cregit-Linux how code gets into the kernel

Release 4.7 kernel/ptrace.c

Directory: kernel
/*
 * 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/export.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/ptrace.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/uio.h>
#include <linux/audit.h>
#include <linux/pid_namespace.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
#include <linux/cn_proc.h>
#include <linux/compat.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_entry)); list_add(&child->ptrace_entry, &new_parent->ptraced); child->parent = new_parent; }

Contributors

PersonTokensPropCommitsCommitProp
ingo molnaringo molnar3984.78%250.00%
roland mcgrathroland mcgrath48.70%125.00%
eric sesterhenneric sesterhenn36.52%125.00%
Total46100.00%4100.00%

/** * __ptrace_unlink - unlink ptracee and restore its execution state * @child: ptracee to be unlinked * * Remove @child from the ptrace list, move it back to the original parent, * and restore the execution state so that it conforms to the group stop * state. * * Unlinking can happen via two paths - explicit PTRACE_DETACH or ptracer * exiting. For PTRACE_DETACH, unless the ptracee has been killed between * ptrace_check_attach() and here, it's guaranteed to be in TASK_TRACED. * If the ptracer is exiting, the ptracee can be in any state. * * After detach, the ptracee should be in a state which conforms to the * group stop. If the group is stopped or in the process of stopping, the * ptracee should be put into TASK_STOPPED; otherwise, it should be woken * up from TASK_TRACED. * * If the ptracee is in TASK_TRACED and needs to be moved to TASK_STOPPED, * it goes through TRACED -> RUNNING -> STOPPED transition which is similar * to but in the opposite direction of what happens while attaching to a * stopped task. However, in this direction, the intermediate RUNNING * state is not hidden even from the current ptracer and if it immediately * re-attaches and performs a WNOHANG wait(2), it may fail. * * CONTEXT: * write_lock_irq(tasklist_lock) */
void __ptrace_unlink(struct task_struct *child) { BUG_ON(!child->ptrace); child->parent = child->real_parent; list_del_init(&child->ptrace_entry); spin_lock(&child->sighand->siglock); child->ptrace = 0; /* * Clear all pending traps and TRAPPING. TRAPPING should be * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly. */ task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK); task_clear_jobctl_trapping(child); /* * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and * @child isn't dead. */ if (!(child->flags & PF_EXITING) && (child->signal->flags & SIGNAL_STOP_STOPPED || child->signal->group_stop_count)) { child->jobctl |= JOBCTL_STOP_PENDING; /* * This is only possible if this thread was cloned by the * traced task running in the stopped group, set the signal * for the future reports. * FIXME: we should change ptrace_init_task() to handle this * case. */ if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) child->jobctl |= SIGSTOP; } /* * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick * @child in the butt. Note that @resume should be used iff @child * is in TASK_TRACED; otherwise, we might unduly disrupt * TASK_KILLABLE sleeps. */ if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) ptrace_signal_wake_up(child, true); spin_unlock(&child->sighand->siglock); }

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PersonTokensPropCommitsCommitProp
roland mcgrathroland mcgrath5738.51%529.41%
tejun heotejun heo4429.73%529.41%
oleg nesterovoleg nesterov3221.62%423.53%
ingo molnaringo molnar128.11%211.76%
matthew wilcoxmatthew wilcox32.03%15.88%
Total148100.00%17100.00%

/* Ensure that nothing can wake it up, even SIGKILL */
static bool ptrace_freeze_traced(struct task_struct *task) { bool ret = false; /* Lockless, nobody but us can set this flag */ if (task->jobctl & JOBCTL_LISTENING) return ret; spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !__fatal_signal_pending(task)) { task->state = __TASK_TRACED; ret = true; } spin_unlock_irq(&task->sighand->siglock); return ret; }

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PersonTokensPropCommitsCommitProp
oleg nesterovoleg nesterov76100.00%1100.00%
Total76100.00%1100.00%


static void ptrace_unfreeze_traced(struct task_struct *task) { if (task->state != __TASK_TRACED) return; WARN_ON(!task->ptrace || task->parent != current); spin_lock_irq(&task->sighand->siglock); if (__fatal_signal_pending(task)) wake_up_state(task, __TASK_TRACED); else task->state = TASK_TRACED; spin_unlock_irq(&task->sighand->siglock); }

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PersonTokensPropCommitsCommitProp
oleg nesterovoleg nesterov75100.00%1100.00%
Total75100.00%1100.00%

