FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions

Move the test for kernel mode processing from do_signal() into entry.S to also
prevent system call exit tracing and userspace resumption notification handling
happening when returning from kernel exceptions.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 3 insertions, 11 deletions

diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index 5ba23f715ea5..ff3092c18ca2 100644
--- a/arch/frv/kernel/entry.S
+++ b/arch/frv/kernel/entry.S
@@ -1163,7 +1163,9 @@ __syscall_trace_entry:
         # perform syscall exit tracing
 __syscall_exit_work:
         LEDS            0x6340
-        andicc          gr4,#_TIF_SYSCALL_TRACE,gr0,icc0
+        andicc          gr22,#PSR_PS,gr0,icc1   ; don't handle on return to kernel mode
+        andicc.p        gr4,#_TIF_SYSCALL_TRACE,gr0,icc0
+        bne             icc1,#0,__entry_return_direct
         beq             icc0,#1,__entry_work_pending
 
         movsg           psr,gr23
diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c
index 4e134c7eceea..f3b9064c548c 100644
--- a/arch/frv/kernel/signal.c
+++ b/arch/frv/kernel/signal.c
@@ -474,18 +474,8 @@ static void do_signal(void)
 {
         struct k_sigaction ka;
         siginfo_t info;
-        sigset_t *oldset;
         int signr;
 
-        /*
-         * We want the common case to go fast, which
-         * is why we may in certain cases get here from
-         * kernel mode. Just return without doing anything
-         * if so.
-         */
-        if (!user_mode(__frame))
-                return;
-
         signr = get_signal_to_deliver(&info, &ka, __frame, NULL);
         if (signr > 0) {
                 handle_signal(signr, &info, &ka);