[PATCH] riscv: Fix TRACE_IRQFLAGS call points in entry.S

[Yipeng Zou]

TRACE_IRQFLAGS need trace all {Enable,Disable} hard interrupts points
in entry.S.
We miss a path(work_notifysig) that cause an WARN as shown below.

[   50.362431] ------------[ cut here ]------------
[   50.363607] DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled())
[   50.367229] WARNING: CPU: 3 PID: 74 at kernel/locking/lockdep.c:5510 check_flags+0x10a/0x1e0
[   50.368905] Modules linked in:
[   50.369440] CPU: 3 PID: 74 Comm: rcS Tainted: G
[   50.370225] Hardware name: riscv-virtio,qemu (DT)
[   50.370632] epc : check_flags+0x10a/0x1e0
[   50.371015]  ra : check_flags+0x10a/0x1e0
[   50.371751] epc : ffffffff808e2670 ra : ffffffff808e2670 sp : ff20000000c3bca0
[   50.372721]  gp : ffffffff817e2188 tp : ff60000002fe1800 t0 : ffffffff8162a2a8
[   50.373321]  t1 : 0000000000000001 t2 : 2d2d2d2d2d2d2d2d s0 : ff20000000c3bcc0
[   50.373903]  s1 : ffffffff817e3340 a0 : 0000000000000030 a1 : ffffffff81693fa8
[   50.374476]  a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 083151a422b8df00
[   50.375039]  a5 : 083151a422b8df00 a6 : ffffffff8006891e a7 : 083151a422b8df00
[   50.376028]  s2 : ffffffff817e54e0 s3 : ffffffff81695070 s4 : ff600000027d7800
[   50.376978]  s5 : ffffffff80c22770 s6 : 0000000200000022 s7 : ffffffffffffffff
[   50.377779]  s8 : ffffffff82301ed0 s9 : 0000000000001000 s10: 00000000001a9905
[   50.378335]  s11: 000000000014f3e8 t3 : ffffffff822d714f t4 : ffffffff822d714f
[   50.378955]  t5 : ffffffff822d7150 t6 : ff20000000c3ba98
[   50.379783] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
[   50.380810] [<ffffffff808e27be>] lock_is_held_type+0x78/0x14e
[   50.381477] [<ffffffff8003e850>] __might_resched+0x26/0x22c
[   50.382006] [<ffffffff8003ea92>] __might_sleep+0x3c/0x66
[   50.382477] [<ffffffff8002324e>] get_signal+0xaa/0x912
[   50.382947] [<ffffffff80005368>] do_notify_resume+0x82/0x434
[   50.383839] [<ffffffff80003bec>] ret_from_exception+0x0/0x10

Fixes: 3c4697982982 ("riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT")
Signed-off-by: Yipeng Zou <zouyipeng at huawei.com>
---
 arch/riscv/kernel/entry.S | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index b9eda3fcbd6d..f4d23995a4f1 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -370,16 +370,20 @@ resume_kernel:
 
 work_pending:
 	/* Enter slow path for supplementary processing */
-	la ra, ret_from_exception
 	andi s1, s0, _TIF_NEED_RESCHED
 	bnez s1, work_resched
 work_notifysig:
+#ifdef CONFIG_TRACE_IRQFLAGS
+	call __trace_hardirqs_on
+#endif
+	la ra, ret_from_exception
 	/* Handle pending signals and notify-resume requests */
 	csrs CSR_STATUS, SR_IE /* Enable interrupts for do_notify_resume() */
 	move a0, sp /* pt_regs */
 	move a1, s0 /* current_thread_info->flags */
 	tail do_notify_resume
 work_resched:
+	la ra, ret_from_exception
 	tail schedule
 
 /* Slow paths for ptrace. */
-- 
2.17.1