[IA64] utrace syscall.h support for ia64

Add asm/syscall.h for IA64. Utrace requires this.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

3 files changed, 163 insertions, 0 deletions

diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h
index 15f8dcfe6eee..14055c636adf 100644
--- a/arch/ia64/include/asm/ptrace.h
+++ b/arch/ia64/include/asm/ptrace.h
@@ -240,6 +240,12 @@ struct switch_stack {
  */
 # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri)
 
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+        /* FIXME: should this be bspstore + nr_dirty regs? */
+        return regs->ar_bspstore;
+}
+
 #define regs_return_value(regs) ((regs)->r8)
 
 /* Conserve space in histogram by encoding slot bits in address
diff --git a/arch/ia64/include/asm/syscall.h b/arch/ia64/include/asm/syscall.h
new file mode 100644
index 000000000000..3fd4fa6c48dd
--- /dev/null
+++ b/arch/ia64/include/asm/syscall.h
@@ -0,0 +1,92 @@
+/*
+ * Access to user system call parameters and results
+ *
+ * Copyright (C) 2008 Intel Corp.  Shaohua Li <shaohua.li@intel.com>
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ *
+ * See asm-generic/syscall.h for descriptions of what we must do here.
+ */
+
+#ifndef _ASM_SYSCALL_H
+#define _ASM_SYSCALL_H  1
+
+#include <linux/sched.h>
+#include <linux/err.h>
+
+static inline long syscall_get_nr(struct task_struct *task,
+                                  struct pt_regs *regs)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+
+        if ((long)regs->cr_ifs < 0) /* Not a syscall */
+                return -1;
+        return regs->r15;
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+                                    struct pt_regs *regs)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+        /* do nothing */
+}
+
+static inline long syscall_get_error(struct task_struct *task,
+                                     struct pt_regs *regs)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+
+        return regs->r10 == -1 ? regs->r8:0;
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+                                            struct pt_regs *regs)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+
+        return regs->r8;
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+                                            struct pt_regs *regs,
+                                            int error, long val)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+
+        if (error) {
+                /* error < 0, but ia64 uses > 0 return value */
+                regs->r8 = -error;
+                regs->r10 = -1;
+        } else {
+                regs->r8 = val;
+                regs->r10 = 0;
+        }
+}
+
+extern void ia64_syscall_get_set_arguments(struct task_struct *task,
+        struct pt_regs *regs, unsigned int i, unsigned int n,
+        unsigned long *args, int rw);
+static inline void syscall_get_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         unsigned long *args)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+        BUG_ON(i + n > 6);
+
+        ia64_syscall_get_set_arguments(task, regs, i, n, args, 0);
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+                                         struct pt_regs *regs,
+                                         unsigned int i, unsigned int n,
+                                         unsigned long *args)
+{
+        BUG_ON(IS_IA32_PROCESS(regs));
+        BUG_ON(i + n > 6);
+
+        ia64_syscall_get_set_arguments(task, regs, i, n, args, 1);
+}
+#endif  /* _ASM_SYSCALL_H */
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 2a9943b5947f..12b1e9f0b7ae 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -2199,3 +2199,68 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
 #endif
         return &user_ia64_view;
 }
+
+struct syscall_get_set_args {
+        unsigned int i;
+        unsigned int n;
+        unsigned long *args;
+        struct pt_regs *regs;
+        int rw;
+};
+
+static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
+{
+        struct syscall_get_set_args *args = data;
+        struct pt_regs *pt = args->regs;
+        unsigned long *krbs, cfm, ndirty;
+        int i, count;
+
+        if (unw_unwind_to_user(info) < 0)
+                return;
+
+        cfm = pt->cr_ifs;
+        krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
+        ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
+
+        count = 0;
+        if (in_syscall(pt))
+                count = min_t(int, args->n, cfm & 0x7f);
+
+        for (i = 0; i < count; i++) {
+                if (args->rw)
+                        *ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
+                                args->args[i];
+                else
+                        args->args[i] = *ia64_rse_skip_regs(krbs,
+                                ndirty + i + args->i);
+        }
+
+        if (!args->rw) {
+                while (i < args->n) {
+                        args->args[i] = 0;
+                        i++;
+                }
+        }
+}
+
+void ia64_syscall_get_set_arguments(struct task_struct *task,
+        struct pt_regs *regs, unsigned int i, unsigned int n,
+        unsigned long *args, int rw)
+{
+        struct syscall_get_set_args data = {
+                .i = i,
+                .n = n,
+                .args = args,
+                .regs = regs,
+                .rw = rw,
+        };
+
+        if (task == current)
+                unw_init_running(syscall_get_set_args_cb, &data);
+        else {
+                struct unw_frame_info ufi;
+                memset(&ufi, 0, sizeof(ufi));
+                unw_init_from_blocked_task(&ufi, task);
+                syscall_get_set_args_cb(&ufi, &data);
+        }
+}