rpms/kernel/devel linux-2.6-utrace-ptrace.patch, NONE, 1.1 kernel.spec, 1.1872, 1.1873 linux-2.6-tracehook.patch, 1.9, 1.10 linux-2.6-utrace.patch, 1.118, 1.119
roland
roland at fedoraproject.org
Wed Dec 16 22:09:43 UTC 2009
Author: roland
Update of /cvs/pkgs/rpms/kernel/devel
In directory cvs1.fedora.phx.redhat.com:/tmp/cvs-serv25951
Modified Files:
kernel.spec linux-2.6-tracehook.patch linux-2.6-utrace.patch
Added Files:
linux-2.6-utrace-ptrace.patch
Log Message:
utrace update, now testing the utrace-based ptrace!
linux-2.6-utrace-ptrace.patch:
include/linux/ptrace.h | 2
kernel/Makefile | 1
kernel/ptrace-utrace.c | 1080 +++++++++++++++++++++++++++++++++++++++++++++++++
kernel/ptrace.c | 597 +++++++++++++--------------
kernel/utrace.c | 16
5 files changed, 1391 insertions(+), 305 deletions(-)
--- NEW FILE linux-2.6-utrace-ptrace.patch ---
utrace: ptrace cooperation
This adds the CONFIG_UTRACE_PTRACE option under CONFIG_UTRACE.
When set, parts of ptrace are replaced so it uses the utrace
facilities for noticing events, stopping and resuming threads.
This makes ptrace play nicely with other utrace-based things
tracing the same threads. It also makes all ptrace uses rely on
some of the utrace code working right, even when you are not
using any other utrace-based things. So it's experimental and
not real well proven yet. But it's recommended if you enable
CONFIG_UTRACE and want to try new utrace things.
Signed-off-by: Roland McGrath <roland at redhat.com>
---
include/linux/ptrace.h | 2 +-
kernel/Makefile | 1 +
kernel/ptrace-utrace.c | 1080 ++++++++++++++++++++++++++++++++++++++++++++++++
kernel/ptrace.c | 572 +++++++++++++-------------
kernel/utrace.c | 16 +
5 files changed, 1378 insertions(+), 293 deletions(-)
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 4802e2a..03f8fc7 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -79,7 +79,7 @@
#include <linux/compiler.h> /* For unlikely. */
#include <linux/sched.h> /* For struct task_struct. */
-
+extern void ptrace_notify_stop(struct task_struct *tracee);
extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
extern int ptrace_traceme(void);
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
diff --git a/kernel/Makefile b/kernel/Makefile
index 263bb19..42cb1ec 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_RESOURCE_COUNTERS) += res_c
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_UTRACE) += utrace.o
+obj-$(CONFIG_UTRACE) += ptrace-utrace.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o audit_watch.o
obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
obj-$(CONFIG_GCOV_KERNEL) += gcov/
diff --git a/kernel/ptrace-utrace.c b/kernel/ptrace-utrace.c
new file mode 100644
index ...ea419ee 100644
--- /dev/null
+++ b/kernel/ptrace-utrace.c
@@ -0,0 +1,1080 @@
+/*
+ * 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/utrace.h>
+#include <linux/security.h>
+#include <linux/signal.h>
+#include <linux/audit.h>
+#include <linux/pid_namespace.h>
+#include <linux/syscalls.h>
+#include <linux/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_entry));
+ list_add(&child->ptrace_entry, &new_parent->ptraced);
+ child->parent = new_parent;
+}
+
+/*
+ * 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;
+ child->parent = child->real_parent;
+ list_del_init(&child->ptrace_entry);
+
+ arch_ptrace_untrace(child);
+}
+
+struct ptrace_context {
+ int options;
+
+ int signr;
+ siginfo_t *siginfo;
+
+ int stop_code;
+ unsigned long eventmsg;
+
+ enum utrace_resume_action resume;
+};
+
+#define PT_UTRACED 0x00001000
+
+#define PTRACE_O_SYSEMU 0x100
+
+#define PTRACE_EVENT_SYSCALL (1 << 16)
+#define PTRACE_EVENT_SIGTRAP (2 << 16)
+#define PTRACE_EVENT_SIGNAL (3 << 16)
+/* events visible to user-space */
+#define PTRACE_EVENT_MASK 0xFFFF
+
+static inline bool ptrace_event_pending(struct ptrace_context *ctx)
+{
+ return ctx->stop_code != 0;
+}
+
+static inline int get_stop_event(struct ptrace_context *ctx)
+{
+ return ctx->stop_code >> 8;
+}
+
+static inline void set_stop_code(struct ptrace_context *ctx, int event)
+{
+ ctx->stop_code = (event << 8) | SIGTRAP;
+}
+
+static inline struct ptrace_context *
+ptrace_context(struct utrace_engine *engine)
+{
+ return engine->data;
+}
+
+static const struct utrace_engine_ops ptrace_utrace_ops; /* forward decl */
+
+static struct utrace_engine *ptrace_lookup_engine(struct task_struct *tracee)
+{
+ return utrace_attach_task(tracee, UTRACE_ATTACH_MATCH_OPS,
+ &ptrace_utrace_ops, NULL);
+}
+
+static struct utrace_engine *
+ptrace_reuse_engine(struct task_struct *tracee)
+{
+ struct utrace_engine *engine;
+ struct ptrace_context *ctx;
+ int err = -EPERM;
+
+ engine = ptrace_lookup_engine(tracee);
+ if (IS_ERR(engine))
+ return engine;
+
+ ctx = ptrace_context(engine);
+ if (unlikely(ctx->resume == UTRACE_DETACH)) {
+ /*
+ * Try to reuse this self-detaching engine.
+ * The only caller which can hit this case is ptrace_attach(),
+ * it holds ->cred_guard_mutex.
+ */
+ ctx->options = 0;
+ ctx->eventmsg = 0;
+
+ /* make sure we don't get unwanted reports */
+ err = utrace_set_events(tracee, engine, UTRACE_EVENT(QUIESCE));
+ if (!err || err == -EINPROGRESS) {
+ ctx->resume = UTRACE_RESUME;
+ /* synchronize with ptrace_report_signal() */
+ err = utrace_barrier(tracee, engine);
+ }
+ WARN_ON(!err != (engine->ops == &ptrace_utrace_ops));
+
+ if (!err)
+ return engine;
+ }
+
+ utrace_engine_put(engine);
+ return ERR_PTR(err);
+}
+
+static struct utrace_engine *
+ptrace_attach_engine(struct task_struct *tracee)
+{
+ struct utrace_engine *engine;
+ struct ptrace_context *ctx;
+
+ if (unlikely(task_utrace_flags(tracee))) {
+ engine = ptrace_reuse_engine(tracee);
+ if (!IS_ERR(engine) || IS_ERR(engine) == -EPERM)
+ return engine;
+ }
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (unlikely(!ctx))
+ return ERR_PTR(-ENOMEM);
+
+ ctx->resume = UTRACE_RESUME;
+
+ engine = utrace_attach_task(tracee, UTRACE_ATTACH_CREATE |
+ UTRACE_ATTACH_EXCLUSIVE |
+ UTRACE_ATTACH_MATCH_OPS,
+ &ptrace_utrace_ops, ctx);
+ if (unlikely(IS_ERR(engine))) {
+ if (engine != ERR_PTR(-ESRCH) &&
+ engine != ERR_PTR(-ERESTARTNOINTR))
+ engine = ERR_PTR(-EPERM);
+ kfree(ctx);
+ }
+
+ return engine;
+}
+
+static inline int ptrace_set_events(struct task_struct *target,
+ struct utrace_engine *engine,
+ unsigned long options)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+ /*
+ * We need QUIESCE for resume handling, CLONE to check
+ * for CLONE_PTRACE, other events are always reported.
+ */
+ unsigned long events = UTRACE_EVENT(QUIESCE) | UTRACE_EVENT(CLONE) |
+ UTRACE_EVENT(EXEC) | UTRACE_EVENT_SIGNAL_ALL;
+
+ ctx->options = options;
+ if (options & PTRACE_O_TRACEEXIT)
+ events |= UTRACE_EVENT(EXIT);
+
+ return utrace_set_events(target, engine, events);
+}
+
+/*
+ * Attach a utrace engine for ptrace and set up its event mask.
+ * Returns error code or 0 on success.
+ */
+static int ptrace_attach_task(struct task_struct *tracee, int options)
+{
+ struct utrace_engine *engine;
+ int err;
+
+ engine = ptrace_attach_engine(tracee);
+ if (IS_ERR(engine))
+ return PTR_ERR(engine);
+ /*
+ * It can fail only if the tracee is dead, the caller
+ * must notice this before setting PT_UTRACED.
+ */
+ err = ptrace_set_events(tracee, engine, options);
+ WARN_ON(err && !tracee->exit_state);
+ utrace_engine_put(engine);
+ return 0;
+}
+
+static int ptrace_wake_up(struct task_struct *tracee,
+ struct utrace_engine *engine,
+ enum utrace_resume_action action,
+ bool force_wakeup)
+{
+ if (force_wakeup) {
+ unsigned long flags;
+ /*
+ * Preserve the compatibility bug. Historically ptrace
+ * wakes up the tracee even if it should not. Clear
+ * SIGNAL_STOP_STOPPED for utrace_wakeup().
+ */
+ if (lock_task_sighand(tracee, &flags)) {
+ tracee->signal->flags &= ~SIGNAL_STOP_STOPPED;
+ unlock_task_sighand(tracee, &flags);
+ }
+ }
+
+ if (action != UTRACE_REPORT)
+ ptrace_context(engine)->stop_code = 0;
+
+ return utrace_control(tracee, engine, action);
+}
+
+static void ptrace_detach_task(struct task_struct *tracee, int sig)
+{
+ /*
+ * If true, the caller is PTRACE_DETACH, otherwise
+ * the tracer detaches implicitly during exit.
