MN10300: Add utrace/tracehooks support

Add utrace/tracehooks support to MN10300.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 231 insertions, 223 deletions

diff --git a/arch/mn10300/kernel/ptrace.c b/arch/mn10300/kernel/ptrace.c
index d6d6cdc75c52..e143339ad28e 100644
--- a/arch/mn10300/kernel/ptrace.c
+++ b/arch/mn10300/kernel/ptrace.c
@@ -17,6 +17,9 @@
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+#include <linux/tracehook.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -64,12 +67,6 @@ static inline int get_stack_long(struct task_struct *task, int offset)
                 ((unsigned long) task->thread.uregs + offset);
 }
 
-/*
- * this routine will put a word on the processes privileged stack.
- * the offset is how far from the base addr as stored in the TSS.
- * 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)
 {
@@ -80,94 +77,233 @@ int put_stack_long(struct task_struct *task, int offset, unsigned long data)
         return 0;
 }
 
-static inline unsigned long get_fpregs(struct fpu_state_struct *buf,
-                                       struct task_struct *tsk)
+/*
+ * retrieve the contents of MN10300 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)
 {
-        return __copy_to_user(buf, &tsk->thread.fpu_state,
-                              sizeof(struct fpu_state_struct));
+        const struct pt_regs *regs = task_pt_regs(target);
+        int ret;
+
+        /* we need to skip regs->next */
+        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  regs, 0, PT_ORIG_D0 * sizeof(long));
+        if (ret < 0)
+                return ret;
+
+        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
+                                  NR_PTREGS * sizeof(long));
+        if (ret < 0)
+                return ret;
+
+        return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+                                        NR_PTREGS * sizeof(long), -1);
 }
 
-static inline unsigned long set_fpregs(struct task_struct *tsk,
-                                       struct fpu_state_struct *buf)
+/*
+ * update the contents of the MN10300 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)
 {
-        return __copy_from_user(&tsk->thread.fpu_state, buf,
-                                sizeof(struct fpu_state_struct));
+        struct pt_regs *regs = task_pt_regs(target);
+        unsigned long tmp;
+        int ret;
+
+        /* we need to skip regs->next */
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 regs, 0, PT_ORIG_D0 * sizeof(long));
+        if (ret < 0)
+                return ret;
+
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 &regs->orig_d0, PT_ORIG_D0 * sizeof(long),
+                                 PT_EPSW * sizeof(long));
+        if (ret < 0)
+                return ret;
+
+        /* we need to mask off changes to EPSW */
+        tmp = regs->epsw;
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 &tmp, PT_EPSW * sizeof(long),
+                                 PT_PC * sizeof(long));
+        tmp &= EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N | EPSW_FLAG_Z;
+        tmp |= regs->epsw & ~(EPSW_FLAG_V | EPSW_FLAG_C | EPSW_FLAG_N |
+                              EPSW_FLAG_Z);
+        regs->epsw = tmp;
+
+        if (ret < 0)
+                return ret;
+
+        /* and finally load the PC */
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 &regs->pc, PT_PC * sizeof(long),
+                                 NR_PTREGS * sizeof(long));
+
+        if (ret < 0)
+                return ret;
+
+        return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+                                         NR_PTREGS * sizeof(long), -1);
 }
 
-static inline void fpsave_init(struct task_struct *task)
+/*
+ * retrieve the contents of MN10300 userspace FPU registers
+ */
+static int fpuregs_get(struct task_struct *target,
+                       const struct user_regset *regset,
+                       unsigned int pos, unsigned int count,
+                       void *kbuf, void __user *ubuf)
 {
-        memset(&task->thread.fpu_state, 0, sizeof(struct fpu_state_struct));
+        const struct fpu_state_struct *fpregs = &target->thread.fpu_state;
+        int ret;
+
+        unlazy_fpu(target);
+
+        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  fpregs, 0, sizeof(*fpregs));
+        if (ret < 0)
+                return ret;
+
+        return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+                                        sizeof(*fpregs), -1);
 }
 
