[PATCH] riscv: reject invalid syscalls below -1

David Abdurachmanov
2019-12-18T08:48:09Z

Running "stress-ng --enosys 4 -t 20 -v" showed a large number of kernel oops
with "Unable to handle kernel paging request at virtual address" message. This
happens when enosys stressor starts testing random non-valid syscalls.

I forgot to redirect any syscall below -1 to sys_ni_syscall.

With the patch kernel oops messages are gone while running stress-ng enosys
stressor.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>
Fixes: 5340627e3fe0 ("riscv: add support for SECCOMP and SECCOMP_FILTER")
---
arch/riscv/kernel/entry.S | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index a1349ca64669..e163b7b64c86 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -246,6 +246,7 @@ check_syscall_nr:
*/
li t1, -1
beq a7, t1, ret_from_syscall_rejected
+ blt a7, t1, 1f
/* Call syscall */
la s0, sys_call_table
slli t0, a7, RISCV_LGPTR
--
2.24.1