Merge tag 'v5.16-rc4' into media_tree

Linux 5.16-rc4

* tag 'v5.16-rc4': (984 commits)
  Linux 5.16-rc4
  KVM: SVM: Do not terminate SEV-ES guests on GHCB validation failure
  KVM: SEV: Fall back to vmalloc for SEV-ES scratch area if necessary
  KVM: SEV: Return appropriate error codes if SEV-ES scratch setup fails
  parisc: Mark cr16 CPU clocksource unstable on all SMP machines
  parisc: Fix "make install" on newer debian releases
  sched/uclamp: Fix rq->uclamp_max not set on first enqueue
  preempt/dynamic: Fix setup_preempt_mode() return value
  cifs: avoid use of dstaddr as key for fscache client cookie
  cifs: add server conn_id to fscache client cookie
  cifs: wait for tcon resource_id before getting fscache super
  cifs: fix missed refcounting of ipc tcon
  x86/xen: Add xenpv_restore_regs_and_return_to_usermode()
  x86/entry: Use the correct fence macro after swapgs in kernel CR3
  fget: check that the fd still exists after getting a ref to it
  x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()
  x86/sev: Fix SEV-ES INS/OUTS instructions for word, dword, and qword
  powercap: DTPM: Drop unused local variable from init_dtpm()
  io-wq: don't retry task_work creation failure on fatal conditions
  serial: 8250_bcm7271: UART errors after resuming from S2
  ...

1 files changed, 29 insertions, 7 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 7c4b7ae714d4..a629b11bf3e0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1298,6 +1298,12 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
 	return ret;
 }
 
+enum sig_handler {
+	HANDLER_CURRENT, /* If reachable use the current handler */
+	HANDLER_SIG_DFL, /* Always use SIG_DFL handler semantics */
+	HANDLER_EXIT,	 /* Only visible as the process exit code */
+};
+
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1310,7 +1316,8 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
  * that is why we also clear SIGNAL_UNKILLABLE.
  */
 static int
-force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl)
+force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t,
+	enum sig_handler handler)
 {
 	unsigned long int flags;
 	int ret, blocked, ignored;
@@ -1321,9 +1328,10 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool
 	action = &t->sighand->action[sig-1];
 	ignored = action->sa.sa_handler == SIG_IGN;
 	blocked = sigismember(&t->blocked, sig);
-	if (blocked || ignored || sigdfl) {
+	if (blocked || ignored || (handler != HANDLER_CURRENT)) {
 		action->sa.sa_handler = SIG_DFL;
-		action->sa.sa_flags |= SA_IMMUTABLE;
+		if (handler == HANDLER_EXIT)
+			action->sa.sa_flags |= SA_IMMUTABLE;
 		if (blocked) {
 			sigdelset(&t->blocked, sig);
 			recalc_sigpending_and_wake(t);
@@ -1343,7 +1351,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool
 
 int force_sig_info(struct kernel_siginfo *info)
 {
-	return force_sig_info_to_task(info, current, false);
+	return force_sig_info_to_task(info, current, HANDLER_CURRENT);
 }
 
 /*
@@ -1660,7 +1668,20 @@ void force_fatal_sig(int sig)
 	info.si_code = SI_KERNEL;
 	info.si_pid = 0;
 	info.si_uid = 0;
-	force_sig_info_to_task(&info, current, true);
+	force_sig_info_to_task(&info, current, HANDLER_SIG_DFL);
+}
+
+void force_exit_sig(int sig)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code = SI_KERNEL;
+	info.si_pid = 0;
+	info.si_uid = 0;
+	force_sig_info_to_task(&info, current, HANDLER_EXIT);
 }
 
 /*
@@ -1693,7 +1714,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 	info.si_flags = flags;
 	info.si_isr = isr;
 #endif
-	return force_sig_info_to_task(&info, t, false);
+	return force_sig_info_to_task(&info, t, HANDLER_CURRENT);
 }
 
 int force_sig_fault(int sig, int code, void __user *addr
@@ -1813,7 +1834,8 @@ int force_sig_seccomp(int syscall, int reason, bool force_coredump)
 	info.si_errno = reason;
 	info.si_arch = syscall_get_arch(current);
 	info.si_syscall = syscall;
-	return force_sig_info_to_task(&info, current, force_coredump);
+	return force_sig_info_to_task(&info, current,
+		force_coredump ? HANDLER_EXIT : HANDLER_CURRENT);
 }
 
 /* For the crazy architectures that include trap information in