Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* By Ross Biro 1/23/92 */

/*

 * Pentium III FXSR, SSE support

 *      Gareth Hughes <gareth@valinux.com>, May 2000

 */

#include <linux/kernel.h>

#include <linux/sched.h>

#include <linux/mm.h>

#include <linux/smp.h>

#include <linux/errno.h>

#include <linux/ptrace.h>

#include <linux/user.h>

#include <linux/security.h>

#include <linux/audit.h>

#include <linux/seccomp.h>

#include <linux/signal.h>

#include <asm/uaccess.h>

#include <asm/pgtable.h>

#include <asm/system.h>

#include <asm/processor.h>

#include <asm/i387.h>

#include <asm/debugreg.h>

#include <asm/ldt.h>

#include <asm/desc.h>

/*

 * does not yet catch signals sent when the child dies.

 * in exit.c or in signal.c.

 */

/*

 * Determines which flags the user has access to [1 = access, 0 = no access].

 * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).

 * Also masks reserved bits (31-22, 15, 5, 3, 1).

 */

#define FLAG_MASK 0x00050dd5

/* set's the trap flag. */

#define TRAP_FLAG 0x100

/*

 * Offset of eflags on child stack..

 */

#define EFL_OFFSET offsetof(struct pt_regs, eflags)

static inline struct pt_regs *get_child_regs(struct task_struct *task)

{

        void *stack_top = (void *)task->thread.esp0;

        return stack_top - sizeof(struct pt_regs);

}

/*

 * This routine will get a word off of the processes privileged stack.

 * the offset is bytes into the pt_regs structure on the stack.

 * This routine assumes that all the privileged stacks are in our

 * data space.

 */

static inline int get_stack_long(struct task_struct *task, int offset)

{

        unsigned char *stack;

        stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);

        stack += offset;

        return (*((int *)stack));

}

/*

 * This routine will put a word on the processes privileged stack.

 * the offset is bytes into the pt_regs structure on the stack.

 * This routine assumes that all the privileged stacks are in our

 * data space.

 */

static inline int put_stack_long(struct task_struct *task, int offset,

        unsigned long data)

{

        unsigned char * stack;

        stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs);

        stack += offset;

        *(unsigned long *) stack = data;

        return 0;

}

static int putreg(struct task_struct *child,

        unsigned long regno, unsigned long value)

{

        switch (regno >> 2) {

                case GS:

                        if (value && (value & 3) != 3)

                                return -EIO;

                        child->thread.gs = value;

                        return 0;

                case DS:

                case ES:

                case FS:

                        if (value && (value & 3) != 3)

                                return -EIO;

                        value &= 0xffff;

                        break;

                case SS:

                case CS:

                        if ((value & 3) != 3)

                                return -EIO;

                        value &= 0xffff;

                        break;

                case EFL:

                        value &= FLAG_MASK;

                        value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK;

                        break;

        }

        if (regno > FS*4)

                regno -= 1*4;

        put_stack_long(child, regno, value);

        return 0;

}

static unsigned long getreg(struct task_struct *child,

        unsigned long regno)

{

        unsigned long retval = ~0UL;

        switch (regno >> 2) {

                case GS:

                        retval = child->thread.gs;

                        break;

                case DS:

                case ES:

                case FS:

                case SS:

                case CS:

                        retval = 0xffff;

                        /* fall through */

                default:

                        if (regno > FS*4)

                                regno -= 1*4;

                        retval &= get_stack_long(child, regno);

        }

        return retval;

}

#define LDT_SEGMENT 4

static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs)

{

        unsigned long addr, seg;

        addr = regs->eip;

        seg = regs->xcs & 0xffff;

        if (regs->eflags & VM_MASK) {

                addr = (addr & 0xffff) + (seg << 4);

                return addr;

        }

        /*

         * We'll assume that the code segments in the GDT

         * are all zero-based. That is largely true: the

         * TLS segments are used for data, and the PNPBIOS

         * and APM bios ones we just ignore here.

