projects / xen.git / commitdiff
? search:
summary | shortlog | log | commit | commitdiff | tree
raw | patch | inline | side by side (parent: ed80a0a)
Fix local_irq_save() and irqs_disabled() to be preemption-safe.
authorkaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Sun, 16 Oct 2005 10:45:51 +0000 (11:45 +0100)
committerkaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Sun, 16 Oct 2005 10:45:51 +0000 (11:45 +0100)
Signed-off-by: Keir Fraser <keir@xensource.com>
linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h patch | blob | history
linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h patch | blob | history

diff --git a/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h b/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
index f930c4cec6bd45e123bb6adc14eab0cd45253c98..592f20023ed391c4c008a5926970cf1c0d290092 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/asm-i386/system.h
@@ -497,22 +497,11 @@ __asm__ __volatile__("6667:movl %1, %0\n6668:\n"                    \
  * includes these barriers, for example.
  */
 
-/*
- * Don't use smp_processor_id() in preemptible code: debug builds will barf.
- * It's okay in these cases as we only read the upcall mask in preemptible
- * regions, which is always safe.
- */
-#ifdef CONFIG_SMP
-#define __this_cpu()   __smp_processor_id()
-#else
-#define __this_cpu()   0
-#endif
-
 #define __cli()                                                                \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
        barrier();                                                      \
@@ -523,7 +512,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        _vcpu->evtchn_upcall_mask = 0;                                  \
        barrier(); /* unmask then check (avoid races) */                \
        if ( unlikely(_vcpu->evtchn_upcall_pending) )                   \
@@ -534,8 +523,10 @@ do {                                                                       \
 #define __save_flags(x)                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        (x) = _vcpu->evtchn_upcall_mask;                                \
+       preempt_enable();                                               \
 } while (0)
 
 #define __restore_flags(x)                                             \
@@ -543,7 +534,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        if ((_vcpu->evtchn_upcall_mask = (x)) == 0) {                   \
                barrier(); /* unmask then check (avoid races) */        \
                if ( unlikely(_vcpu->evtchn_upcall_pending) )           \
@@ -559,7 +550,7 @@ do {                                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        (x) = _vcpu->evtchn_upcall_mask;                                \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
@@ -572,8 +563,15 @@ do {                                                                       \
 #define local_irq_disable()    __cli()
 #define local_irq_enable()     __sti()
 
+/* Cannot use preempt_enable() here as we would recurse in preempt_sched(). */
 #define irqs_disabled()                                                        \
-       HYPERVISOR_shared_info->vcpu_data[__this_cpu()].evtchn_upcall_mask
+({     int ___x;                                                       \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       ___x = (_vcpu->evtchn_upcall_mask != 0);                        \
+       preempt_enable_no_resched();                                    \
+       ___x; })
 
 /*
  * disable hlt during certain critical i/o operations
diff --git a/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h b/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
index cf3badc58c28c2b63408d46975932a19a0f5eba8..bbecfc56ed12cf5d364f575255a8c9bdcc69d8e4 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/asm-x86_64/system.h
@@ -321,22 +321,11 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
  * includes these barriers, for example.
  */
 
-/*
- * Don't use smp_processor_id() in preemptible code: debug builds will barf.
- * It's okay in these cases as we only read the upcall mask in preemptible
- * regions, which is always safe.
- */
-#ifdef CONFIG_SMP
-#define __this_cpu()   __smp_processor_id()
-#else
-#define __this_cpu()   0
-#endif
-
 #define __cli()                                                                \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
        barrier();                                                      \
@@ -347,7 +336,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        _vcpu->evtchn_upcall_mask = 0;                                  \
        barrier(); /* unmask then check (avoid races) */                \
        if ( unlikely(_vcpu->evtchn_upcall_pending) )                   \
@@ -358,8 +347,10 @@ do {                                                                       \
 #define __save_flags(x)                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        (x) = _vcpu->evtchn_upcall_mask;                                \
+       preempt_enable();                                               \
 } while (0)
 
 #define __restore_flags(x)                                             \
@@ -367,7 +358,7 @@ do {                                                                        \
        vcpu_info_t *_vcpu;                                             \
        barrier();                                                      \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        if ((_vcpu->evtchn_upcall_mask = (x)) == 0) {                   \
                barrier(); /* unmask then check (avoid races) */        \
                if ( unlikely(_vcpu->evtchn_upcall_pending) )           \
@@ -383,7 +374,7 @@ do {                                                                        \
 do {                                                                   \
        vcpu_info_t *_vcpu;                                             \
        preempt_disable();                                              \
-       _vcpu = &HYPERVISOR_shared_info->vcpu_data[__this_cpu()];       \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
        (x) = _vcpu->evtchn_upcall_mask;                                \
        _vcpu->evtchn_upcall_mask = 1;                                  \
        preempt_enable_no_resched();                                    \
@@ -398,8 +389,15 @@ void cpu_idle_wait(void);
 #define local_irq_disable()    __cli()
 #define local_irq_enable()     __sti()
 
+/* Cannot use preempt_enable() here as we would recurse in preempt_sched(). */
 #define irqs_disabled()                                                        \
-       HYPERVISOR_shared_info->vcpu_data[__this_cpu()].evtchn_upcall_mask
+({     int ___x;                                                       \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_data[smp_processor_id()]; \
+       ___x = (_vcpu->evtchn_upcall_mask != 0);                        \
+       preempt_enable_no_resched();                                    \
+       ___x; })
 
 /*
  * disable hlt during certain critical i/o operations
Unnamed repository; edit this file 'description' to name the repository.