/** * ptrace_check_attach - check whether ptracee is ready for ptrace operation * @child: ptracee to check for * @ignore_state: don't check whether @child is currently %TASK_TRACED * * Check whether @child is being ptraced by %current and ready for further * ptrace operations. If @ignore_state is %false, @child also should be in * %TASK_TRACED state and on return the child is guaranteed to be traced * and not executing. If @ignore_state is %true, @child can be in any * state. * * CONTEXT: * Grabs and releases tasklist_lock and @child->sighand->siglock. * * RETURNS: * 0 on success, -ESRCH if %child is not ready. */
static int ptrace_check_attach(struct task_struct *child, bool ignore_state) { 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 && child->parent == current) { WARN_ON(child->state == __TASK_TRACED); /* * child->sighand can't be NULL, release_task() * does ptrace_unlink() before __exit_signal(). */ if (ignore_state || ptrace_freeze_traced(child)) ret = 0; } read_unlock(&tasklist_lock); if (!ret && !ignore_state) { if (!wait_task_inactive(child, __TASK_TRACED)) { /* * This can only happen if may_ptrace_stop() fails and * ptrace_stop() changes ->state back to TASK_RUNNING, * so we should not worry about leaking __TASK_TRACED. */ WARN_ON(child->state == __TASK_TRACED); ret = -ESRCH; } } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
roland mcgrathroland mcgrath4137.27%325.00%
linus torvaldslinus torvalds3128.18%216.67%
oleg nesterovoleg nesterov3027.27%325.00%
tejun heotejun heo54.55%216.67%
matthew wilcoxmatthew wilcox21.82%18.33%
david howellsdavid howells10.91%18.33%
Total110100.00%12100.00%


static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) { if (mode & PTRACE_MODE_NOAUDIT) return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); else return has_ns_capability(current, ns, CAP_SYS_PTRACE); }

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eric pariseric paris42100.00%1100.00%
Total42100.00%1100.00%

/* Returns 0 on success, -errno on denial. */
static int __ptrace_may_access(struct task_struct *task, unsigned int mode) { const struct cred *cred = current_cred(), *tcred; int dumpable = 0; kuid_t caller_uid; kgid_t caller_gid; if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) { WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n"); return -EPERM; } /* 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. */ /* Don't let security modules deny introspection */ if (same_thread_group(task, current)) return 0; rcu_read_lock(); if (mode & PTRACE_MODE_FSCREDS) { caller_uid = cred->fsuid; caller_gid = cred->fsgid; } else { /* * Using the euid would make more sense here, but something * in userland might rely on the old behavior, and this * shouldn't be a security problem since * PTRACE_MODE_REALCREDS implies that the caller explicitly * used a syscall that requests access to another process * (and not a filesystem syscall to procfs). */ caller_uid = cred->uid; caller_gid = cred->gid; } tcred = __task_cred(task); if (uid_eq(caller_uid, tcred->euid) && uid_eq(caller_uid, tcred->suid) && uid_eq(caller_uid, tcred->uid) && gid_eq(caller_gid, tcred->egid) && gid_eq(caller_gid, tcred->sgid) && gid_eq(caller_gid, tcred->gid)) goto ok; if (ptrace_has_cap(tcred->user_ns, mode)) goto ok; rcu_read_unlock(); return -EPERM; ok: rcu_read_unlock(); smp_rmb(); if (task->mm) dumpable = get_dumpable(task->mm); rcu_read_lock(); if (dumpable != SUID_DUMP_USER && !ptrace_has_cap(__task_cred(task)->user_ns, mode)) { rcu_read_unlock(); return -EPERM; } rcu_read_unlock(); return security_ptrace_access_check(task, mode); }

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PersonTokensPropCommitsCommitProp
jann hornjann horn7828.68%15.56%
eric w. biedermaneric w. biederman5620.59%316.67%
linus torvaldslinus torvalds4115.07%15.56%
david howellsdavid howells3412.50%211.11%
serge hallynserge hallyn228.09%15.56%
miklos szeredimiklos szeredi165.88%15.56%
stephen d. smalleystephen d. smalley72.57%15.56%
eric pariseric paris62.21%211.11%
mark a. grondonamark a. grondona41.47%15.56%
hidehiro kawaihidehiro kawai31.10%15.56%
kees cookkees cook20.74%15.56%
ingo molnaringo molnar10.37%15.56%
andrew mortonandrew morton10.37%15.56%
tetsuo handatetsuo handa10.37%15.56%
Total272100.00%18100.00%


bool ptrace_may_access(struct task_struct *task, unsigned int mode) { int err; task_lock(task); err = __ptrace_may_access(task, mode); task_unlock(task); return !err; }

