diff options
Diffstat (limited to 'arch/avr32/kernel/ptrace.c')
-rw-r--r-- | arch/avr32/kernel/ptrace.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/arch/avr32/kernel/ptrace.c b/arch/avr32/kernel/ptrace.c new file mode 100644 index 000000000000..3c89e59029ab --- /dev/null +++ b/arch/avr32/kernel/ptrace.c @@ -0,0 +1,371 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#undef DEBUG +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp_lock.h> +#include <linux/ptrace.h> +#include <linux/errno.h> +#include <linux/user.h> +#include <linux/security.h> +#include <linux/unistd.h> +#include <linux/notifier.h> + +#include <asm/traps.h> +#include <asm/uaccess.h> +#include <asm/ocd.h> +#include <asm/mmu_context.h> +#include <asm/kdebug.h> + +static struct pt_regs *get_user_regs(struct task_struct *tsk) +{ + return (struct pt_regs *)((unsigned long) tsk->thread_info + + THREAD_SIZE - sizeof(struct pt_regs)); +} + +static void ptrace_single_step(struct task_struct *tsk) +{ + pr_debug("ptrace_single_step: pid=%u, SR=0x%08lx\n", + tsk->pid, tsk->thread.cpu_context.sr); + if (!(tsk->thread.cpu_context.sr & SR_D)) { + /* + * Set a breakpoint at the current pc to force the + * process into debug mode. The syscall/exception + * exit code will set a breakpoint at the return + * address when this flag is set. + */ + pr_debug("ptrace_single_step: Setting TIF_BREAKPOINT\n"); + set_tsk_thread_flag(tsk, TIF_BREAKPOINT); + } + + /* The monitor code will do the actual step for us */ + set_tsk_thread_flag(tsk, TIF_SINGLE_STEP); +} + +/* + * Called by kernel/ptrace.c when detaching + * + * Make sure any single step bits, etc. are not set + */ +void ptrace_disable(struct task_struct *child) +{ + clear_tsk_thread_flag(child, TIF_SINGLE_STEP); +} + +/* + * Handle hitting a breakpoint + */ +static void ptrace_break(struct task_struct *tsk, struct pt_regs *regs) +{ + siginfo_t info; + + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_BRKPT; + info.si_addr = (void __user *)instruction_pointer(regs); + + pr_debug("ptrace_break: Sending SIGTRAP to PID %u (pc = 0x%p)\n", + tsk->pid, info.si_addr); + force_sig_info(SIGTRAP, &info, tsk); +} + +/* + * Read the word at offset "offset" into the task's "struct user". We + * actually access the pt_regs struct stored on the kernel stack. + */ +static int ptrace_read_user(struct task_struct *tsk, unsigned long offset, + unsigned long __user *data) +{ + unsigned long *regs; + unsigned long value; + + pr_debug("ptrace_read_user(%p, %#lx, %p)\n", + tsk, offset, data); + + if (offset & 3 || offset >= sizeof(struct user)) { + printk("ptrace_read_user: invalid offset 0x%08lx\n", offset); + return -EIO; + } + + regs = (unsigned long *)get_user_regs(tsk); + + value = 0; + if (offset < sizeof(struct pt_regs)) + value = regs[offset / sizeof(regs[0])]; + + return put_user(value, data); +} + +/* + * Write the word "value" to offset "offset" into the task's "struct + * user". We actually access the pt_regs struct stored on the kernel + * stack. + */ +static int ptrace_write_user(struct task_struct *tsk, unsigned long offset, + unsigned long value) +{ + unsigned long *regs; + + if (offset & 3 || offset >= sizeof(struct user)) { + printk("ptrace_write_user: invalid offset 0x%08lx\n", offset); + return -EIO; + } + + if (offset >= sizeof(struct pt_regs)) + return 0; + + regs = (unsigned long *)get_user_regs(tsk); + regs[offset / sizeof(regs[0])] = value; + + return 0; +} + +static int ptrace_getregs(struct task_struct *tsk, void __user *uregs) +{ + struct pt_regs *regs = get_user_regs(tsk); + + return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0; +} + +static int ptrace_setregs(struct task_struct *tsk, const void __user *uregs) +{ + struct pt_regs newregs; + int ret; + + ret = -EFAULT; + if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) { + struct pt_regs *regs = get_user_regs(tsk); + + ret = -EINVAL; + if (valid_user_regs(&newregs)) { + *regs = newregs; + ret = 0; + } + } + + return ret; +} + +long arch_ptrace(struct task_struct *child, long request, long addr, long data) +{ + unsigned long tmp; + int ret; + + pr_debug("arch_ptrace(%ld, %ld, %#lx, %#lx)\n", + request, child->pid, addr, data); + + pr_debug("ptrace: Enabling monitor mode...