From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
Helge Deller <deller@gmx.de>,
"David S. Miller" <davem@davemloft.net>,
Michael Ellerman <mpe@ellerman.id.au>,
Rich Felker <dalias@libc.org>, Heiko Carstens <hca@linux.ibm.com>,
Kees Cook <keescook@chromium.org>,
Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Subject: [patch V2 10/13] x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
Date: Wed, 10 Feb 2021 00:40:51 +0100 [thread overview]
Message-ID: <20210210002513.068033456@linutronix.de> (raw)
In-Reply-To: 20210209234041.127454039@linutronix.de
From: Thomas Gleixner <tglx@linutronix.de>
Now that all invocations of irq_exit_rcu() happen on the irq stack, turn on
CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK which causes the core code to invoke
__do_softirq() directly without going through do_softirq_own_stack().
That means do_softirq_own_stack() is only invoked from task context which
means it can't be on the irq stack. Remove the conditional from
run_softirq_on_irqstack_cond() and rename the function accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/irq_stack.h | 19 ++++++++-----------
arch/x86/kernel/irq_64.c | 2 +-
3 files changed, 10 insertions(+), 12 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -187,6 +187,7 @@ config X86
select HAVE_HW_BREAKPOINT
select HAVE_IDE
select HAVE_IOREMAP_PROT
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_GZIP
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -189,19 +189,16 @@
"call %P[__func] \n"
/*
- * Macro to invoke __do_softirq on the irq stack. Contrary to the above
- * the only check which is necessary is whether the interrupt stack is
- * in use already.
+ * Macro to invoke __do_softirq on the irq stack. This is only called from
+ * task context when bottom halfs are about to be reenabled and soft
+ * interrupts are pending to be processed. The interrupt stack cannot be in
+ * use here.
*/
-#define run_softirq_on_irqstack_cond() \
+#define run_softirq_on_irqstack() \
{ \
- if (__this_cpu_read(hardirq_stack_inuse)) { \
- __do_softirq(); \
- } else { \
- __this_cpu_write(hardirq_stack_inuse, true); \
- call_on_irqstack(__do_softirq, ASM_CALL_SOFTIRQ); \
- __this_cpu_write(hardirq_stack_inuse, false); \
- } \
+ __this_cpu_write(hardirq_stack_inuse, true); \
+ call_on_irqstack(__do_softirq, ASM_CALL_SOFTIRQ); \
+ __this_cpu_write(hardirq_stack_inuse, false); \
}
#else /* CONFIG_X86_64 */
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -76,5 +76,5 @@ int irq_init_percpu_irqstack(unsigned in
void do_softirq_own_stack(void)
{
- run_softirq_on_irqstack_cond();
+ run_softirq_on_irqstack();
}
next prev parent reply other threads:[~2021-02-10 2:09 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 23:40 [patch V2 00/13] x86/irq/64: Inline irq stack switching Thomas Gleixner
2021-02-09 23:40 ` [patch V2 01/13] x86/entry: Fix instrumentation annotation Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 02/13] x86/irq: Sanitize irq stack tracking Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 03/13] x86/irq/64: Adjust the per CPU irq stack pointer by 8 Thomas Gleixner
2021-02-10 11:41 ` David Laight
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 04/13] x86/apic: Split out spurious handling code Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 05/13] x86/irq: Provide macro for inlining irq stack switching Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 06/13] x86/entry: Convert system vectors to irq stack macro Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 07/13] x86/entry: Convert device interrupts to inline stack switching Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 08/13] x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 09/13] x86/softirq: Remove indirection in do_softirq_own_stack() Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` Thomas Gleixner [this message]
2021-02-11 0:50 ` [tip: x86/entry] x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 11/13] softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig Thomas Gleixner
2021-02-10 7:03 ` Kees Cook
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 12/13] softirq: Move do_softirq_own_stack() to generic asm header Thomas Gleixner
2021-02-10 7:04 ` Kees Cook
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-09 23:40 ` [patch V2 13/13] x86/softirq/64: Inline do_softirq_own_stack() Thomas Gleixner
2021-02-11 0:50 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2021-02-15 16:39 ` [patch V2 13/13] " Guenter Roeck
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