X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fptrace.c;h=6af9cdd558b7b28b5d7e44cc78e3e7cced8582d5;hb=c19eb8f0d1bd442ed1aff0b413dd822620771c29;hp=38fdfea1a15a0f9b18cb6bf09be17f0fda493bfd;hpb=4b105cbbaf7c06e01c27391957dc3c446328d087;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 38fdfea..6af9cdd 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include @@ -22,6 +21,7 @@ #include #include #include +#include /* @@ -75,7 +75,6 @@ void __ptrace_unlink(struct task_struct *child) child->parent = child->real_parent; list_del_init(&child->ptrace_entry); - arch_ptrace_untrace(child); if (task_is_traced(child)) ptrace_untrace(child); } @@ -152,7 +151,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) if (!dumpable && !capable(CAP_SYS_PTRACE)) return -EPERM; - return security_ptrace_may_access(task, mode); + return security_ptrace_access_check(task, mode); } bool ptrace_may_access(struct task_struct *task, unsigned int mode) @@ -181,8 +180,8 @@ int ptrace_attach(struct task_struct *task) * interference; SUID, SGID and LSM creds get determined differently * under ptrace. */ - retval = mutex_lock_interruptible(&task->cred_guard_mutex); - if (retval < 0) + retval = -ERESTARTNOINTR; + if (mutex_lock_interruptible(&task->cred_guard_mutex)) goto out; task_lock(task); @@ -266,9 +265,10 @@ static int ignoring_children(struct sighand_struct *sigh) * 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. + * 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) { @@ -278,8 +278,10 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) if (!task_detached(p) && thread_group_empty(p)) { if (!same_thread_group(p->real_parent, tracer)) do_notify_parent(p, p->exit_signal); - else if (ignoring_children(tracer->sighand)) + else if (ignoring_children(tracer->sighand)) { + __wake_up_parent(p, tracer); p->exit_signal = -1; + } } if (task_detached(p)) { /* Mark it as in the process of being reaped. */ @@ -424,37 +426,33 @@ static int ptrace_setoptions(struct task_struct *child, long data) static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) { + unsigned long flags; int error = -ESRCH; - read_lock(&tasklist_lock); - if (likely(child->sighand != NULL)) { + if (lock_task_sighand(child, &flags)) { error = -EINVAL; - spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { *info = *child->last_siginfo; error = 0; } - spin_unlock_irq(&child->sighand->siglock); + unlock_task_sighand(child, &flags); } - read_unlock(&tasklist_lock); return error; } static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) { + unsigned long flags; int error = -ESRCH; - read_lock(&tasklist_lock); - if (likely(child->sighand != NULL)) { + if (lock_task_sighand(child, &flags)) { error = -EINVAL; - spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { *child->last_siginfo = *info; error = 0; } - spin_unlock_irq(&child->sighand->siglock); + unlock_task_sighand(child, &flags); } - read_unlock(&tasklist_lock); return error; } @@ -512,6 +510,47 @@ static int ptrace_resume(struct task_struct *child, long request, long data) return 0; } +#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; +} + +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); +} + +#endif + int ptrace_request(struct task_struct *child, long request, long addr, long data) { @@ -574,6 +613,26 @@ int ptrace_request(struct task_struct *child, long request, 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 = (struct iovec __user *) data; + + 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 default: break; } @@ -581,26 +640,16 @@ int ptrace_request(struct task_struct *child, long request, 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. - */ -struct task_struct *ptrace_get_task_struct(pid_t pid) +static struct task_struct *ptrace_get_task_struct(pid_t pid) { struct task_struct *child; - read_lock(&tasklist_lock); + rcu_read_lock(); child = find_task_by_vpid(pid); if (child) get_task_struct(child); + rcu_read_unlock(); - read_unlock(&tasklist_lock); if (!child) return ERR_PTR(-ESRCH); return child; @@ -615,10 +664,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) struct task_struct *child; long ret; - /* - * This lock_kernel fixes a subtle race with suid exec - */ - lock_kernel(); if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); if (!ret) @@ -652,7 +697,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) out_put_task_struct: put_task_struct(child); out: - unlock_kernel(); return ret; } @@ -722,6 +766,32 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, 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); @@ -736,10 +806,6 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, struct task_struct *child; long ret; - /* - * This lock_kernel fixes a subtle race with suid exec - */ - lock_kernel(); if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); goto out; @@ -769,7 +835,6 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, out_put_task_struct: put_task_struct(child); out: - unlock_kernel(); return ret; } #endif /* CONFIG_COMPAT */