| /* |
| * Kernel support for the ptrace() and syscall tracing interfaces. |
| * |
| * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc. |
| * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx> |
| * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/smp_lock.h> |
| #include <linux/errno.h> |
| #include <linux/ptrace.h> |
| #include <linux/user.h> |
| #include <linux/personality.h> |
| #include <linux/security.h> |
| #include <linux/compat.h> |
| #include <linux/signal.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/processor.h> |
| #include <asm/asm-offsets.h> |
| |
| /* PSW bits we allow the debugger to modify */ |
| #define USER_PSW_BITS (PSW_N | PSW_V | PSW_CB) |
| |
| #undef DEBUG_PTRACE |
| |
| #ifdef DEBUG_PTRACE |
| #define DBG(x...) printk(x) |
| #else |
| #define DBG(x...) |
| #endif |
| |
| #ifdef __LP64__ |
| |
| /* This function is needed to translate 32 bit pt_regs offsets in to |
| * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel |
| * will request offset 12 if it wants gr3, but the lower 32 bits of |
| * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4). |
| * This code relies on a 32 bit pt_regs being comprised of 32 bit values |
| * except for the fp registers which (a) are 64 bits, and (b) follow |
| * the gr registers at the start of pt_regs. The 32 bit pt_regs should |
| * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[] |
| * being 64 bit in both cases. |
| */ |
| |
| static long translate_usr_offset(long offset) |
| { |
| if (offset < 0) |
| return -1; |
| else if (offset <= 32*4) /* gr[0..31] */ |
| return offset * 2 + 4; |
| else if (offset <= 32*4+32*8) /* gr[0..31] + fr[0..31] */ |
| return offset + 32*4; |
| else if (offset < sizeof(struct pt_regs)/2 + 32*4) |
| return offset * 2 + 4 - 32*8; |
| else |
| return -1; |
| } |
| #endif |
| |
| /* |
| * 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 trap bits are not set */ |
| pa_psw(child)->r = 0; |
| pa_psw(child)->t = 0; |
| pa_psw(child)->h = 0; |
| pa_psw(child)->l = 0; |
| } |
| |
| long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
| { |
| long ret; |
| #ifdef DEBUG_PTRACE |
| long oaddr=addr, odata=data; |
| #endif |
| |
| switch (request) { |
| case PTRACE_PEEKTEXT: /* read word at location addr. */ |
| case PTRACE_PEEKDATA: { |
| int copied; |
| |
| #ifdef __LP64__ |
| if (is_compat_task(child)) { |
| unsigned int tmp; |
| |
| addr &= 0xffffffffL; |
| copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); |
| ret = -EIO; |
| if (copied != sizeof(tmp)) |
| goto out_tsk; |
| ret = put_user(tmp,(unsigned int *) data); |
| DBG("sys_ptrace(PEEK%s, %d, %lx, %lx) returning %ld, data %x\n", |
| request == PTRACE_PEEKTEXT ? "TEXT" : "DATA", |
| pid, oaddr, odata, ret, tmp); |
| } |
| else |
| #endif |
| { |
| unsigned long tmp; |
| |
| copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); |
| ret = -EIO; |
| if (copied != sizeof(tmp)) |
| goto out_tsk; |
| ret = put_user(tmp,(unsigned long *) data); |
| } |
| goto out_tsk; |
| } |
| |
| /* when I and D space are separate, this will have to be fixed. */ |
| case PTRACE_POKETEXT: /* write the word at location addr. */ |
| case PTRACE_POKEDATA: |
| ret = 0; |
| #ifdef __LP64__ |
| if (is_compat_task(child)) { |
| unsigned int tmp = (unsigned int)data; |
| DBG("sys_ptrace(POKE%s, %d, %lx, %lx)\n", |
| request == PTRACE_POKETEXT ? "TEXT" : "DATA", |
| pid, oaddr, odata); |
| addr &= 0xffffffffL; |
| if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1) == sizeof(tmp)) |
| goto out_tsk; |
