[PATCHv2 1/5] arm64/entry-common: push the judgement of nmi ahead
From: Pingfan Liu <hidden>
Date: 2021-09-24 13:33:08
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
In enter_el1_irq_or_nmi(), it can be the case which NMI interrupts an irq, which makes the condition !interrupts_enabled(regs) fail to detect the NMI. This will cause a mistaken account for irq. Introducing two interfaces: handle_arch_nmi and interrupt_is_nmi to judge NMI at this stage. Signed-off-by: Pingfan Liu <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Julien Thierry <redacted> Cc: Thomas Gleixner <redacted> Cc: Yuichi Ito <redacted> Cc: linux-kernel@vger.kernel.org To: linux-arm-kernel@lists.infradead.org --- arch/arm64/include/asm/irq.h | 5 ++++ arch/arm64/kernel/entry-common.c | 45 ++++++++++++++++++++++---------- arch/arm64/kernel/irq.c | 29 ++++++++++++++++++++ 3 files changed, 65 insertions(+), 14 deletions(-)
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index fac08e18bcd5..a59b1745f458 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h@@ -12,6 +12,11 @@ int set_handle_irq(void (*handle_irq)(struct pt_regs *)); #define set_handle_irq set_handle_irq int set_handle_fiq(void (*handle_fiq)(struct pt_regs *)); +extern void (*handle_arch_irq)(struct pt_regs *regs); +extern void (*handle_arch_fiq)(struct pt_regs *regs); +extern void (*handle_arch_nmi)(struct pt_regs *regs); +extern bool (*interrupt_is_nmi)(void); + static inline int nr_legacy_irqs(void) { return 0;
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 32f9796c4ffe..69a8cc082712 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c@@ -24,6 +24,7 @@ #include <asm/stacktrace.h> #include <asm/sysreg.h> #include <asm/system_misc.h> +#include <asm/irq.h> /* * Handle IRQ/context state management when entering from kernel mode.
@@ -219,17 +220,28 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs) lockdep_hardirqs_on(CALLER_ADDR0); } -static void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) +static inline bool arm64_in_nmi(struct pt_regs *regs) { - if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) + if (!interrupts_enabled(regs) || (*interrupt_is_nmi)()) + return true; + return false; +} + +/* return true if in irq, otherwise in nmi */ +static bool noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) +{ + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && arm64_in_nmi(regs)) { arm64_enter_nmi(regs); - else + return false; + } else { enter_from_kernel_mode(regs); + return true; + } } -static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) +static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs, bool in_irq) { - if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !in_irq) arm64_exit_nmi(regs); else exit_to_kernel_mode(regs);
@@ -269,9 +281,6 @@ static void do_interrupt_handler(struct pt_regs *regs, handler(regs); } -extern void (*handle_arch_irq)(struct pt_regs *); -extern void (*handle_arch_fiq)(struct pt_regs *); - static void noinstr __panic_unhandled(struct pt_regs *regs, const char *vector, unsigned int esr) {
@@ -433,12 +442,20 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) } static void noinstr el1_interrupt(struct pt_regs *regs, - void (*handler)(struct pt_regs *)) + void (*handler)(struct pt_regs *), + void (*nmi_handler)(struct pt_regs *)) { + bool in_irq; + void (*h)(struct pt_regs *regs); + write_sysreg(DAIF_PROCCTX_NOIRQ, daif); - enter_el1_irq_or_nmi(regs); - do_interrupt_handler(regs, handler); + in_irq = enter_el1_irq_or_nmi(regs); + if (in_irq) + h = handler; + else + h = nmi_handler; + do_interrupt_handler(regs, h); /* * Note: thread_info::preempt_count includes both thread_info::count
@@ -449,17 +466,17 @@ static void noinstr el1_interrupt(struct pt_regs *regs, READ_ONCE(current_thread_info()->preempt_count) == 0) arm64_preempt_schedule_irq(); - exit_el1_irq_or_nmi(regs); + exit_el1_irq_or_nmi(regs, in_irq); } asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) { - el1_interrupt(regs, handle_arch_irq); + el1_interrupt(regs, handle_arch_irq, handle_arch_nmi); } asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) { - el1_interrupt(regs, handle_arch_fiq); + el1_interrupt(regs, handle_arch_fiq, handle_arch_nmi); } asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs)
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index bda49430c9ea..e67435eb4cba 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c@@ -81,8 +81,19 @@ static void default_handle_fiq(struct pt_regs *regs) panic("FIQ taken without a root FIQ handler\n"); } +static void default_handle_nmi(struct pt_regs *unused) +{ +} + +static bool default_nmi_discriminator(void) +{ + return false; +} + void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq; void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq; +void (*handle_arch_nmi)(struct pt_regs *) __ro_after_init = default_handle_nmi; +bool (*interrupt_is_nmi)(void) __ro_after_init = default_nmi_discriminator; int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) {
@@ -104,6 +115,24 @@ int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *)) return 0; } +int __init set_handle_nmi(void (*handle_nmi)(struct pt_regs *)) +{ + if (handle_arch_nmi != default_handle_nmi) + return -EBUSY; + + handle_arch_nmi = handle_nmi; + return 0; +} + +int __init set_nmi_discriminator(bool (*discriminator)(void)) +{ + if (interrupt_is_nmi != default_nmi_discriminator) + return -EBUSY; + + interrupt_is_nmi = discriminator; + return 0; +} + void __init init_IRQ(void) { init_irq_stacks();
--
2.31.1
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