\n"); + __mtdr(DBGREG_DC, __mfdr(DBGREG_DC) | DC_MM | DC_DBE); + + switch (request) { + /* Read the word at location addr in the child process */ + case PTRACE_PEEKTEXT: + case PTRACE_PEEKDATA: + ret = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); + if (ret == sizeof(tmp)) + ret = put_user(tmp, (unsigned long __user *)data); + else + ret = -EIO; + break; + + case PTRACE_PEEKUSR: + ret = ptrace_read_user(child, addr, + (unsigned long __user *)data); + break; + + /* Write the word in data at location addr */ + case PTRACE_POKETEXT: + case PTRACE_POKEDATA: + ret = access_process_vm(child, addr, &data, sizeof(data), 1); + if (ret == sizeof(data)) + ret = 0; + else + ret = -EIO; + break; + + case PTRACE_POKEUSR: + ret = ptrace_write_user(child, addr, data); + break; + + /* continue and stop at next (return from) syscall */ + case PTRACE_SYSCALL: + /* restart after signal */ + case PTRACE_CONT: + ret = -EIO; + if (!valid_signal(data)) + break; + if (request == PTRACE_SYSCALL) + set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + else + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + child->exit_code = data; + /* XXX: Are we sure no breakpoints are active here? */ + wake_up_process(child); + ret = 0; + break; + + /* + * Make the child exit. Best I can do is send it a + * SIGKILL. Perhaps it should be put in the status that it + * wants to exit. + */ + case PTRACE_KILL: + ret = 0; + if (child->exit_state == EXIT_ZOMBIE) + break; + child->exit_code = SIGKILL; + wake_up_process(child); + break; + + /* + * execute single instruction. + */ + case PTRACE_SINGLESTEP: + ret = -EIO; + if (!valid_signal(data)) + break; + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + ptrace_single_step(child); + child->exit_code = data; + wake_up_process(child); + ret = 0; + break; + + /* Detach a process that was attached */ + case PTRACE_DETACH: + ret = ptrace_detach(child, data); + break; + + case PTRACE_GETREGS: + ret = ptrace_getregs(child, (void __user *)data); + break; + + case PTRACE_SETREGS: + ret = ptrace_setregs(child, (const void __user *)data); + break; + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + pr_debug("sys_ptrace returning %d (DC = 0x%08lx)\n", ret, __mfdr(DBGREG_DC)); + return ret; +} + +asmlinkage void syscall_trace(void) +{ + pr_debug("syscall_trace called\n"); + if (!test_thread_flag(TIF_SYSCALL_TRACE)) + return; + if (!(current->ptrace & PT_PTRACED)) + return; + + pr_debug("syscall_trace: notifying parent\n"); + /* The 0x80 provides a way for the tracing parent to + * distinguish between a syscall stop and SIGTRAP delivery */ + ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) + ? 0x80 : 0)); + + /* + * this isn't the same as continuing with a signal, but it + * will do for normal use. strace only continues with a + * signal if the stopping signal is not SIGTRAP. -brl + */ + if (current->exit_code) { + pr_debug("syscall_trace: sending signal %d to PID %u\n", + current->exit_code, current->pid); + send_sig(current->exit_code, current, 1); + current->exit_code = 0; + } +} + +asmlinkage void do_debug_priv(struct pt_regs *regs) +{ + unsigned long dc, ds; + unsigned long die_val; + + ds = __mfdr(DBGREG_DS); + + pr_debug("do_debug_priv: pc = %08lx, ds = %08lx\n", regs->pc, ds); + + if (ds & DS_SSS) + die_val = DIE_SSTEP; + else + die_val = DIE_BREAKPOINT; + + if (notify_die(die_val, regs, 0, SIGTRAP) == NOTIFY_STOP) + return; + + if (likely(ds & DS_SSS)) { + extern void itlb_miss(void); + extern void tlb_miss_common(void); + struct thread_info *ti; + + dc = __mfdr(DBGREG_DC); + dc &= ~DC_SS; + __mtdr(DBGREG_DC, dc); + + ti = current_thread_info(); + ti->flags |= _TIF_BREAKPOINT; + + /* The TLB miss handlers don't check thread flags */ + if ((regs->pc >= (unsigned long)&itlb_miss) + && (regs->pc <= (unsigned long)&tlb_miss_common)) { + __mtdr(DBGREG_BWA2A, sysreg_read(RAR_EX)); + __mtdr(DBGREG_BWC2A, 0x40000001 | (get_asid() << 1)); + } + + /* + * If we're running in supervisor mode, the breakpoint + * will take us where we want directly, no need to + * single step. + */ + if ((regs->sr & MODE_MASK) != MODE_SUPERVISOR) + ti->flags |= TIF_SINGLE_STEP; + } else { + panic("Unable to handle debug trap at pc = %08lx\n", + regs->pc); + } +} + +/* + * Handle breakpoints, single steps and other debuggy things. To keep + * things simple initially, we run with interrupts and exceptions + * disabled all the time. + */ +asmlinkage void do_debug(struct pt_regs *regs) +{ + unsigned long dc, ds; + + ds = __mfdr(DBGREG_DS); + pr_debug("do_debug: pc = %08lx, ds = %08lx\n", regs->pc, ds); + + if (test_thread_flag(TIF_BREAKPOINT)) { + pr_debug("TIF_BREAKPOINT set\n"); + /* We're taking care of it */ + clear_thread_flag(TIF_BREAKPOINT); + __mtdr(DBGREG_BWC2A, 0); + } + + if (test_thread_flag(TIF_SINGLE_STEP)) { + pr_debug("TIF_SINGLE_STEP set, ds = 0x%08lx\n", ds); + if (ds & DS_SSS) { + dc = __mfdr(DBGREG_DC); + dc &= ~DC_SS; + __mtdr(DBGREG_DC, dc); + + clear_thread_flag(TIF_SINGLE_STEP); + ptrace_break(current, regs); + } + } else { + /* regular breakpoint */ + ptrace_break(current, regs); + } +} |