+ */
+ bool voluntary = (sig >= 0);
+ struct utrace_engine *engine = ptrace_lookup_engine(tracee);
+ enum utrace_resume_action action = UTRACE_DETACH;
+
+ if (unlikely(IS_ERR(engine)))
+ return;
+
+ if (sig) {
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ switch (get_stop_event(ctx)) {
+ case PTRACE_EVENT_SYSCALL:
+ if (voluntary)
+ send_sig_info(sig, SEND_SIG_PRIV, tracee);
+ break;
+
+ case PTRACE_EVENT_SIGNAL:
+ if (voluntary)
+ ctx->signr = sig;
+ ctx->resume = UTRACE_DETACH;
+ action = UTRACE_RESUME;
+ break;
+ }
+ }
+
+ ptrace_wake_up(tracee, engine, action, voluntary);
+ utrace_engine_put(engine);
+}
+
+static void ptrace_abort_attach(struct task_struct *tracee)
+{
+ ptrace_detach_task(tracee, 0);
+}
+
+static u32 ptrace_report_exit(u32 action, struct utrace_engine *engine,
+ long orig_code, long *code)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ WARN_ON(ptrace_event_pending(ctx) &&
+ !signal_group_exit(current->signal));
+
+ set_stop_code(ctx, PTRACE_EVENT_EXIT);
+ ctx->eventmsg = *code;
+
+ return UTRACE_STOP;
+}
+
+static void ptrace_clone_attach(struct task_struct *child,
+ int options)
+{
+ struct task_struct *parent = current;
+ struct task_struct *tracer;
+ bool abort = true;
+
+ if (unlikely(ptrace_attach_task(child, options))) {
+ WARN_ON(1);
+ return;
+ }
+
+ write_lock_irq(&tasklist_lock);
+ tracer = parent->parent;
+ if (!(tracer->flags & PF_EXITING) && parent->ptrace) {
+ child->ptrace = parent->ptrace;
+ __ptrace_link(child, tracer);
+ abort = false;
+ }
+ write_unlock_irq(&tasklist_lock);
+ if (unlikely(abort)) {
+ ptrace_abort_attach(child);
+ return;
+ }
+
+ sigaddset(&child->pending.signal, SIGSTOP);
+ set_tsk_thread_flag(child, TIF_SIGPENDING);
+}
+
+static u32 ptrace_report_clone(u32 action, struct utrace_engine *engine,
+ unsigned long clone_flags,
+ struct task_struct *child)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+ int event = 0;
+
+ WARN_ON(ptrace_event_pending(ctx));
+
+ if (clone_flags & CLONE_UNTRACED) {
+ /* no events reported */
+ } else if (clone_flags & CLONE_VFORK) {
+ if (ctx->options & PTRACE_O_TRACEVFORK)
+ event = PTRACE_EVENT_VFORK;
+ else if (ctx->options & PTRACE_O_TRACEVFORKDONE)
+ event = PTRACE_EVENT_VFORK_DONE;
+ } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
+ if (ctx->options & PTRACE_O_TRACECLONE)
+ event = PTRACE_EVENT_CLONE;
+ } else if (ctx->options & PTRACE_O_TRACEFORK) {
+ event = PTRACE_EVENT_FORK;
+ }
+ /*
+ * Any of these reports implies auto-attaching the new child.
+ * So does CLONE_PTRACE, even with no event to report.
+ */
+ if ((event && event != PTRACE_EVENT_VFORK_DONE) ||
+ (clone_flags & CLONE_PTRACE))
+ ptrace_clone_attach(child, ctx->options);
+
+ if (!event)
+ return UTRACE_RESUME;
+
+ set_stop_code(ctx, event);
+ ctx->eventmsg = child->pid;
+ /*
+ * We shouldn't stop now, inside the do_fork() path.
+ * We will stop later, before return to user-mode.
+ */
+ if (event == PTRACE_EVENT_VFORK_DONE)
+ return UTRACE_REPORT;
+ else
+ return UTRACE_STOP;
+}
+
+static inline void set_syscall_code(struct ptrace_context *ctx)
+{
+ set_stop_code(ctx, PTRACE_EVENT_SYSCALL);
+ if (ctx->options & PTRACE_O_TRACESYSGOOD)
+ ctx->stop_code |= 0x80;
+}
+
+static u32 ptrace_report_syscall_entry(u32 action, struct utrace_engine *engine,
+ struct pt_regs *regs)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ if (action & UTRACE_SYSCALL_RESUMED) {
+ /*
+ * We already reported the first time.
+ * Nothing more to do now.
+ */
+ if (unlikely(ctx->options & PTRACE_O_SYSEMU))
+ return UTRACE_SYSCALL_ABORT | UTRACE_REPORT;
+ return utrace_syscall_action(action) | UTRACE_RESUME;
+ }
+
+ WARN_ON(ptrace_event_pending(ctx));
+
+ set_syscall_code(ctx);
+
+ if (unlikely(ctx->options & PTRACE_O_SYSEMU))
+ return UTRACE_SYSCALL_ABORT | UTRACE_REPORT;
+ /*
+ * Stop now to report. We will get another callback after
+ * we resume, with the UTRACE_SYSCALL_RESUMED flag set.
+ */
+ return UTRACE_SYSCALL_RUN | UTRACE_STOP;
+}
+
+static u32 ptrace_report_syscall_exit(u32 action, struct utrace_engine *engine,
+ struct pt_regs *regs)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ if (ptrace_event_pending(ctx))
+ return UTRACE_STOP;
+
+ if (ctx->resume != UTRACE_RESUME) {
+ WARN_ON(ctx->resume != UTRACE_BLOCKSTEP &&
+ ctx->resume != UTRACE_SINGLESTEP);
+ ctx->resume = UTRACE_RESUME;
+
+ ctx->signr = SIGTRAP;
+ return UTRACE_INTERRUPT;
+ }
+
+ set_syscall_code(ctx);
+ return UTRACE_STOP;
+}
+
+static u32 ptrace_report_exec(u32 action, struct utrace_engine *engine,
+ const struct linux_binfmt *fmt,
+ const struct linux_binprm *bprm,
+ struct pt_regs *regs)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ WARN_ON(ptrace_event_pending(ctx));
+
+ if (!(ctx->options & PTRACE_O_TRACEEXEC)) {
+ /*
+ * Old-fashioned ptrace'd exec just posts a plain signal.
+ */
+ send_sig(SIGTRAP, current, 0);
+ return UTRACE_RESUME;
+ }
+
+ set_stop_code(ctx, PTRACE_EVENT_EXEC);
+ return UTRACE_STOP;
+}
+
+static enum utrace_signal_action resume_signal(struct ptrace_context *ctx,
+ struct k_sigaction *return_ka)
+{
+ siginfo_t *info = ctx->siginfo;
+ int signr = ctx->signr;
+
+ ctx->siginfo = NULL;
+ ctx->signr = 0;
+
+ /* Did the debugger cancel the sig? */
+ if (!signr)
+ return UTRACE_SIGNAL_IGN;
+ /*
+ * Update the siginfo structure if the signal has changed.
+ * If the debugger wanted something specific in the siginfo
+ * then it should have updated *info via PTRACE_SETSIGINFO.
+ */
+ if (info->si_signo != signr) {
+ info->si_signo = signr;
+ info->si_errno = 0;
+ info->si_code = SI_USER;
+ info->si_pid = task_pid_vnr(current->parent);
+ info->si_uid = task_uid(current->parent);
+ }
+
+ /* If the (new) signal is now blocked, requeue it. */
+ if (sigismember(¤t->blocked, signr)) {
+ send_sig_info(signr, info, current);
+ return UTRACE_SIGNAL_IGN;
+ }
+
+ spin_lock_irq(¤t->sighand->siglock);
+ *return_ka = current->sighand->action[signr - 1];
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ return UTRACE_SIGNAL_DELIVER;
+}
+
+static u32 ptrace_report_signal(u32 action, struct utrace_engine *engine,
+ struct pt_regs *regs,
+ siginfo_t *info,
+ const struct k_sigaction *orig_ka,
+ struct k_sigaction *return_ka)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+ enum utrace_resume_action resume = ctx->resume;
+
+ if (ptrace_event_pending(ctx)) {
+ action = utrace_signal_action(action);
+ WARN_ON(action != UTRACE_SIGNAL_REPORT);
+ return action | UTRACE_STOP;
+ }
+
+ switch (utrace_signal_action(action)) {
+ case UTRACE_SIGNAL_HANDLER:
+ if (WARN_ON(ctx->siginfo))
+ ctx->siginfo = NULL;
+
+ if (resume != UTRACE_RESUME) {
+ WARN_ON(resume != UTRACE_BLOCKSTEP &&
+ resume != UTRACE_SINGLESTEP);
+
+ set_stop_code(ctx, PTRACE_EVENT_SIGTRAP);
+ return UTRACE_STOP | UTRACE_SIGNAL_IGN;
+ }
+
+ case UTRACE_SIGNAL_REPORT:
+ if (!ctx->siginfo) {
+ if (ctx->signr) {
+ /* set by ptrace_resume(SYSCALL_EXIT) */
+ WARN_ON(ctx->signr != SIGTRAP);
+ user_single_step_siginfo(current, regs, info);
+ force_sig_info(SIGTRAP, info, current);
+ }
+
+ return resume | UTRACE_SIGNAL_IGN;
+ }
+
+ if (WARN_ON(ctx->siginfo != info))
+ return resume | UTRACE_SIGNAL_IGN;
+
+ return resume | resume_signal(ctx, return_ka);
+
+ default:
+ break;
+ }
+
+ WARN_ON(ctx->siginfo);
+ ctx->siginfo = info;
+ /*
+ * ctx->siginfo points to the caller's stack.
+ * Make sure the subsequent UTRACE_SIGNAL_REPORT clears
+ * ->siginfo before return from get_signal_to_deliver().
+ */
+ if (utrace_control(current, engine, UTRACE_INTERRUPT))
+ WARN_ON(1);
+
+ ctx->signr = info->si_signo;
+ ctx->stop_code = (PTRACE_EVENT_SIGNAL << 8) | ctx->signr;
+
+ return UTRACE_STOP | UTRACE_SIGNAL_IGN;
+}
+
+static u32 ptrace_report_quiesce(u32 action, struct utrace_engine *engine,
+ unsigned long event)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+
+ if (ptrace_event_pending(ctx))
+ return UTRACE_STOP;
+
+ return event ? UTRACE_RESUME : ctx->resume;
+}
+
+static void ptrace_release(void *data)
+{
+ kfree(data);
+}
+
+static const struct utrace_engine_ops ptrace_utrace_ops = {
+ .report_signal = ptrace_report_signal,
+ .report_quiesce = ptrace_report_quiesce,
+ .report_exec = ptrace_report_exec,
+ .report_exit = ptrace_report_exit,
+ .report_clone = ptrace_report_clone,
+ .report_syscall_entry = ptrace_report_syscall_entry,
+ .report_syscall_exit = ptrace_report_syscall_exit,
+ .release = ptrace_release,
+};
+
+int ptrace_check_attach(struct task_struct *child, int kill)
+{
+ struct utrace_engine *engine;
+ struct utrace_examiner exam;
+ int ret = -ESRCH;
+
+ engine = ptrace_lookup_engine(child);
+ if (IS_ERR(engine))
+ return ret;
+
+ if (child->parent != current)
+ goto out;
+
+ if (unlikely(kill))
+ ret = 0;
+
+ if (!task_is_stopped_or_traced(child))
+ goto out;
+ /*
+ * Make sure our engine has already stopped the child.
