From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
Kees Cook <keescook@chromium.org>
Subject: [patch 09/12] x86/softirq: Remove indirection in do_softirq_own_stack()
Date: Thu, 04 Feb 2021 21:49:12 +0100 [thread overview]
Message-ID: <20210204211155.006560617@linutronix.de> (raw)
In-Reply-To: 20210204204903.350275743@linutronix.de
Use the new inline stack switching and remove the old ASM indirect call
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/entry_64.S | 39 -----------------------------
arch/x86/include/asm/irq_stack.h | 52 ++++++++++++---------------------------
arch/x86/kernel/irq_64.c | 2 -
3 files changed, 17 insertions(+), 76 deletions(-)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -756,45 +756,6 @@ SYM_CODE_START_LOCAL_NOALIGN(.Lbad_gs)
SYM_CODE_END(.Lbad_gs)
.previous
-/*
- * rdi: New stack pointer points to the top word of the stack
- * rsi: Function pointer
- * rdx: Function argument (can be NULL if none)
- */
-SYM_FUNC_START(asm_call_on_stack)
- /*
- * Save the frame pointer unconditionally. This allows the ORC
- * unwinder to handle the stack switch.
- */
- pushq %rbp
- mov %rsp, %rbp
-
- /*
- * The unwinder relies on the word at the top of the new stack
- * page linking back to the previous RSP.
- */
- mov %rsp, (%rdi)
- mov %rdi, %rsp
- /* Move the argument to the right place */
- mov %rdx, %rdi
-
-1:
- .pushsection .discard.instr_begin
- .long 1b - .
- .popsection
-
- CALL_NOSPEC rsi
-
-2:
- .pushsection .discard.instr_end
- .long 2b - .
- .popsection
-
- /* Restore the previous stack pointer from RBP. */
- leaveq
- ret
-SYM_FUNC_END(asm_call_on_stack)
-
#ifdef CONFIG_XEN_PV
/*
* A note on the "critical region" in our callback handler.
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -191,20 +191,23 @@
IRQ_CONSTRAINTS, regs, vector); \
}
-static __always_inline bool irqstack_active(void)
-{
- return __this_cpu_read(hardirq_stack_inuse);
-}
-
-void asm_call_on_stack(void *sp, void (*func)(void), void *arg);
+#define ASM_CALL_SOFTIRQ \
+ "call %P[__func] \n"
-static __always_inline void __run_on_irqstack(void (*func)(void))
-{
- void *tos = __this_cpu_read(hardirq_stack_ptr);
-
- __this_cpu_write(hardirq_stack_inuse, true);
- asm_call_on_stack(tos, func, NULL);
- __this_cpu_write(hardirq_stack_inuse, false);
+/*
+ * 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.
+ */
+#define run_softirq_on_irqstack_cond() \
+{ \
+ 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); \
+ } \
}
#else /* CONFIG_X86_64 */
@@ -225,29 +228,6 @@ static __always_inline void __run_on_irq
irq_exit_rcu(); \
}
-static inline bool irqstack_active(void) { return false; }
-static inline void __run_on_irqstack(void (*func)(void)) { }
#endif /* !CONFIG_X86_64 */
-static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
-{
- if (IS_ENABLED(CONFIG_X86_32))
- return false;
- if (!regs)
- return !irqstack_active();
- return !user_mode(regs) && !irqstack_active();
-}
-
-
-static __always_inline void run_on_irqstack_cond(void (*func)(void),
- struct pt_regs *regs)
-{
- lockdep_assert_irqs_disabled();
-
- if (irq_needs_irq_stack(regs))
- __run_on_irqstack(func);
- else
- func();
-}
-
#endif
--- 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_on_irqstack_cond(__do_softirq, NULL);
+ run_softirq_on_irqstack_cond();
}
next prev parent reply other threads:[~2021-02-05 1:00 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-04 20:49 [patch 00/12] x86/irq/64: Inline irq stack switching Thomas Gleixner
2021-02-04 20:49 ` [patch 01/12] x86/entry: Fix instrumentation annotation Thomas Gleixner
2021-02-05 12:02 ` Borislav Petkov
2021-02-04 20:49 ` [patch 02/12] x86/irq: Sanitize irq stack tracking Thomas Gleixner
2021-02-04 20:49 ` [patch 03/12] x86/irq/64: Adjust the per CPU irq stack pointer by 8 Thomas Gleixner
2021-02-05 13:53 ` Peter Zijlstra
2021-02-05 15:00 ` Thomas Gleixner
2021-02-04 20:49 ` [patch 04/12] x86/apic: Split out spurious handling code Thomas Gleixner
2021-02-04 20:49 ` [patch 05/12] x86/irq: Provide macro for inlining irq stack switching Thomas Gleixner
2021-02-08 15:06 ` Borislav Petkov
2021-02-08 20:42 ` Josh Poimboeuf
2021-02-09 15:12 ` Thomas Gleixner
2021-02-09 16:22 ` Josh Poimboeuf
2021-02-09 18:14 ` Thomas Gleixner
2021-02-04 20:49 ` [patch 06/12] x86/entry: Convert system vectors to irq stack macro Thomas Gleixner
2021-02-05 3:52 ` kernel test robot
2021-02-05 14:13 ` Peter Zijlstra
2021-02-07 8:15 ` [kbuild-all] " Rong Chen
2021-02-08 14:19 ` Borislav Petkov
2021-02-09 8:57 ` Rong Chen
2021-02-09 10:46 ` Borislav Petkov
2021-02-04 20:49 ` [patch 07/12] x86/entry: Convert device interrupts to inline stack switching Thomas Gleixner
2021-02-04 20:49 ` [patch 08/12] x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall Thomas Gleixner
2021-02-05 7:28 ` kernel test robot
2021-02-04 20:49 ` Thomas Gleixner [this message]
2021-02-04 20:49 ` [patch 10/12] x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK Thomas Gleixner
2021-02-04 20:49 ` [patch 11/12] softirq: Allow inlining do_softirq_own_stack() Thomas Gleixner
2021-02-05 10:14 ` Lai Jiangshan
2021-02-05 11:38 ` Thomas Gleixner
2021-02-09 20:43 ` Thomas Gleixner
2021-02-04 20:49 ` [patch 12/12] x86/softirq/64: Inline do_softirq_own_stack() Thomas Gleixner
2021-02-08 21:47 ` [patch 00/12] x86/irq/64: Inline irq stack switching Kees Cook
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