From d17fc238ac1486906ff724b4a5fe4ec169f554c5 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Tue, 28 May 2013 20:21:10 +0100
Subject: [PATCH] MN10300: Enable IRQs more in system call exit work path
Enable IRQs when calling schedule() for TIF_NEED_RESCHED and
do_notify_resume(). If interrupts are enabled during do_notify_resume(), a
warning can be seen (see lower down).
Whilst we're at it, resume_userspace can be made local to entry.S as it is not
called outside of there and it can be merged with the part of work_resched that
occurs after schedule() is called.
WARNING: at kernel/softirq.c:160 local_bh_enable+0x42/0xa0()
Call Trace:
local_bh_enable+0x42/0xa0
unix_release_sock+0x86/0x23c
unix_release+0x20/0x28
sock_release+0x17/0x88
sock_close+0x20/0x28
__fput+0xc9/0x1fc
____fput+0xb/0x10
task_work_run+0x64/0x78
do_notify_resume+0x53d/0x544
work_notifysig+0xa/0xc
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ken Cox <jkc@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/mn10300/kernel/entry.S | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index 9420057537200..222152a3f7519 100644
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -108,10 +108,10 @@ syscall_exit_work:
and EPSW_nSL,d0
beq resume_kernel # returning to supervisor mode
- btst _TIF_SYSCALL_TRACE,d2
- beq work_pending
LOCAL_IRQ_ENABLE # could let syscall_trace_exit() call
# schedule() instead
+ btst _TIF_SYSCALL_TRACE,d2
+ beq work_pending
mov fp,d0
call syscall_trace_exit[],0 # do_syscall_trace(regs)
jmp resume_userspace
@@ -124,6 +124,7 @@ work_pending:
work_resched:
call schedule[],0
+resume_userspace:
# make sure we don't miss an interrupt setting need_resched or
# sigpending between sampling and the rti
LOCAL_IRQ_DISABLE
@@ -132,6 +133,8 @@ work_resched:
mov (TI_flags,a2),d2
btst _TIF_WORK_MASK,d2
beq restore_all
+
+ LOCAL_IRQ_ENABLE
btst _TIF_NEED_RESCHED,d2
bne work_resched
@@ -170,17 +173,6 @@ ret_from_intr:
and EPSW_nSL,d0
beq resume_kernel # returning to supervisor mode
-ENTRY(resume_userspace)
- # make sure we don't miss an interrupt setting need_resched or
- # sigpending between sampling and the rti
- LOCAL_IRQ_DISABLE
-
- # is there any work to be done on int/exception return?
- mov (TI_flags,a2),d2
- btst _TIF_WORK_MASK,d2
- bne work_pending
- jmp restore_all
-
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
LOCAL_IRQ_DISABLE
--
2.30.2