+ * Then wait for it to be off the CPU.
+ */
+ if (!utrace_control(child, engine, UTRACE_STOP) &&
+ !utrace_prepare_examine(child, engine, &exam))
+ ret = 0;
+out:
+ utrace_engine_put(engine);
+ return ret;
+}
+
+int ptrace_attach(struct task_struct *task)
+{
+ int retval;
+
+ 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;
+ * interference; SUID, SGID and LSM creds get determined differently
+ * under ptrace.
+ */
+ retval = -ERESTARTNOINTR;
+ if (mutex_lock_interruptible(&task->cred_guard_mutex))
+ goto out;
+
+ task_lock(task);
+ retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
+ task_unlock(task);
+ if (retval)
+ goto unlock_creds;
+
+ retval = ptrace_attach_task(task, 0);
+ if (unlikely(retval))
+ goto unlock_creds;
+
+ write_lock_irq(&tasklist_lock);
+ retval = -EPERM;
+ if (unlikely(task->exit_state))
+ goto unlock_tasklist;
+
+ BUG_ON(task->ptrace);
+ task->ptrace = PT_UTRACED;
+ if (capable(CAP_SYS_PTRACE))
+ task->ptrace |= PT_PTRACE_CAP;
+
+ __ptrace_link(task, current);
+ send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
+
+ retval = 0;
+unlock_tasklist:
+ write_unlock_irq(&tasklist_lock);
+unlock_creds:
+ mutex_unlock(&task->cred_guard_mutex);
+out:
+ return retval;
+}
+
+/*
+ * Performs checks and sets PT_UTRACED.
+ * Should be used by all ptrace implementations for PTRACE_TRACEME.
+ */
+int ptrace_traceme(void)
+{
+ bool detach = true;
+ int ret = ptrace_attach_task(current, 0);
+
+ if (unlikely(ret))
+ return ret;
+
+ ret = -EPERM;
+ write_lock_irq(&tasklist_lock);
+ BUG_ON(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_UTRACED;
+ __ptrace_link(current, current->real_parent);
+ detach = false;
+ }
+ write_unlock_irq(&tasklist_lock);
+
+ if (detach)
+ ptrace_abort_attach(current);
+ return ret;
+}
+
+static void ptrace_do_detach(struct task_struct *tracee, unsigned int data)
+{
+ bool detach, release;
+
+ write_lock_irq(&tasklist_lock);
+ /*
+ * This tracee can be already killed. Make sure de_thread() or
+ * our sub-thread doing do_wait() didn't do release_task() yet.
+ */
+ detach = tracee->ptrace != 0;
+ release = false;
+ if (likely(detach))
+ release = __ptrace_detach(current, tracee);
+ write_unlock_irq(&tasklist_lock);
+
+ if (unlikely(release))
+ release_task(tracee);
+ else if (likely(detach))
+ ptrace_detach_task(tracee, data);
+}
+
+int ptrace_detach(struct task_struct *child, unsigned int data)
+{
+ if (!valid_signal(data))
+ return -EIO;
+
+ ptrace_do_detach(child, data);
+
+ return 0;
+}
+
+/*
+ * Detach all tasks we were using ptrace on.
+ */
+void exit_ptrace(struct task_struct *tracer)
+{
+ for (;;) {
+ struct task_struct *tracee = NULL;
+
+ read_lock(&tasklist_lock);
+ if (!list_empty(&tracer->ptraced)) {
+ tracee = list_first_entry(&tracer->ptraced,
+ struct task_struct, ptrace_entry);
+ get_task_struct(tracee);
+ }
+ read_unlock(&tasklist_lock);
+ if (!tracee)
+ break;
+
+ ptrace_do_detach(tracee, -1);
+ put_task_struct(tracee);
+ }
+}
+
+static int ptrace_set_options(struct task_struct *tracee,
+ struct utrace_engine *engine, long data)
+{
+ BUILD_BUG_ON(PTRACE_O_MASK & PTRACE_O_SYSEMU);
+
+ ptrace_set_events(tracee, engine, data & PTRACE_O_MASK);
+ return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
+}
+
+static int ptrace_rw_siginfo(struct task_struct *tracee,
+ struct ptrace_context *ctx,
+ siginfo_t *info, bool write)
+{
+ unsigned long flags;
+ int err;
+
+ switch (get_stop_event(ctx)) {
+ case 0: /* jctl stop */
+ return -EINVAL;
+
+ case PTRACE_EVENT_SIGNAL:
+ err = -ESRCH;
+ if (lock_task_sighand(tracee, &flags)) {
+ if (likely(task_is_traced(tracee))) {
+ if (write)
+ *ctx->siginfo = *info;
+ else
+ *info = *ctx->siginfo;
+ err = 0;
+ }
+ unlock_task_sighand(tracee, &flags);
+ }
+
+ return err;
+
+ default:
+ if (!write) {
+ memset(info, 0, sizeof(*info));
+ info->si_signo = SIGTRAP;
+ info->si_code = ctx->stop_code & PTRACE_EVENT_MASK;
+ info->si_pid = task_pid_vnr(tracee);
+ info->si_uid = task_uid(tracee);
+ }
+
+ return 0;
+ }
+}
+
+static void do_ptrace_notify_stop(struct ptrace_context *ctx,
+ struct task_struct *tracee)
+{
+ /*
+ * This can race with SIGKILL, but we borrow this race from
+ * the old ptrace implementation. ->exit_code is only needed
+ * for wait_task_stopped()->task_stopped_code(), we should
+ * change it to use ptrace_context.
+ */
+ tracee->exit_code = ctx->stop_code & PTRACE_EVENT_MASK;
+ WARN_ON(!tracee->exit_code);
+
+ read_lock(&tasklist_lock);
+ /*
+ * Don't want to allow preemption here, because
+ * sys_ptrace() needs this task to be inactive.
+ */
+ preempt_disable();
+ /*
+ * It can be killed and then released by our subthread,
+ * or ptrace_attach() has not completed yet.
+ */
+ if (task_ptrace(tracee))
+ do_notify_parent_cldstop(tracee, CLD_TRAPPED);
+ read_unlock(&tasklist_lock);
+ preempt_enable_no_resched();
+}
+
+void ptrace_notify_stop(struct task_struct *tracee)
+{
+ struct utrace_engine *engine = ptrace_lookup_engine(tracee);
+
+ if (IS_ERR(engine))
+ return;
+
+ do_ptrace_notify_stop(ptrace_context(engine), tracee);
+ utrace_engine_put(engine);
+}
+
+static int ptrace_resume_action(struct task_struct *tracee,
+ struct utrace_engine *engine, long request)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+ unsigned long events;
+ int action;
+
+ ctx->options &= ~PTRACE_O_SYSEMU;
+ events = engine->flags & ~UTRACE_EVENT_SYSCALL;
+ action = UTRACE_RESUME;
+
+ switch (request) {
+#ifdef PTRACE_SINGLEBLOCK
+ case PTRACE_SINGLEBLOCK:
+ if (unlikely(!arch_has_block_step()))
+ return -EIO;
+ action = UTRACE_BLOCKSTEP;
+ events |= UTRACE_EVENT(SYSCALL_EXIT);
+ break;
+#endif
+
+#ifdef PTRACE_SINGLESTEP
+ case PTRACE_SINGLESTEP:
+ if (unlikely(!arch_has_single_step()))
+ return -EIO;
+ action = UTRACE_SINGLESTEP;
+ events |= UTRACE_EVENT(SYSCALL_EXIT);
+ break;
+#endif
+
+#ifdef PTRACE_SYSEMU
+ case PTRACE_SYSEMU_SINGLESTEP:
+ if (unlikely(!arch_has_single_step()))
+ return -EIO;
+ action = UTRACE_SINGLESTEP;
+ case PTRACE_SYSEMU:
+ ctx->options |= PTRACE_O_SYSEMU;
+ events |= UTRACE_EVENT(SYSCALL_ENTRY);
+ break;
+#endif
+
+ case PTRACE_SYSCALL:
+ events |= UTRACE_EVENT_SYSCALL;
+ break;
+
+ case PTRACE_CONT:
+ break;
+ default:
+ return -EIO;
+ }
+
+ if (events != engine->flags &&
+ utrace_set_events(tracee, engine, events))
+ return -ESRCH;
+
+ return action;
+}
+
+static int ptrace_resume(struct task_struct *tracee,
+ struct utrace_engine *engine,
+ long request, long data)
+{
+ struct ptrace_context *ctx = ptrace_context(engine);
+ int action;
+
+ if (!valid_signal(data))
+ return -EIO;
+
+ action = ptrace_resume_action(tracee, engine, request);
+ if (action < 0)
+ return action;
+
+ switch (get_stop_event(ctx)) {
+ case PTRACE_EVENT_VFORK:
+ if (ctx->options & PTRACE_O_TRACEVFORKDONE) {
+ set_stop_code(ctx, PTRACE_EVENT_VFORK_DONE);
+ action = UTRACE_REPORT;
+ }
+ break;
+
+ case PTRACE_EVENT_EXEC:
+ case PTRACE_EVENT_FORK:
+ case PTRACE_EVENT_CLONE:
+ case PTRACE_EVENT_VFORK_DONE:
+ if (request == PTRACE_SYSCALL) {
+ set_syscall_code(ctx);
+ do_ptrace_notify_stop(ctx, tracee);
+ return 0;
+ }
+
+ if (action != UTRACE_RESUME) {
+ /*
+ * single-stepping. UTRACE_SIGNAL_REPORT will
+ * synthesize a trap to follow the syscall insn.
