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Diffstat (limited to 'arch/cris/arch-v32/kernel/ptrace.c')
-rw-r--r--arch/cris/arch-v32/kernel/ptrace.c490
1 files changed, 490 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/kernel/ptrace.c b/arch/cris/arch-v32/kernel/ptrace.c
new file mode 100644
index 000000000..f085229cf
--- /dev/null
+++ b/arch/cris/arch-v32/kernel/ptrace.c
@@ -0,0 +1,490 @@
+/*
+ * Copyright (C) 2000-2007, Axis Communications AB.
+ */
+
+#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/signal.h>
+#include <linux/security.h>
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <arch/hwregs/supp_reg.h>
+
+/*
+ * Determines which bits in CCS the user has access to.
+ * 1 = access, 0 = no access.
+ */
+#define CCS_MASK 0x00087c00 /* SXNZVC */
+
+#define SBIT_USER (1 << (S_CCS_BITNR + CCS_SHIFT))
+
+static int put_debugreg(long pid, unsigned int regno, long data);
+static long get_debugreg(long pid, unsigned int regno);
+static unsigned long get_pseudo_pc(struct task_struct *child);
+void deconfigure_bp(long pid);
+
+extern unsigned long cris_signal_return_page;
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+long get_reg(struct task_struct *task, unsigned int regno)
+{
+ /* USP is a special case, it's not in the pt_regs struct but
+ * in the tasks thread struct
+ */
+ unsigned long ret;
+
+ if (regno <= PT_EDA)
+ ret = ((unsigned long *)task_pt_regs(task))[regno];
+ else if (regno == PT_USP)
+ ret = task->thread.usp;
+ else if (regno == PT_PPC)
+ ret = get_pseudo_pc(task);
+ else if (regno <= PT_MAX)
+ ret = get_debugreg(task->pid, regno);
+ else
+ ret = 0;
+
+ return ret;
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+int put_reg(struct task_struct *task, unsigned int regno, unsigned long data)
+{
+ if (regno <= PT_EDA)
+ ((unsigned long *)task_pt_regs(task))[regno] = data;
+ else if (regno == PT_USP)
+ task->thread.usp = data;
+ else if (regno == PT_PPC) {
+ /* Write pseudo-PC to ERP only if changed. */
+ if (data != get_pseudo_pc(task))
+ task_pt_regs(task)->erp = data;
+ } else if (regno <= PT_MAX)
+ return put_debugreg(task->pid, regno, data);
+ else
+ return -1;
+ return 0;
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+ unsigned long tmp;
+
+ /*
+ * Set up SPC if not set already (in which case we have no other
+ * choice but to trust it).
+ */
+ if (!get_reg(child, PT_SPC)) {
+ /* In case we're stopped in a delay slot. */
+ tmp = get_reg(child, PT_ERP) & ~1;
+ put_reg(child, PT_SPC, tmp);
+ }
+ tmp = get_reg(child, PT_CCS) | SBIT_USER;
+ put_reg(child, PT_CCS, tmp);
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+ put_reg(child, PT_SPC, 0);
+
+ if (!get_debugreg(child->pid, PT_BP_CTRL)) {
+ unsigned long tmp;
+ /* If no h/w bp configured, disable S bit. */
+ tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
+ put_reg(child, PT_CCS, tmp);
+ }
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching.
+ *
+ * Make sure the single step bit is not set.
+ */
+void
+ptrace_disable(struct task_struct *child)
+{
+ /* Deconfigure SPC and S-bit. */
+ user_disable_single_step(child);
+ put_reg(child, PT_SPC, 0);
+
+ /* Deconfigure any watchpoints associated with the child. */
+ deconfigure_bp(child->pid);
+}
+
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret;
+ unsigned int regno = addr >> 2;
+ unsigned long __user *datap = (unsigned long __user *)data;
+
+ switch (request) {
+ /* Read word at location address. */
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA: {
+ unsigned long tmp;
+ int copied;
+
+ ret = -EIO;
+
+ /* The signal trampoline page is outside the normal user-addressable
+ * space but still accessible. This is hack to make it possible to
+ * access the signal handler code in GDB.
