Merge tag 'v5.0-rc7' into patchwork

Linux 5.0-rc7

* tag 'v5.0-rc7': (1667 commits)
  Linux 5.0-rc7
  Input: elan_i2c - add ACPI ID for touchpad in Lenovo V330-15ISK
  Input: st-keyscan - fix potential zalloc NULL dereference
  Input: apanel - switch to using brightness_set_blocking()
  powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present()
  efi/arm: Revert "Defer persistent reservations until after paging_init()"
  arm64, mm, efi: Account for GICv3 LPI tables in static memblock reserve table
  sunrpc: fix 4 more call sites that were using stack memory with a scatterlist
  include/linux/module.h: copy __init/__exit attrs to init/cleanup_module
  Compiler Attributes: add support for __copy (gcc >= 9)
  lib/crc32.c: mark crc32_le_base/__crc32c_le_base aliases as __pure
  auxdisplay: ht16k33: fix potential user-after-free on module unload
  x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls
  i2c: bcm2835: Clear current buffer pointers and counts after a transfer
  i2c: cadence: Fix the hold bit setting
  drm: Use array_size() when creating lease
  dm thin: fix bug where bio that overwrites thin block ignores FUA
  Revert "exec: load_script: don't blindly truncate shebang string"
  Revert "gfs2: read journal in large chunks to locate the head"
  net: ethernet: freescale: set FEC ethtool regs version
  ...

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 62 insertions, 4 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index e1d7ad8e6ab1..57b7771e20d7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -688,6 +688,48 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, kernel_siginfo_t *in
 }
 EXPORT_SYMBOL_GPL(dequeue_signal);
 
+static int dequeue_synchronous_signal(kernel_siginfo_t *info)
+{
+	struct task_struct *tsk = current;
+	struct sigpending *pending = &tsk->pending;
+	struct sigqueue *q, *sync = NULL;
+
+	/*
+	 * Might a synchronous signal be in the queue?
+	 */
+	if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK))
+		return 0;
+
+	/*
+	 * Return the first synchronous signal in the queue.
+	 */
+	list_for_each_entry(q, &pending->list, list) {
+		/* Synchronous signals have a postive si_code */
+		if ((q->info.si_code > SI_USER) &&
+		    (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
+			sync = q;
+			goto next;
+		}
+	}
+	return 0;
+next:
+	/*
+	 * Check if there is another siginfo for the same signal.
+	 */
+	list_for_each_entry_continue(q, &pending->list, list) {
+		if (q->info.si_signo == sync->info.si_signo)
+			goto still_pending;
+	}
+
+	sigdelset(&pending->signal, sync->info.si_signo);
+	recalc_sigpending();
+still_pending:
+	list_del_init(&sync->list);
+	copy_siginfo(info, &sync->info);
+	__sigqueue_free(sync);
+	return info->si_signo;
+}
+
 /*
  * Tell a process that it has a new active signal..
  *
@@ -1057,10 +1099,9 @@ static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struc
 
 	result = TRACE_SIGNAL_DELIVERED;
 	/*
-	 * Skip useless siginfo allocation for SIGKILL SIGSTOP,
-	 * and kernel threads.
+	 * Skip useless siginfo allocation for SIGKILL and kernel threads.
 	 */
-	if (sig_kernel_only(sig) || (t->flags & PF_KTHREAD))
+	if ((sig == SIGKILL) || (t->flags & PF_KTHREAD))
 		goto out_set;
 
 	/*
@@ -2394,6 +2435,14 @@ relock:
 		goto relock;
 	}
 
+	/* Has this task already been marked for death? */
+	if (signal_group_exit(signal)) {
+		ksig->info.si_signo = signr = SIGKILL;
+		sigdelset(&current->pending.signal, SIGKILL);
+		recalc_sigpending();
+		goto fatal;
+	}
+
 	for (;;) {
 		struct k_sigaction *ka;
 
@@ -2407,7 +2456,15 @@ relock:
 			goto relock;
 		}
 
-		signr = dequeue_signal(current, &current->blocked, &ksig->info);
+		/*
+		 * Signals generated by the execution of an instruction
+		 * need to be delivered before any other pending signals
+		 * so that the instruction pointer in the signal stack
+		 * frame points to the faulting instruction.
+		 */
+		signr = dequeue_synchronous_signal(&ksig->info);
+		if (!signr)
+			signr = dequeue_signal(current, &current->blocked, &ksig->info);
 
 		if (!signr)
 			break; /* will return 0 */
@@ -2489,6 +2546,7 @@ relock:
 			continue;
 		}
 
+	fatal:
 		spin_unlock_irq(&sighand->siglock);
 
 		/*