+ */
+ ctx->signr = SIGTRAP;
+ action = UTRACE_INTERRUPT;
+ }
+ break;
+
+ case PTRACE_EVENT_SYSCALL:
+ if (data)
+ send_sig_info(data, SEND_SIG_PRIV, tracee);
+ break;
+
+ case PTRACE_EVENT_SIGNAL:
+ ctx->signr = data;
+ break;
+ }
+
+ ctx->resume = action;
+ ptrace_wake_up(tracee, engine, action, true);
+ return 0;
+}
+
+int ptrace_request(struct task_struct *child, long request,
+ long addr, long data)
+{
+ struct utrace_engine *engine = ptrace_lookup_engine(child);
+ siginfo_t siginfo;
+ int ret;
+
+ if (unlikely(IS_ERR(engine)))
+ return -ESRCH;
+
+ switch (request) {
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA:
+ ret = generic_ptrace_peekdata(child, addr, data);
+ break;
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ ret = generic_ptrace_pokedata(child, addr, data);
+ break;
+
+#ifdef PTRACE_OLDSETOPTIONS
+ case PTRACE_OLDSETOPTIONS:
+#endif
+ case PTRACE_SETOPTIONS:
+ ret = ptrace_set_options(child, engine, data);
+ break;
+ case PTRACE_GETEVENTMSG:
+ ret = put_user(ptrace_context(engine)->eventmsg,
+ (unsigned long __user *) data);
+ break;
+
+ case PTRACE_GETSIGINFO:
+ ret = ptrace_rw_siginfo(child, ptrace_context(engine),
+ &siginfo, false);
+ if (!ret)
+ ret = copy_siginfo_to_user((siginfo_t __user *) data,
+ &siginfo);
+ break;
+
+ case PTRACE_SETSIGINFO:
+ if (copy_from_user(&siginfo, (siginfo_t __user *) data,
+ sizeof siginfo))
+ ret = -EFAULT;
+ else
+ ret = ptrace_rw_siginfo(child, ptrace_context(engine),
+ &siginfo, true);
+ break;
+
+ case PTRACE_DETACH: /* detach a process that was attached. */
+ ret = ptrace_detach(child, data);
+ break;
+
+ case PTRACE_KILL:
+ /* Ugly historical behaviour. */
+ if (task_is_traced(child))
+ ptrace_resume(child, engine, PTRACE_CONT, SIGKILL);
+ ret = 0;
+ break;
+
+ default:
+ ret = ptrace_resume(child, engine, request, data);
+ break;
+ }
+
+ utrace_engine_put(engine);
+ return ret;
+}
+
+#if defined CONFIG_COMPAT
+#include <linux/compat.h>
+
+int compat_ptrace_request(struct task_struct *child, compat_long_t request,
+ compat_ulong_t addr, compat_ulong_t data)
+{
+ struct utrace_engine *engine = ptrace_lookup_engine(child);
+ compat_ulong_t __user *datap = compat_ptr(data);
+ compat_ulong_t word;
+ siginfo_t siginfo;
+ int ret;
+
+ if (unlikely(IS_ERR(engine)))
+ return -ESRCH;
+
+ 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)ptrace_context(engine)->eventmsg,
+ datap);
+ break;
+
+ case PTRACE_GETSIGINFO:
+ ret = ptrace_rw_siginfo(child, ptrace_context(engine),
+ &siginfo, false);
+ 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_rw_siginfo(child, ptrace_context(engine),
+ &siginfo, true);
+ break;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ }
+
+ utrace_engine_put(engine);
+ return ret;
+}
+#endif /* CONFIG_COMPAT */
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index a408bf7..4e87441 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -16,7 +16,6 @@
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include <linux/ptrace.h>
-#include <linux/utrace.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/audit.h>
@@ -24,7 +23,286 @@
#include <linux/syscalls.h>
#include <linux/uaccess.h>
+int __ptrace_may_access(struct task_struct *task, unsigned int mode)
+{
+ const struct cred *cred = current_cred(), *tcred;
+
+ /* 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;
+ rcu_read_lock();
+ tcred = __task_cred(task);
+ if ((cred->uid != tcred->euid ||
+ cred->uid != tcred->suid ||
+ cred->uid != tcred->uid ||
+ cred->gid != tcred->egid ||
+ cred->gid != tcred->sgid ||
+ cred->gid != tcred->gid) &&
+ !capable(CAP_SYS_PTRACE)) {
+ rcu_read_unlock();
+ return -EPERM;
+ }
+ rcu_read_unlock();
+ smp_rmb();
+ if (task->mm)
+ dumpable = get_dumpable(task->mm);
+ if (!dumpable && !capable(CAP_SYS_PTRACE))
+ return -EPERM;
+
+ return security_ptrace_access_check(task, mode);
+}
+
+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;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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().
+ */
+bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
+{
+ __ptrace_unlink(p);
+
+ if (p->exit_state == EXIT_ZOMBIE) {
+ 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)) {
+ __wake_up_parent(p, tracer);
+ p->exit_signal = -1;
+ }
+ }
+ if (task_detached(p)) {
+ /* Mark it as in the process of being reaped. */
+ p->exit_state = EXIT_DEAD;
+ return true;
+ }
+ }
+
+ return false;
+}
+
+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 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;
+}
+
+#ifndef arch_ptrace_attach
+#define arch_ptrace_attach(child) do { } while (0)
+#endif
+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)
+ 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) {
+ ret = ptrace_attach(child);
+ /*
+ * 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);
+ if (ret < 0)
+ goto out_put_task_struct;
+
+ ret = arch_ptrace(child, request, addr, data);
+
+ out_put_task_struct:
+ put_task_struct(child);
+ out:
+ unlock_kernel();
+ return ret;
+}
+
+int generic_ptrace_peekdata(struct task_struct *tsk, long addr, 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);
+}
+
+int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data)
+{
+ int copied;
+
+ copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
+ return (copied == sizeof(data)) ? 0 : -EIO;
+}
+
+#if defined CONFIG_COMPAT
+#include <linux/compat.h>
+
+asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
+ compat_long_t addr, compat_long_t 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();
+ goto out;
+ }
+
+ child = ptrace_get_task_struct(pid);
+ if (IS_ERR(child)) {
+ ret = PTR_ERR(child);
+ goto out;
+ }
+
+ if (request == PTRACE_ATTACH) {
+ ret = ptrace_attach(child);
+ /*
+ * 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);
+ if (!ret)
+ ret = compat_arch_ptrace(child, request, addr, data);
+
+ out_put_task_struct:
+ put_task_struct(child);
+ out:
+ unlock_kernel();
+ return ret;
+}
+#endif /* CONFIG_COMPAT */
+
+#ifndef CONFIG_UTRACE
/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
@@ -101,76 +379,21 @@ int ptrace_check_attach(struct task_stru
/*
* child->sighand can't be NULL, release_task()
* does ptrace_unlink() before __exit_signal().
- */
- spin_lock_irq(&child->sighand->siglock);
- if (task_is_stopped(child))
- child->state = TASK_TRACED;
- else if (!task_is_traced(child) && !kill)
- ret = -ESRCH;
- spin_unlock_irq(&child->sighand->siglock);
- }
- read_unlock(&tasklist_lock);
-
- if (!ret && !kill)
- ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
-
- /* All systems go.. */
- return ret;
-}
-
-int __ptrace_may_access(struct task_struct *task, unsigned int mode)
-{
- const struct cred *cred = current_cred(), *tcred;
-
- /* 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;
- rcu_read_lock();
- tcred = __task_cred(task);
- if ((cred->uid != tcred->euid ||
- cred->uid != tcred->suid ||
- cred->uid != tcred->uid ||
- cred->gid != tcred->egid ||
- cred->gid != tcred->sgid ||
- cred->gid != tcred->gid) &&
- !capable(CAP_SYS_PTRACE)) {
- rcu_read_unlock();
- return -EPERM;
- }
- rcu_read_unlock();
- smp_rmb();
- if (task->mm)
- dumpable = get_dumpable(task->mm);
- if (!dumpable && !capable(CAP_SYS_PTRACE))
- return -EPERM;
-
- return security_ptrace_access_check(task, mode);
-}
+ */
+ spin_lock_irq(&child->sighand->siglock);
+ if (task_is_stopped(child))
+ child->state = TASK_TRACED;
+ else if (!task_is_traced(child) && !kill)
+ ret = -ESRCH;
+ spin_unlock_irq(&child->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
-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;
-}
+ if (!ret && !kill)
+ ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
-/*
- * For experimental use of utrace, exclude ptrace on the same task.
- */
-static inline bool exclude_ptrace(struct task_struct *task)
-{
- return unlikely(!!task_utrace_flags(task));
+ /* All systems go.. */
+ return ret;
}
int ptrace_attach(struct task_struct *task)
@@ -196,8 +419,6 @@ int ptrace_attach(struct task_struct *ta
task_lock(task);
retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
- if (!retval && exclude_ptrace(task))
- retval = -EBUSY;
task_unlock(task);
if (retval)
goto unlock_creds;
@@ -235,9 +456,6 @@ int ptrace_traceme(void)
{
int ret = -EPERM;
- if (exclude_ptrace(current)) /* XXX locking */
- return -EBUSY;
-
write_lock_irq(&tasklist_lock);
/* Are we already being traced? */
if (!current->ptrace) {
@@ -257,57 +475,6 @@ int ptrace_traceme(void)
return ret;
}
-/*
- * 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;
-}
-
-/*
- * 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().