+ */
+ if ((addr & PAGE_MASK) == cris_signal_return_page) {
+ /* The trampoline page is globally mapped, no page table to traverse.*/
+ tmp = *(unsigned long*)addr;
+ } else {
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+
+ if (copied != sizeof(tmp))
+ break;
+ }
+
+ ret = put_user(tmp,datap);
+ break;
+ }
+
+ /* Read the word at location address in the USER area. */
+ case PTRACE_PEEKUSR: {
+ unsigned long tmp;
+
+ ret = -EIO;
+ if ((addr & 3) || regno > PT_MAX)
+ break;
+
+ tmp = get_reg(child, regno);
+ ret = put_user(tmp, datap);
+ break;
+ }
+
+ /* Write the word at location address. */
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ ret = generic_ptrace_pokedata(child, addr, data);
+ break;
+
+ /* Write the word at location address in the USER area. */
+ case PTRACE_POKEUSR:
+ ret = -EIO;
+ if ((addr & 3) || regno > PT_MAX)
+ break;
+
+ if (regno == PT_CCS) {
+ /* don't allow the tracing process to change stuff like
+ * interrupt enable, kernel/user bit, dma enables etc.
+ */
+ data &= CCS_MASK;
+ data |= get_reg(child, PT_CCS) & ~CCS_MASK;
+ }
+ if (put_reg(child, regno, data))
+ break;
+ ret = 0;
+ break;
+
+ /* Get all GP registers from the child. */
+ case PTRACE_GETREGS: {
+ int i;
+ unsigned long tmp;
+
+ for (i = 0; i <= PT_MAX; i++) {
+ tmp = get_reg(child, i);
+
+ if (put_user(tmp, datap)) {
+ ret = -EFAULT;
+ goto out_tsk;
+ }
+
+ datap++;
+ }
+
+ ret = 0;
+ break;
+ }
+
+ /* Set all GP registers in the child. */
+ case PTRACE_SETREGS: {
+ int i;
+ unsigned long tmp;
+
+ for (i = 0; i <= PT_MAX; i++) {
+ if (get_user(tmp, datap)) {
+ ret = -EFAULT;
+ goto out_tsk;
+ }
+
+ if (i == PT_CCS) {
+ tmp &= CCS_MASK;
+ tmp |= get_reg(child, PT_CCS) & ~CCS_MASK;
+ }
+
+ put_reg(child, i, tmp);
+ datap++;
+ }
+
+ ret = 0;
+ break;
+ }
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+out_tsk:
+ return ret;
+}
+
+void do_syscall_trace(void)
+{
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+
+ /* the 0x80 provides a way for the tracing parent to distinguish
+ between a syscall stop and SIGTRAP delivery */
+ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+ ? 0x80 : 0));
+
+ /*
+ * This isn't the same as continuing with a signal, but it will do for
+ * normal use.
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+}
+
+/* Returns the size of an instruction that has a delay slot. */
+
+static int insn_size(struct task_struct *child, unsigned long pc)
+{
+ unsigned long opcode;
+ int copied;
+ int opsize = 0;
+
+ /* Read the opcode at pc (do what PTRACE_PEEKTEXT would do). */
+ copied = access_process_vm(child, pc, &opcode, sizeof(opcode), 0);
+ if (copied != sizeof(opcode))
+ return 0;
+
+ switch ((opcode & 0x0f00) >> 8) {
+ case 0x0:
+ case 0x9:
+ case 0xb:
+ opsize = 2;
+ break;
+ case 0xe:
+ case 0xf:
+ opsize = 6;
+ break;
+ case 0xd:
+ /* Could be 4 or 6; check more bits. */
+ if ((opcode & 0xff) == 0xff)
+ opsize = 4;
+ else
+ opsize = 6;
+ break;
+ default:
+ panic("ERROR: Couldn't find size of opcode 0x%lx at 0x%lx\n",
+ opcode, pc);
+ }
+
+ return opsize;
+}
+
+static unsigned long get_pseudo_pc(struct task_struct *child)
+{
+ /* Default value for PC is ERP. */
+ unsigned long pc = get_reg(child, PT_ERP);
+
+ if (pc & 0x1) {
+ unsigned long spc = get_reg(child, PT_SPC);
+ /* Delay slot bit set. Report as stopped on proper
+ instruction. */
+ if (spc) {
+ /* Rely on SPC if set. FIXME: We might want to check
+ that EXS indicates we stopped due to a single-step