 /*
- * make sure the single step bit is not set
+ * update the contents of the MN10300 userspace FPU registers
  */
-void ptrace_disable(struct task_struct *child)
+static int fpuregs_set(struct task_struct *target,
+                       const struct user_regset *regset,
+                       unsigned int pos, unsigned int count,
+                       const void *kbuf, const void __user *ubuf)
+{
+        struct fpu_state_struct fpu_state = target->thread.fpu_state;
+        int ret;
+
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                                 &fpu_state, 0, sizeof(fpu_state));
+        if (ret < 0)
+                return ret;
+
+        fpu_kill_state(target);
+        target->thread.fpu_state = fpu_state;
+        set_using_fpu(target);
+
+        return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+                                         sizeof(fpu_state), -1);
+}
+
+/*
+ * determine if the FPU registers have actually been used
+ */
+static int fpuregs_active(struct task_struct *target,
+                          const struct user_regset *regset)
+{
+        return is_using_fpu(target) ? regset->n : 0;
+}
+
+/*
+ * Define the register sets available on the MN10300 under Linux
+ */
+enum mn10300_regset {
+        REGSET_GENERAL,
+        REGSET_FPU,
+};
+
+static const struct user_regset mn10300_regsets[] = {
+        /*
+         * General register format is:
+         *      A3, A2, D3, D2, MCVF, MCRL, MCRH, MDRQ
+         *      E1, E0, E7...E2, SP, LAR, LIR, MDR
+         *      A1, A0, D1, D0, ORIG_D0, EPSW, PC
+         */
+        [REGSET_GENERAL] = {
+                .core_note_type = NT_PRSTATUS,
+                .n              = ELF_NGREG,
+                .size           = sizeof(long),
+                .align          = sizeof(long),
+                .get            = genregs_get,
+                .set            = genregs_set,
+        },
+        /*
+         * FPU register format is:
+         *      FS0-31, FPCR
+         */
+        [REGSET_FPU] = {
+                .core_note_type = NT_PRFPREG,
+                .n              = sizeof(struct fpu_state_struct) / sizeof(long),
+                .size           = sizeof(long),
+                .align          = sizeof(long),
+                .get            = fpuregs_get,
+                .set            = fpuregs_set,
+                .active         = fpuregs_active,
+        },
+};
+
+static const struct user_regset_view user_mn10300_native_view = {
+        .name           = "mn10300",
+        .e_machine      = EM_MN10300,
+        .regsets        = mn10300_regsets,
+        .n              = ARRAY_SIZE(mn10300_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+        return &user_mn10300_native_view;
+}
+
+/*
+ * set the single-step bit
+ */
+void user_enable_single_step(struct task_struct *child)
 {
 #ifndef CONFIG_MN10300_USING_JTAG
         struct user *dummy = NULL;
         long tmp;
 
         tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
-        tmp &= ~EPSW_T;
+        tmp |= EPSW_T;
         put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
 #endif
 }
 
 /*
- * set the single step bit
+ * make sure the single-step bit is not set
  */
-void ptrace_enable(struct task_struct *child)
+void user_disable_single_step(struct task_struct *child)
 {
 #ifndef CONFIG_MN10300_USING_JTAG
         struct user *dummy = NULL;
         long tmp;
 
         tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
-        tmp |= EPSW_T;
+        tmp &= ~EPSW_T;
         put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
 #endif
 }
 
+void ptrace_disable(struct task_struct *child)
+{
+        user_disable_single_step(child);
+}
+
 /*
  * handle the arch-specific side of process tracing
  */
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
-        struct fpu_state_struct fpu_state;
-        int i, ret;
+        unsigned long tmp;
+        int ret;
 
         switch (request) {
-        /* read the word at location addr. */
-        case PTRACE_PEEKTEXT: {
-                unsigned long tmp;
-                int copied;
-
-                copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
-                ret = -EIO;
-                if (copied != sizeof(tmp))
-                        break;
-                ret = put_user(tmp, (unsigned long *) data);
-                break;
-        }
-
-        /* read the word at location addr. */
-        case PTRACE_PEEKDATA: {
-                unsigned long tmp;
-                int copied;
-
-                copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
-                ret = -EIO;
-                if (copied != sizeof(tmp))
-                        break;
-                ret = put_user(tmp, (unsigned long *) data);
-                break;
-        }
-
         /* read the word at location addr in the USER area. */
-        case PTRACE_PEEKUSR: {
-                unsigned long tmp;
-
+        case PTRACE_PEEKUSR:
                 ret = -EIO;
                 if ((addr & 3) || addr < 0 ||
                     addr > sizeof(struct user) - 3)
@@ -179,17 +315,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                                              ptrace_regid_to_frame[addr]);
                 ret = put_user(tmp, (unsigned long *) data);
                 break;
-        }
-
-        /* write the word at location addr. */
-        case PTRACE_POKETEXT:
-        case PTRACE_POKEDATA:
-                if (access_process_vm(child, addr, &data, sizeof(data), 1) ==
-                    sizeof(data))
-                        ret = 0;
-                else
-                        ret = -EIO;
-                break;
 
                 /* write the word at location addr in the USER area */
         case PTRACE_POKEUSR:
@@ -204,132 +329,32 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                                              data);
                 break;
 