- */
-bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
-{
- __ptrace_unlink(p);
-
- if (p->exit_state == EXIT_ZOMBIE) {
- 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)) {
- __wake_up_parent(p, tracer);
- p->exit_signal = -1;
- }
- }
- if (task_detached(p)) {
- /* Mark it as in the process of being reaped. */
- p->exit_state = EXIT_DEAD;
- return true;
- }
- }
-
- return false;
-}
-
int ptrace_detach(struct task_struct *child, unsigned int data)
{
bool dead = false;
@@ -361,56 +528,6 @@ void exit_ptrace(struct task_struct *tra
}
}
-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;
@@ -594,93 +710,7 @@ int ptrace_request(struct task_struct *c
return ret;
}
-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;
-}
-
-#ifndef arch_ptrace_attach
-#define arch_ptrace_attach(child) do { } while (0)
-#endif
-
-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)
- 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) {
- ret = ptrace_attach(child);
- /*
- * 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);
- if (ret < 0)
- goto out_put_task_struct;
-
- ret = arch_ptrace(child, request, addr, data);
-
- out_put_task_struct:
- put_task_struct(child);
- out:
- unlock_kernel();
- return ret;
-}
-
-int generic_ptrace_peekdata(struct task_struct *tsk, long addr, 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);
-}
-
-int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data)
-{
- int copied;
-
- copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
- return (copied == sizeof(data)) ? 0 : -EIO;
-}
-
#if defined CONFIG_COMPAT
-#include <linux/compat.h>
-
int compat_ptrace_request(struct task_struct *child, compat_long_t request,
compat_ulong_t addr, compat_ulong_t data)
{
@@ -732,47 +762,5 @@ int compat_ptrace_request(struct task_st
return ret;
}
-
-asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
- compat_long_t addr, compat_long_t 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();
- goto out;
- }
-
- child = ptrace_get_task_struct(pid);
- if (IS_ERR(child)) {
- ret = PTR_ERR(child);
- goto out;
- }
-
- if (request == PTRACE_ATTACH) {
- ret = ptrace_attach(child);
- /*
- * 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);
- if (!ret)
- ret = compat_arch_ptrace(child, request, addr, data);
-
- out_put_task_struct:
- put_task_struct(child);
- out:
- unlock_kernel();
- return ret;
-}
#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_UTRACE */
diff --git a/kernel/utrace.c b/kernel/utrace.c
index cb62fcd..9353cc5 100644
--- a/kernel/utrace.c
+++ b/kernel/utrace.c
@@ -811,6 +811,22 @@ relock:
spin_unlock_irq(&task->sighand->siglock);
spin_unlock(&utrace->lock);
+ /*
+ * If ptrace is among the reasons for this stop, do its
+ * notification now. This could not just be done in
+ * ptrace's own event report callbacks because it has to
+ * be done after we are in TASK_TRACED. This makes the
+ * synchronization with ptrace_do_wait() work right.
+ *
+ * It's only because of the bad old overloading of the do_wait()
+ * logic for handling ptrace stops that we need this special case
+ * here. One day we will clean up ptrace so it does not need to
+ * work this way. New things that are designed sensibly don't need
+ * a wakeup that synchronizes with tasklist_lock and ->state, so
+ * the proper utrace API does not try to support this weirdness.
+ */
+ ptrace_notify_stop(task);
+
schedule();
utrace_finish_stop();
Index: kernel.spec
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/devel/kernel.spec,v
retrieving revision 1.1872
retrieving revision 1.1873
diff -u -p -r1.1872 -r1.1873
--- kernel.spec 14 Dec 2009 20:16:53 -0000 1.1872
+++ kernel.spec 16 Dec 2009 22:09:41 -0000 1.1873
@@ -617,6 +617,7 @@ Patch20: linux-2.6-hotfixes.patch
Patch21: linux-2.6-tracehook.patch
Patch22: linux-2.6-utrace.patch
+Patch23: linux-2.6-utrace-ptrace.patch
# More workaround for BIOS brokenness, fix intel_iommu=igfx_off oops
Patch100: linux-2.6-iommu-updates.patch
@@ -1147,8 +1148,9 @@ ApplyOptionalPatch linux-2.6-upstream-re
ApplyPatch linux-2.6-hotfixes.patch
# Roland's utrace ptrace replacement.
-#ApplyPatch linux-2.6-tracehook.patch # merged
+ApplyPatch linux-2.6-tracehook.patch
ApplyPatch linux-2.6-utrace.patch
+ApplyPatch linux-2.6-utrace-ptrace.patch
# Architecture patches
# x86(-64)
@@ -2001,6 +2003,9 @@ fi
# and build.
%changelog
+* Wed Dec 16 2009 Roland McGrath <roland at redhat.com> 2.6.32.1-10
+- utrace update, now testing the utrace-based ptrace!
+
* Mon Dec 14 2009 Kyle McMartin <kyle at redhat.com> 2.6.32.1-9
- 2.6.32.1
- ext4 patches and more...
@@ -2064,7 +2069,7 @@ fi
+CONFIG_SLOW_WORK_PROC=y
* Mon Nov 30 2009 Kyle McMartin <kyle at redhat.com>
-- drm-i915-fix-sync-to-vbl-when-vga-is-off.patch: add, (rhbz#541670)
+- drm-i915-fix-sync-to-vbl-when-vga-is-off.patch: add, (rhbz#541670)
* Sun Nov 29 2009 Kyle McMartin <kyle at redhat.com>
- linux-2.6-sysrq-c.patch: drop, was made consistent upstream.
linux-2.6-tracehook.patch:
arch/powerpc/include/asm/ptrace.h | 2 +
arch/powerpc/kernel/traps.c | 9 ++++++
arch/x86/include/asm/ptrace.h | 2 +
arch/x86/kernel/ptrace.c | 51 ++++++++++++++++++++------------------
include/linux/ptrace.h | 24 +++++++++++------
include/linux/sched.h | 1
include/linux/tracehook.h | 15 ++++++++---
kernel/ptrace.c | 2 -
kernel/signal.c | 13 ++++-----
9 files changed, 76 insertions(+), 43 deletions(-)
Index: linux-2.6-tracehook.patch
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/devel/linux-2.6-tracehook.patch,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -p -r1.9 -r1.10
--- linux-2.6-tracehook.patch 8 Apr 2009 01:31:58 -0000 1.9
+++ linux-2.6-tracehook.patch 16 Dec 2009 22:09:41 -0000 1.10
@@ -1,194 +1,336 @@
-signals: tracehook_notify_jctl change
+From: Oleg Nesterov <oleg at redhat.com>
-This changes tracehook_notify_jctl() so it's called with the siglock held,
-and changes its argument and return value definition. These clean-ups make
-it a better fit for what new tracing hooks need to check.
+[PATCH] signals: check ->group_stop_count after tracehook_get_signal()
-Tracing needs the siglock here, held from the time TASK_STOPPED was set,
-to avoid potential SIGCONT races if it wants to allow any blocking in its
-tracing hooks.
+Move the call to do_signal_stop() down, after tracehook call.
+This makes ->group_stop_count condition visible to tracers before
+do_signal_stop() will participate in this group-stop.
-This also folds the finish_stop() function into its caller do_signal_stop().
-The function is short, called only once and only unconditionally. It aids
-readability to fold it in.
+Currently the patch has no effect, tracehook_get_signal() always
+returns 0.
+Signed-off-by: Oleg Nesterov <oleg at redhat.com>
Signed-off-by: Roland McGrath <roland at redhat.com>
---
- include/linux/tracehook.h | 25 ++++++++++------
- kernel/signal.c | 69 +++++++++++++++++++++++----------------------
- 2 files changed, 51 insertions(+), 43 deletions(-)
+ arch/powerpc/include/asm/ptrace.h | 2 +
+ arch/powerpc/kernel/traps.c | 9 ++++++
+ arch/x86/include/asm/ptrace.h | 2 +
+ arch/x86/kernel/ptrace.c | 51 ++++++++++++++++++++----------------
+ include/linux/ptrace.h | 24 +++++++++++------
+ include/linux/sched.h | 1 +
+ include/linux/tracehook.h | 15 ++++++++---
+ kernel/ptrace.c | 2 +-
+ kernel/signal.c | 13 ++++-----
+ 9 files changed, 76 insertions(+), 43 deletions(-)
-diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
-index c7aa154..4ec4821 100644
---- a/include/linux/tracehook.h
-+++ b/include/linux/tracehook.h
-@@ -1,7 +1,7 @@
- /*
- * Tracing hooks
- *
-- * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
-+ * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
-@@ -464,22 +464,29 @@ static inline int tracehook_get_signal(s
+diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
+index 8c34149..cbd759e 100644
+--- a/arch/powerpc/include/asm/ptrace.h
++++ b/arch/powerpc/include/asm/ptrace.h
+@@ -140,6 +140,8 @@ extern void user_enable_single_step(stru
+ extern void user_enable_block_step(struct task_struct *);
+ extern void user_disable_single_step(struct task_struct *);
- /**
- * tracehook_notify_jctl - report about job control stop/continue
-- * @notify: nonzero if this is the last thread in the group to stop
-+ * @notify: zero, %CLD_STOPPED or %CLD_CONTINUED
- * @why: %CLD_STOPPED or %CLD_CONTINUED
- *
- * This is called when we might call do_notify_parent_cldstop().
-- * It's called when about to stop for job control; we are already in
-- * %TASK_STOPPED state, about to call schedule(). It's also called when
-- * a delayed %CLD_STOPPED or %CLD_CONTINUED report is ready to be made.
- *
-- * Return nonzero to generate a %SIGCHLD with @why, which is
-- * normal if @notify is nonzero.
-+ * @notify is zero if we would not ordinarily send a %SIGCHLD,
-+ * or is the %CLD_STOPPED or %CLD_CONTINUED .si_code for %SIGCHLD.
- *
-- * Called with no locks held.
-+ * @why is %CLD_STOPPED when about to stop for job control;
-+ * we are already in %TASK_STOPPED state, about to call schedule().
-+ * It might also be that we have just exited (check %PF_EXITING),
-+ * but need to report that a group-wide stop is complete.
-+ *
-+ * @why is %CLD_CONTINUED when waking up after job control stop and
-+ * ready to make a delayed @notify report.
-+ *
-+ * Return the %CLD_* value for %SIGCHLD, or zero to generate no signal.
-+ *
-+ * Called with the siglock held.