Contributors

PersonTokensPropCommitsCommitProp
miklos szeredimiklos szeredi3177.50%150.00%
stephen d. smalleystephen d. smalley922.50%150.00%
Total40100.00%2100.00%


static int ptrace_attach(struct task_struct *task, long request, unsigned long addr, unsigned long flags) { bool seize = (request == PTRACE_SEIZE); int retval; retval = -EIO; if (seize) { if (addr != 0) goto out; if (flags & ~(unsigned long)PTRACE_O_MASK) goto out; flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT); } else { flags = PT_PTRACED; } audit_ptrace(task); retval = -EPERM; if (unlikely(task->flags & PF_KTHREAD)) goto out; if (same_thread_group(task, current)) goto out; /* * Protect exec's credential calculations against our interference; * SUID, SGID and LSM creds get determined differently * under ptrace. */ retval = -ERESTARTNOINTR; if (mutex_lock_interruptible(&task->signal->cred_guard_mutex)) goto out; task_lock(task); retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); task_unlock(task); if (retval) goto unlock_creds; write_lock_irq(&tasklist_lock); retval = -EPERM; if (unlikely(task->exit_state)) goto unlock_tasklist; if (task->ptrace) goto unlock_tasklist; if (seize) flags |= PT_SEIZED; rcu_read_lock(); if (ns_capable(__task_cred(task)->user_ns, CAP_SYS_PTRACE)) flags |= PT_PTRACE_CAP; rcu_read_unlock(); task->ptrace = flags; __ptrace_link(task, current); /* SEIZE doesn't trap tracee on attach */ if (!seize) send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); spin_lock(&task->sighand->siglock); /* * If the task is already STOPPED, set JOBCTL_TRAP_STOP and * TRAPPING, and kick it so that it transits to TRACED. TRAPPING * will be cleared if the child completes the transition or any * event which clears the group stop states happens. We'll wait * for the transition to complete before returning from this * function. * * This hides STOPPED -> RUNNING -> TRACED transition from the * attaching thread but a different thread in the same group can * still observe the transient RUNNING state. IOW, if another * thread's WNOHANG wait(2) on the stopped tracee races against * ATTACH, the wait(2) may fail due to the transient RUNNING. * * The following task_is_stopped() test is safe as both transitions * in and out of STOPPED are protected by siglock. */ if (task_is_stopped(task) && task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) signal_wake_up_state(task, __TASK_STOPPED); spin_unlock(&task->sighand->siglock); retval = 0; unlock_tasklist: write_unlock_irq(&tasklist_lock); unlock_creds: mutex_unlock(&task->signal->cred_guard_mutex); out: if (!retval) { /* * We do not bother to change retval or clear JOBCTL_TRAPPING * if wait_on_bit() was interrupted by SIGKILL. The tracer will * not return to user-mode, it will exit and clear this bit in * __ptrace_unlink() if it wasn't already cleared by the tracee; * and until then nobody can ptrace this task. */ wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE); proc_ptrace_connector(task, PTRACE_ATTACH); } return retval; }

Contributors

PersonTokensPropCommitsCommitProp
tejun heotejun heo9526.24%719.44%
oleg nesterovoleg nesterov7119.61%719.44%
denys vlasenkodenys vlasenko5715.75%25.56%
linus torvaldslinus torvalds4813.26%513.89%
miklos szeredimiklos szeredi226.08%12.78%
david howellsdavid howells195.25%25.56%
eric w. biedermaneric w. biederman143.87%25.56%
vladimir zapolskiyvladimir zapolskiy92.49%12.78%
greg kroah-hartmangreg kroah-hartman61.66%25.56%
al viroal viro51.38%12.78%
pavel emelianovpavel emelianov41.10%12.78%
kosaki motohirokosaki motohiro41.10%12.78%
eric pariseric paris30.83%12.78%
ingo molnaringo molnar20.55%12.78%
serge hallynserge hallyn20.55%12.78%
jann hornjann horn10.28%12.78%
Total362100.00%36100.00%

/** * ptrace_traceme -- helper for PTRACE_TRACEME * * Performs checks and sets PT_PTRACED. * Should be used by all ptrace implementations for PTRACE_TRACEME. */
static int ptrace_traceme(void) { int ret = -EPERM; write_lock_irq(&tasklist_lock); /* Are we already being traced? */ if (!current->ptrace) { ret = security_ptrace_traceme(current->parent); /* * Check PF_EXITING to ensure ->real_parent has not passed * exit_ptrace(). Otherwise we don't report the error but * pretend ->real_parent untraces us right after return. */ if (!ret && !(current->real_parent->flags & PF_EXITING)) { current->ptrace = PT_PTRACED; __ptrace_link(current, current->real_parent); } } write_unlock_irq(&tasklist_lock); return ret; }

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PersonTokensPropCommitsCommitProp
oleg nesterovoleg nesterov8198.78%266.67%
linus torvaldslinus torvalds11.22%133.33%
Total82100.00%3100.00%

/* * Called with irqs disabled, returns true if childs should reap themselves. */
static int ignoring_children(struct sighand_struct *sigh) { int ret; spin_lock(&sigh->siglock); ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); spin_unlock(&sigh->siglock); return ret; }

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PersonTokensPropCommitsCommitProp
oleg nesterovoleg nesterov69100.00%1100.00%
Total69100.00%1100.00%

