litmus-rt.git - The LITMUS^RT kernel.

diff options

author	Linus Torvalds <torvalds@linux-foundation.org>	2009-01-13 11:19:42 -0500
committer	Linus Torvalds <torvalds@linux-foundation.org>	2009-01-13 11:19:42 -0500
commit	ccbf04f24c55ead791dac5df8ddeb1a640fbaad8 (patch)
tree	8f291886f3f04a5daf9c3727938f20a1db1c06b2 /fs/filesystems.c
parent	51eb9ab91abc9c384118b1d947e4b99cc2bc5fc5 (diff)
parent	8c9ea7fe96afb30660673da77853114827fac0ca (diff)

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: IB/iser: Add dependency on INFINIBAND_ADDR_TRANS IPoIB: Do not join broadcast group if interface is brought down RDMA/nes: Fix for NIPQUAD removal IPoIB: Fix loss of connectivity after bonding failover on both sides IB/mlx4: Don't register IB device for adapters with no IB ports mlx4_core: Fix warning from min() IB/ehca: spin_lock_irqsave() takes an unsigned long

Diffstat (limited to 'fs/filesystems.c')

0 files changed, 0 insertions, 0 deletions

/* * linux/kernel/ptrace.c * * (C) Copyright 1999 Linus Torvalds * * Common interfaces for "ptrace()" which we do not want * to continually duplicate across every architecture. */ #include <linux/capability.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/errno.h> #include <linux/mm.h> #include <linux/highmem.h> #include <linux/pagemap.h> #include <linux/smp_lock.h> #include <linux/ptrace.h> #include <linux/security.h> #include <linux/signal.h> #include <asm/pgtable.h> #include <asm/uaccess.h> /* * ptrace a task: make the debugger its new parent and * move it to the ptrace list. * * Must be called with the tasklist lock write-held. */ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) { BUG_ON(!list_empty(&child->ptrace_list)); if (child->parent == new_parent) return; list_add(&child->ptrace_list, &child->parent->ptrace_children); remove_parent(child); child->parent = new_parent; add_parent(child); } /* * Turn a tracing stop into a normal stop now, since with no tracer there * would be no way to wake it up with SIGCONT or SIGKILL. If there was a * signal sent that would resume the child, but didn't because it was in * TASK_TRACED, resume it now. * Requires that irqs be disabled. */ void ptrace_untrace(struct task_struct *child) { spin_lock(&child->sighand->siglock); if (child->state == TASK_TRACED) { if (child->signal->flags & SIGNAL_STOP_STOPPED) { child->state = TASK_STOPPED; } else { signal_wake_up(child, 1); } } spin_unlock(&child->sighand->siglock); } /* * unptrace a task: move it back to its original parent and * remove it from the ptrace list. * * Must be called with the tasklist lock write-held. */ void __ptrace_unlink(struct task_struct *child) { BUG_ON(!child->ptrace); child->ptrace = 0; if (!list_empty(&child->ptrace_list)) { list_del_init(&child->ptrace_list); remove_parent(child); child->parent = child->real_parent; add_parent(child); } if (child->state == TASK_TRACED) ptrace_untrace(child); } /* * Check that we have indeed attached to the thing.. */ int ptrace_check_attach(struct task_struct *child, int kill) { int ret = -ESRCH; /* * We take the read lock around doing both checks to close a * possible race where someone else was tracing our child and * detached between these two checks. After this locked check, * we are sure that this is our traced child and that can only * be changed by us so it's not changing right after this. */ read_lock(&tasklist_lock); if ((child->ptrace & PT_PTRACED) && child->parent == current && (!(child->ptrace & PT_ATTACHED) || child->real_parent != current) && child->signal != NULL) { ret = 0; spin_lock_irq(&child->sighand->siglock); if (child->state == TASK_STOPPED) { child->state = TASK_TRACED; } else if (child->state != TASK_TRACED && !kill) { ret = -ESRCH; } spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); if (!ret && !kill) { wait_task_inactive(child); } /* All systems go.. */ return ret; } static int may_attach(struct task_struct *task) { /* May we inspect the given task? * This check is used both for attaching with ptrace * and for allowing access to sensitive information in /proc. * * ptrace_attach denies several cases that /proc allows * because setting up the necessary parent/child relationship * or halting the specified task is impossible. */ int dumpable = 0; /* Don't let security modules deny introspection */ if (task == current) return 0; if (((current->uid != task->euid) || (current->uid != task->suid) || (current->uid != task->uid) || (current->gid != task->egid) || (current->gid != task->sgid) || (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE)) return -EPERM; smp_rmb(); if (task->mm) dumpable = task->mm->dumpable; if (!dumpable && !capable(CAP_SYS_PTRACE)) return -EPERM; return security_ptrace(current, task); } int ptrace_may_attach(struct task_struct *task) { int err; task_lock(task); err = may_attach(task); task_unlock(task); return !err; } int ptrace_attach(struct task_struct *task) { int retval; retval = -EPERM; if (task->pid <= 1) goto out; if (task->tgid == current->tgid) goto out; repeat: /* * Nasty, nasty. * * We want to hold both the task-lock and the * tasklist_lock for writing at the same time. * But