- */
- static inline int tracehook_notify_jctl(int notify, int why)
++#define ARCH_HAS_USER_SINGLE_STEP_INFO
++
+ #endif /* __ASSEMBLY__ */
+
+ #endif /* __KERNEL__ */
+diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
+index 6f0ae1a..83b57ac 100644
+--- a/arch/powerpc/kernel/traps.c
++++ b/arch/powerpc/kernel/traps.c
+@@ -174,6 +174,15 @@ int die(const char *str, struct pt_regs
+ return 0;
+ }
+
++void user_single_step_siginfo(struct task_struct *tsk,
++ struct pt_regs *regs, siginfo_t *info)
++{
++ memset(info, 0, sizeof(*info));
++ info->si_signo = SIGTRAP;
++ info->si_code = TRAP_TRACE;
++ info->si_addr = (void __user *)regs->nip;
++}
++
+ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
-- return notify || (current->ptrace & PT_PTRACED);
-+ return notify ?: (current->ptrace & PT_PTRACED) ? why : 0;
+ siginfo_t info;
+diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
+index 0f0d908..7a88a82 100644
+--- a/arch/x86/include/asm/ptrace.h
++++ b/arch/x86/include/asm/ptrace.h
+@@ -230,6 +230,8 @@ extern void user_enable_block_step(struc
+ #define arch_has_block_step() (boot_cpu_data.x86 >= 6)
+ #endif
+
++#define ARCH_HAS_USER_SINGLE_STEP_INFO
++
+ struct user_desc;
+ extern int do_get_thread_area(struct task_struct *p, int idx,
+ struct user_desc __user *info);
+diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
+index 7b058a2..ea35dee 100644
+--- a/arch/x86/kernel/ptrace.c
++++ b/arch/x86/kernel/ptrace.c
+@@ -1437,21 +1437,33 @@ const struct user_regset_view *task_user
+ #endif
}
- #define DEATH_REAP -1
-diff --git a/kernel/signal.c b/kernel/signal.c
-index d803473..424eff2 100644
---- a/kernel/signal.c
-+++ b/kernel/signal.c
-@@ -702,7 +702,7 @@ static int prepare_signal(int sig, struc
+-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
+- int error_code, int si_code)
++static void fill_sigtrap_info(struct task_struct *tsk,
++ struct pt_regs *regs,
++ int error_code, int si_code,
++ struct siginfo *info)
+ {
+- struct siginfo info;
+-
+ tsk->thread.trap_no = 1;
+ tsk->thread.error_code = error_code;
- if (why) {
- /*
-- * The first thread which returns from finish_stop()
-+ * The first thread which returns from do_signal_stop()
- * will take ->siglock, notice SIGNAL_CLD_MASK, and
- * notify its parent. See get_signal_to_deliver().
- */
-@@ -1665,29 +1665,6 @@ void ptrace_notify(int exit_code)
- spin_unlock_irq(¤t->sighand->siglock);
+- memset(&info, 0, sizeof(info));
+- info.si_signo = SIGTRAP;
+- info.si_code = si_code;
++ memset(info, 0, sizeof(*info));
++ info->si_signo = SIGTRAP;
++ info->si_code = si_code;
++ info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
++}
+
+- /* User-mode ip? */
+- info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
++void user_single_step_siginfo(struct task_struct *tsk,
++ struct pt_regs *regs,
++ struct siginfo *info)
++{
++ fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
++}
++
++void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
++ int error_code, int si_code)
++{
++ struct siginfo info;
+
++ fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
+ /* Send us the fake SIGTRAP */
+ force_sig_info(SIGTRAP, &info, tsk);
}
+@@ -1516,29 +1528,22 @@ asmregparm long syscall_trace_enter(stru
--static void
--finish_stop(int stop_count)
--{
-- /*
-- * If there are no other threads in the group, or if there is
-- * a group stop in progress and we are the last to stop,
-- * report to the parent. When ptraced, every thread reports itself.
+ asmregparm void syscall_trace_leave(struct pt_regs *regs)
+ {
++ bool step;
++
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
+
+ if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+ trace_sys_exit(regs, regs->ax);
+
+- if (test_thread_flag(TIF_SYSCALL_TRACE))
+- tracehook_report_syscall_exit(regs, 0);
+-
+ /*
+ * If TIF_SYSCALL_EMU is set, we only get here because of
+ * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
+ * We already reported this syscall instruction in
+- * syscall_trace_enter(), so don't do any more now.
- */
-- if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) {
-- read_lock(&tasklist_lock);
-- do_notify_parent_cldstop(current, CLD_STOPPED);
-- read_unlock(&tasklist_lock);
-- }
+- if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
+- return;
-
-- do {
-- schedule();
-- } while (try_to_freeze());
- /*
-- * Now we don't run again until continued.
-- */
-- current->exit_code = 0;
+- * If we are single-stepping, synthesize a trap to follow the
+- * system call instruction.
++ * syscall_trace_enter().
+ */
+- if (test_thread_flag(TIF_SINGLESTEP) &&
+- tracehook_consider_fatal_signal(current, SIGTRAP))
+- send_sigtrap(current, regs, 0, TRAP_BRKPT);
++ step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
++ !test_thread_flag(TIF_SYSCALL_EMU);
++ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
++ tracehook_report_syscall_exit(regs, step);
+ }
+diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
+index 7456d7d..4802e2a 100644
+--- a/include/linux/ptrace.h
++++ b/include/linux/ptrace.h
+@@ -85,6 +85,7 @@ extern int ptrace_traceme(void);
+ extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
+ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
+ extern int ptrace_attach(struct task_struct *tsk);
++extern bool __ptrace_detach(struct task_struct *tracer, struct task_struct *tracee);
+ extern int ptrace_detach(struct task_struct *, unsigned int);
+ extern void ptrace_disable(struct task_struct *);
+ extern int ptrace_check_attach(struct task_struct *task, int kill);
+@@ -105,12 +106,7 @@ static inline int ptrace_reparented(stru
+ {
+ return child->real_parent != child->parent;
+ }
+-static inline void ptrace_link(struct task_struct *child,
+- struct task_struct *new_parent)
+-{
+- if (unlikely(child->ptrace))
+- __ptrace_link(child, new_parent);
-}
--
- /*
- * This performs the stopping for SIGSTOP and other stop signals.
- * We have to stop all threads in the thread group.
-@@ -1698,6 +1675,7 @@ static int do_signal_stop(int signr)
- {
- struct signal_struct *sig = current->signal;
- int stop_count;
-+ int notify;
++
+ static inline void ptrace_unlink(struct task_struct *child)
+ {
+ if (unlikely(child->ptrace))
+@@ -169,9 +165,9 @@ static inline void ptrace_init_task(stru
+ INIT_LIST_HEAD(&child->ptraced);
+ child->parent = child->real_parent;
+ child->ptrace = 0;
+- if (unlikely(ptrace)) {
++ if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
+ child->ptrace = current->ptrace;
+- ptrace_link(child, current->parent);
++ __ptrace_link(child, current->parent);
+ }
+ }
- if (sig->group_stop_count > 0) {
- /*
-@@ -1737,8 +1715,30 @@ static int do_signal_stop(int signr)
- current->exit_code = sig->group_exit_code;
- __set_current_state(TASK_STOPPED);
-
-+ /*
-+ * If there are no other threads in the group, or if there is
-+ * a group stop in progress and we are the last to stop,
-+ * report to the parent. When ptraced, every thread reports itself.
-+ */
-+ notify = tracehook_notify_jctl(stop_count == 0 ? CLD_STOPPED : 0,
-+ CLD_STOPPED);
-+
- spin_unlock_irq(¤t->sighand->siglock);
-- finish_stop(stop_count);
-+
-+ if (notify) {
-+ read_lock(&tasklist_lock);
-+ do_notify_parent_cldstop(current, notify);
-+ read_unlock(&tasklist_lock);
+@@ -278,6 +274,18 @@ static inline void user_enable_block_ste
+ }
+ #endif /* arch_has_block_step */
+
++#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
++extern void user_single_step_siginfo(struct task_struct *tsk,
++ struct pt_regs *regs, siginfo_t *info);
++#else
++static inline void user_single_step_siginfo(struct task_struct *tsk,
++ struct pt_regs *regs, siginfo_t *info)
++{
++ memset(info, 0, sizeof(*info));
++ info->si_signo = SIGTRAP;
++}
++#endif
++
+ #ifndef arch_ptrace_stop_needed
+ /**
+ * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
+diff --git a/include/linux/sched.h b/include/linux/sched.h
+index 75e6e60..6c8928b 100644
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -2060,6 +2060,7 @@ extern int kill_pgrp(struct pid *pid, in
+ extern int kill_pid(struct pid *pid, int sig, int priv);
+ extern int kill_proc_info(int, struct siginfo *, pid_t);
+ extern int do_notify_parent(struct task_struct *, int);
++extern void do_notify_parent_cldstop(struct task_struct *, int);
+ extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
+ extern void force_sig(int, struct task_struct *);
+ extern void force_sig_specific(int, struct task_struct *);
+diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
+index 1eb44a9..c78b2f4 100644
+--- a/include/linux/tracehook.h
++++ b/include/linux/tracehook.h
+@@ -134,6 +134,13 @@ static inline __must_check int tracehook
+ */
+ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
+ {
++ if (step && (task_ptrace(current) & PT_PTRACED)) {
++ siginfo_t info;
++ user_single_step_siginfo(current, regs, &info);
++ force_sig_info(SIGTRAP, &info, current);
++ return;
+ }
+
-+ do {
-+ schedule();
-+ } while (try_to_freeze());
-+ /*
-+ * Now we don't run again until continued.
