Linux-2.6.12-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!
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
new file mode 100644
index 0000000..647233c
--- /dev/null
+++ b/arch/s390/kernel/ptrace.c
@@ -0,0 +1,738 @@
+/*
+ * arch/s390/kernel/ptrace.c
+ *
+ * S390 version
+ * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
+ * Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * Based on PowerPC version
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Derived from "arch/m68k/kernel/ptrace.c"
+ * Copyright (C) 1994 by Hamish Macdonald
+ * Taken from linux/kernel/ptrace.c and modified for M680x0.
+ * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
+ *
+ * Modified by Cort Dougan (cort@cs.nmt.edu)
+ *
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file README.legal in the main directory of
+ * this archive for more details.
+ */
+
+#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/security.h>
+#include <linux/audit.h>
+
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_S390_SUPPORT
+#include "compat_ptrace.h"
+#endif
+
+static void
+FixPerRegisters(struct task_struct *task)
+{
+ struct pt_regs *regs;
+ per_struct *per_info;
+
+ regs = __KSTK_PTREGS(task);
+ per_info = (per_struct *) &task->thread.per_info;
+ per_info->control_regs.bits.em_instruction_fetch =
+ per_info->single_step | per_info->instruction_fetch;
+
+ if (per_info->single_step) {
+ per_info->control_regs.bits.starting_addr = 0;
+#ifdef CONFIG_S390_SUPPORT
+ if (test_thread_flag(TIF_31BIT))
+ per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
+ else
+#endif
+ per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
+ } else {
+ per_info->control_regs.bits.starting_addr =
+ per_info->starting_addr;
+ per_info->control_regs.bits.ending_addr =
+ per_info->ending_addr;
+ }
+ /*
+ * if any of the control reg tracing bits are on
+ * we switch on per in the psw
+ */
+ if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
+ regs->psw.mask |= PSW_MASK_PER;
+ else
+ regs->psw.mask &= ~PSW_MASK_PER;
+
+ if (per_info->control_regs.bits.em_storage_alteration)
+ per_info->control_regs.bits.storage_alt_space_ctl = 1;
+ else
+ per_info->control_regs.bits.storage_alt_space_ctl = 0;
+}
+
+void
+set_single_step(struct task_struct *task)
+{
+ task->thread.per_info.single_step = 1;
+ FixPerRegisters(task);
+}
+
+void
+clear_single_step(struct task_struct *task)
+{
+ task->thread.per_info.single_step = 0;
+ FixPerRegisters(task);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void
+ptrace_disable(struct task_struct *child)
+{
+ /* make sure the single step bit is not set. */
+ clear_single_step(child);
+}
+
+#ifndef CONFIG_ARCH_S390X
+# define __ADDR_MASK 3
+#else
+# define __ADDR_MASK 7
+#endif
+
+/*
+ * Read the word at offset addr from the user area of a process. The
+ * trouble here is that the information is littered over different
+ * locations. The process registers are found on the kernel stack,
+ * the floating point stuff and the trace settings are stored in
+ * the task structure. In addition the different structures in
+ * struct user contain pad bytes that should be read as zeroes.
+ * Lovely...
+ */
+static int
+peek_user(struct task_struct *child, addr_t addr, addr_t data)
+{
+ struct user *dummy = NULL;
+ addr_t offset, tmp;
+
+ /*
+ * Stupid gdb peeks/pokes the access registers in 64 bit with
+ * an alignment of 4. Programmers from hell...
+ */
+ if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK)
+ return -EIO;
+
+ if (addr < (addr_t) &dummy->regs.acrs) {
+ /*
+ * psw and gprs are stored on the stack
+ */
+ tmp = *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr);
+ if (addr == (addr_t) &dummy->regs.psw.mask)
+ /* Remove per bit from user psw. */
+ tmp &= ~PSW_MASK_PER;
+
+ } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
+ /*
+ * access registers are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy->regs.acrs;
+ tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
+
+ } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
+ /*
+ * orig_gpr2 is stored on the kernel stack
+ */
+ tmp = (addr_t) __KSTK_PTREGS(child)->orig_gpr2;
+
+ } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
+ /*
+ * floating point regs. are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy->regs.fp_regs;
+ tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
+
+ } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
+ /*
+ * per_info is found in the thread structure
+ */
+ offset = addr - (addr_t) &dummy->regs.per_info;
+ tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
+
+ } else
+ tmp = 0;
+
+ return put_user(tmp, (addr_t __user *) data);
+}
+
+/*
+ * Write a word to the user area of a process at location addr. This
+ * operation does have an additional problem compared to peek_user.