+ exception. */
+ pc = spc;
+ } else {
+ /* Calculate the PC from the size of the instruction
+ that the delay slot we're in belongs to. */
+ pc += insn_size(child, pc & ~1) - 1;
+ }
+ }
+ return pc;
+}
+
+static long bp_owner = 0;
+
+/* Reachable from exit_thread in signal.c, so not static. */
+void deconfigure_bp(long pid)
+{
+ int bp;
+
+ /* Only deconfigure if the pid is the owner. */
+ if (bp_owner != pid)
+ return;
+
+ for (bp = 0; bp < 6; bp++) {
+ unsigned long tmp;
+ /* Deconfigure start and end address (also gets rid of ownership). */
+ put_debugreg(pid, PT_BP + 3 + (bp * 2), 0);
+ put_debugreg(pid, PT_BP + 4 + (bp * 2), 0);
+
+ /* Deconfigure relevant bits in control register. */
+ tmp = get_debugreg(pid, PT_BP_CTRL) & ~(3 << (2 + (bp * 4)));
+ put_debugreg(pid, PT_BP_CTRL, tmp);
+ }
+ /* No owner now. */
+ bp_owner = 0;
+}
+
+static int put_debugreg(long pid, unsigned int regno, long data)
+{
+ int ret = 0;
+ register int old_srs;
+
+#ifdef CONFIG_ETRAX_KGDB
+ /* Ignore write, but pretend it was ok if value is 0
+ (we don't want POKEUSR/SETREGS failing unnessecarily). */
+ return (data == 0) ? ret : -1;
+#endif
+
+ /* Simple owner management. */
+ if (!bp_owner)
+ bp_owner = pid;
+ else if (bp_owner != pid) {
+ /* Ignore write, but pretend it was ok if value is 0
+ (we don't want POKEUSR/SETREGS failing unnessecarily). */
+ return (data == 0) ? ret : -1;
+ }
+
+ /* Remember old SRS. */
+ SPEC_REG_RD(SPEC_REG_SRS, old_srs);
+ /* Switch to BP bank. */
+ SUPP_BANK_SEL(BANK_BP);
+
+ switch (regno - PT_BP) {
+ case 0:
+ SUPP_REG_WR(0, data); break;
+ case 1:
+ case 2:
+ if (data)
+ ret = -1;
+ break;
+ case 3:
+ SUPP_REG_WR(3, data); break;
+ case 4:
+ SUPP_REG_WR(4, data); break;
+ case 5:
+ SUPP_REG_WR(5, data); break;
+ case 6:
+ SUPP_REG_WR(6, data); break;
+ case 7:
+ SUPP_REG_WR(7, data); break;
+ case 8:
+ SUPP_REG_WR(8, data); break;
+ case 9:
+ SUPP_REG_WR(9, data); break;
+ case 10:
+ SUPP_REG_WR(10, data); break;
+ case 11:
+ SUPP_REG_WR(11, data); break;
+ case 12:
+ SUPP_REG_WR(12, data); break;
+ case 13:
+ SUPP_REG_WR(13, data); break;
+ case 14:
+ SUPP_REG_WR(14, data); break;
+ default:
+ ret = -1;
+ break;
+ }
+
+ /* Restore SRS. */
+ SPEC_REG_WR(SPEC_REG_SRS, old_srs);
+ /* Just for show. */
+ NOP();
+ NOP();
+ NOP();
+
+ return ret;
+}
+
+static long get_debugreg(long pid, unsigned int regno)
+{
+ register int old_srs;
+ register long data;
+
+ if (pid != bp_owner) {
+ return 0;
+ }
+
+ /* Remember old SRS. */
+ SPEC_REG_RD(SPEC_REG_SRS, old_srs);
+ /* Switch to BP bank. */
+ SUPP_BANK_SEL(BANK_BP);
+
+ switch (regno - PT_BP) {
+ case 0:
+ SUPP_REG_RD(0, data); break;
+ case 1:
+ case 2:
+ /* error return value? */
+ data = 0;
+ break;
+ case 3:
+ SUPP_REG_RD(3, data); break;
+ case 4:
+ SUPP_REG_RD(4, data); break;
+ case 5:
+ SUPP_REG_RD(5, data); break;
+ case 6:
+ SUPP_REG_RD(6, data); break;
+ case 7:
+ SUPP_REG_RD(7, data); break;
+ case 8:
+ SUPP_REG_RD(8, data); break;
+ case 9:
+ SUPP_REG_RD(9, data); break;
+ case 10:
+ SUPP_REG_RD(10, data); break;
+ case 11:
+ SUPP_REG_RD(11, data); break;
+ case 12:
+ SUPP_REG_RD(12, data); break;
+ case 13:
+ SUPP_REG_RD(13, data); break;
+ case 14:
+ SUPP_REG_RD(14, data); break;
+ default:
+ /* error return value? */
+ data = 0;
+ }
+
+ /* Restore SRS. */
+ SPEC_REG_WR(SPEC_REG_SRS, old_srs);
+ /* Just for show. */
+ NOP();
+ NOP();
+ NOP();
+
+ return data;
+}
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