-+ */
-+ current->exit_code = 0;
-+
- return 1;
- }
-
-@@ -1807,14 +1807,15 @@ relock:
- int why = (signal->flags & SIGNAL_STOP_CONTINUED)
- ? CLD_CONTINUED : CLD_STOPPED;
- signal->flags &= ~SIGNAL_CLD_MASK;
-- spin_unlock_irq(&sighand->siglock);
+ ptrace_report_syscall(regs);
+ }
-- if (unlikely(!tracehook_notify_jctl(1, why)))
-- goto relock;
-+ why = tracehook_notify_jctl(why, CLD_CONTINUED);
-+ spin_unlock_irq(&sighand->siglock);
+@@ -149,7 +156,7 @@ static inline int tracehook_unsafe_exec(
+ {
+ int unsafe = 0;
+ int ptrace = task_ptrace(task);
+- if (ptrace & PT_PTRACED) {
++ if (ptrace) {
+ if (ptrace & PT_PTRACE_CAP)
+ unsafe |= LSM_UNSAFE_PTRACE_CAP;
+ else
+@@ -171,7 +178,7 @@ static inline int tracehook_unsafe_exec(
+ */
+ static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk)
+ {
+- if (task_ptrace(tsk) & PT_PTRACED)
++ if (task_ptrace(tsk))
+ return rcu_dereference(tsk->parent);
+ return NULL;
+ }
+@@ -379,7 +386,7 @@ static inline void tracehook_signal_hand
+ const struct k_sigaction *ka,
+ struct pt_regs *regs, int stepping)
+ {
+- if (stepping)
++ if (stepping && (task_ptrace(current) & PT_PTRACED))
+ ptrace_notify(SIGTRAP);
+ }
-- read_lock(&tasklist_lock);
-- do_notify_parent_cldstop(current->group_leader, why);
-- read_unlock(&tasklist_lock);
-+ if (why) {
-+ read_lock(&tasklist_lock);
-+ do_notify_parent_cldstop(current->group_leader, why);
-+ read_unlock(&tasklist_lock);
-+ }
- goto relock;
- }
+@@ -485,7 +492,7 @@ static inline int tracehook_get_signal(s
+ */
+ static inline int tracehook_notify_jctl(int notify, int why)
+ {
+- return notify ?: (current->ptrace & PT_PTRACED) ? why : 0;
++ return notify ?: task_ptrace(current) ? why : 0;
+ }
-@@ -1979,14 +1980,14 @@ void exit_signals(struct task_struct *ts
- if (unlikely(tsk->signal->group_stop_count) &&
- !--tsk->signal->group_stop_count) {
- tsk->signal->flags = SIGNAL_STOP_STOPPED;
-- group_stop = 1;
-+ group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED);
- }
- out:
- spin_unlock_irq(&tsk->sighand->siglock);
+ /**
+diff --git a/kernel/ptrace.c b/kernel/ptrace.c
+index 23bd09c..b7c1d32 100644
+--- a/kernel/ptrace.c
++++ b/kernel/ptrace.c
+@@ -271,7 +271,7 @@ static int ignoring_children(struct sigh
+ * 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 __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
+ {
+ __ptrace_unlink(p);
-- if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) {
-+ if (unlikely(group_stop)) {
- read_lock(&tasklist_lock);
-- do_notify_parent_cldstop(tsk, CLD_STOPPED);
-+ do_notify_parent_cldstop(tsk, group_stop);
- read_unlock(&tasklist_lock);
- }
+diff --git a/kernel/signal.c b/kernel/signal.c
+index 6705320..9908335 100644
+--- a/kernel/signal.c
++++ b/kernel/signal.c
+@@ -1461,7 +1461,7 @@ int do_notify_parent(struct task_struct
+ return ret;
}
+
+-static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
++void do_notify_parent_cldstop(struct task_struct *tsk, int why)
+ {
+ struct siginfo info;
+ unsigned long flags;
+@@ -1731,7 +1731,7 @@ static int do_signal_stop(int signr)
+ static int ptrace_signal(int signr, siginfo_t *info,
+ struct pt_regs *regs, void *cookie)
+ {
+- if (!task_ptrace(current))
++ if (!(task_ptrace(current) & PT_PTRACED))
+ return signr;
+
+ ptrace_signal_deliver(regs, cookie);
+@@ -1807,11 +1807,6 @@ relock:
+
+ for (;;) {
+ struct k_sigaction *ka;
+-
+- if (unlikely(signal->group_stop_count > 0) &&
+- do_signal_stop(0))
+- goto relock;
+-
+ /*
+ * Tracing can induce an artifical signal and choose sigaction.
+ * The return value in @signr determines the default action,
+@@ -1823,6 +1818,10 @@ relock:
+ if (unlikely(signr != 0))
+ ka = return_ka;
+ else {
++ if (unlikely(signal->group_stop_count > 0) &&
++ do_signal_stop(0))
++ goto relock;
++
+ signr = dequeue_signal(current, ¤t->blocked,
+ info);
+
linux-2.6-utrace.patch:
Documentation/DocBook/Makefile | 2
Documentation/DocBook/utrace.tmpl | 590 +++++++++
fs/proc/array.c | 3
include/linux/sched.h | 5
include/linux/tracehook.h | 87 +
include/linux/utrace.h | 694 ++++++++++
init/Kconfig | 9
kernel/Makefile | 1
kernel/fork.c | 3
kernel/ptrace.c | 14
kernel/utrace.c | 2424 ++++++++++++++++++++++++++++++++++++++
11 files changed, 3830 insertions(+), 2 deletions(-)
View full diff with command:
/usr/bin/cvs -n -f diff -kk -u -p -N -r 1.118 -r 1.119 linux-2.6-utrace.patchIndex: linux-2.6-utrace.patch
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/devel/linux-2.6-utrace.patch,v
retrieving revision 1.118
retrieving revision 1.119
diff -u -p -r1.118 -r1.119
--- linux-2.6-utrace.patch 28 Sep 2009 05:09:49 -0000 1.118
+++ linux-2.6-utrace.patch 16 Dec 2009 22:09:42 -0000 1.119
@@ -1,5 +1,45 @@
+utrace core
+
+This adds the utrace facility, a new modular interface in the kernel for
+implementing user thread tracing and debugging. This fits on top of the
+tracehook_* layer, so the new code is well-isolated.
+
+The new interface is in <linux/utrace.h> and the DocBook utrace book
+describes it. It allows for multiple separate tracing engines to work in
+parallel without interfering with each other. Higher-level tracing
+facilities can be implemented as loadable kernel modules using this layer.
+
+The new facility is made optional under CONFIG_UTRACE.
+When this is not enabled, no new code is added.
+It can only be enabled on machines that have all the
+prerequisites and select CONFIG_HAVE_ARCH_TRACEHOOK.
+
+In this initial version, utrace and ptrace do not play together at all.
+If ptrace is attached to a thread, the attach calls in the utrace kernel
+API return -EBUSY. If utrace is attached to a thread, the PTRACE_ATTACH
+or PTRACE_TRACEME request will return EBUSY to userland. The old ptrace
+code is otherwise unchanged and nothing using ptrace should be affected
+by this patch as long as utrace is not used at the same time. In the
+future we can clean up the ptrace implementation and rework it to use
+the utrace API.
+
+Signed-off-by: Roland McGrath <roland at redhat.com>
+---
+ Documentation/DocBook/Makefile | 2 +-
+ Documentation/DocBook/utrace.tmpl | 590 +++++++++
+ fs/proc/array.c | 3 +
+ include/linux/sched.h | 5 +
+ include/linux/tracehook.h | 87 ++-
+ include/linux/utrace.h | 694 +++++++++++
+ init/Kconfig | 9 +
+ kernel/Makefile | 1 +
+ kernel/fork.c | 3 +
+ kernel/ptrace.c | 14 +
+ kernel/utrace.c | 2424 +++++++++++++++++++++++++++++++++++++
+ 11 files changed, 3830 insertions(+), 2 deletions(-)
+
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
-index ab8300f..95f59e4 100644
+index ab8300f..95f59e4 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -9,7 +9,7 @@
@@ -13,7 +53,7 @@ index ab8300f..95f59e4 100644
mac80211.xml debugobjects.xml sh.xml regulator.xml \
diff --git a/Documentation/DocBook/utrace.tmpl b/Documentation/DocBook/utrace.tmpl
new file mode 100644
-index 0000000..6cc58a1
+index ...e149f49 100644
--- /dev/null
+++ b/Documentation/DocBook/utrace.tmpl
@@ -0,0 +1,590 @@
@@ -472,7 +512,7 @@ index 0000000..6cc58a1
+ <function>utrace_finish_examine</function> surrounding the calls to
+ <structname>struct user_regset</structname> functions or direct examination
+ of task data structures. <function>utrace_prepare_examine</function> returns
-+ an error if the task is not properly stopped and not dead. After a
++ an error if the task is not properly stopped, or is dead. After a
+ successful examination, the paired <function>utrace_finish_examine</function>
+ call returns an error if the task ever woke up during the examination. If
+ so, any data gathered may be scrambled and should be discarded. This means
@@ -608,18 +648,18 @@ index 0000000..6cc58a1
+
+</book>
diff --git a/fs/proc/array.c b/fs/proc/array.c
-index 07f77a7..882dc90 100644
+index 822c2d5..9069c91 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
-@@ -83,6 +83,7 @@
+@@ -82,6 +82,7 @@
+ #include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
- #include <linux/swapops.h>
+#include <linux/utrace.h>
+ #include <linux/swapops.h>
#include <asm/pgtable.h>
- #include <asm/processor.h>
-@@ -189,6 +190,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
+@@ -189,6 +190,8 @@ static inline void task_state(struct seq
cred->uid, cred->euid, cred->suid, cred->fsuid,
cred->gid, cred->egid, cred->sgid, cred->fsgid);
@@ -628,36 +668,16 @@ index 07f77a7..882dc90 100644
task_lock(p);
if (p->files)
fdt = files_fdtable(p->files);
-diff --git a/include/linux/init_task.h b/include/linux/init_task.h
-index 21a6f5d..a598a6b 100644
---- a/include/linux/init_task.h
-+++ b/include/linux/init_task.h
-@@ -177,6 +177,7 @@ extern struct cred init_cred;
- [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \
- }, \
- .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \
-+ INIT_UTRACE(tsk) \
- INIT_IDS \
- INIT_PERF_EVENTS(tsk) \
- INIT_TRACE_IRQFLAGS \
diff --git a/include/linux/sched.h b/include/linux/sched.h
-index 75e6e60..94ca5c5 100644
+index 6c8928b..139d300 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
-@@ -61,6 +61,7 @@ struct sched_param {
- #include <linux/errno.h>
- #include <linux/nodemask.h>
- #include <linux/mm_types.h>
-+#include <linux/utrace_struct.h>
-
- #include <asm/system.h>
- #include <asm/page.h>
-@@ -1393,6 +1394,11 @@ struct task_struct {
+@@ -1393,6 +1393,11 @@ struct task_struct {
#endif
seccomp_t seccomp;
+#ifdef CONFIG_UTRACE
-+ struct utrace utrace;
++ struct utrace *utrace;
+ unsigned long utrace_flags;
+#endif
+
@@ -665,7 +685,7 @@ index 75e6e60..94ca5c5 100644
u32 parent_exec_id;
u32 self_exec_id;
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
-index 1eb44a9..17c103e 100644
+index c78b2f4..0f5a48c 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -49,6 +49,7 @@
@@ -685,7 +705,7 @@ index 1eb44a9..17c103e 100644
return (task_ptrace(task) & PT_PTRACED) != 0;
}
-@@ -111,6 +114,9 @@ static inline void ptrace_report_syscall(struct pt_regs *regs)
+@@ -111,6 +114,9 @@ static inline void ptrace_report_syscall
static inline __must_check int tracehook_report_syscall_entry(
struct pt_regs *regs)
{
@@ -695,16 +715,17 @@ index 1eb44a9..17c103e 100644
ptrace_report_syscall(regs);
return 0;
}
-@@ -134,6 +140,8 @@ static inline __must_check int tracehook_report_syscall_entry(
+@@ -134,6 +140,9 @@ static inline __must_check int tracehook
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
+ if (task_utrace_flags(current) & UTRACE_EVENT(SYSCALL_EXIT))
+ utrace_report_syscall_exit(regs);
- ptrace_report_syscall(regs);
- }
-
-@@ -194,6 +202,8 @@ static inline void tracehook_report_exec(struct linux_binfmt *fmt,
++
+ if (step && (task_ptrace(current) & PT_PTRACED)) {
+ siginfo_t info;
+ user_single_step_siginfo(current, regs, &info);
+@@ -201,6 +210,8 @@ static inline void tracehook_report_exec
struct linux_binprm *bprm,
struct pt_regs *regs)
{
@@ -713,7 +734,7 @@ index 1eb44a9..17c103e 100644
if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
unlikely(task_ptrace(current) & PT_PTRACED))
send_sig(SIGTRAP, current, 0);
-@@ -211,6 +221,8 @@ static inline void tracehook_report_exec(struct linux_binfmt *fmt,
+@@ -218,10 +229,37 @@ static inline void tracehook_report_exec
*/
static inline void tracehook_report_exit(long *exit_code)
{
@@ -722,15 +743,36 @@ index 1eb44a9..17c103e 100644
ptrace_event(PT_TRACE_EXIT, PTRACE_EVENT_EXIT, *exit_code);
}
-@@ -254,6 +266,7 @@ static inline int tracehook_prepare_clone(unsigned clone_flags)
- static inline void tracehook_finish_clone(struct task_struct *child,
- unsigned long clone_flags, int trace)
- {
-+ utrace_init_task(child);
- ptrace_init_task(child, (clone_flags & CLONE_PTRACE) || trace);
- }
-
-@@ -278,6 +291,8 @@ static inline void tracehook_report_clone(struct pt_regs *regs,
[...2806 lines suppressed...]