+ * Stores to the program status word and on the floating point
+ * control register needs to get checked for validity.
+ */
+static int
+poke_user(struct task_struct *child, addr_t addr, addr_t data)
+{
+ struct user *dummy = NULL;
+ addr_t offset;
+
+ /*
+ * Stupid gdb peeks/pokes the access registers in 64 bit with
+ * an alignment of 4. Programmers from hell indeed...
+ */
+ if ((addr & 3) || addr > sizeof(struct user) - __ADDR_MASK)
+ return -EIO;
+
+ if (addr < (addr_t) &dummy->regs.acrs) {
+ /*
+ * psw and gprs are stored on the stack
+ */
+ if (addr == (addr_t) &dummy->regs.psw.mask &&
+#ifdef CONFIG_S390_SUPPORT
+ data != PSW_MASK_MERGE(PSW_USER32_BITS, data) &&
+#endif
+ data != PSW_MASK_MERGE(PSW_USER_BITS, data))
+ /* Invalid psw mask. */
+ return -EINVAL;
+#ifndef CONFIG_ARCH_S390X
+ if (addr == (addr_t) &dummy->regs.psw.addr)
+ /* I'd like to reject addresses without the
+ high order bit but older gdb's rely on it */
+ data |= PSW_ADDR_AMODE;
+#endif
+ *(addr_t *)((addr_t) &__KSTK_PTREGS(child)->psw + addr) = data;
+
+ } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
+ /*
+ * access registers are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy->regs.acrs;
+ *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
+
+ } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
+ /*
+ * orig_gpr2 is stored on the kernel stack
+ */
+ __KSTK_PTREGS(child)->orig_gpr2 = data;
+
+ } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
+ /*
+ * floating point regs. are stored in the thread structure
+ */
+ if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
+ (data & ~FPC_VALID_MASK) != 0)
+ return -EINVAL;
+ offset = addr - (addr_t) &dummy->regs.fp_regs;
+ *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
+
+ } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
+ /*
+ * per_info is found in the thread structure
+ */
+ offset = addr - (addr_t) &dummy->regs.per_info;
+ *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
+
+ }
+
+ FixPerRegisters(child);
+ return 0;
+}
+
+static int
+do_ptrace_normal(struct task_struct *child, long request, long addr, long data)
+{
+ unsigned long tmp;
+ ptrace_area parea;
+ int copied, ret;
+
+ switch (request) {
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA:
+ /* Remove high order bit from address (only for 31 bit). */
+ addr &= PSW_ADDR_INSN;
+ /* read word at location addr. */
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+ if (copied != sizeof(tmp))
+ return -EIO;
+ return put_user(tmp, (unsigned long __user *) data);
+
+ case PTRACE_PEEKUSR:
+ /* read the word at location addr in the USER area. */
+ return peek_user(child, addr, data);
+
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ /* Remove high order bit from address (only for 31 bit). */
+ addr &= PSW_ADDR_INSN;
+ /* write the word at location addr. */
+ copied = access_process_vm(child, addr, &data, sizeof(data),1);
+ if (copied != sizeof(data))
+ return -EIO;
+ return 0;
+
+ case PTRACE_POKEUSR:
+ /* write the word at location addr in the USER area */
+ return poke_user(child, addr, data);
+
+ case PTRACE_PEEKUSR_AREA:
+ case PTRACE_POKEUSR_AREA:
+ if (copy_from_user(&parea, (void __user *) addr,
+ sizeof(parea)))
+ return -EFAULT;
+ addr = parea.kernel_addr;
+ data = parea.process_addr;
+ copied = 0;
+ while (copied < parea.len) {
+ if (request == PTRACE_PEEKUSR_AREA)
+ ret = peek_user(child, addr, data);
+ else {
+ addr_t tmp;
+ if (get_user (tmp, (addr_t __user *) data))
+ return -EFAULT;
+ ret = poke_user(child, addr, tmp);
+ }
+ if (ret)
+ return ret;
+ addr += sizeof(unsigned long);
+ data += sizeof(unsigned long);
+ copied += sizeof(unsigned long);
+ }
+ return 0;
+ }
+ return ptrace_request(child, request, addr, data);
+}
+
+#ifdef CONFIG_S390_SUPPORT
+/*
+ * Now the fun part starts... a 31 bit program running in the
+ * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
+ * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
+ * to handle, the difference to the 64 bit versions of the requests
+ * is that the access is done in multiples of 4 byte instead of
+ * 8 bytes (sizeof(unsigned long) on 31/64 bit).
+ * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
+ * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
+ * is a 31 bit program too, the content of struct user can be
+ * emulated. A 31 bit program peeking into the struct user of
+ * a 64 bit program is a no-no.
+ */
+
+/*
+ * Same as peek_user but for a 31 bit program.
+ */
+static int
+peek_user_emu31(struct task_struct *child, addr_t addr, addr_t data)
+{
+ struct user32 *dummy32 = NULL;
+ per_struct32 *dummy_per32 = NULL;
+ addr_t offset;
+ __u32 tmp;
+
+ if (!test_thread_flag(TIF_31BIT) ||
+ (addr & 3) || addr > sizeof(struct user) - 3)
+ return -EIO;
+
+ if (addr < (addr_t) &dummy32->regs.acrs) {
+ /*
+ * psw and gprs are stored on the stack
+ */
+ if (addr == (addr_t) &dummy32->regs.psw.mask) {
+ /* Fake a 31 bit psw mask. */
+ tmp = (__u32)(__KSTK_PTREGS(child)->psw.mask >> 32);
+ tmp = PSW32_MASK_MERGE(PSW32_USER_BITS, tmp);
+ } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
+ /* Fake a 31 bit psw address. */
+ tmp = (__u32) __KSTK_PTREGS(child)->psw.addr |
+ PSW32_ADDR_AMODE31;
+ } else {
+ /* gpr 0-15 */
+ tmp = *(__u32 *)((addr_t) &__KSTK_PTREGS(child)->psw +
+ addr*2 + 4);
+ }
+ } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
+ /*
+ * access registers are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy32->regs.acrs;
+ tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
+
+ } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
+ /*
+ * orig_gpr2 is stored on the kernel stack
+ */
+ tmp = *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4);
+
+ } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
+ /*
+ * floating point regs. are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy32->regs.fp_regs;
+ tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
+
+ } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
+ /*
+ * per_info is found in the thread structure
+ */
+ offset = addr - (addr_t) &dummy32->regs.per_info;
+ /* This is magic. See per_struct and per_struct32. */
+ if ((offset >= (addr_t) &dummy_per32->control_regs &&
+ offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
+ (offset >= (addr_t) &dummy_per32->starting_addr &&
+ offset <= (addr_t) &dummy_per32->ending_addr) ||
+ offset == (addr_t) &dummy_per32->lowcore.words.address)
+ offset = offset*2 + 4;
+ else
+ offset = offset*2;
+ tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
+
+ } else
+ tmp = 0;
+
+ return put_user(tmp, (__u32 __user *) data);
+}
+
+/*
+ * Same as poke_user but for a 31 bit program.
