Initial import

1 files changed, 334 insertions, 0 deletions

diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c
new file mode 100644
index 000000000..d9ee81769
--- /dev/null
+++ b/arch/alpha/kernel/ptrace.c
@@ -0,0 +1,334 @@
+/* ptrace.c */
+/* By Ross Biro 1/23/92 */
+/* edited by Linus Torvalds */
+/* mangled further by Bob Manson (manson@santafe.edu) */
+/* more mutilation by David Mosberger (davidm@azstarnet.com) */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/security.h>
+#include <linux/signal.h>
+#include <linux/tracehook.h>
+#include <linux/audit.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/fpu.h>
+
+#include "proto.h"
+
+#define DEBUG	DBG_MEM
+#undef DEBUG
+
+#ifdef DEBUG
+enum {
+	DBG_MEM		= (1<<0),
+	DBG_BPT		= (1<<1),
+	DBG_MEM_ALL	= (1<<2)
+};
+#define DBG(fac,args)	{if ((fac) & DEBUG) printk args;}
+#else
+#define DBG(fac,args)
+#endif
+
+#define BREAKINST	0x00000080	/* call_pal bpt */
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Processes always block with the following stack-layout:
+ *
+ *  +================================+ <---- task + 2*PAGE_SIZE
+ *  | PALcode saved frame (ps, pc,   | ^
+ *  | gp, a0, a1, a2)		     | |
+ *  +================================+ | struct pt_regs
+ *  |	        		     | |
+ *  | frame generated by SAVE_ALL    | |
+ *  |	        		     | v
+ *  +================================+
+ *  |	        		     | ^
+ *  | frame saved by do_switch_stack | | struct switch_stack
+ *  |	        		     | v
+ *  +================================+
+ */
+
+/* 
+ * The following table maps a register index into the stack offset at
+ * which the register is saved.  Register indices are 0-31 for integer
+ * regs, 32-63 for fp regs, and 64 for the pc.  Notice that sp and
+ * zero have no stack-slot and need to be treated specially (see
+ * get_reg/put_reg below).
+ */
+enum {
+	REG_R0 = 0, REG_F0 = 32, REG_FPCR = 63, REG_PC = 64
+};
+
+#define PT_REG(reg) \
+  (PAGE_SIZE*2 - sizeof(struct pt_regs) + offsetof(struct pt_regs, reg))
+
+#define SW_REG(reg) \
+ (PAGE_SIZE*2 - sizeof(struct pt_regs) - sizeof(struct switch_stack) \
+  + offsetof(struct switch_stack, reg))
+
+static int regoff[] = {
+	PT_REG(	   r0), PT_REG(	   r1), PT_REG(	   r2), PT_REG(	  r3),
+	PT_REG(	   r4), PT_REG(	   r5), PT_REG(	   r6), PT_REG(	  r7),
+	PT_REG(	   r8), SW_REG(	   r9), SW_REG(	  r10), SW_REG(	 r11),
+	SW_REG(	  r12), SW_REG(	  r13), SW_REG(	  r14), SW_REG(	 r15),
+	PT_REG(	  r16), PT_REG(	  r17), PT_REG(	  r18), PT_REG(	 r19),
+	PT_REG(	  r20), PT_REG(	  r21), PT_REG(	  r22), PT_REG(	 r23),
+	PT_REG(	  r24), PT_REG(	  r25), PT_REG(	  r26), PT_REG(	 r27),
+	PT_REG(	  r28), PT_REG(	   gp),		   -1,		   -1,
+	SW_REG(fp[ 0]), SW_REG(fp[ 1]), SW_REG(fp[ 2]), SW_REG(fp[ 3]),
+	SW_REG(fp[ 4]), SW_REG(fp[ 5]), SW_REG(fp[ 6]), SW_REG(fp[ 7]),
+	SW_REG(fp[ 8]), SW_REG(fp[ 9]), SW_REG(fp[10]), SW_REG(fp[11]),
+	SW_REG(fp[12]), SW_REG(fp[13]), SW_REG(fp[14]), SW_REG(fp[15]),
+	SW_REG(fp[16]), SW_REG(fp[17]), SW_REG(fp[18]), SW_REG(fp[19]),
+	SW_REG(fp[20]), SW_REG(fp[21]), SW_REG(fp[22]), SW_REG(fp[23]),
+	SW_REG(fp[24]), SW_REG(fp[25]), SW_REG(fp[26]), SW_REG(fp[27]),
+	SW_REG(fp[28]), SW_REG(fp[29]), SW_REG(fp[30]), SW_REG(fp[31]),
+	PT_REG(	   pc)
+};
+
+static unsigned long zero;
+
+/*
+ * Get address of register REGNO in task TASK.
