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Diffstat (limited to 'fs/coredump.c')
-rw-r--r--fs/coredump.c84
1 files changed, 56 insertions, 28 deletions
diff --git a/fs/coredump.c b/fs/coredump.c
index c6479658d487..ec306cc9a28a 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -263,7 +263,6 @@ static int zap_process(struct task_struct *start, int exit_code)
struct task_struct *t;
int nr = 0;
- start->signal->flags = SIGNAL_GROUP_EXIT;
start->signal->group_exit_code = exit_code;
start->signal->group_stop_count = 0;
@@ -280,8 +279,8 @@ static int zap_process(struct task_struct *start, int exit_code)
return nr;
}
-static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
- struct core_state *core_state, int exit_code)
+static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
+ struct core_state *core_state, int exit_code)
{
struct task_struct *g, *p;
unsigned long flags;
@@ -291,11 +290,16 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
if (!signal_group_exit(tsk->signal)) {
mm->core_state = core_state;
nr = zap_process(tsk, exit_code);
+ tsk->signal->group_exit_task = tsk;
+ /* ignore all signals except SIGKILL, see prepare_signal() */
+ tsk->signal->flags = SIGNAL_GROUP_COREDUMP;
+ clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
}
spin_unlock_irq(&tsk->sighand->siglock);
if (unlikely(nr < 0))
return nr;
+ tsk->flags = PF_DUMPCORE;
if (atomic_read(&mm->mm_users) == nr + 1)
goto done;
/*
@@ -340,6 +344,7 @@ static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
if (unlikely(p->mm == mm)) {
lock_task_sighand(p, &flags);
nr += zap_process(p, exit_code);
+ p->signal->flags = SIGNAL_GROUP_EXIT;
unlock_task_sighand(p, &flags);
}
break;
@@ -386,11 +391,18 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
return core_waiters;
}
-static void coredump_finish(struct mm_struct *mm)
+static void coredump_finish(struct mm_struct *mm, bool core_dumped)
{
struct core_thread *curr, *next;
struct task_struct *task;
+ spin_lock_irq(&current->sighand->siglock);
+ if (core_dumped && !__fatal_signal_pending(current))
+ current->signal->group_exit_code |= 0x80;
+ current->signal->group_exit_task = NULL;
+ current->signal->flags = SIGNAL_GROUP_EXIT;
+ spin_unlock_irq(&current->sighand->siglock);
+
next = mm->core_state->dumper.next;
while ((curr = next) != NULL) {
next = curr->next;
@@ -407,6 +419,17 @@ static void coredump_finish(struct mm_struct *mm)
mm->core_state = NULL;
}
+static bool dump_interrupted(void)
+{
+ /*
+ * SIGKILL or freezing() interrupt the coredumping. Perhaps we
+ * can do try_to_freeze() and check __fatal_signal_pending(),
+ * but then we need to teach dump_write() to restart and clear
+ * TIF_SIGPENDING.
+ */
+ return signal_pending(current);
+}
+
static void wait_for_dump_helpers(struct file *file)
{
struct pipe_inode_info *pipe;
@@ -416,17 +439,20 @@ static void wait_for_dump_helpers(struct file *file)
pipe_lock(pipe);
pipe->readers++;
pipe->writers--;
+ wake_up_interruptible_sync(&pipe->wait);
+ kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
+ pipe_unlock(pipe);
- while ((pipe->readers > 1) && (!signal_pending(current))) {
- wake_up_interruptible_sync(&pipe->wait);
- kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
- pipe_wait(pipe);
- }
+ /*
+ * We actually want wait_event_freezable() but then we need
+ * to clear TIF_SIGPENDING and improve dump_interrupted().
+ */
+ wait_event_interruptible(pipe->wait, pipe->readers == 1);
+ pipe_lock(pipe);
pipe->readers--;
pipe->writers++;
pipe_unlock(pipe);
-
}
/*
@@ -471,6 +497,7 @@ void do_coredump(siginfo_t *siginfo)
int ispipe;
struct files_struct *displaced;
bool need_nonrelative = false;
+ bool core_dumped = false;
static atomic_t core_dump_count = ATOMIC_INIT(0);
struct coredump_params cprm = {
.siginfo = siginfo,
@@ -514,17 +541,12 @@ void do_coredump(siginfo_t *siginfo)
old_cred = override_creds(cred);
- /*
- * Clear any false indication of pending signals that might
- * be seen by the filesystem code called to write the core file.
- */
- clear_thread_flag(TIF_SIGPENDING);
-
ispipe = format_corename(&cn, &cprm);
- if (ispipe) {
+ if (ispipe) {
int dump_count;
char **helper_argv;
+ struct subprocess_info *sub_info;
if (ispipe < 0) {
printk(KERN_WARNING "format_corename failed\n");
@@ -571,15 +593,20 @@ void do_coredump(siginfo_t *siginfo)
goto fail_dropcount;
}
- retval = call_usermodehelper_fns(helper_argv[0], helper_argv,
- NULL, UMH_WAIT_EXEC, umh_pipe_setup,
- NULL, &cprm);
+ retval = -ENOMEM;
+ sub_info = call_usermodehelper_setup(helper_argv[0],
+ helper_argv, NULL, GFP_KERNEL,
+ umh_pipe_setup, NULL, &cprm);
+ if (sub_info)
+ retval = call_usermodehelper_exec(sub_info,
+ UMH_WAIT_EXEC);
+
argv_free(helper_argv);
if (retval) {
- printk(KERN_INFO "Core dump to %s pipe failed\n",
+ printk(KERN_INFO "Core dump to %s pipe failed\n",
cn.corename);
goto close_fail;
- }
+ }
} else {
struct inode *inode;
@@ -629,9 +656,7 @@ void do_coredump(siginfo_t *siginfo)
goto close_fail;
if (displaced)
put_files_struct(displaced);
- retval = binfmt->core_dump(&cprm);
- if (retval)
- current->signal->group_exit_code |= 0x80;
+ core_dumped = !dump_interrupted() && binfmt->core_dump(&cprm);
if (ispipe && core_pipe_limit)
wait_for_dump_helpers(cprm.file);
@@ -644,7 +669,7 @@ fail_dropcount:
fail_unlock:
kfree(cn.corename);
fail_corename:
- coredump_finish(mm);
+ coredump_finish(mm, core_dumped);
revert_creds(old_cred);
fail_creds:
put_cred(cred);
@@ -659,7 +684,9 @@ fail:
*/
int dump_write(struct file *file, const void *addr, int nr)
{
- return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+ return !dump_interrupted() &&
+ access_ok(VERIFY_READ, addr, nr) &&
+ file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}
EXPORT_SYMBOL(dump_write);
@@ -668,7 +695,8 @@ int dump_seek(struct file *file, loff_t off)
int ret = 1;
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
- if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+ if (dump_interrupted() ||
+ file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-25 16:54:15 +0000