/* * Called with tasklist_lock held for writing. * Unlink a traced task, and clean it up if it was a traced zombie. * Return true if it needs to be reaped with release_task(). * (We can't call release_task() here because we already hold tasklist_lock.) * * If it's a zombie, our attachedness prevented normal parent notification * or self-reaping. Do notification now if it would have happened earlier. * If it should reap itself, return true. * * If it's our own child, there is no notification to do. But if our normal * children self-reap, then this child was prevented by ptrace and we must * reap it now, in that case we must also wake up sub-threads sleeping in * do_wait(). */
static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) { bool dead; __ptrace_unlink(p); if (p->exit_state != EXIT_ZOMBIE) return false; dead = !thread_group_leader(p); if (!dead && thread_group_empty(p)) { if (!same_thread_group(p->real_parent, tracer)) dead = do_notify_parent(p, p->exit_signal); else if (ignoring_children(tracer->sighand)) { __wake_up_parent(p, tracer); dead = true; } } /* Mark it as in the process of being reaped. */ if (dead) p->exit_state = EXIT_DEAD; return dead; }

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oleg nesterovoleg nesterov115100.00%3100.00%
Total115100.00%3100.00%


static int ptrace_detach(struct task_struct *child, unsigned int data) { if (!valid_signal(data)) return -EIO; /* Architecture-specific hardware disable .. */ ptrace_disable(child); clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); write_lock_irq(&tasklist_lock); /* * We rely on ptrace_freeze_traced(). It can't be killed and * untraced by another thread, it can't be a zombie. */ WARN_ON(!child->ptrace || child->exit_state); /* * tasklist_lock avoids the race with wait_task_stopped(), see * the comment in ptrace_resume(). */ child->exit_code = data; __ptrace_detach(current, child); write_unlock_irq(&tasklist_lock); proc_ptrace_connector(child, PTRACE_DETACH); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds4752.81%222.22%
oleg nesterovoleg nesterov2426.97%444.44%
vladimir zapolskiyvladimir zapolskiy77.87%111.11%
roland mcgrathroland mcgrath77.87%111.11%
jesper juhljesper juhl44.49%111.11%
Total89100.00%9100.00%

/* * Detach all tasks we were using ptrace on. Called with tasklist held * for writing. */
void exit_ptrace(struct task_struct *tracer, struct list_head *dead) { struct task_struct *p, *n; list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { if (unlikely(p->ptrace & PT_EXITKILL)) send_sig_info(SIGKILL, SEND_SIG_FORCED, p); if (__ptrace_detach(tracer, p)) list_add(&p->ptrace_entry, dead); } }

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PersonTokensPropCommitsCommitProp
oleg nesterovoleg nesterov74100.00%3100.00%
Total74100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12899.22%266.67%
linus torvaldslinus torvalds10.78%133.33%
Total129100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12899.22%266.67%
linus torvaldslinus torvalds10.78%133.33%
Total129100.00%3100.00%


static int ptrace_setoptions(struct task_struct *child, unsigned long data) { unsigned flags; if (data & ~(unsigned long)PTRACE_O_MASK) return -EINVAL; if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) { if (!config_enabled(CONFIG_CHECKPOINT_RESTORE) || !config_enabled(CONFIG_SECCOMP)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; if (seccomp_mode(&current->seccomp) != SECCOMP_MODE_DISABLED || current->ptrace & PT_SUSPEND_SECCOMP) return -EPERM; } /* Avoid intermediate state when all opts are cleared */ flags = child->ptrace; flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); flags |= (data << PT_OPT_FLAG_SHIFT); child->ptrace = flags; return 0; }

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PersonTokensPropCommitsCommitProp
tycho andersentycho andersen6348.84%112.50%
denys vlasenkodenys vlasenko3527.13%225.00%
daniel jacobowitzdaniel jacobowitz3023.26%450.00%
namhyung kimnamhyung kim10.78%112.50%
Total129100.00%8100.00%


static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) { unsigned long flags; int error = -ESRCH; if (lock_task_sighand(child, &flags)) { error = -EINVAL; if (likely(child->last_siginfo != NULL)) { *info = *child->last_siginfo; error = 0; } unlock_task_sighand(child, &flags); } return error; }

Contributors

PersonTokensPropCommitsCommitProp
prasanna medaprasanna meda4152.56%228.57%
daniel jacobowitzdaniel jacobowitz1721.79%114.29%
oleg nesterovoleg nesterov1215.38%114.29%
roland mcgrathroland mcgrath67.69%228.57%
linus torvaldslinus torvalds22.56%114.29%
Total78100.00%7100.00%


static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) { unsigned long flags; int error = -ESRCH; if (lock_task_sighand(child, &flags)) { error = -EINVAL; if (likely(child->last_siginfo != NULL)) { *child->last_siginfo = *info; error = 0; } unlock_task_sighand(child, &flags); } return error; }

