From 5f0b6ac3905fc961f3b685a08eb4962ff071ea7d Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Wed, 26 Feb 2020 03:35:39 +1000
Subject: [PATCH] powerpc/64/syscall: Reconcile interrupts
References: jsc#SLE-9246
Patch-mainline: v5.7-rc1
Git-commit: 5f0b6ac3905fc961f3b685a08eb4962ff071ea7d
This reconciles interrupts in the system call case like all other
interrupts. This allows system_call_common to be shared with the scv
system call implementation in a subsequent patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-31-npiggin@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/entry_64.S | 11 +++++++++++
arch/powerpc/kernel/syscall_64.c | 24 ++++++++++--------------
2 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 95905ed3d86e..63f0a4414618 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -119,6 +119,17 @@ END_BTB_FLUSH_SECTION
ld r11,exception_marker@toc(r2)
std r11,-16(r10) /* "regshere" marker */
+ /*
+ * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
+ * would clobber syscall parameters. Also we always enter with IRQs
+ * enabled and nothing pending. system_call_exception() will call
+ * trace_hardirqs_off().
+ */
+ li r11,IRQS_ALL_DISABLED
+ li r12,PACA_IRQ_HARD_DIS
+ stb r11,PACAIRQSOFTMASK(r13)
+ stb r12,PACAIRQHAPPENED(r13)
+
/* Calling convention has r9 = orig r0, r10 = regs */
mr r9,r0
bl system_call_exception
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index a986effee1e0..cf06eb443a80 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -17,13 +17,19 @@
typedef long (*syscall_fn)(long, long, long, long, long, long);
-/* Has to run notrace because it is entered "unreconciled" */
-notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
- unsigned long r0, struct pt_regs *regs)
+/* Has to run notrace because it is entered not completely "reconciled" */
+notrace long system_call_exception(long r3, long r4, long r5,
+ long r6, long r7, long r8,
+ unsigned long r0, struct pt_regs *regs)
{
unsigned long ti_flags;
syscall_fn f;
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+ BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
+
+ trace_hardirqs_off(); /* finish reconciling */
+
if (IS_ENABLED(CONFIG_PPC_BOOK3S))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
@@ -44,16 +50,6 @@ notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7,
kuap_check_amr();
- /*
- * A syscall should always be called with interrupts enabled
- * so we just unconditionally hard-enable here. When some kind
- * of irq tracing is used, we additionally check that condition
- * is correct
- */
- if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
- WARN_ON(irq_soft_mask_return() != IRQS_ENABLED);
- WARN_ON(local_paca->irq_happened);
- }
/*
* This is not required for the syscall exit path, but makes the
* stack frame look nicer. If this was initialised in the first stack
@@ -62,7 +58,7 @@ notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7,
*/
regs->softe = IRQS_ENABLED;
- __hard_irq_enable();
+ local_irq_enable();
ti_flags = current_thread_info()->flags;
if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
--
2.28.0