FRV: Implement new-style ptrace

Implement the new-style ptrace for FRV, including adding appropriate
tracehooks.

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

1 files changed, 123 insertions, 0 deletions

diff --git a/arch/frv/include/asm/syscall.h b/arch/frv/include/asm/syscall.h
new file mode 100644
index 000000000000..70689eb29b98
--- /dev/null
+++ b/arch/frv/include/asm/syscall.h
@@ -0,0 +1,123 @@
+/* syscall parameter access functions
+ *
+ * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _ASM_SYSCALL_H
+#define _ASM_SYSCALL_H
+
+#include <linux/err.h>
+#include <asm/ptrace.h>
+
+/*
+ * Get the system call number or -1
+ */
+static inline long syscall_get_nr(struct task_struct *task,
+                                  struct pt_regs *regs)
+{
+        return regs->syscallno;
+}
+
+/*
+ * Restore the clobbered GR8 register
+ * (1st syscall arg was overwritten with syscall return or error)
+ */
+static inline void syscall_rollback(struct task_struct *task,
+                                    struct pt_regs *regs)
+{
+        regs->gr8 = regs->orig_gr8;
+}
+
+/*
+ * See if the syscall return value is an error, returning it if it is and 0 if
+ * not
+ */
+static inline long syscall_get_error(struct task_struct *task,
+                                     struct pt_regs *regs)
+{
+        return IS_ERR_VALUE(regs->gr8) ? regs->gr8 : 0;
+}
+
+/*
+ * Get the syscall return value
+ */
+static inline long syscall_get_return_value(struct task_struct *task,
+                                            struct pt_regs *regs)
+{
+        return regs->gr8;
+}
+
+/*
+ * Set the syscall return value
+ */
+static inline void syscall_set_return_value(struct task_struct *task,
+                                            struct pt_regs *regs,
+                                            int error, long val)
+{
+        if (error)
+                regs->gr8 = -error;
+        else
+                regs->gr8 = val;
+}
+
+/*
+ * Retrieve the system call arguments
+ */
+static inline void syscall_get_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         unsigned long *args)
+{
+        /*
+         * Do this simply for now. If we need to start supporting
+         * fetching arguments from arbitrary indices, this will need some
+         * extra logic. Presently there are no in-tree users that depend
+         * on this behaviour.
+         */
+        BUG_ON(i);
+
+        /* Argument pattern is: GR8, GR9, GR10, GR11, GR12, GR13 */
+        switch (n) {
+        case 6: args[5] = regs->gr13;
+        case 5: args[4] = regs->gr12;
+        case 4: args[3] = regs->gr11;
+        case 3: args[2] = regs->gr10;
+        case 2: args[1] = regs->gr9;
+        case 1: args[0] = regs->gr8;
+                break;
+        default:
+                BUG();
+        }
+}
+
+/*
+ * Alter the system call arguments
+ */
+static inline void syscall_set_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         const unsigned long *args)
+{
+        /* Same note as above applies */
+        BUG_ON(i);
+
+        switch (n) {
+        case 6: regs->gr13 = args[5];
+        case 5: regs->gr12 = args[4];
+        case 4: regs->gr11 = args[3];
+        case 3: regs->gr10 = args[2];
+        case 2: regs->gr9  = args[1];
+        case 1: regs->gr8  = args[0];
+                break;
+        default:
+                BUG();
+        }
+}
+
+#endif /* _ASM_SYSCALL_H */