Contributors

PersonTokensPropCommitsCommitProp
prasanna medaprasanna meda4253.16%233.33%
daniel jacobowitzdaniel jacobowitz1924.05%116.67%
oleg nesterovoleg nesterov1215.19%116.67%
roland mcgrathroland mcgrath45.06%116.67%
linus torvaldslinus torvalds22.53%116.67%
Total79100.00%6100.00%


static int ptrace_peek_siginfo(struct task_struct *child, unsigned long addr, unsigned long data) { struct ptrace_peeksiginfo_args arg; struct sigpending *pending; struct sigqueue *q; int ret, i; ret = copy_from_user(&arg, (void __user *) addr, sizeof(struct ptrace_peeksiginfo_args)); if (ret) return -EFAULT; if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED) return -EINVAL; /* unknown flags */ if (arg.nr < 0) return -EINVAL; if (arg.flags & PTRACE_PEEKSIGINFO_SHARED) pending = &child->signal->shared_pending; else pending = &child->pending; for (i = 0; i < arg.nr; ) { siginfo_t info; s32 off = arg.off + i; spin_lock_irq(&child->sighand->siglock); list_for_each_entry(q, &pending->list, list) { if (!off--) { copy_siginfo(&info, &q->info); break; } } spin_unlock_irq(&child->sighand->siglock); if (off >= 0) /* beyond the end of the list */ break; #ifdef CONFIG_COMPAT if (unlikely(in_compat_syscall())) { compat_siginfo_t __user *uinfo = compat_ptr(data); if (copy_siginfo_to_user32(uinfo, &info) || __put_user(info.si_code, &uinfo->si_code)) { ret = -EFAULT; break; } } else #endif { siginfo_t __user *uinfo = (siginfo_t __user *) data; if (copy_siginfo_to_user(uinfo, &info) || __put_user(info.si_code, &uinfo->si_code)) { ret = -EFAULT; break; } } data += sizeof(siginfo_t); i++; if (signal_pending(current)) break; cond_resched(); } if (i > 0) return i; return ret; }

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PersonTokensPropCommitsCommitProp
andrey vaginandrey vagin32095.24%133.33%
mathieu desnoyersmathieu desnoyers154.46%133.33%
andy lutomirskiandy lutomirski10.30%133.33%
Total336100.00%3100.00%

#ifdef PTRACE_SINGLESTEP #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) #else #define is_singlestep(request) 0 #endif #ifdef PTRACE_SINGLEBLOCK #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) #else #define is_singleblock(request) 0 #endif #ifdef PTRACE_SYSEMU #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) #else #define is_sysemu_singlestep(request) 0 #endif
static int ptrace_resume(struct task_struct *child, long request, unsigned long data) { bool need_siglock; if (!valid_signal(data)) return -EIO; if (request == PTRACE_SYSCALL) set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); #ifdef TIF_SYSCALL_EMU if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) set_tsk_thread_flag(child, TIF_SYSCALL_EMU); else clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); #endif if (is_singleblock(request)) { if (unlikely(!arch_has_block_step())) return -EIO; user_enable_block_step(child); } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { if (unlikely(!arch_has_single_step())) return -EIO; user_enable_single_step(child); } else { user_disable_single_step(child); } /* * Change ->exit_code and ->state under siglock to avoid the race * with wait_task_stopped() in between; a non-zero ->exit_code will * wrongly look like another report from tracee. * * Note that we need siglock even if ->exit_code == data and/or this * status was not reported yet, the new status must not be cleared by * wait_task_stopped() after resume. * * If data == 0 we do not care if wait_task_stopped() reports the old * status and clears the code too; this can't race with the tracee, it * takes siglock after resume. */ need_siglock = data && !thread_group_empty(current); if (need_siglock) spin_lock_irq(&child->sighand->siglock); child->exit_code = data; wake_up_state(child, __TASK_TRACED); if (need_siglock) spin_unlock_irq(&child->sighand->siglock); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
roland mcgrathroland mcgrath16177.78%350.00%
oleg nesterovoleg nesterov4521.74%233.33%
namhyung kimnamhyung kim10.48%116.67%
Total207100.00%6100.00%

#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
static const struct user_regset * find_regset(const struct user_regset_view *view, unsigned int type) { const struct user_regset *regset; int n; for (n = 0; n < view->n; ++n) { regset = view->regsets + n; if (regset->core_note_type == type) return regset; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
suresh siddhasuresh siddha67100.00%1100.00%
Total67100.00%1100.00%


static int ptrace_regset(struct task_struct *task, int req, unsigned int type, struct iovec *kiov) { const struct user_regset_view *view = task_user_regset_view(task); const struct user_regset *regset = find_regset(view, type); int regset_no; if (!regset || (kiov->iov_len % regset->size) != 0) return -EINVAL; regset_no = regset - view->regsets; kiov->iov_len = min(kiov->iov_len, (__kernel_size_t) (regset->n * regset->size)); if (req == PTRACE_GETREGSET) return copy_regset_to_user(task, view, regset_no, 0, kiov->iov_len, kiov->iov_base); else return copy_regset_from_user(task, view, regset_no, 0, kiov->iov_len, kiov->iov_base); }

