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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/alpha/kernel/ptrace.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/alpha/kernel/ptrace.c')
-rw-r--r--arch/alpha/kernel/ptrace.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c
new file mode 100644
index 000000000000..d00583161574
--- /dev/null
+++ b/arch/alpha/kernel/ptrace.c
@@ -0,0 +1,415 @@
+/* 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/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.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
+};
+
+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->pcb.usp;
+ } else if (regno == 65) {
+ addr = &task->thread_info->pcb.unique;
+ } else if (regno == 31 || regno > 65) {
+ zero = 0;
+ addr = &zero;
+ } else {
+ addr = (void *)task->thread_info + 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->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->ieee_state
+ = ((task->thread_info->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;
+ child->thread_info->bpt_addr[nsaved++] = pc + 4;
+ if (displ) /* guard against unoptimized code */
+ child->thread_info->bpt_addr[nsaved++]
+ = pc + 4 + displ;
+ DBG(DBG_BPT, ("execing branch\n"));
+ } else if (op_code == 0x1a) {
+ reg_b = (insn >> 16) & 0x1f;
+ child->thread_info->bpt_addr[nsaved++] = get_reg(child, reg_b);
+ DBG(DBG_BPT, ("execing jump\n"));
+ } else {
+ child->thread_info->bpt_addr[nsaved++] = pc + 4;
+ DBG(DBG_BPT, ("execing normal insn\n"));
+ }
+
+ /* install breakpoints: */
+ for (i = 0; i < nsaved; ++i) {
+ res = read_int(child, child->thread_info->bpt_addr[i],
+ (int *) &insn);
+ if (res < 0)
+ return res;
+ child->thread_info->bpt_insn[i] = insn;
+ DBG(DBG_BPT, (" -> next_pc=%lx\n",
+ child->thread_info->bpt_addr[i]));
+ res = write_int(child, child->thread_info->bpt_addr[i],
+ BREAKINST);
+ if (res < 0)
+ return res;
+ }
+ child->thread_info->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 = child->thread_info->bpt_nsaved;
+
+ child->thread_info->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, child->thread_info->bpt_addr[i],
+ child->thread_info->bpt_insn[i]);
+ }
+ return (nsaved != 0);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ ptrace_cancel_bpt(child);
+}
+
+asmlinkage long
+do_sys_ptrace(long request, long pid, long addr, long data,
+ struct pt_regs *regs)
+{
+ struct task_struct *child;
+ unsigned long tmp;
+ size_t copied;
+ long ret;
+
+ lock_kernel();
+ DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",
+ request, pid, addr, data));
+ ret = -EPERM;
+ if (request == PTRACE_TRACEME) {
+ /* are we already being traced? */
+ if (current->ptrace & PT_PTRACED)
+ goto out_notsk;
+ ret = security_ptrace(current->parent, current);
+ if (ret)
+ goto out_notsk;
+ /* set the ptrace bit in the process ptrace flags. */
+ current->ptrace |= PT_PTRACED;
+ ret = 0;
+ goto out_notsk;
+ }
+ if (pid == 1) /* you may not mess with init */
+ goto out_notsk;
+
+ 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_notsk;
+
+ if (request == PTRACE_ATTACH) {
+ ret = ptrace_attach(child);
+ goto out;
+ }
+
+ ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ if (ret < 0)
+ goto out;
+
+ 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;
+
+ regs->r0 = 0; /* special return: no errors */
+ ret = tmp;
+ break;
+
+ /* Read register number ADDR. */
+ case PTRACE_PEEKUSR:
+ regs->r0 = 0; /* special return: no errors */
+ ret = get_reg(child, addr);
+ DBG(DBG_MEM, ("peek $%ld->%#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:
+ tmp = data;
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1);
+ ret = (copied == sizeof(tmp)) ? 0 : -EIO;
+ break;
+
+ case PTRACE_POKEUSR: /* write the specified register */
+ DBG(DBG_MEM, ("poke $%ld<-%#lx\n", addr, data));
+ ret = put_reg(child, addr, data);
+ break;
+
+ case PTRACE_SYSCALL:
+ /* continue and stop at next (return from) 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 single-step breakpoint is gone. */
+ ptrace_cancel_bpt(child);
+ 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->exit_state == EXIT_ZOMBIE)
+ break;
+ child->exit_code = SIGKILL;
+ /* make sure single-step breakpoint is gone. */
+ ptrace_cancel_bpt(child);
+ wake_up_process(child);
+ goto out;
+
+ case PTRACE_SINGLESTEP: /* execute single instruction. */
+ ret = -EIO;
+ if ((unsigned long) data > _NSIG)
+ break;
+ /* Mark single stepping. */
+ child->thread_info->bpt_nsaved = -1;
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ child->exit_code = data;
+ wake_up_process(child);
+ /* give it a chance to run. */
+ ret = 0;
+ goto out;
+
+ case PTRACE_DETACH: /* detach a process that was attached. */
+ ret = ptrace_detach(child, data);
+ goto out;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ goto out;
+ }
+ out:
+ put_task_struct(child);
+ out_notsk:
+ unlock_kernel();
+ return ret;
+}
+
+asmlinkage void
+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;
+ }
+}