+ */
+static unsigned long *
+get_reg_addr(struct task_struct * task, unsigned long regno)
+{
+	unsigned long *addr;
+
+	if (regno == 30) {
+		addr = &task_thread_info(task)->pcb.usp;
+	} else if (regno == 65) {
+		addr = &task_thread_info(task)->pcb.unique;
+	} else if (regno == 31 || regno > 65) {
+		zero = 0;
+		addr = &zero;
+	} else {
+		addr = task_stack_page(task) + regoff[regno];
+	}
+	return addr;
+}
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+static unsigned long
+get_reg(struct task_struct * task, unsigned long regno)
+{
+	/* Special hack for fpcr -- combine hardware and software bits.  */
+	if (regno == 63) {
+		unsigned long fpcr = *get_reg_addr(task, regno);
+		unsigned long swcr
+		  = task_thread_info(task)->ieee_state & IEEE_SW_MASK;
+		swcr = swcr_update_status(swcr, fpcr);
+		return fpcr | swcr;
+	}
+	return *get_reg_addr(task, regno);
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static int
+put_reg(struct task_struct *task, unsigned long regno, unsigned long data)
+{
+	if (regno == 63) {
+		task_thread_info(task)->ieee_state
+		  = ((task_thread_info(task)->ieee_state & ~IEEE_SW_MASK)
+		     | (data & IEEE_SW_MASK));
+		data = (data & FPCR_DYN_MASK) | ieee_swcr_to_fpcr(data);
+	}
+	*get_reg_addr(task, regno) = data;
+	return 0;
+}
+
+static inline int
+read_int(struct task_struct *task, unsigned long addr, int * data)
+{
+	int copied = access_process_vm(task, addr, data, sizeof(int), 0);
+	return (copied == sizeof(int)) ? 0 : -EIO;
+}
+
+static inline int
+write_int(struct task_struct *task, unsigned long addr, int data)
+{
+	int copied = access_process_vm(task, addr, &data, sizeof(int), 1);
+	return (copied == sizeof(int)) ? 0 : -EIO;
+}
+
+/*
+ * Set breakpoint.
+ */
+int
+ptrace_set_bpt(struct task_struct * child)
+{
+	int displ, i, res, reg_b, nsaved = 0;
+	unsigned int insn, op_code;
+	unsigned long pc;
+
+	pc  = get_reg(child, REG_PC);
+	res = read_int(child, pc, (int *) &insn);
+	if (res < 0)
+		return res;
+
+	op_code = insn >> 26;
+	if (op_code >= 0x30) {
+		/*
+		 * It's a branch: instead of trying to figure out
+		 * whether the branch will be taken or not, we'll put
+		 * a breakpoint at either location.  This is simpler,
+		 * more reliable, and probably not a whole lot slower
+		 * than the alternative approach of emulating the
+		 * branch (emulation can be tricky for fp branches).