Contributors

PersonTokensPropCommitsCommitProp
suresh siddhasuresh siddha150100.00%2100.00%
Total150100.00%2100.00%

/* * This is declared in linux/regset.h and defined in machine-dependent * code. We put the export here, near the primary machine-neutral use, * to ensure no machine forgets it. */ EXPORT_SYMBOL_GPL(task_user_regset_view); #endif
int ptrace_request(struct task_struct *child, long request, unsigned long addr, unsigned long data) { bool seized = child->ptrace & PT_SEIZED; int ret = -EIO; siginfo_t siginfo, *si; void __user *datavp = (void __user *) data; unsigned long __user *datalp = datavp; unsigned long flags; switch (request) { case PTRACE_PEEKTEXT: case PTRACE_PEEKDATA: return generic_ptrace_peekdata(child, addr, data); case PTRACE_POKETEXT: case PTRACE_POKEDATA: return generic_ptrace_pokedata(child, addr, data); #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, datalp); break; case PTRACE_PEEKSIGINFO: ret = ptrace_peek_siginfo(child, addr, data); break; case PTRACE_GETSIGINFO: ret = ptrace_getsiginfo(child, &siginfo); if (!ret) ret = copy_siginfo_to_user(datavp, &siginfo); break; case PTRACE_SETSIGINFO: if (copy_from_user(&siginfo, datavp, sizeof siginfo)) ret = -EFAULT; else ret = ptrace_setsiginfo(child, &siginfo); break; case PTRACE_GETSIGMASK: if (addr != sizeof(sigset_t)) { ret = -EINVAL; break; } if (copy_to_user(datavp, &child->blocked, sizeof(sigset_t))) ret = -EFAULT; else ret = 0; break; case PTRACE_SETSIGMASK: { sigset_t new_set; if (addr != sizeof(sigset_t)) { ret = -EINVAL; break; } if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) { ret = -EFAULT; break; } sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); /* * Every thread does recalc_sigpending() after resume, so * retarget_shared_pending() and recalc_sigpending() are not * called here. */ spin_lock_irq(&child->sighand->siglock); child->blocked = new_set; spin_unlock_irq(&child->sighand->siglock); ret = 0; break; } case PTRACE_INTERRUPT: /* * Stop tracee without any side-effect on signal or job * control. At least one trap is guaranteed to happen * after this request. If @child is already trapped, the * current trap is not disturbed and another trap will * happen after the current trap is ended with PTRACE_CONT. * * The actual trap might not be PTRACE_EVENT_STOP trap but * the pending condition is cleared regardless. */ if (unlikely(!seized || !lock_task_sighand(child, &flags))) break; /* * INTERRUPT doesn't disturb existing trap sans one * exception. If ptracer issued LISTEN for the current * STOP, this INTERRUPT should clear LISTEN and re-trap * tracee into STOP. */ if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); unlock_task_sighand(child, &flags); ret = 0; break; case PTRACE_LISTEN: /* * Listen for events. Tracee must be in STOP. It's not * resumed per-se but is not considered to be in TRACED by * wait(2) or ptrace(2). If an async event (e.g. group * stop state change) happens, tracee will enter STOP trap * again. Alternatively, ptracer can issue INTERRUPT to * finish listening and re-trap tracee into STOP. */ if (unlikely(!seized || !lock_task_sighand(child, &flags))) break; si = child->last_siginfo; if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) { child->jobctl |= JOBCTL_LISTENING; /* * If NOTIFY is set, it means event happened between * start of this trap and now. Trigger re-trap. */ if (child->jobctl & JOBCTL_TRAP_NOTIFY) ptrace_signal_wake_up(child, true); ret = 0; } unlock_task_sighand(child, &flags); break; case PTRACE_DETACH: /* detach a process that was attached. */ ret = ptrace_detach(child, data); break; #ifdef CONFIG_BINFMT_ELF_FDPIC case PTRACE_GETFDPIC: { struct mm_struct *mm = get_task_mm(child); unsigned long tmp = 0; ret = -ESRCH; if (!mm) break; switch (addr) { case PTRACE_GETFDPIC_EXEC: tmp = mm->context.exec_fdpic_loadmap; break; case PTRACE_GETFDPIC_INTERP: tmp = mm->context.interp_fdpic_loadmap; break; default: break; } mmput(mm); ret = put_user(tmp, datalp); break; } #endif #ifdef PTRACE_SINGLESTEP case PTRACE_SINGLESTEP: #endif #ifdef PTRACE_SINGLEBLOCK case PTRACE_SINGLEBLOCK: #endif #ifdef PTRACE_SYSEMU case PTRACE_SYSEMU: case PTRACE_SYSEMU_SINGLESTEP: #endif case PTRACE_SYSCALL: case PTRACE_CONT: return ptrace_resume(child, request, data); case PTRACE_KILL: if (child->exit_state) /* already dead */ return 0; return ptrace_resume(child, request, SIGKILL); #ifdef CONFIG_HAVE_ARCH_TRACEHOOK case PTRACE_GETREGSET: case PTRACE_SETREGSET: { struct iovec kiov; struct iovec __user *uiov = datavp; if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) return -EFAULT; if (__get_user(kiov.iov_base, &uiov->iov_base) || __get_user(kiov.iov_len, &uiov->iov_len)) return -EFAULT; ret = ptrace_regset(child, request, addr, &kiov); if (!ret) ret = __put_user(kiov.iov_len, &uiov->iov_len); break; } #endif case PTRACE_SECCOMP_GET_FILTER: ret = seccomp_get_filter(child, addr, datavp); break; default: break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
andrey vaginandrey vagin15920.00%210.00%
tejun heotejun heo14317.99%210.00%
roland mcgrathroland mcgrath14117.74%420.00%
suresh siddhasuresh siddha10813.58%15.00%
daniel jacobowitzdaniel jacobowitz9111.45%315.00%
mike frysingermike frysinger577.17%15.00%
oleg nesterovoleg nesterov405.03%315.00%
namhyung kimnamhyung kim273.40%210.00%
tycho andersentycho andersen151.89%15.00%
alexey dobriyanalexey dobriyan141.76%15.00%
Total795100.00%20100.00%


