/* * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds * these modifications are Copyright 2004-2010 Analog Devices Inc. * * Licensed under the GPL-2 */ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/elf.h> #include <linux/errno.h> #include <linux/ptrace.h> #include <linux/user.h> #include <linux/regset.h> #include <linux/signal.h> #include <linux/tracehook.h> #include <linux/uaccess.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/processor.h> #include <asm/asm-offsets.h> #include <asm/dma.h> #include <asm/fixed_code.h> #include <asm/cacheflush.h> #include <asm/mem_map.h> #include <asm/mmu_context.h> /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * Get contents of register REGNO in task TASK. */ static inline long get_reg(struct task_struct *task, unsigned long regno, unsigned long __user *datap) { long tmp; struct pt_regs *regs = task_pt_regs(task); if (regno & 3 || regno > PT_LAST_PSEUDO) return -EIO; switch (regno) { case PT_TEXT_ADDR: tmp = task->mm->start_code; break; case PT_TEXT_END_ADDR: tmp = task->mm->end_code; break; case PT_DATA_ADDR: tmp = task->mm->start_data; break; case PT_USP: tmp = task->thread.usp; break; default: if (regno < sizeof(*regs)) { void *reg_ptr = regs; tmp = *(long *)(reg_ptr + regno); } else return -EIO; } return put_user(tmp, datap); } /* * Write contents of register REGNO in task TASK. */ static inline int put_reg(struct task_struct *task, unsigned long regno, unsigned long data) { struct pt_regs *regs = task_pt_regs(task); if (regno & 3 || regno > PT_LAST_PSEUDO) return -EIO; switch (regno) { case PT_PC: /*********************************************************************/ /* At this point the kernel is most likely in exception. */ /* The RETX register will be used to populate the pc of the process. */ /*********************************************************************/ regs->retx = data; regs->pc = data; break; case PT_RETX: break; /* regs->retx = data; break; */ case PT_USP: regs->usp = data; task->thread.usp = data; break; case PT_SYSCFG: /* don't let userspace screw with this */ if ((data & ~1) != 0x6) pr_warning("ptrace: ignore syscfg write of %#lx\n", data); break; /* regs->syscfg = data; break; */ default: if (regno < sizeof(*regs)) { void *reg_offset = regs; *(long *)(reg_offset + regno) = data; } /* Ignore writes to pseudo registers */ } return 0; } /* * check that an address falls within the bounds of the target process's memory mappings */ int is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len) { bool valid; struct vm_area_struct *vma; struct sram_list_struct *sraml; /* overflow */ if (start + len < start) return -EIO; down_read(&child->mm->mmap_sem); vma = find_vma(child->mm, start); valid = vma && start >= vma->vm_start && start + len <= vma->vm_end; up_read(&child->mm->mmap_sem); if (valid) return 0; for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next) if (start >= (unsigned long)sraml->addr && start + len < (unsigned long)sraml->addr + sraml->length) return 0; if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END) return 0; #ifdef CONFIG_APP_STACK_L1 if (child->mm->context.l1_stack_save) if (start >= (unsigned long)l1_stack_base && start + len < (unsigned long)l1_stack_base + l1_stack_len) return 0; #endif return -EIO; } /* * retrieve the contents of Blackfin userspace general registers */ static int genregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { struct pt_regs *regs = task_pt_regs(target); int ret; /* This sucks ... */ regs->usp = target->thread.usp; ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, sizeof(*regs)); if (ret < 0) return ret; return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, sizeof(*regs), -1); } /* * update the contents of the Blackfin userspace general registers */ 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; /* Don't let people set SYSCFG (it's at the end of pt_regs) */ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, PT_SYSCFG); if (ret < 0) return ret; /* This sucks ... */ target->thread.usp = regs->usp; /* regs->retx = regs->pc; */ return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, PT_SYSCFG, -1); } /* * Define the register sets available on the Blackfin under Linux */ enum bfin_regset { REGSET_GENERAL, }; static const struct user_regset