ARC: ptrace support

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 134 insertions, 2 deletions

diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index 1cf944a77f33..c6a81c58d0f3 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -7,6 +7,122 @@
  */
 
 #include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/regset.h>
+#include <linux/unistd.h>
+#include <linux/elf.h>
+
+static struct callee_regs *task_callee_regs(struct task_struct *tsk)
+{
+        struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
+        return tmp;
+}
+
+static int genregs_get(struct task_struct *target,
+                       const struct user_regset *regset,
+                       unsigned int pos, unsigned int count,
+                       void *kbuf, void __user *ubuf)
+{
+        const struct pt_regs *ptregs = task_pt_regs(target);
+        const struct callee_regs *cregs = task_callee_regs(target);
+        int ret = 0;
+        unsigned int stop_pc_val;
+
+#define REG_O_CHUNK(START, END, PTR)    \
+        if (!ret)       \
+                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
+                        offsetof(struct user_regs_struct, START), \
+                        offsetof(struct user_regs_struct, END));
+
+#define REG_O_ONE(LOC, PTR)     \
+        if (!ret)               \
+                ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
+                        offsetof(struct user_regs_struct, LOC), \
+                        offsetof(struct user_regs_struct, LOC) + 4);
+
+        REG_O_CHUNK(scratch, callee, ptregs);
+        REG_O_CHUNK(callee, efa, cregs);
+        REG_O_CHUNK(efa, stop_pc, &target->thread.fault_address);
+
+        if (!ret) {
+                if (in_brkpt_trap(ptregs)) {
+                        stop_pc_val = target->thread.fault_address;
+                        pr_debug("\t\tstop_pc (brk-pt)\n");
+                } else {
+                        stop_pc_val = ptregs->ret;
+                        pr_debug("\t\tstop_pc (others)\n");
+                }
+
+                REG_O_ONE(stop_pc, &stop_pc_val);
+        }
+
+        return ret;
+}
+
+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)
+{
+        const struct pt_regs *ptregs = task_pt_regs(target);
+        const struct callee_regs *cregs = task_callee_regs(target);
+        int ret = 0;
+
+#define REG_IN_CHUNK(FIRST, NEXT, PTR)  \
+        if (!ret)                       \
+                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
+                        (void *)(PTR), \
+                        offsetof(struct user_regs_struct, FIRST), \
+                        offsetof(struct user_regs_struct, NEXT));
+
+#define REG_IN_ONE(LOC, PTR)            \
+        if (!ret)                       \
+                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
+                        (void *)(PTR), \
+                        offsetof(struct user_regs_struct, LOC), \
+                        offsetof(struct user_regs_struct, LOC) + 4);
+
+#define REG_IGNORE_ONE(LOC)             \
+        if (!ret)                       \
+                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
+                        offsetof(struct user_regs_struct, LOC), \
+                        offsetof(struct user_regs_struct, LOC) + 4);
+
+        /* TBD: disallow updates to STATUS32, orig_r8 etc*/
+        REG_IN_CHUNK(scratch, callee, ptregs);  /* pt_regs[bta..orig_r8] */
+        REG_IN_CHUNK(callee, efa, cregs);       /* callee_regs[r25..r13] */
+        REG_IGNORE_ONE(efa);                    /* efa update invalid */
+        REG_IN_ONE(stop_pc, &ptregs->ret);      /* stop_pc: PC update */
+
+        return ret;
+}
+
+enum arc_getset {
+        REGSET_GENERAL,
+};
+
+static const struct user_regset arc_regsets[] = {
+        [REGSET_GENERAL] = {
+               .core_note_type = NT_PRSTATUS,
+               .n = ELF_NGREG,
+               .size = sizeof(unsigned long),
+               .align = sizeof(unsigned long),
+               .get = genregs_get,
+               .set = genregs_set,
+        }
+};
+
+static const struct user_regset_view user_arc_view = {
+        .name           = UTS_MACHINE,
+        .e_machine      = EM_ARCOMPACT,
+        .regsets        = arc_regsets,
+        .n              = ARRAY_SIZE(arc_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+        return &user_arc_view;
+}
 
 void ptrace_disable(struct task_struct *child)
 {
@@ -16,11 +132,27 @@ long arch_ptrace(struct task_struct *child, long request,
                  unsigned long addr, unsigned long data)
 {
         int ret = -EIO;
+
+        pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
+
+        switch (request) {
+        default:
+                ret = ptrace_request(child, request, addr, data);
+                break;
+        }
+
         return ret;
 }
 
+asmlinkage int syscall_trace_entry(struct pt_regs *regs)
+{
+        if (tracehook_report_syscall_entry(regs))
+                return ULONG_MAX;
 
-const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+        return regs->r8;
+}
+
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-        return (const struct user_regset_view *)NULL;
+        tracehook_report_syscall_exit(regs, 0);
 }