+ */
+static int
+poke_user_emu31(struct task_struct *child, addr_t addr, addr_t data)
+{
+ struct user32 *dummy32 = NULL;
+ per_struct32 *dummy_per32 = NULL;
+ addr_t offset;
+ __u32 tmp;
+
+ if (!test_thread_flag(TIF_31BIT) ||
+ (addr & 3) || addr > sizeof(struct user32) - 3)
+ return -EIO;
+
+ tmp = (__u32) data;
+
+ if (addr < (addr_t) &dummy32->regs.acrs) {
+ /*
+ * psw, gprs, acrs and orig_gpr2 are stored on the stack
+ */
+ if (addr == (addr_t) &dummy32->regs.psw.mask) {
+ /* Build a 64 bit psw mask from 31 bit mask. */
+ if (tmp != PSW32_MASK_MERGE(PSW32_USER_BITS, tmp))
+ /* Invalid psw mask. */
+ return -EINVAL;
+ __KSTK_PTREGS(child)->psw.mask =
+ PSW_MASK_MERGE(PSW_USER32_BITS, (__u64) tmp << 32);
+ } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
+ /* Build a 64 bit psw address from 31 bit address. */
+ __KSTK_PTREGS(child)->psw.addr =
+ (__u64) tmp & PSW32_ADDR_INSN;
+ } else {
+ /* gpr 0-15 */
+ *(__u32*)((addr_t) &__KSTK_PTREGS(child)->psw
+ + addr*2 + 4) = tmp;
+ }
+ } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
+ /*
+ * access registers are stored in the thread structure
+ */
+ offset = addr - (addr_t) &dummy32->regs.acrs;
+ *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
+
+ } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
+ /*
+ * orig_gpr2 is stored on the kernel stack
+ */
+ *(__u32*)((addr_t) &__KSTK_PTREGS(child)->orig_gpr2 + 4) = tmp;
+
+ } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
+ /*
+ * floating point regs. are stored in the thread structure
+ */
+ if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
+ (tmp & ~FPC_VALID_MASK) != 0)
+ /* Invalid floating point control. */
+ return -EINVAL;
+ offset = addr - (addr_t) &dummy32->regs.fp_regs;
+ *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
+
+ } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
+ /*
+ * per_info is found in the thread structure.
+ */
+ offset = addr - (addr_t) &dummy32->regs.per_info;
+ /*
+ * This is magic. See per_struct and per_struct32.
+ * By incident the offsets in per_struct are exactly
+ * twice the offsets in per_struct32 for all fields.
+ * The 8 byte fields need special handling though,
+ * because the second half (bytes 4-7) is needed and
+ * not the first half.
+ */
+ if ((offset >= (addr_t) &dummy_per32->control_regs &&
+ offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
+ (offset >= (addr_t) &dummy_per32->starting_addr &&
+ offset <= (addr_t) &dummy_per32->ending_addr) ||
+ offset == (addr_t) &dummy_per32->lowcore.words.address)
+ offset = offset*2 + 4;
+ else
+ offset = offset*2;
+ *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
+
+ }
+
+ FixPerRegisters(child);
+ return 0;
+}
+
+static int
+do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
+{
+ unsigned int tmp; /* 4 bytes !! */
+ ptrace_area_emu31 parea;
+ int copied, ret;
+
+ switch (request) {
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA:
+ /* read word at location addr. */
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+ if (copied != sizeof(tmp))
+ return -EIO;
+ return put_user(tmp, (unsigned int __user *) data);
+
+ case PTRACE_PEEKUSR:
+ /* read the word at location addr in the USER area. */
+ return peek_user_emu31(child, addr, data);
+
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ /* write the word at location addr. */
+ tmp = data;
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1);
+ if (copied != sizeof(tmp))
+ return -EIO;
+ return 0;
+
+ case PTRACE_POKEUSR:
+ /* write the word at location addr in the USER area */
+ return poke_user_emu31(child, addr, data);
+
+ case PTRACE_PEEKUSR_AREA:
+ case PTRACE_POKEUSR_AREA:
+ if (copy_from_user(&parea, (void __user *) addr,
+ sizeof(parea)))
+ return -EFAULT;
+ addr = parea.kernel_addr;
+ data = parea.process_addr;
+ copied = 0;
+ while (copied < parea.len) {
+ if (request == PTRACE_PEEKUSR_AREA)
+ ret = peek_user_emu31(child, addr, data);
+ else {
+ __u32 tmp;
+ if (get_user (tmp, (__u32 __user *) data))
+ return -EFAULT;
+ ret = poke_user_emu31(child, addr, tmp);
+ }
+ if (ret)
+ return ret;
+ addr += sizeof(unsigned int);
+ data += sizeof(unsigned int);
+ copied += sizeof(unsigned int);
+ }
+ return 0;
+ case PTRACE_GETEVENTMSG:
+ return put_user((__u32) child->ptrace_message,
+ (unsigned int __user *) data);
+ case PTRACE_GETSIGINFO:
+ if (child->last_siginfo == NULL)
+ return -EINVAL;
+ return copy_siginfo_to_user32((compat_siginfo_t __user *) data,
+ child->last_siginfo);
+ case PTRACE_SETSIGINFO:
+ if (child->last_siginfo == NULL)
+ return -EINVAL;
+ return copy_siginfo_from_user32(child->last_siginfo,
+ (compat_siginfo_t __user *) data);
+ }
+ return ptrace_request(child, request, addr, data);
+}
+#endif
+
+#define PT32_IEEE_IP 0x13c
+
+static int
+do_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+ int ret;
+
+ if (request == PTRACE_ATTACH)
+ return ptrace_attach(child);
+
+ /*
+ * Special cases to get/store the ieee instructions pointer.
