Interrupt is allowed during exception handling.
There are warning messages if the kernel enables the configuration
'CONFIG_DEBUG_ATOMIC_SLEEP=y'.
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23
in_atomic(): 0, irqs_disabled(): 1, pid: 43, name: ash
CPU: 0 PID: 43 Comm: ash Tainted: G W 4.15.0-rc8-00089-g89ffdae-dirty #17
Call Trace:
[<000000009abb1587>] walk_stackframe+0x0/0x7a
[<00000000d4f3d088>] ___might_sleep+0x102/0x11a
[<00000000b1fd792a>] down_read+0x18/0x28
[<000000000289ec01>] do_page_fault+0x86/0x2f6
[<00000000012441f6>] _do_fork+0x1b4/0x1e0
[<00000000f46c3e3b>] ret_from_syscall+0xa/0xe
Signed-off-by: Zong Li <[email protected]>
---
arch/riscv/kernel/entry.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 7404ec2..61f063e 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -169,6 +169,9 @@ ENTRY(handle_exception)
move a1, sp /* pt_regs */
tail do_IRQ
1:
+ /* Exceptions run with interrupts enabled */
+ csrs sstatus, SR_SIE
+
/* Handle syscalls */
li t0, EXC_SYSCALL
beq s4, t0, handle_syscall
@@ -195,8 +198,6 @@ handle_syscall:
*/
addi s2, s2, 0x4
REG_S s2, PT_SEPC(sp)
- /* System calls run with interrupts enabled */
- csrs sstatus, SR_SIE
/* Trace syscalls, but only if requested by the user. */
REG_L t0, TASK_TI_FLAGS(tp)
andi t0, t0, _TIF_SYSCALL_TRACE
--
2.9.3
Looks fine:
Reviewed-by: Christoph Hellwig <[email protected]>
On Fri, 02 Feb 2018 01:45:28 PST (-0800), Christoph Hellwig wrote:
> Looks fine:
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Thanks, I'm still working through my FOSDEM-related email backlog. I'll target
this for the next RC, as it seems like a small enough fix. It should be in the
next linux-next.