| } |
| else |
| #endif |
| { |
| if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) |
| goto out_tsk; |
| } |
| ret = -EIO; |
| goto out_tsk; |
| |
| /* Read the word at location addr in the USER area. For ptraced |
| processes, the kernel saves all regs on a syscall. */ |
| case PTRACE_PEEKUSR: { |
| ret = -EIO; |
| #ifdef __LP64__ |
| if (is_compat_task(child)) { |
| unsigned int tmp; |
| |
| if (addr & (sizeof(int)-1)) |
| goto out_tsk; |
| if ((addr = translate_usr_offset(addr)) < 0) |
| goto out_tsk; |
| |
| tmp = *(unsigned int *) ((char *) task_regs(child) + addr); |
| ret = put_user(tmp, (unsigned int *) data); |
| DBG("sys_ptrace(PEEKUSR, %d, %lx, %lx) returning %ld, addr %lx, data %x\n", |
| pid, oaddr, odata, ret, addr, tmp); |
| } |
| else |
| #endif |
| { |
| unsigned long tmp; |
| |
| if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs)) |
| goto out_tsk; |
| tmp = *(unsigned long *) ((char *) task_regs(child) + addr); |
| ret = put_user(tmp, (unsigned long *) data); |
| } |
| goto out_tsk; |
| } |
| |
| /* Write the word at location addr in the USER area. This will need |
| to change when the kernel no longer saves all regs on a syscall. |
| FIXME. There is a problem at the moment in that r3-r18 are only |
| saved if the process is ptraced on syscall entry, and even then |
| those values are overwritten by actual register values on syscall |
| exit. */ |
| case PTRACE_POKEUSR: |
| ret = -EIO; |
| /* Some register values written here may be ignored in |
| * entry.S:syscall_restore_rfi; e.g. iaoq is written with |
| * r31/r31+4, and not with the values in pt_regs. |
| */ |
| /* PT_PSW=0, so this is valid for 32 bit processes under 64 |
| * bit kernels. |
| */ |
| if (addr == PT_PSW) { |
| /* PT_PSW=0, so this is valid for 32 bit processes |
| * under 64 bit kernels. |
| * |
| * Allow writing to Nullify, Divide-step-correction, |
| * and carry/borrow bits. |
| * BEWARE, if you set N, and then single step, it won't |
| * stop on the nullified instruction. |
| */ |
| DBG("sys_ptrace(POKEUSR, %d, %lx, %lx)\n", |
| pid, oaddr, odata); |
| data &= USER_PSW_BITS; |
| task_regs(child)->gr[0] &= ~USER_PSW_BITS; |
| task_regs(child)->gr[0] |= data; |
| ret = 0; |
| goto out_tsk; |
| } |
| #ifdef __LP64__ |
| if (is_compat_task(child)) { |
| if (addr & (sizeof(int)-1)) |
| goto out_tsk; |
| if ((addr = translate_usr_offset(addr)) < 0) |
| goto out_tsk; |
| DBG("sys_ptrace(POKEUSR, %d, %lx, %lx) addr %lx\n", |
| pid, oaddr, odata, addr); |
| if (addr >= PT_FR0 && addr <= PT_FR31 + 4) { |
| /* Special case, fp regs are 64 bits anyway */ |
| *(unsigned int *) ((char *) task_regs(child) + addr) = data; |
| ret = 0; |
| } |
| else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) || |
| addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 || |
| addr == PT_SAR+4) { |
| /* Zero the top 32 bits */ |
| *(unsigned int *) ((char *) task_regs(child) + addr - 4) = 0; |
| *(unsigned int *) ((char *) task_regs(child) + addr) = data; |
| ret = 0; |
| } |
| goto out_tsk; |
| } |
| else |
| #endif |
| { |
| if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs)) |
| goto out_tsk; |
| if ((addr >= PT_GR1 && addr <= PT_GR31) || |
| addr == PT_IAOQ0 || addr == PT_IAOQ1 || |
| (addr >= PT_FR0 && addr <= PT_FR31 + 4) || |
| addr == PT_SAR) { |
| *(unsigned long *) ((char *) task_regs(child) + addr) = data; |
| ret = 0; |
| } |
| goto out_tsk; |
| } |
| |
| case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ |
| case PTRACE_CONT: |
| ret = -EIO; |