         */

        if (seg & LDT_SEGMENT) {

                u32 *desc;

                unsigned long base;

                seg &= ~7UL;

                mutex_lock(&child->mm->context.lock);

                if (unlikely((seg >> 3) >= child->mm->context.size))

                        addr = -1L; /* bogus selector, access would fault */

                else {

                        desc = child->mm->context.ldt + seg;

                        base = ((desc[0] >> 16) |

                                ((desc[1] & 0xff) << 16) |

                                (desc[1] & 0xff000000));

                        /* 16-bit code segment? */

                        if (!((desc[1] >> 22) & 1))

                                addr &= 0xffff;

                        addr += base;

                }

                mutex_unlock(&child->mm->context.lock);

        }

        return addr;

}

static inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)

{

        int i, copied;

        unsigned char opcode[15];

        unsigned long addr = convert_eip_to_linear(child, regs);

        copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0);

        for (i = 0; i < copied; i++) {

                switch (opcode[i]) {

                /* popf and iret */

                case 0x9d: case 0xcf:

                        return 1;

                /* opcode and address size prefixes */

                case 0x66: case 0x67:

                        continue;

                /* irrelevant prefixes (segment overrides and repeats) */

                case 0x26: case 0x2e:

                case 0x36: case 0x3e:

                case 0x64: case 0x65:

                case 0xf0: case 0xf2: case 0xf3:

                        continue;

                /*

                 * pushf: NOTE! We should probably not let

                 * the user see the TF bit being set. But

                 * it's more pain than it's worth to avoid

                 * it, and a debugger could emulate this

                 * all in user space if it _really_ cares.

                 */

                case 0x9c:

                default:

                        return 0;

                }

        }

        return 0;

}

static void set_singlestep(struct task_struct *child)

{

        struct pt_regs *regs = get_child_regs(child);

        /*

         * Always set TIF_SINGLESTEP - this guarantees that

         * we single-step system calls etc..  This will also

         * cause us to set TF when returning to user mode.

         */

        set_tsk_thread_flag(child, TIF_SINGLESTEP);

        /*

         * If TF was already set, don't do anything else

         */

        if (regs->eflags & TRAP_FLAG)

                return;

        /* Set TF on the kernel stack.. */

        regs->eflags |= TRAP_FLAG;

        /*

         * ..but if TF is changed by the instruction we will trace,

         * don't mark it as being "us" that set it, so that we

         * won't clear it by hand later.

         */

        if (is_setting_trap_flag(child, regs))

                return;

        child->ptrace |= PT_DTRACE;

}

static void clear_singlestep(struct task_struct *child)

{

        /* Always clear TIF_SINGLESTEP... */

        clear_tsk_thread_flag(child, TIF_SINGLESTEP);

        /* But touch TF only if it was set by us.. */

        if (child->ptrace & PT_DTRACE) {

                struct pt_regs *regs = get_child_regs(child);

                regs->eflags &= ~TRAP_FLAG;

                child->ptrace &= ~PT_DTRACE;

        }

}

/*

 * Called by kernel/ptrace.c when detaching..

 *

 * Make sure the single step bit is not set.

 */

void ptrace_disable(struct task_struct *child)

{

        clear_singlestep(child);

        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);

}

/*

 * Perform get_thread_area on behalf of the traced child.

 */

static int

ptrace_get_thread_area(struct task_struct *child,

                       int idx, struct user_desc __user *user_desc)

{

        struct user_desc info;

        struct desc_struct *desc;

/*

 * Get the current Thread-Local Storage area:

 */

#define GET_BASE(desc) ( \

        (((desc)->a >> 16) & 0x0000ffff) | \

        (((desc)->b << 16) & 0x00ff0000) | \

        ( (desc)->b        & 0xff000000)   )

#define GET_LIMIT(desc) ( \

        ((desc)->a & 0x0ffff) | \

         ((desc)->b & 0xf0000) )

#define GET_32BIT(desc)         (((desc)->b >> 22) & 1)

#define GET_CONTENTS(desc)      (((desc)->b >> 10) & 3)

#define GET_WRITABLE(desc)      (((desc)->b >>  9) & 1)

#define GET_LIMIT_PAGES(desc)   (((desc)->b >> 23) & 1)

#define GET_PRESENT(desc)       (((desc)->b >> 15) & 1)

#define GET_USEABLE(desc)       (((desc)->b >> 20) & 1)

        if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)

                return -EINVAL;

        desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;

        info.entry_number = idx;

        info.base_addr = GET_BASE(desc);

        info.limit = GET_LIMIT(desc);

        info.seg_32bit = GET_32BIT(desc);

        info.contents = GET_CONTENTS(desc);

        info.read_exec_only = !GET_WRITABLE(desc);

        info.limit_in_pages = GET_LIMIT_PAGES(desc);

        info.seg_not_present = !GET_PRESENT(desc);

        info.useable = GET_USEABLE(desc);

        if (copy_to_user(user_desc, &info, sizeof(info)))

                return -EFAULT;

        return 0;

}

/*

 * Perform set_thread_area on behalf of the traced child.