-                /* continue and stop at next (return from) syscall */
-        case PTRACE_SYSCALL:
-                /* restart after signal. */
-        case PTRACE_CONT:
-                ret = -EIO;
-                if ((unsigned long) data > _NSIG)
-                        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;
-                ptrace_disable(child);
-                wake_up_process(child);
-                ret = 0;
-                break;
-
-                /*
-                 * make the child exit
-                 * - the 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;
-                clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-                ptrace_disable(child);
-                wake_up_process(child);
-                break;
-
-        case PTRACE_SINGLESTEP: /* set the trap flag. */
-#ifndef CONFIG_MN10300_USING_JTAG
-                ret = -EIO;
-                if ((unsigned long) data > _NSIG)
-                        break;
-                clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-                ptrace_enable(child);
-                child->exit_code = data;
-                wake_up_process(child);
-                ret = 0;
-#else
-                ret = -EINVAL;
-#endif
-                break;
-
-        case PTRACE_DETACH:     /* detach a process that was attached. */
-                ret = ptrace_detach(child, data);
-                break;
-
-                /* Get all gp regs from the child. */
-        case PTRACE_GETREGS: {
-                unsigned long tmp;
-
-                if (!access_ok(VERIFY_WRITE, (unsigned *) data, NR_PTREGS << 2)) {
-                        ret = -EIO;
-                        break;
-                }
-
-                for (i = 0; i < NR_PTREGS << 2; i += 4) {
-                        tmp = get_stack_long(child, ptrace_regid_to_frame[i]);
-                        __put_user(tmp, (unsigned long *) data);
-                        data += sizeof(tmp);
-                }
-                ret = 0;
-                break;
-        }
-
-        case PTRACE_SETREGS: { /* Set all gp regs in the child. */
-                unsigned long tmp;
-
-                if (!access_ok(VERIFY_READ, (unsigned long *)data,
-                               sizeof(struct pt_regs))) {
-                        ret = -EIO;
-                        break;
-                }
-
-                for (i = 0; i < NR_PTREGS << 2; i += 4) {
-                        __get_user(tmp, (unsigned long *) data);
-                        put_stack_long(child, ptrace_regid_to_frame[i], tmp);
-                        data += sizeof(tmp);
-                }
-                ret = 0;
-                break;
-        }
-
-        case PTRACE_GETFPREGS: { /* Get the child FPU state. */
-                if (is_using_fpu(child)) {
-                        unlazy_fpu(child);
-                        fpu_state = child->thread.fpu_state;
-                } else {
-                        memset(&fpu_state, 0, sizeof(fpu_state));
-                }
-
-                ret = -EIO;
-                if (copy_to_user((void *) data, &fpu_state,
-                                 sizeof(fpu_state)) == 0)
-                        ret = 0;
-                break;
-        }
-
-        case PTRACE_SETFPREGS: { /* Set the child FPU state. */
-                ret = -EFAULT;
-                if (copy_from_user(&fpu_state, (const void *) data,
-                                   sizeof(fpu_state)) == 0) {
-                        fpu_kill_state(child);
-                        child->thread.fpu_state = fpu_state;
-                        set_using_fpu(child);
-                        ret = 0;
-                }
-                break;
-        }
-
-        case PTRACE_SETOPTIONS: {
-                if (data & PTRACE_O_TRACESYSGOOD)
-                        child->ptrace |= PT_TRACESYSGOOD;
-                else
-                        child->ptrace &= ~PT_TRACESYSGOOD;
-                ret = 0;
-                break;
-        }
+        case PTRACE_GETREGS:    /* Get all integer regs from the child. */
+                return copy_regset_to_user(child, &user_mn10300_native_view,
+                                           REGSET_GENERAL,
+                                           0, NR_PTREGS * sizeof(long),
+                                           (void __user *)data);
+
+        case PTRACE_SETREGS:    /* Set all integer regs in the child. */
+                return copy_regset_from_user(child, &user_mn10300_native_view,
+                                             REGSET_GENERAL,
+                                             0, NR_PTREGS * sizeof(long),
+                                             (const void __user *)data);
+
+        case PTRACE_GETFPREGS:  /* Get the child FPU state. */
+                return copy_regset_to_user(child, &user_mn10300_native_view,
+                                           REGSET_FPU,
+                                           0, sizeof(struct fpu_state_struct),
+                                           (void __user *)data);
+
+        case PTRACE_SETFPREGS:  /* Set the child FPU state. */
+                return copy_regset_from_user(child, &user_mn10300_native_view,
+                                             REGSET_FPU,
+                                             0, sizeof(struct fpu_state_struct),
+                                             (const void __user *)data);
 
         default:
-                ret = -EIO;
+                ret = ptrace_request(child, request, addr, data);
                 break;
         }
 
@@ -337,43 +362,26 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 }
 
 /*
- * notification of system call entry/exit
- * - triggered by current->work.syscall_trace
+ * handle tracing of system call entry
+ * - return the revised system call number or ULONG_MAX to cause ENOSYS
  */
-asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
+asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
 {
-#if 0
-        /* just in case... */
-        printk(KERN_DEBUG "[%d] syscall_%lu(%lx,%lx,%lx,%lx) = %lx\n",
-               current->pid,
-               regs->orig_d0,
-               regs->a0,
-               regs->d1,
-               regs->a3,
-               regs->a2,
-               regs->d0);
-        return;
-#endif
-
-        if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
-            !test_thread_flag(TIF_SINGLESTEP))
-                return;
-        if (!(current->ptrace & PT_PTRACED))
-                return;
+        if (tracehook_report_syscall_entry(regs))
+                /* tracing decided this syscall should not happen, so
+                 * We'll return a bogus call number to get an ENOSYS
+                 * error, but leave the original number in
+                 * regs->orig_d0
+                 */
+                return ULONG_MAX;
 
-        /* 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) &&
-                       !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
+        return regs->orig_d0;
+}
 
-        /*
-         * 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;
-        }
+/*
+ * handle tracing of system call exit
+ */
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
+        tracehook_report_syscall_exit(regs, 0);
 }