+ */
+ if (child == current) {
+ if (request == PTRACE_PEEKUSR && addr == PT_IEEE_IP)
+ return peek_user(child, addr, data);
+ if (request == PTRACE_POKEUSR && addr == PT_IEEE_IP)
+ return poke_user(child, addr, data);
+#ifdef CONFIG_S390_SUPPORT
+ if (request == PTRACE_PEEKUSR &&
+ addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT))
+ return peek_user_emu31(child, addr, data);
+ if (request == PTRACE_POKEUSR &&
+ addr == PT32_IEEE_IP && test_thread_flag(TIF_31BIT))
+ return poke_user_emu31(child, addr, data);
+#endif
+ }
+
+ ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ if (ret < 0)
+ return ret;
+
+ switch (request) {
+ case PTRACE_SYSCALL:
+ /* continue and stop at next (return from) syscall */
+ case PTRACE_CONT:
+ /* restart after signal. */
+ if ((unsigned long) data >= _NSIG)
+ return -EIO;
+ 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. */
+ clear_single_step(child);
+ wake_up_process(child);
+ return 0;
+
+ case PTRACE_KILL:
+ /*
+ * 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.
+ */
+ if (child->exit_state == EXIT_ZOMBIE) /* already dead */
+ return 0;
+ child->exit_code = SIGKILL;
+ /* make sure the single step bit is not set. */
+ clear_single_step(child);
+ wake_up_process(child);
+ return 0;
+
+ case PTRACE_SINGLESTEP:
+ /* set the trap flag. */
+ if ((unsigned long) data >= _NSIG)
+ return -EIO;
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ child->exit_code = data;
+ if (data)
+ set_tsk_thread_flag(child, TIF_SINGLE_STEP);
+ else
+ set_single_step(child);
+ /* give it a chance to run. */
+ wake_up_process(child);
+ return 0;
+
+ case PTRACE_DETACH:
+ /* detach a process that was attached. */
+ return ptrace_detach(child, data);
+
+
+ /* Do requests that differ for 31/64 bit */
+ default:
+#ifdef CONFIG_S390_SUPPORT
+ if (test_thread_flag(TIF_31BIT))
+ return do_ptrace_emu31(child, request, addr, data);
+#endif
+ return do_ptrace_normal(child, request, addr, data);
+ }
+ /* Not reached. */
+ return -EIO;
+}
+
+asmlinkage long
+sys_ptrace(long request, long pid, long addr, long data)
+{
+ struct task_struct *child;
+ int ret;
+
+ lock_kernel();
+
+ if (request == PTRACE_TRACEME) {
+ /* are we already being traced? */
+ ret = -EPERM;
+ if (current->ptrace & PT_PTRACED)
+ goto out;
+ ret = security_ptrace(current->parent, current);
+ if (ret)
+ goto out;
+ /* set the ptrace bit in the process flags. */
+ current->ptrace |= PT_PTRACED;
+ goto out;
+ }
+
+ ret = -EPERM;
+ if (pid == 1) /* you may not mess with init */
+ 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 = do_ptrace(child, request, addr, data);
+
+ put_task_struct(child);
+out:
+ unlock_kernel();
+ return ret;
+}
+
+asmlinkage void
+syscall_trace(struct pt_regs *regs, int entryexit)
+{
+ if (unlikely(current->audit_context)) {
+ if (!entryexit)
+ audit_syscall_entry(current, regs->gprs[2],
+ regs->orig_gpr2, regs->gprs[3],
+ regs->gprs[4], regs->gprs[5]);
+ else
+ audit_syscall_exit(current, regs->gprs[2]);
+ }
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+ 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;
+ }
+}