static struct task_struct *ptrace_get_task_struct(pid_t pid) { struct task_struct *child; rcu_read_lock(); child = find_task_by_vpid(pid); if (child) get_task_struct(child); rcu_read_unlock(); if (!child) return ERR_PTR(-ESRCH); return child; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig4788.68%250.00%
oleg nesterovoleg nesterov59.43%125.00%
pavel emelianovpavel emelianov11.89%125.00%
Total53100.00%4100.00%

#ifndef arch_ptrace_attach #define arch_ptrace_attach(child) do { } while (0) #endif SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, unsigned long, data) { struct task_struct *child; long ret; if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); if (!ret) arch_ptrace_attach(current); goto out; } child = ptrace_get_task_struct(pid); if (IS_ERR(child)) { ret = PTR_ERR(child); goto out; } if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { ret = ptrace_attach(child, request, addr, data); /* * Some architectures need to do book-keeping after * a ptrace attach. */ if (!ret) arch_ptrace_attach(child); goto out_put_task_struct; } ret = ptrace_check_attach(child, request == PTRACE_KILL || request == PTRACE_INTERRUPT); if (ret < 0) goto out_put_task_struct; ret = arch_ptrace(child, request, addr, data); if (ret || request != PTRACE_DETACH) ptrace_unfreeze_traced(child); out_put_task_struct: put_task_struct(child); out: return ret; }
int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, unsigned long data) { unsigned long tmp; int copied; copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); if (copied != sizeof(tmp)) return -EIO; return put_user(tmp, (unsigned long __user *)data); }

Contributors

PersonTokensPropCommitsCommitProp
alexey dobriyanalexey dobriyan6997.18%150.00%
namhyung kimnamhyung kim22.82%150.00%
Total71100.00%2100.00%


int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, unsigned long data) { int copied; copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); return (copied == sizeof(data)) ? 0 : -EIO; }

Contributors

PersonTokensPropCommitsCommitProp
alexey dobriyanalexey dobriyan5396.36%150.00%
namhyung kimnamhyung kim23.64%150.00%
Total55100.00%2100.00%