 */

static int

ptrace_set_thread_area(struct task_struct *child,

                       int idx, struct user_desc __user *user_desc)

{

        struct user_desc info;

        struct desc_struct *desc;

        if (copy_from_user(&info, user_desc, sizeof(info)))

                return -EFAULT;

        if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)

                return -EINVAL;

        desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;

        if (LDT_empty(&info)) {

                desc->a = 0;

                desc->b = 0;

        } else {

                desc->a = LDT_entry_a(&info);

                desc->b = LDT_entry_b(&info);

        }

        return 0;

}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)

{

        struct user * dummy = NULL;

        int i, ret;

        unsigned long __user *datap = (unsigned long __user *)data;

        switch (request) {

        /* when I and D space are separate, these will need to be fixed. */

        case PTRACE_PEEKTEXT: /* read word at location addr. */

        case PTRACE_PEEKDATA:

                ret = generic_ptrace_peekdata(child, addr, data);

                break;

        /* read the word at location addr in the USER area. */

        case PTRACE_PEEKUSR: {

                unsigned long tmp;

                ret = -EIO;

                if ((addr & 3) || addr < 0 ||

                    addr > sizeof(struct user) - 3)

                        break;

                tmp = 0;  /* Default return condition */

                if(addr < FRAME_SIZE*sizeof(long))

                        tmp = getreg(child, addr);

                if(addr >= (long) &dummy->u_debugreg[0] &&

                   addr <= (long) &dummy->u_debugreg[7]){

                        addr -= (long) &dummy->u_debugreg[0];

                        addr = addr >> 2;

                        tmp = child->thread.debugreg[addr];

                }

                ret = put_user(tmp, datap);

                break;

        }

        /* 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 = generic_ptrace_pokedata(child, addr, data);

                break;

        case PTRACE_POKEUSR: /* write the word at location addr in the USER area */

                ret = -EIO;

                if ((addr & 3) || addr < 0 ||

                    addr > sizeof(struct user) - 3)

                        break;

                if (addr < FRAME_SIZE*sizeof(long)) {

                        ret = putreg(child, addr, data);

                        break;

                }

                /* We need to be very careful here.  We implicitly

                   want to modify a portion of the task_struct, and we

                   have to be selective about what portions we allow someone

                   to modify. */

                  ret = -EIO;

                  if(addr >= (long) &dummy->u_debugreg[0] &&

                     addr <= (long) &dummy->u_debugreg[7]){

                          if(addr == (long) &dummy->u_debugreg[4]) break;

                          if(addr == (long) &dummy->u_debugreg[5]) break;

                          if(addr < (long) &dummy->u_debugreg[4] &&

                             ((unsigned long) data) >= TASK_SIZE-3) break;

                          /* Sanity-check data. Take one half-byte at once with

                           * check = (val >> (16 + 4*i)) & 0xf. It contains the

                           * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits

                           * 2 and 3 are LENi. Given a list of invalid values,

                           * we do mask |= 1 << invalid_value, so that

                           * (mask >> check) & 1 is a correct test for invalid

                           * values.

                           *

                           * R/Wi contains the type of the breakpoint /

                           * watchpoint, LENi contains the length of the watched

                           * data in the watchpoint case.

                           *

                           * The invalid values are:

                           * - LENi == 0x10 (undefined), so mask |= 0x0f00.

                           * - R/Wi == 0x10 (break on I/O reads or writes), so

                           *   mask |= 0x4444.

                           * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=

                           *   0x1110.

                           *

                           * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.

                           *

                           * See the Intel Manual "System Programming Guide",

                           * 15.2.4

                           *

                           * Note that LENi == 0x10 is defined on x86_64 in long

                           * mode (i.e. even for 32-bit userspace software, but

                           * 64-bit kernel), so the x86_64 mask value is 0x5454.

                           * See the AMD manual no. 24593 (AMD64 System

                           * Programming)*/

                          if(addr == (long) &dummy->u_debugreg[7]) {

                                  data &= ~DR_CONTROL_RESERVED;

                                  for(i=0; i<4; i++)

                                          if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)

                                                  goto out_tsk;

                                  if (data)

                                          set_tsk_thread_flag(child, TIF_DEBUG);

                                  else

                                          clear_tsk_thread_flag(child, TIF_DEBUG);

                          }

                          addr -= (long) &dummy->u_debugreg;

                          addr = addr >> 2;

                          child->thread.debugreg[addr] = data;

                          ret = 0;

                  }

                  break;

        case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */

        case PTRACE_SYSCALL:    /* continue and stop at next (return from) syscall */

        case PTRACE_CONT:       /* restart after signal. */

                ret = -EIO;

                if (!valid_signal(data))

                        break;

                if (request == PTRACE_SYSEMU) {

                        set_tsk_thread_flag(child, TIF_SYSCALL_EMU);

