lkml.org 
[lkml]   [2020]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[GIT pull] x86/urgent for for
Linus,

please pull the latest x86/urgent branch from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2020-09-27

up to: 86a82ae0b509: x86/ioapic: Unbreak check_timer()


Two fixes for the x86 interrupt code:

- Unbreak the magic 'search the timer interrupt' logic in IO/APIC code
which got wreckaged when the core interrupt code made the state
tracking logic stricter. That caused the interrupt line to stay masked
after switching from IO/APIC to PIC delivery mode, which obviously
prevents interrupts from being delivered.

- Make run_on_irqstack_code() typesafe. The function argument is a void
pointer which is then casted to 'void (*fun)(void *). This breaks
Control Flow Integrity checking in clang. Use proper helper functions
for the three variants reuqired.

Thanks,

tglx

------------------>
Thomas Gleixner (2):
x86/irq: Make run_on_irqstack_cond() typesafe
x86/ioapic: Unbreak check_timer()


arch/x86/entry/common.c | 2 +-
arch/x86/entry/entry_64.S | 2 ++
arch/x86/include/asm/idtentry.h | 2 +-
arch/x86/include/asm/irq_stack.h | 69 +++++++++++++++++++++++++++++++++++-----
arch/x86/kernel/apic/io_apic.c | 1 +
arch/x86/kernel/irq.c | 2 +-
arch/x86/kernel/irq_64.c | 2 +-
7 files changed, 68 insertions(+), 12 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 2f84c7ca74ea..870efeec8bda 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -299,7 +299,7 @@ __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
old_regs = set_irq_regs(regs);

instrumentation_begin();
- run_on_irqstack_cond(__xen_pv_evtchn_do_upcall, NULL, regs);
+ run_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs);
instrumentation_begin();

set_irq_regs(old_regs);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 70dea9337816..d977079a7d02 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -682,6 +682,8 @@ SYM_CODE_END(.Lbad_gs)
* rdx: Function argument (can be NULL if none)
*/
SYM_FUNC_START(asm_call_on_stack)
+SYM_INNER_LABEL(asm_call_sysvec_on_stack, SYM_L_GLOBAL)
+SYM_INNER_LABEL(asm_call_irq_on_stack, SYM_L_GLOBAL)
/*
* Save the frame pointer unconditionally. This allows the ORC
* unwinder to handle the stack switch.
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index a43366191212..a0638640f1ed 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -242,7 +242,7 @@ __visible noinstr void func(struct pt_regs *regs) \
instrumentation_begin(); \
irq_enter_rcu(); \
kvm_set_cpu_l1tf_flush_l1d(); \
- run_on_irqstack_cond(__##func, regs, regs); \
+ run_sysvec_on_irqstack_cond(__##func, regs); \
irq_exit_rcu(); \
instrumentation_end(); \
irqentry_exit(regs, state); \
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h
index 4ae66f097101..775816965c6a 100644
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -12,20 +12,50 @@ static __always_inline bool irqstack_active(void)
return __this_cpu_read(irq_count) != -1;
}

-void asm_call_on_stack(void *sp, void *func, void *arg);
+void asm_call_on_stack(void *sp, void (*func)(void), void *arg);
+void asm_call_sysvec_on_stack(void *sp, void (*func)(struct pt_regs *regs),
+ struct pt_regs *regs);
+void asm_call_irq_on_stack(void *sp, void (*func)(struct irq_desc *desc),
+ struct irq_desc *desc);

-static __always_inline void __run_on_irqstack(void *func, void *arg)
+static __always_inline void __run_on_irqstack(void (*func)(void))
{
void *tos = __this_cpu_read(hardirq_stack_ptr);

__this_cpu_add(irq_count, 1);
- asm_call_on_stack(tos - 8, func, arg);
+ asm_call_on_stack(tos - 8, func, NULL);
+ __this_cpu_sub(irq_count, 1);
+}
+
+static __always_inline void
+__run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
+ struct pt_regs *regs)
+{
+ void *tos = __this_cpu_read(hardirq_stack_ptr);
+
+ __this_cpu_add(irq_count, 1);
+ asm_call_sysvec_on_stack(tos - 8, func, regs);
+ __this_cpu_sub(irq_count, 1);
+}
+
+static __always_inline void
+__run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
+ struct irq_desc *desc)
+{
+ void *tos = __this_cpu_read(hardirq_stack_ptr);
+
+ __this_cpu_add(irq_count, 1);
+ asm_call_irq_on_stack(tos - 8, func, desc);
__this_cpu_sub(irq_count, 1);
}

#else /* CONFIG_X86_64 */
static inline bool irqstack_active(void) { return false; }
-static inline void __run_on_irqstack(void *func, void *arg) { }
+static inline void __run_on_irqstack(void (*func)(void)) { }
+static inline void __run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
+ struct pt_regs *regs) { }
+static inline void __run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
+ struct irq_desc *desc) { }
#endif /* !CONFIG_X86_64 */

static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
@@ -37,17 +67,40 @@ static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
return !user_mode(regs) && !irqstack_active();
}

-static __always_inline void run_on_irqstack_cond(void *func, void *arg,
+
+static __always_inline void run_on_irqstack_cond(void (*func)(void),
struct pt_regs *regs)
{
- void (*__func)(void *arg) = func;
+ lockdep_assert_irqs_disabled();
+
+ if (irq_needs_irq_stack(regs))
+ __run_on_irqstack(func);
+ else
+ func();
+}
+
+static __always_inline void
+run_sysvec_on_irqstack_cond(void (*func)(struct pt_regs *regs),
+ struct pt_regs *regs)
+{
+ lockdep_assert_irqs_disabled();

+ if (irq_needs_irq_stack(regs))
+ __run_sysvec_on_irqstack(func, regs);
+ else
+ func(regs);
+}
+
+static __always_inline void
+run_irq_on_irqstack_cond(void (*func)(struct irq_desc *desc), struct irq_desc *desc,
+ struct pt_regs *regs)
+{
lockdep_assert_irqs_disabled();

if (irq_needs_irq_stack(regs))
- __run_on_irqstack(__func, arg);
+ __run_irq_on_irqstack(func, desc);
else
- __func(arg);
+ func(desc);
}

#endif
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 779a89e31c4c..21f9c7f11779 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2243,6 +2243,7 @@ static inline void __init check_timer(void)
legacy_pic->init(0);
legacy_pic->make_irq(0);
apic_write(APIC_LVT0, APIC_DM_EXTINT);
+ legacy_pic->unmask(0);

unlock_ExtINT_logic();

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 181060247e3c..c5dd50369e2f 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -227,7 +227,7 @@ static __always_inline void handle_irq(struct irq_desc *desc,
struct pt_regs *regs)
{
if (IS_ENABLED(CONFIG_X86_64))
- run_on_irqstack_cond(desc->handle_irq, desc, regs);
+ run_irq_on_irqstack_cond(desc->handle_irq, desc, regs);
else
__handle_irq(desc, regs);
}
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 1b4fe93a86c5..440eed558558 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -74,5 +74,5 @@ int irq_init_percpu_irqstack(unsigned int cpu)

void do_softirq_own_stack(void)
{
- run_on_irqstack_cond(__do_softirq, NULL, NULL);
+ run_on_irqstack_cond(__do_softirq, NULL);
}
\
 
 \ /
  Last update: 2020-09-27 17:08    [W:0.077 / U:2.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site