The patch titled
ptrace: don't take tasklist to get/set ->last_siginfo
has been added to the -mm tree. Its filename is
ptrace-dont-take-tasklist-to-get-set-last_siginfo.patch
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------------------------------------------------------
Subject: ptrace: don't take tasklist to get/set ->last_siginfo
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock. Perhaps it makes sense to make a single helper
with "bool rw" argument.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/ptrace.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff -puN kernel/ptrace.c~ptrace-dont-take-tasklist-to-get-set-last_siginfo kernel/ptrace.c
--- a/kernel/ptrace.c~ptrace-dont-take-tasklist-to-get-set-last_siginfo
+++ a/kernel/ptrace.c
@@ -422,37 +422,33 @@ static int ptrace_setoptions(struct task
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;
}
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
linux-next.patch
slow_work_thread-should-do-the-exclusive-wait.patch
rework-fix-is_single_threaded.patch
getrusage-fill-ru_maxrss-value.patch
allow_signal-kill-the-bogus-mm-check-add-a-note-about-clone_sighand.patch
ptrace-remove-pt_dtrace-from-arch-h8300.patch
ptrace-remove-pt_dtrace-from-avr32-mn10300-parisc-s390-sh-xtensa.patch
ptrace-remove-pt_dtrace-from-m68k-m68knommu.patch
ptrace-remove-pt_dtrace-from-arch-m32r.patch
ptrace-mm_need_new_owner-use-real_parent-to-search-in-the-siblings.patch
ptrace-tracehook_unsafe_exec-remove-the-stale-comment.patch
ptrace-tracehook_unsafe_exec-remove-the-stale-comment-fix.patch
ptrace-do-not-use-task-ptrace-directly-in-core-kernel.patch
ptrace-ptrace_attach-check-pf_kthread-exit_state-instead-of-mm.patch
ptrace-cleanup-check-set-of-pt_ptraced-during-attach.patch
ptrace-do-not-use-task_lock-for-attach.patch
ptrace_get_task_struct-s-tasklist-rcu-make-it-static.patch
ptrace-wait_task_zombie-s-parent-real_parent.patch
ptrace-do_notify_parent_cldstop-fix-the-wrong-nsproxy-usage.patch
ptrace-dont-take-tasklist-to-get-set-last_siginfo.patch
signals-tracehook_notify_jctl-change.patch
utrace-core.patch
copy_process-remove-the-unneeded-clear_tsk_thread_flagtif_sigpending.patch
elf_core_dump-use-rcu_read_lock-to-access-real_parent.patch
shift-ptrace-implies-wuntraced-from-ptrace_do_wait-to-wait_task_stopped.patch
introduce-struct-wait_opts-to-simplify-do_wait-pathes.patch
do_wait-simplify-retval-tsk_result-notask_error-mess.patch
do_wait-kill-the-old-bug_on-use-while_each_thread.patch
do_wait-fix-the-theoretical-race-with-stop-trace-cont.patch
mm-exitc-reorder-wait_opts-to-remove-padding-on-64-bit-builds.patch
wait_task_-cleanups-split-wait_noreap_copyout.patch
wait_task_-cleanups-use-copy_wait_opts_to_user-in-wait_task_stopped.patch
wait_task_-cleanups-use-copy_wait_opts_to_user-in-do_wait.patch
wait_task_-cleanups-use-copy_wait_opts_to_user-in-wait_task_zombie.patch
wait_task_-cleanups-use-copy_wait_opts_to_user-in-wait_task_continued.patch
kthreads-simplify-the-startup-synchronization.patch
kthreads-rework-kthread_stop.patch
kthreads-simplify-migration_thread-exit-path.patch
pids-clean-up-find_task_by_pid-variants.patch
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