git: 6a3a6fe34bf3 - main - riscv: Assert that SUM is not set in SSTATUS for exceptions.

[John Baldwin]

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=6a3a6fe34bf36b6e745b3e9ad1a991de057729c7

commit 6a3a6fe34bf36b6e745b3e9ad1a991de057729c7
Author:     John Baldwin <jhb at FreeBSD.org>
AuthorDate: 2021-04-21 20:57:20 +0000
Commit:     John Baldwin <jhb at FreeBSD.org>
CommitDate: 2021-04-21 20:57:20 +0000

    riscv: Assert that SUM is not set in SSTATUS for exceptions.
    
    Reviewed by:    mhorne
    Sponsored by:   DARPA
    Differential Revision:  https://reviews.freebsd.org/D29764
---
 sys/riscv/riscv/trap.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sys/riscv/riscv/trap.c b/sys/riscv/riscv/trap.c
index 599fd64b56be..0aaaf46eb629 100644
--- a/sys/riscv/riscv/trap.c
+++ b/sys/riscv/riscv/trap.c
@@ -274,6 +274,9 @@ do_trap_supervisor(struct trapframe *frame)
 	KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) ==
 	    SSTATUS_SPP, ("Came from S mode with interrupts enabled"));
 
+	KASSERT((csr_read(sstatus) & (SSTATUS_SUM)) == 0,
+	    ("Came from S mode with SUM enabled"));
+
 	exception = frame->tf_scause & SCAUSE_CODE;
 	if ((frame->tf_scause & SCAUSE_INTR) != 0) {
 		/* Interrupt */
@@ -342,6 +345,9 @@ do_trap_user(struct trapframe *frame)
 	KASSERT((csr_read(sstatus) & (SSTATUS_SPP | SSTATUS_SIE)) == 0,
 	    ("Came from U mode with interrupts enabled"));
 
+	KASSERT((csr_read(sstatus) & (SSTATUS_SUM)) == 0,
+	    ("Came from U mode with SUM enabled"));
+
 	exception = frame->tf_scause & SCAUSE_CODE;
 	if ((frame->tf_scause & SCAUSE_INTR) != 0) {
 		/* Interrupt */