#if defined CONFIG_COMPAT
int compat_ptrace_request(struct task_struct *child, compat_long_t request, compat_ulong_t addr, compat_ulong_t data) { compat_ulong_t __user *datap = compat_ptr(data); compat_ulong_t word; siginfo_t siginfo; int ret; switch (request) { case PTRACE_PEEKTEXT: case PTRACE_PEEKDATA: ret = access_process_vm(child, addr, &word, sizeof(word), 0); if (ret != sizeof(word)) ret = -EIO; else ret = put_user(word, datap); break; case PTRACE_POKETEXT: case PTRACE_POKEDATA: ret = access_process_vm(child, addr, &data, sizeof(data), 1); ret = (ret != sizeof(data) ? -EIO : 0); break; case PTRACE_GETEVENTMSG: ret = put_user((compat_ulong_t) child->ptrace_message, datap); break; case PTRACE_GETSIGINFO: ret = ptrace_getsiginfo(child, &siginfo); if (!ret) ret = copy_siginfo_to_user32( (struct compat_siginfo __user *) datap, &siginfo); break; case PTRACE_SETSIGINFO: memset(&siginfo, 0, sizeof siginfo); if (copy_siginfo_from_user32( &siginfo, (struct compat_siginfo __user *) datap)) ret = -EFAULT; else ret = ptrace_setsiginfo(child, &siginfo); break; #ifdef CONFIG_HAVE_ARCH_TRACEHOOK case PTRACE_GETREGSET: case PTRACE_SETREGSET: { struct iovec kiov; struct compat_iovec __user *uiov = (struct compat_iovec __user *) datap; compat_uptr_t ptr; compat_size_t len; if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) return -EFAULT; if (__get_user(ptr, &uiov->iov_base) || __get_user(len, &uiov->iov_len)) return -EFAULT; kiov.iov_base = compat_ptr(ptr); kiov.iov_len = len; ret = ptrace_regset(child, request, addr, &kiov); if (!ret) ret = __put_user(kiov.iov_len, &uiov->iov_len); break; } #endif default: ret = ptrace_request(child, request, addr, data); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
roland mcgrathroland mcgrath25365.71%266.67%
suresh siddhasuresh siddha13234.29%133.33%
Total385100.00%3100.00%

COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, compat_long_t, addr, compat_long_t, data) { struct task_struct *child; long ret; if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); goto out; } child = ptrace_get_task_struct(pid); if (IS_ERR(child)) { ret = PTR_ERR(child); goto out; } if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { ret = ptrace_attach(child, request, addr, data); /* * Some architectures need to do book-keeping after * a ptrace attach. */ if (!ret) arch_ptrace_attach(child); goto out_put_task_struct; } ret = ptrace_check_attach(child, request == PTRACE_KILL || request == PTRACE_INTERRUPT); if (!ret) { ret = compat_arch_ptrace(child, request, addr, data); if (ret || request != PTRACE_DETACH) ptrace_unfreeze_traced(child); } out_put_task_struct: put_task_struct(child); out: return ret; } #endif /* CONFIG_COMPAT */

Overall Contributors

PersonTokensPropCommitsCommitProp
roland mcgrathroland mcgrath86618.13%1711.81%
oleg nesterovoleg nesterov79416.62%2920.14%
andrey vaginandrey vagin48210.09%21.39%
suresh siddhasuresh siddha4659.73%21.39%
tejun heotejun heo3136.55%128.33%
pre-gitpre-git2715.67%42.78%
christoph hellwigchristoph hellwig1863.89%53.47%
linus torvaldslinus torvalds1743.64%85.56%
daniel jacobowitzdaniel jacobowitz1573.29%53.47%
alexey dobriyanalexey dobriyan1362.85%32.08%
denys vlasenkodenys vlasenko962.01%32.08%
prasanna medaprasanna meda831.74%21.39%
jann hornjann horn791.65%10.69%
tycho andersentycho andersen781.63%21.39%
eric w. biedermaneric w. biederman701.47%32.08%
miklos szeredimiklos szeredi691.44%10.69%
ingo molnaringo molnar581.21%32.08%
mike frysingermike frysinger571.19%10.69%
david howellsdavid howells541.13%53.47%
eric pariseric paris511.07%21.39%
heiko carstensheiko carstens380.80%21.39%
namhyung kimnamhyung kim350.73%21.39%
serge hallynserge hallyn240.50%10.69%
vladimir zapolskiyvladimir zapolskiy190.40%10.69%
stephen d. smalleystephen d. smalley160.33%10.69%
mathieu desnoyersmathieu desnoyers150.31%10.69%
haavard skinnemoenhaavard skinnemoen100.21%10.69%
greg kroah-hartmangreg kroah-hartman90.19%32.08%
al viroal viro80.17%10.69%
pavel emelianovpavel emelianov80.17%32.08%
jesper juhljesper juhl70.15%10.69%
josh stonejosh stone60.13%10.69%
matthew wilcoxmatthew wilcox50.10%10.69%
kosaki motohirokosaki motohiro40.08%10.69%
andrew mortonandrew morton40.08%21.39%
mark a. grondonamark a. grondona40.08%10.69%
hidehiro kawaihidehiro kawai30.06%10.69%
adrian bunkadrian bunk30.06%10.69%
frederic weisbeckerfrederic weisbecker30.06%10.69%
kent overstreetkent overstreet30.06%10.69%
randy dunlaprandy dunlap30.06%10.69%
eric sesterhenneric sesterhenn30.06%10.69%
arnaldo carvalho de meloarnaldo carvalho de melo20.04%10.69%
tetsuo handatetsuo handa20.04%10.69%
kees cookkees cook20.04%10.69%
andy lutomirskiandy lutomirski10.02%10.69%
paul gortmakerpaul gortmaker10.02%10.69%
Total4777100.00%144100.00%
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