++ utrace = task_utrace_struct(task);
++ if (utrace->resume < UTRACE_RESUME ||
++ utrace->pending_attach || utrace->signal_handler) {
++ enum utrace_resume_action resume;
++
+ /*
+ * We've been asked for an explicit report before we
+ * even check for pending signals.
@@ -3660,19 +3704,14 @@ index 0000000..74b5fc5
+
+ splice_attaching(utrace);
+
-+ if (unlikely(!utrace->interrupt) && unlikely(!utrace->report))
-+ report.result = UTRACE_SIGNAL_IGN;
-+ else if (utrace->signal_handler)
-+ report.result = UTRACE_SIGNAL_HANDLER;
-+ else
-+ report.result = UTRACE_SIGNAL_REPORT;
++ report.result = utrace->signal_handler ?
++ UTRACE_SIGNAL_HANDLER : UTRACE_SIGNAL_REPORT;
++ utrace->signal_handler = 0;
+
-+ /*
-+ * We are now making the report and it's on the
-+ * interrupt path, so clear the flags asking for those.
-+ */
-+ utrace->interrupt = utrace->report = utrace->signal_handler = 0;
-+ utrace->stopped = 0;
++ resume = utrace->resume;
++ utrace->resume = UTRACE_RESUME;
++
++ spin_unlock(&utrace->lock);
+
+ /*
+ * Make sure signal_pending() only returns true
@@ -3684,13 +3723,21 @@ index 0000000..74b5fc5
+ spin_unlock_irq(&task->sighand->siglock);
+ }
+
-+ spin_unlock(&utrace->lock);
-+
-+ if (unlikely(report.result == UTRACE_SIGNAL_IGN))
++ if (resume > UTRACE_REPORT) {
++ /*
++ * We only got here to process utrace->resume.
++ * Despite no callbacks, this report is not spurious.
++ */
++ report.action = resume;
++ report.spurious = false;
++ finish_resume_report(task, utrace, &report);
++ return -1;
++ } else if (!(task->utrace_flags & UTRACE_EVENT(QUIESCE))) {
+ /*
+ * We only got here to clear utrace->signal_handler.
+ */
+ return -1;
++ }
+
+ /*
+ * Do a reporting pass for no signal, just for EVENT(QUIESCE).
@@ -3701,22 +3748,15 @@ index 0000000..74b5fc5
+ event = 0;
+ ka = NULL;
+ memset(return_ka, 0, sizeof *return_ka);
-+ } else if ((task->utrace_flags & UTRACE_EVENT_SIGNAL_ALL) == 0 &&
-+ !utrace->stopped) {
++ } else if (!(task->utrace_flags & UTRACE_EVENT_SIGNAL_ALL) ||
++ unlikely(task->signal->group_stop_count)) {
+ /*
-+ * If no engine is interested in intercepting signals,
-+ * let the caller just dequeue them normally.
++ * If no engine is interested in intercepting signals or
++ * we must stop, let the caller just dequeue them normally
++ * or participate in group-stop.
+ */
+ return 0;
+ } else {
-+ if (unlikely(utrace->stopped)) {
-+ spin_unlock_irq(&task->sighand->siglock);
-+ spin_lock(&utrace->lock);
-+ utrace->stopped = 0;
-+ spin_unlock(&utrace->lock);
-+ spin_lock_irq(&task->sighand->siglock);
-+ }
-+
+ /*
+ * Steal the next signal so we can let tracing engines
+ * examine it. From the signal number and sigaction,
@@ -3801,11 +3841,11 @@ index 0000000..74b5fc5
+
+ if (ops->report_signal)
+ ret = (*ops->report_signal)(
-+ report.result | report.action, engine, task,
++ report.result | report.action, engine,
+ regs, info, ka, return_ka);
+ else
+ ret = (report.result | (*ops->report_quiesce)(
-+ report.action, engine, task, event));
++ report.action, engine, event));
+
+ /*
+ * Avoid a tight loop reporting again and again if some
@@ -3820,7 +3860,7 @@ index 0000000..74b5fc5
+ break;
+ }
+
-+ finish_callback(utrace, &report, engine, ret);
++ finish_callback(task, utrace, &report, engine, ret);
+ }
+
+ /*
@@ -3867,7 +3907,7 @@ index 0000000..74b5fc5
+ */
+ if (report.action != UTRACE_RESUME)
+ report.action = UTRACE_INTERRUPT;
-+ finish_report(&report, task, utrace);
++ finish_report(task, utrace, &report, true);
+
+ if (unlikely(report.result & UTRACE_SIGNAL_HOLD))
+ push_back_signal(task, info);
@@ -3900,9 +3940,9 @@ index 0000000..74b5fc5
+ * as in utrace_resume(), above. After we've dealt with that,
+ * our caller will relock and come back through here.
+ */
-+ finish_resume_report(&report, task, utrace);
++ finish_resume_report(task, utrace, &report);
+
-+ if (unlikely(report.killed)) {
++ if (unlikely(fatal_signal_pending(task))) {
+ /*
+ * The only reason we woke up now was because of a
+ * SIGKILL. Don't do normal dequeuing in case it
@@ -3932,12 +3972,25 @@ index 0000000..74b5fc5
+
+ /*
+ * Complete the bookkeeping after the report.
-+ * This sets utrace->report if UTRACE_STOP was used.
++ * This sets utrace->resume if UTRACE_STOP was used.
+ */
-+ finish_report(&report, task, utrace);
++ finish_report(task, utrace, &report, true);
+
+ return_ka->sa.sa_handler = SIG_DFL;
+
++ /*
++ * If this signal is fatal, si_signo gets through as exit_code.
++ * We can't allow a completely bogus value there or else core
++ * kernel code can freak out. (If an engine wants to control
++ * the exit_code value exactly, it can do so in report_exit.)
++ * We'll produce a big complaint in dmesg, but won't crash.
++ * That's nicer for debugging your utrace engine.
++ */
++ if (unlikely(info->si_signo & 0x80)) {
++ WARN(1, "utrace engine left bogus si_signo value!");
++ info->si_signo = SIGTRAP;
++ }
++
+ if (unlikely(report.result & UTRACE_SIGNAL_HOLD))
+ push_back_signal(task, info);
+ else
@@ -3963,11 +4016,13 @@ index 0000000..74b5fc5
+ spin_lock(&utrace->lock);
+
+ utrace->signal_handler = 1;
-+ if (stepping) {
-+ utrace->interrupt = 1;
-+ set_tsk_thread_flag(task, TIF_SIGPENDING);
-+ } else {
-+ set_tsk_thread_flag(task, TIF_NOTIFY_RESUME);
++ if (utrace->resume > UTRACE_INTERRUPT) {
++ if (stepping) {
++ utrace->resume = UTRACE_INTERRUPT;
++ set_tsk_thread_flag(task, TIF_SIGPENDING);
++ } else if (utrace->resume == UTRACE_RESUME) {
++ set_tsk_thread_flag(task, TIF_NOTIFY_RESUME);
++ }
+ }
+
+ spin_unlock(&utrace->lock);
@@ -3983,7 +4038,7 @@ index 0000000..74b5fc5
+ * &struct user_regset calls, or direct access to thread-synchronous fields.
+ *
+ * When @target is current, this call is superfluous. When @target is
-+ * another thread, it must held stopped via %UTRACE_STOP by @engine.
++ * another thread, it must be held stopped via %UTRACE_STOP by @engine.
+ *
+ * This call may block the caller until @target stays stopped, so it must
+ * be called only after the caller is sure @target is about to unschedule.
@@ -4094,10 +4149,5 @@ index 0000000..74b5fc5
+ */
+void task_utrace_proc_status(struct seq_file *m, struct task_struct *p)
+{
-+ struct utrace *utrace = &p->utrace;
-+ seq_printf(m, "Utrace:\t%lx%s%s%s\n",
-+ p->utrace_flags,
-+ utrace->stopped ? " (stopped)" : "",
-+ utrace->report ? " (report)" : "",
-+ utrace->interrupt ? " (interrupt)" : "");
++ seq_printf(m, "Utrace:\t%lx\n", p->utrace_flags);
+}
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