                        clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

                } else if (request == PTRACE_SYSCALL) {

                        set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

                        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);

                } else {

                        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);

                        clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

                }

                child->exit_code = data;

                /* make sure the single step bit is not set. */

                clear_singlestep(child);

                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)   /* already dead */

                        break;

                child->exit_code = SIGKILL;

                /* make sure the single step bit is not set. */

                clear_singlestep(child);

                wake_up_process(child);

                break;

        case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */

        case PTRACE_SINGLESTEP: /* set the trap flag. */

                ret = -EIO;

                if (!valid_signal(data))

                        break;

                if (request == PTRACE_SYSEMU_SINGLESTEP)

                        set_tsk_thread_flag(child, TIF_SYSCALL_EMU);

                else

                        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);

                clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

                set_singlestep(child);

                child->exit_code = data;

                /* give it a chance to run. */

                wake_up_process(child);

                ret = 0;

                break;

        case PTRACE_GETREGS: { /* Get all gp regs from the child. */

                if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {

                        ret = -EIO;

                        break;

                }

                for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {

                        __put_user(getreg(child, i), datap);

                        datap++;

                }

                ret = 0;

                break;

        }

        case PTRACE_SETREGS: { /* Set all gp regs in the child. */

                unsigned long tmp;

                if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {

                        ret = -EIO;

                        break;

                }

                for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {

                        __get_user(tmp, datap);

                        putreg(child, i, tmp);

                        datap++;

                }

                ret = 0;

                break;

        }

        case PTRACE_GETFPREGS: { /* Get the child FPU state. */

                if (!access_ok(VERIFY_WRITE, datap,

                               sizeof(struct user_i387_struct))) {

                        ret = -EIO;

                        break;

                }

                ret = 0;

                if (!tsk_used_math(child))

                        init_fpu(child);

                get_fpregs((struct user_i387_struct __user *)data, child);

                break;

        }

        case PTRACE_SETFPREGS: { /* Set the child FPU state. */

                if (!access_ok(VERIFY_READ, datap,

                               sizeof(struct user_i387_struct))) {

                        ret = -EIO;

                        break;

                }

                set_stopped_child_used_math(child);

                set_fpregs(child, (struct user_i387_struct __user *)data);

                ret = 0;

                break;

        }

        case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */

                if (!access_ok(VERIFY_WRITE, datap,

                               sizeof(struct user_fxsr_struct))) {

                        ret = -EIO;

                        break;

                }

                if (!tsk_used_math(child))

                        init_fpu(child);

                ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);

                break;

        }

        case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */

                if (!access_ok(VERIFY_READ, datap,

                               sizeof(struct user_fxsr_struct))) {

                        ret = -EIO;

                        break;

                }

                set_stopped_child_used_math(child);

                ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);

                break;

        }

        case PTRACE_GET_THREAD_AREA:

                ret = ptrace_get_thread_area(child, addr,

                                        (struct user_desc __user *) data);

                break;

        case PTRACE_SET_THREAD_AREA:

                ret = ptrace_set_thread_area(child, addr,

                                        (struct user_desc __user *) data);

                break;

        default:

                ret = ptrace_request(child, request, addr, data);

                break;

        }

 out_tsk:

        return ret;

}

void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)

{

        struct siginfo info;

        tsk->thread.trap_no = 1;

        tsk->thread.error_code = error_code;

        memset(&info, 0, sizeof(info));

        info.si_signo = SIGTRAP;

        info.si_code = TRAP_BRKPT;

        /* User-mode eip? */

        info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;

        /* Send us the fake SIGTRAP */

        force_sig_info(SIGTRAP, &info, tsk);

}

/* notification of system call entry/exit

 * - triggered by current->work.syscall_trace

 */

__attribute__((regparm(3)))

int do_syscall_trace(struct pt_regs *regs, int entryexit)

{

        int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);

        /*

         * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall

         * interception

         */

        int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);

        int ret = 0;

        /* do the secure computing check first */

        if (!entryexit)

                secure_computing(regs->orig_eax);

        if (unlikely(current->audit_context)) {

                if (entryexit)

                        audit_syscall_exit(AUDITSC_RESULT(regs->eax),

                                                regs->eax);

                /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only

                 * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is

                 * not used, entry.S will call us only on syscall exit, not

                 * entry; so when TIF_SYSCALL_AUDIT is used we must avoid

                 * calling send_sigtrap() on syscall entry.

                 *

                 * Note that when PTRACE_SYSEMU_SINGLESTEP is used,

                 * is_singlestep is false, despite his name, so we will still do