C6X: ptrace support
Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/c6x/kernel/ptrace.c b/arch/c6x/kernel/ptrace.c
new file mode 100644
index 0000000..3c494e8
--- /dev/null
+++ b/arch/c6x/kernel/ptrace.c
@@ -0,0 +1,187 @@
+/*
+ * Port on Texas Instruments TMS320C6x architecture
+ *
+ * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
+ * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+
+#include <asm/cacheflush.h>
+
+#define PT_REG_SIZE (sizeof(struct pt_regs))
+
+/*
+ * Called by kernel/ptrace.c when detaching.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ /* nothing to do */
+}
+
+/*
+ * Get a register number from live pt_regs for the specified task.
+ */
+static inline long get_reg(struct task_struct *task, int regno)
+{
+ long *addr = (long *)task_pt_regs(task);
+
+ if (regno == PT_TSR || regno == PT_CSR)
+ return 0;
+
+ return addr[regno];
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static inline int put_reg(struct task_struct *task,
+ int regno,
+ unsigned long data)
+{
+ unsigned long *addr = (unsigned long *)task_pt_regs(task);
+
+ if (regno != PT_TSR && regno != PT_CSR)
+ addr[regno] = data;
+
+ return 0;
+}
+
+/* regset get/set implementations */
+
+static int gpr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct pt_regs *regs = task_pt_regs(target);
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ regs,
+ 0, sizeof(*regs));
+}
+
+static int gpr_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct pt_regs *regs = task_pt_regs(target);
+
+ /* Don't copyin TSR or CSR */
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ ®s,
+ 0, PT_TSR * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+ PT_TSR * sizeof(long),
+ (PT_TSR + 1) * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ ®s,
+ (PT_TSR + 1) * sizeof(long),
+ PT_CSR * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+ PT_CSR * sizeof(long),
+ (PT_CSR + 1) * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ ®s,
+ (PT_CSR + 1) * sizeof(long), -1);
+ return ret;
+}
+
+enum c6x_regset {
+ REGSET_GPR,
+};
+
+static const struct user_regset c6x_regsets[] = {
+ [REGSET_GPR] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = ELF_NGREG,
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .get = gpr_get,
+ .set = gpr_set
+ },
+};
+
+static const struct user_regset_view user_c6x_native_view = {
+ .name = "tic6x",
+ .e_machine = EM_TI_C6000,
+ .regsets = c6x_regsets,
+ .n = ARRAY_SIZE(c6x_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+ return &user_c6x_native_view;
+}
+
+/*
+ * Perform ptrace request
+ */
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret = 0;
+
+ switch (request) {
+ /*
+ * write the word at location addr.
+ */
+ case PTRACE_POKETEXT:
+ ret = generic_ptrace_pokedata(child, addr, data);
+ if (ret == 0 && request == PTRACE_POKETEXT)
+ flush_icache_range(addr, addr + 4);
+ break;
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * handle tracing of system call entry
+ * - return the revised system call number or ULONG_MAX to cause ENOSYS
+ */
+asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
+{
+ 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_a4
+ */
+ return ULONG_MAX;
+
+ return regs->b0;
+}
+
+/*
+ * handle tracing of system call exit
+ */
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
+ tracehook_report_syscall_exit(regs, 0);
+}