that's against the rules (tasklist_lock * is taken for reading by interrupts on other * cpu's that may have task_lock). */ task_lock(task); local_irq_disable(); if (!write_trylock(&tasklist_lock)) { local_irq_enable(); task_unlock(task); do { cpu_relax(); } while (!write_can_lock(&tasklist_lock)); goto repeat; } if (!task->mm) goto bad; /* the same process cannot be attached many times */ if (task->ptrace & PT_PTRACED) goto bad; retval = may_attach(task); if (retval) goto bad; /* Go */ task->ptrace |= PT_PTRACED | ((task->real_parent != current) ? PT_ATTACHED : 0); if (capable(CAP_SYS_PTRACE)) task->ptrace |= PT_PTRACE_CAP; __ptrace_link(task, current); force_sig_specific(SIGSTOP, task); bad: write_unlock_irq(&tasklist_lock); task_unlock(task); out: return retval; } static inline void __ptrace_detach(struct task_struct *child, unsigned int data) { child->exit_code = data; /* .. re-parent .. */ __ptrace_unlink(child); /* .. and wake it up. */ if (child->exit_state != EXIT_ZOMBIE) wake_up_process(child); } int ptrace_detach(struct task_struct *child, unsigned int data) { if (!valid_signal(data)) return -EIO; /* Architecture-specific hardware disable .. */ ptrace_disable(child); write_lock_irq(&tasklist_lock); /* protect against de_thread()->release_task() */ if (child->ptrace) __ptrace_detach(child, data); write_unlock_irq(&tasklist_lock); return 0; } int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) { int copied = 0; while (len > 0) { char buf[128]; int this_len, retval; this_len = (len > sizeof(buf)) ? sizeof(buf) : len; retval = access_process_vm(tsk, src, buf, this_len, 0); if (!retval) { if (copied) break; return -EIO; } if (copy_to_user(dst, buf, retval)) return -EFAULT; copied += retval; src += retval; dst += retval; len -= retval; } return copied; } int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) { int copied = 0; while (len > 0) { char buf[128]; int this_len, retval; this_len = (len > sizeof(buf)) ? sizeof(buf) : len; if (copy_from_user(buf, src, this_len)) return -EFAULT; retval = access_process_vm(tsk, dst, buf, this_len, 1); if (!retval) { if (copied) break; return -EIO; } copied += retval; src += retval; dst += retval; len -= retval; } return copied; } static int ptrace_setoptions(struct task_struct *child, long data) { child->ptrace &= ~PT_TRACE_MASK; if (data & PTRACE_O_TRACESYSGOOD) child->ptrace |= PT_TRACESYSGOOD; if (data & PTRACE_O_TRACEFORK) child->ptrace |= PT_TRACE_FORK; if (data & PTRACE_O_TRACEVFORK) child->ptrace |= PT_TRACE_VFORK; if (data & PTRACE_O_TRACECLONE) child->ptrace |= PT_TRACE_CLONE; if (data & PTRACE_O_TRACEEXEC) child->ptrace |= PT_TRACE_EXEC; if (data & PTRACE_O_TRACEVFORKDONE) child->ptrace |= PT_TRACE_VFORK_DONE; if (data & PTRACE_O_TRACEEXIT) child->ptrace |= PT_TRACE_EXIT; return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; } static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) { siginfo_t lastinfo; int error = -ESRCH; read_lock(&tasklist_lock); if (likely(child->sighand != NULL)) { error = -EINVAL; spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { lastinfo = *child->last_siginfo; error = 0; } spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); if (!error) return copy_siginfo_to_user(data, &lastinfo); return error; } static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) { siginfo_t newinfo; int error = -ESRCH; if (copy_from_user(&newinfo, data, sizeof (siginfo_t))) return -EFAULT; read_lock(&tasklist_lock); if (likely(child->sighand != NULL)) { error = -EINVAL; spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { *child->last_siginfo = newinfo; error = 0; } spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); return error; } int ptrace_request(struct task_struct *child, long request, long addr, long data) { int ret = -EIO; switch (request) { #ifdef PTRACE_OLDSETOPTIONS case PTRACE_OLDSETOPTIONS: #endif case PTRACE_SETOPTIONS: ret = ptrace_setoptions(child, data); break; case PTRACE_GETEVENTMSG: ret = put_user(child->ptrace_message, (unsigned long __user *) data); break; case PTRACE_GETSIGINFO: ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); break; case PTRACE_SETSIGINFO: ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); break; default: break; } return ret; } /** * ptrace_traceme -- helper for PTRACE_TRACEME * * Performs checks and sets PT_PTRACED. * Should be used by all ptrace implementations for PTRACE_TRACEME. */ int ptrace_traceme(void) { int ret = -EPERM; /* * Are we already being traced? */ task_lock(current); if (!(current->ptrace & PT_PTRACED)) { ret = security_ptrace(current->parent, current); /* * Set the ptrace bit in the process ptrace flags. */ if (!ret) current->ptrace |= PT_PTRACED; } task_unlock(current); return ret; } /** * ptrace_get_task_struct -- grab a task struct reference for ptrace * @pid: process id to grab a task_struct reference of * * This function is a helper for ptrace implementations. It checks * permissions and then grabs a task struct for use of the actual * ptrace implementation. * * Returns the task_struct for @pid or an ERR_PTR() on failure. */


context:
space:
mode: