modified but valid syscall number */ return regs->gpr[0]; skip: /* * If we are aborting explicitly, or if the syscall number is * now invalid, set the return value to -ENOSYS. */ regs->gpr[3] = -ENOSYS; return -1; } void do_syscall_trace_leave(struct pt_regs *regs) { int step; audit_syscall_exit(regs); if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_exit(regs, regs->result); step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, step); } void __init pt_regs_check(void); /* * Dummy function, its purpose is to break the build if struct pt_regs and * struct user_pt_regs don't match. */ void __init pt_regs_check(void) { BUILD_BUG_ON(offsetof(struct pt_regs, gpr) != offsetof(struct user_pt_regs, gpr)); BUILD_BUG_ON(offsetof(struct pt_regs, nip) != offsetof(struct user_pt_regs, nip)); BUILD_BUG_ON(offsetof(struct pt_regs, msr) != offsetof(struct user_pt_regs, msr)); BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) != offsetof(struct user_pt_regs, orig_gpr3)); BUILD_BUG_ON(offsetof(struct pt_regs, ctr) != offsetof(struct user_pt_regs, ctr)); BUILD_BUG_ON(offsetof(struct pt_regs, link) != offsetof(struct user_pt_regs, link)); BUILD_BUG_ON(offsetof(struct pt_regs, xer) != offsetof(struct user_pt_regs, xer)); BUILD_BUG_ON(offsetof(struct pt_regs, ccr) != offsetof(struct user_pt_regs, ccr)); #ifdef __powerpc64__ BUILD_BUG_ON(offsetof(struct pt_regs, softe) != offsetof(struct user_pt_regs, softe)); #else BUILD_BUG_ON(offsetof(struct pt_regs, mq) != offsetof(struct user_pt_regs, mq)); #endif BUILD_BUG_ON(offsetof(struct pt_regs, trap) != offsetof(struct user_pt_regs, trap)); BUILD_BUG_ON(offsetof(struct pt_regs, dar) != offsetof(struct user_pt_regs, dar)); BUILD_BUG_ON(offsetof(struct pt_regs, dear) != offsetof(struct user_pt_regs, dar)); BUILD_BUG_ON(offsetof(struct pt_regs, dsisr) != offsetof(struct user_pt_regs, dsisr)); BUILD_BUG_ON(offsetof(struct pt_regs, esr) != offsetof(struct user_pt_regs, dsisr)); BUILD_BUG_ON(offsetof(struct pt_regs, result) != offsetof(struct user_pt_regs, result)); BUILD_BUG_ON(sizeof(struct user_pt_regs) > sizeof(struct pt_regs)); // Now check that the pt_regs offsets match the uapi #defines #define CHECK_REG(_pt, _reg) \ BUILD_BUG_ON(_pt != (offsetof(struct user_pt_regs, _reg) / \ sizeof(unsigned long))); CHECK_REG(PT_R0, gpr[0]); CHECK_REG(PT_R1, gpr[1]); CHECK_REG(PT_R2, gpr[2]); CHECK_REG(PT_R3, gpr[3]); CHECK_REG(PT_R4, gpr[4]); CHECK_REG(PT_R5, gpr[5]); CHECK_REG(PT_R6, gpr[6]); CHECK_REG(PT_R7, gpr[7]); CHECK_REG(PT_R8, gpr[8]); CHECK_REG(PT_R9, gpr[9]); CHECK_REG(PT_R10, gpr[10]); CHECK_REG(PT_R11, gpr[11]); CHECK_REG(PT_R12, gpr[12]); CHECK_REG(PT_R13, gpr[13]); CHECK_REG(PT_R14, gpr[14]); CHECK_REG(PT_R15, gpr[15]); CHECK_REG(PT_R16, gpr[16]); CHECK_REG(PT_R17, gpr[17]); CHECK_REG(PT_R18, gpr[18]); CHECK_REG(PT_R19, gpr[19]); CHECK_REG(PT_R20, gpr[20]); CHECK_REG(PT_R21, gpr[21]); CHECK_REG(PT_R22, gpr[22]); CHECK_REG(PT_R23, gpr[23]); CHECK_REG(PT_R24, gpr[24]); CHECK_REG(PT_R25, gpr[25]); CHECK_REG(PT_R26, gpr[26]); CHECK_REG(PT_R27, gpr[27]); CHECK_REG(PT_R28, gpr[28]); CHECK_REG(PT_R29, gpr[29]); CHECK_REG(PT_R30, gpr[30]); CHECK_REG(PT_R31, gpr[31]); CHECK_REG(PT_NIP, nip); CHECK_REG(PT_MSR, msr); CHECK_REG(PT_ORIG_R3, orig_gpr3); CHECK_REG(PT_CTR, ctr); CHECK_REG(PT_LNK, link); CHECK_REG(PT_XER, xer); CHECK_REG(PT_CCR, ccr); #ifdef CONFIG_PPC64 CHECK_REG(PT_SOFTE, softe); #else CHECK_REG(PT_MQ, mq); #endif CHECK_REG(PT_TRAP, trap); CHECK_REG(PT_DAR, dar); CHECK_REG(PT_DSISR, dsisr); CHECK_REG(PT_RESULT, result); #undef CHECK_REG BUILD_BUG_ON(PT_REGS_COUNT != sizeof(struct user_pt_regs) / sizeof(unsigned long)); /* * PT_DSCR isn't a real reg, but it's important that it doesn't overlap the * real registers. */ BUILD_BUG_ON(PT_DSCR < sizeof(struct user_pt_regs) / sizeof(unsigned long)); // ptrace_get/put_fpr() rely on PPC32 and VSX being incompatible BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_VSX)); }