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-rw-r--r--arch/xtensa/kernel/ptrace.c407
1 files changed, 407 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
new file mode 100644
index 00000000000000..9ef07a4dd2a236
--- /dev/null
+++ b/arch/xtensa/kernel/ptrace.c
@@ -0,0 +1,407 @@
+// TODO some minor issues
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ *
+ * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
+ * Chris Zankel <chris@zankel.net>
+ * Scott Foehner<sfoehner@yahoo.com>,
+ * Kevin Chea
+ * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/security.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/elf.h>
+
+#define TEST_KERNEL // verify kernel operations FIXME: remove
+
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+
+void ptrace_disable(struct task_struct *child)
+{
+ /* Nothing to do.. */
+}
+
+int sys_ptrace(long request, long pid, long addr, long data)
+{
+ struct task_struct *child;
+ int ret = -EPERM;
+
+ lock_kernel();
+
+#if 0
+ if ((int)request != 1)
+ printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
+ (int) request, (int) pid, (unsigned long) addr,
+ (unsigned long) data);
+#endif
+
+ if (request == PTRACE_TRACEME) {
+
+ /* Are we already being traced? */
+
+ if (current->ptrace & PT_PTRACED)
+ goto out;
+
+ if ((ret = security_ptrace(current->parent, current)))
+ goto out;
+
+ /* Set the ptrace bit in the process flags. */
+
+ current->ptrace |= PT_PTRACED;
+ ret = 0;
+ goto out;
+ }
+
+ ret = -ESRCH;
+ read_lock(&tasklist_lock);
+ child = find_task_by_pid(pid);
+ if (child)
+ get_task_struct(child);
+ read_unlock(&tasklist_lock);
+ if (!child)
+ goto out;
+
+ ret = -EPERM;
+ if (pid == 1) /* you may not mess with init */
+ goto out;
+
+ if (request == PTRACE_ATTACH) {
+ ret = ptrace_attach(child);
+ goto out_tsk;
+ }
+
+ if ((ret = ptrace_check_attach(child, request == PTRACE_KILL)) < 0)
+ goto out_tsk;
+
+ switch (request) {
+ case PTRACE_PEEKTEXT: /* read word at location addr. */
+ case PTRACE_PEEKDATA:
+ {
+ unsigned long tmp;
+ int copied;
+
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+ ret = -EIO;
+ if (copied != sizeof(tmp))
+ break;
+ ret = put_user(tmp,(unsigned long *) data);
+
+ goto out;
+ }
+
+ /* Read the word at location addr in the USER area. */
+
+ case PTRACE_PEEKUSR:
+ {
+ struct pt_regs *regs;
+ unsigned long tmp;
+
+ regs = xtensa_pt_regs(child);
+ tmp = 0; /* Default return value. */
+
+ switch(addr) {
+
+ case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
+ {
+ int ar = addr - REG_AR_BASE - regs->windowbase * 4;
+ ar &= (XCHAL_NUM_AREGS - 1);
+ if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
+ tmp = regs->areg[ar];
+ else
+ ret = -EIO;
+ break;
+ }
+ case REG_A_BASE ... REG_A_BASE + 15:
+ tmp = regs->areg[addr - REG_A_BASE];
+ break;
+ case REG_PC:
+ tmp = regs->pc;
+ break;
+ case REG_PS:
+ /* Note: PS.EXCM is not set while user task is running;
+ * its being set in regs is for exception handling
+ * convenience. */
+ tmp = (regs->ps & ~XCHAL_PS_EXCM_MASK);
+ break;
+ case REG_WB:
+ tmp = regs->windowbase;
+ break;
+ case REG_WS:
+ tmp = regs->windowstart;
+ break;
+ case REG_LBEG:
+ tmp = regs->lbeg;
+ break;
+ case REG_LEND:
+ tmp = regs->lend;
+ break;
+ case REG_LCOUNT:
+ tmp = regs->lcount;
+ break;
+ case REG_SAR:
+ tmp = regs->sar;
+ break;
+ case REG_DEPC:
+ tmp = regs->depc;
+ break;
+ case REG_EXCCAUSE:
+ tmp = regs->exccause;
+ break;
+ case REG_EXCVADDR:
+ tmp = regs->excvaddr;
+ break;
+ case SYSCALL_NR:
+ tmp = regs->syscall;
+ break;
+ default:
+ tmp = 0;
+ ret = -EIO;
+ goto out;
+ }
+ ret = put_user(tmp, (unsigned long *) data);
+ goto out;
+ }
+
+ case PTRACE_POKETEXT: /* write the word at location addr. */
+ case PTRACE_POKEDATA:
+ if (access_process_vm(child, addr, &data, sizeof(data), 1)
+ == sizeof(data))
+ break;
+ ret = -EIO;
+ goto out;
+
+ case PTRACE_POKEUSR:
+ {
+ struct pt_regs *regs;
+ regs = xtensa_pt_regs(child);
+
+ switch (addr) {
+ case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
+ {
+ int ar = addr - REG_AR_BASE - regs->windowbase * 4;
+ if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
+ regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data;
+ else
+ ret = -EIO;
+ break;
+ }
+ case REG_A_BASE ... REG_A_BASE + 15:
+ regs->areg[addr - REG_A_BASE] = data;
+ break;
+ case REG_PC:
+ regs->pc = data;
+ break;
+ case SYSCALL_NR:
+ regs->syscall = data;
+ break;
+#ifdef TEST_KERNEL
+ case REG_WB:
+ regs->windowbase = data;
+ break;
+ case REG_WS:
+ regs->windowstart = data;
+ break;
+#endif
+
+ default:
+ /* The rest are not allowed. */
+ ret = -EIO;
+ break;
+ }
+ break;
+ }
+
+ /* continue and stop at next (return from) syscall */
+ case PTRACE_SYSCALL:
+ case PTRACE_CONT: /* restart after signal. */
+ {
+ ret = -EIO;
+ if ((unsigned long) data > _NSIG)
+ break;
+ if (request == PTRACE_SYSCALL)
+ set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ else
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ child->exit_code = data;
+ /* Make sure the single step bit is not set. */
+ child->ptrace &= ~PT_SINGLESTEP;
+ wake_up_process(child);
+ ret = 0;
+ break;
+ }
+
+ /*
+ * make the child exit. Best I can do is send it a sigkill.
+ * perhaps it should be put in the status that it wants to
+ * exit.
+ */
+ case PTRACE_KILL:
+ ret = 0;
+ if (child->state == EXIT_ZOMBIE) /* already dead */
+ break;
+ child->exit_code = SIGKILL;
+ child->ptrace &= ~PT_SINGLESTEP;
+ wake_up_process(child);
+ break;
+
+ case PTRACE_SINGLESTEP:
+ ret = -EIO;
+ if ((unsigned long) data > _NSIG)
+ break;
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ child->ptrace |= PT_SINGLESTEP;
+ child->exit_code = data;
+ wake_up_process(child);
+ ret = 0;
+ break;
+
+ case PTRACE_GETREGS:
+ {
+ /* 'data' points to user memory in which to write.
+ * Mainly due to the non-live register values, we
+ * reformat the register values into something more
+ * standard. For convenience, we use the handy
+ * elf_gregset_t format. */
+
+ xtensa_gregset_t format;
+ struct pt_regs *regs = xtensa_pt_regs(child);
+
+ do_copy_regs (&format, regs, child);
+
+ /* Now, copy to user space nice and easy... */
+ ret = 0;
+ if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t)))
+ ret = -EFAULT;
+ break;
+ }
+
+ case PTRACE_SETREGS:
+ {
+ /* 'data' points to user memory that contains the new
+ * values in the elf_gregset_t format. */
+
+ xtensa_gregset_t format;
+ struct pt_regs *regs = xtensa_pt_regs(child);
+
+ if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){
+ ret = -EFAULT;
+ break;
+ }
+
+ /* FIXME: Perhaps we want some sanity checks on
+ * these user-space values? See ARM version. Are
+ * debuggers a security concern? */
+
+ do_restore_regs (&format, regs, child);
+
+ ret = 0;
+ break;
+ }
+
+ case PTRACE_GETFPREGS:
+ {
+ /* 'data' points to user memory in which to write.
+ * For convenience, we use the handy
+ * elf_fpregset_t format. */
+
+ elf_fpregset_t fpregs;
+ struct pt_regs *regs = xtensa_pt_regs(child);
+
+ do_save_fpregs (&fpregs, regs, child);
+
+ /* Now, copy to user space nice and easy... */
+ ret = 0;
+ if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t)))
+ ret = -EFAULT;
+
+ break;
+ }
+
+ case PTRACE_SETFPREGS:
+ {
+ /* 'data' points to user memory that contains the new
+ * values in the elf_fpregset_t format.
+ */
+ elf_fpregset_t fpregs;
+ struct pt_regs *regs = xtensa_pt_regs(child);
+
+ ret = 0;
+ if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ if (do_restore_fpregs (&fpregs, regs, child))
+ ret = -EIO;
+ break;
+ }
+
+ case PTRACE_GETFPREGSIZE:
+ /* 'data' points to 'unsigned long' set to the size
+ * of elf_fpregset_t
+ */
+ ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data);
+ break;
+
+ case PTRACE_DETACH: /* detach a process that was attached. */
+ ret = ptrace_detach(child, data);
+ break;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ goto out;
+ }
+out_tsk:
+ put_task_struct(child);
+out:
+ unlock_kernel();
+ 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. strace only continues with a signal if the
+ * stopping signal is not SIGTRAP. -brl
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+}
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