+		 */
+		displ = ((s32)(insn << 11)) >> 9;
+		task_thread_info(child)->bpt_addr[nsaved++] = pc + 4;
+		if (displ)		/* guard against unoptimized code */
+			task_thread_info(child)->bpt_addr[nsaved++]
+			  = pc + 4 + displ;
+		DBG(DBG_BPT, ("execing branch\n"));
+	} else if (op_code == 0x1a) {
+		reg_b = (insn >> 16) & 0x1f;
+		task_thread_info(child)->bpt_addr[nsaved++] = get_reg(child, reg_b);
+		DBG(DBG_BPT, ("execing jump\n"));
+	} else {
+		task_thread_info(child)->bpt_addr[nsaved++] = pc + 4;
+		DBG(DBG_BPT, ("execing normal insn\n"));
+	}
+
+	/* install breakpoints: */
+	for (i = 0; i < nsaved; ++i) {
+		res = read_int(child, task_thread_info(child)->bpt_addr[i],
+			       (int *) &insn);
+		if (res < 0)
+			return res;
+		task_thread_info(child)->bpt_insn[i] = insn;
+		DBG(DBG_BPT, ("    -> next_pc=%lx\n",
+			      task_thread_info(child)->bpt_addr[i]));
+		res = write_int(child, task_thread_info(child)->bpt_addr[i],
+				BREAKINST);
+		if (res < 0)
+			return res;
+	}
+	task_thread_info(child)->bpt_nsaved = nsaved;
+	return 0;
+}
+
+/*
+ * Ensure no single-step breakpoint is pending.  Returns non-zero
+ * value if child was being single-stepped.
+ */
+int
+ptrace_cancel_bpt(struct task_struct * child)
+{
+	int i, nsaved = task_thread_info(child)->bpt_nsaved;
+
+	task_thread_info(child)->bpt_nsaved = 0;
+
+	if (nsaved > 2) {
+		printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved);
+		nsaved = 2;
+	}
+
+	for (i = 0; i < nsaved; ++i) {
+		write_int(child, task_thread_info(child)->bpt_addr[i],
+			  task_thread_info(child)->bpt_insn[i]);
+	}
+	return (nsaved != 0);
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+	/* Mark single stepping.  */
+	task_thread_info(child)->bpt_nsaved = -1;
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+	ptrace_cancel_bpt(child);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{ 
+	user_disable_single_step(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	unsigned long tmp;
+	size_t copied;
+	long ret;
+
+	switch (request) {
+	/* When I and D space are separate, these will need to be fixed.  */
+	case PTRACE_PEEKTEXT: /* read word at location addr. */
+	case PTRACE_PEEKDATA:
+		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+		ret = -EIO;
+		if (copied != sizeof(tmp))
+			break;
+		
+		force_successful_syscall_return();
+		ret = tmp;
+		break;
+
+	/* Read register number ADDR. */
+	case PTRACE_PEEKUSR:
+		force_successful_syscall_return();
+		ret = get_reg(child, addr);
+		DBG(DBG_MEM, ("peek $%lu->%#lx\n", addr, ret));
+		break;
+
+	/* When I and D space are separate, this will have to be fixed.  */
+	case PTRACE_POKETEXT: /* write the word at location addr. */
+	case PTRACE_POKEDATA:
+		ret = generic_ptrace_pokedata(child, addr, data);
+		break;
+
+	case PTRACE_POKEUSR: /* write the specified register */
+		DBG(DBG_MEM, ("poke $%lu<-%#lx\n", addr, data));
+		ret = put_reg(child, addr, data);
+		break;
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+	return ret;
+}
+
+asmlinkage unsigned long syscall_trace_enter(void)
+{
+	unsigned long ret = 0;
+	struct pt_regs *regs = current_pt_regs();
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(current_pt_regs()))
+		ret = -1UL;
+	audit_syscall_entry(regs->r0, regs->r16, regs->r17, regs->r18, regs->r19);
+	return ret ?: current_pt_regs()->r0;
+}
+
+asmlinkage void
+syscall_trace_leave(void)
+{
+	audit_syscall_exit(current_pt_regs());
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(current_pt_regs(), 0);
+}