bfin_regsets[] = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = sizeof(struct pt_regs) / sizeof(long), .size = sizeof(long), .align = sizeof(long), .get = genregs_get, .set = genregs_set, }, }; static const struct user_regset_view user_bfin_native_view = { .name = "Blackfin", .e_machine = EM_BLACKFIN, .regsets = bfin_regsets, .n = ARRAY_SIZE(bfin_regsets), }; const struct user_regset_view *task_user_regset_view(struct task_struct *task) { return &user_bfin_native_view; } void user_enable_single_step(struct task_struct *child) { struct pt_regs *regs = task_pt_regs(child); regs->syscfg |= SYSCFG_SSSTEP; set_tsk_thread_flag(child, TIF_SINGLESTEP); } void user_disable_single_step(struct task_struct *child) { struct pt_regs *regs = task_pt_regs(child); regs->syscfg &= ~SYSCFG_SSSTEP; clear_tsk_thread_flag(child, TIF_SINGLESTEP); } long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { int ret; unsigned long __user *datap = (unsigned long __user *)data; void *paddr = (void *)addr; switch (request) { /* when I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKDATA: pr_debug("ptrace: PEEKDATA\n"); /* fall through */ case PTRACE_PEEKTEXT: /* read word at location addr. */ { unsigned long tmp = 0; int copied = 0, to_copy = sizeof(tmp); ret = -EIO; pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy); if (is_user_addr_valid(child, addr, to_copy) < 0) break; pr_debug("ptrace: user address is valid\n"); switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: copied = access_process_vm(child, addr, &tmp, to_copy, 0); if (copied) break; /* hrm, why didn't that work ... maybe no mapping */ if (addr >= FIXED_CODE_START && addr + to_copy <= FIXED_CODE_END) { copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy); copied = to_copy; } else if (addr >= BOOT_ROM_START) { memcpy(&tmp, paddr, to_copy); copied = to_copy; } break; case BFIN_MEM_ACCESS_DMA: if (safe_dma_memcpy(&tmp, paddr, to_copy)) copied = to_copy; break; case BFIN_MEM_ACCESS_ITEST: if (isram_memcpy(&tmp, paddr, to_copy)) copied = to_copy; break; default: copied = 0; break; } pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp); if (copied == to_copy) ret = put_user(tmp, datap); break; } /* when I and D space are separate, this will have to be fixed. */ case PTRACE_POKEDATA: pr_debug("ptrace: PTRACE_PEEKDATA\n"); /* fall through */ case PTRACE_POKETEXT: /* write the word at location addr. */ { int copied = 0, to_copy = sizeof(data); ret = -EIO; pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n", addr, to_copy, data); if (is_user_addr_valid(child, addr, to_copy) < 0) break; pr_debug("ptrace: user address is valid\n"); switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: copied = access_process_vm(child, addr, &data, to_copy, 1); break; case BFIN_MEM_ACCESS_DMA: if (safe_dma_memcpy(paddr, &data, to_copy)) copied = to_copy; break; case BFIN_MEM_ACCESS_ITEST: if (isram_memcpy(paddr, &data, to_copy)) copied = to_copy; break; default: copied = 0; break; } pr_debug("ptrace: copied size %d\n", copied); if (copied == to_copy) ret = 0; break; } case PTRACE_PEEKUSR: switch (addr) { #ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */ case PT_FDPIC_EXEC: request = PTRACE_GETFDPIC; addr = PTRACE_GETFDPIC_EXEC; goto case_default; case PT_FDPIC_INTERP: request = PTRACE_GETFDPIC; addr = PTRACE_GETFDPIC_INTERP; goto case_default; #endif default: ret = get_reg(child, addr, datap); } pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret); break; case PTRACE_POKEUSR: ret = put_reg(child, addr, data); pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret); break; case PTRACE_GETREGS: pr_debug("ptrace: PTRACE_GETREGS\n"); return copy_regset_to_user(child, &user_bfin_native_view, REGSET_GENERAL, 0, sizeof(struct pt_regs), datap); case PTRACE_SETREGS: pr_debug("ptrace: PTRACE_SETREGS\n"); return copy_regset_from_user(child, &user_bfin_native_view, REGSET_GENERAL, 0, sizeof(struct pt_regs), datap); case_default: default: ret = ptrace_request(child, request, addr, data); break; } return ret; } asmlinkage int syscall_trace_enter(struct pt_regs *regs) { int ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE)) ret = tracehook_report_syscall_entry(regs); return ret; } asmlinkage void syscall_trace_leave(struct pt_regs *regs) { int step; step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, step); }