| DBG("sys_ptrace(%s)\n", |
| request == PTRACE_SYSCALL ? "SYSCALL" : "CONT"); |
| if (!valid_signal(data)) |
| goto out_tsk; |
| child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP); |
| 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; |
| goto out_wake_notrap; |
| |
| case PTRACE_KILL: |
| /* |
| * 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. |
| */ |
| DBG("sys_ptrace(KILL)\n"); |
| if (child->exit_state == EXIT_ZOMBIE) /* already dead */ |
| goto out_tsk; |
| child->exit_code = SIGKILL; |
| goto out_wake_notrap; |
| |
| case PTRACE_SINGLEBLOCK: |
| DBG("sys_ptrace(SINGLEBLOCK)\n"); |
| ret = -EIO; |
| if (!valid_signal(data)) |
| goto out_tsk; |
| clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| child->ptrace &= ~PT_SINGLESTEP; |
| child->ptrace |= PT_BLOCKSTEP; |
| child->exit_code = data; |
| |
| /* Enable taken branch trap. */ |
| pa_psw(child)->r = 0; |
| pa_psw(child)->t = 1; |
| pa_psw(child)->h = 0; |
| pa_psw(child)->l = 0; |
| goto out_wake; |
| |
| case PTRACE_SINGLESTEP: |
| DBG("sys_ptrace(SINGLESTEP)\n"); |
| ret = -EIO; |
| if (!valid_signal(data)) |
| goto out_tsk; |
| |
| clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| child->ptrace &= ~PT_BLOCKSTEP; |
| child->ptrace |= PT_SINGLESTEP; |
| child->exit_code = data; |
| |
| if (pa_psw(child)->n) { |
| struct siginfo si; |
| |
| /* Nullified, just crank over the queue. */ |
| task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1]; |
| task_regs(child)->iasq[0] = task_regs(child)->iasq[1]; |
| task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4; |
| pa_psw(child)->n = 0; |
| pa_psw(child)->x = 0; |
| pa_psw(child)->y = 0; |
| pa_psw(child)->z = 0; |
| pa_psw(child)->b = 0; |
| ptrace_disable(child); |
| /* Don't wake up the child, but let the |
| parent know something happened. */ |
| si.si_code = TRAP_TRACE; |
| si.si_addr = (void __user *) (task_regs(child)->iaoq[0] & ~3); |
| si.si_signo = SIGTRAP; |
| si.si_errno = 0; |
| force_sig_info(SIGTRAP, &si, child); |
| //notify_parent(child, SIGCHLD); |
| //ret = 0; |
| goto out_wake; |
| } |
| |
| /* Enable recovery counter traps. The recovery counter |
| * itself will be set to zero on a task switch. If the |
| * task is suspended on a syscall then the syscall return |
| * path will overwrite the recovery counter with a suitable |
| * value such that it traps once back in user space. We |
| * disable interrupts in the childs PSW here also, to avoid |
| * interrupts while the recovery counter is decrementing. |
| */ |
| pa_psw(child)->r = 1; |
| pa_psw(child)->t = 0; |
| pa_psw(child)->h = 0; |
| pa_psw(child)->l = 0; |
| /* give it a chance to run. */ |
| goto out_wake; |
| |
| case PTRACE_DETACH: |
| ret = ptrace_detach(child, data); |
| goto out_tsk; |
| |
| case PTRACE_GETEVENTMSG: |
| ret = put_user(child->ptrace_message, (unsigned int __user *) data); |
| goto out; |
| |
| default: |
| ret = ptrace_request(child, request, addr, data); |
| goto out; |
| } |
| |
| out_wake_notrap: |
| ptrace_disable(child); |
| out_wake: |
| wake_up_process(child); |
| ret = 0; |
| out_tsk: |
| DBG("arch_ptrace(%ld, %d, %lx, %lx) returning %ld\n", |
| request, pid, oaddr, odata, ret); |
| return ret; |
| } |
| |
| void syscall_trace(void) |
| { |
| if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| return; |
| if (!(current->ptrace & PT_PTRACED)) |
| return; |
| 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) { |
| send_sig(current->exit_code, current, 1); |
| current->exit_code = 0; |
| } |
| } |