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Differential D52567 Diff 162149 sys/vm/vm_fault.c

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sys/vm/vm_fault.c

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/* compat definition to keep common code for signal translation */ /* compat definition to keep common code for signal translation */
#define UCODE_PAGEFLT 12 #define UCODE_PAGEFLT 12
#ifdef T_PAGEFLT #ifdef T_PAGEFLT
_Static_assert(UCODE_PAGEFLT == T_PAGEFLT, "T_PAGEFLT"); _Static_assert(UCODE_PAGEFLT == T_PAGEFLT, "T_PAGEFLT");
#endif #endif
/* /*
* vm_fault_trap: * vm_fault_trap:
* *
* Handle a page fault occurring at the given address, * Helper for the page fault trap handlers, wrapping vm_fault().
alcUnsubmitted
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* vm_fault_trap:
*
- * Helper for the page fault trap handlers, wrapping vm_fault().
+ * Helper for the machine-dependent page fault trap handlers, wrapping vm_fault().
* Issues ktrace(2) tracepoints for the faults.
alc:
* requiring the given permissions, in the map specified. * Issues ktrace(2) tracepoints for the faults.
markjUnsubmitted
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* Helper for the page fault trap handlers, wrapping vm_fault().
- * Issues ktrace points for the faults.
+ * Issues ktrace tracepoints for the faults.
*
* If fault cannot be handled successfully by satisfying the required
markj:
* If successful, the page is inserted into the
* associated physical map.
* *
* NOTE: the given address should be truncated to the * If a fault cannot be handled successfully by satisfying the
alcUnsubmitted
Done
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* Issues ktrace(2) tracepoints for the faults.
*
- * If a fault cannot be handled successfully by satisfying the
+ * If the fault cannot be handled successfully by updating the
* required mapping, and the faulted instruction cannot be restarted,
alc:
* proper page address. * required mapping, and the faulted instruction cannot be restarted,
* the signal number and si_code values are returned for trapsignal()
* to deliver.
markjUnsubmitted
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* Issues ktrace points for the faults.
*
- * If fault cannot be handled successfully by satisfying the required
+ * If the fault cannot be handled successfully by satisfying the required
* mapping, and the faulted instruction cannot be restarted, the

or "a fault"

markj: or "a fault"
* *
* KERN_SUCCESS is returned if the page fault is handled; otherwise, * Returns Mach error codes, but callers should only check for
* a standard error specifying why the fault is fatal is returned. * KERN_SUCCESS.
*
* The map in question must be referenced, and remains so.
* Caller may hold no locks.
*/ */
int int
vm_fault_trap(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type, vm_fault_trap(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, int *signo, int *ucode) int fault_flags, int *signo, int *ucode)
{ {
int result; int result;
MPASS(signo == NULL || ucode != NULL); MPASS(signo == NULL || ucode != NULL);
▲ Show 20 Lines • Show All 887 Lines • ▼ Show 20 Lines if (vm_fault_object_needs_getpages(fs->object)) {
if (res == FAULT_CONTINUE) if (res == FAULT_CONTINUE)
VM_OBJECT_WLOCK(fs->object); VM_OBJECT_WLOCK(fs->object);
} else { } else {
res = FAULT_CONTINUE; res = FAULT_CONTINUE;
} }
return (res); return (res);
} }
/*
* vm_fault:
*
* Handle a page fault occurring at the given address, requiring the
* given permissions, in the map specified. If successful, the page
* is inserted into the associated physical map, and optionally
* referenced and returned in *m_hold.
*
* The given address should be truncated to the proper page address.
*
* KERN_SUCCESS is returned if the page fault is handled; otherwise, a
* Mach error specifying why the fault is fatal is returned.
alcUnsubmitted
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* KERN_SUCCESS is returned if the page fault is handled; otherwise, a
- * Mach error specifying why the fault is fatal is returned.
+ * Mach error code explaining why the fault is fatal is returned.
*
* The map in question must be alive, either being the map for current
alc:
*
* The map in question must be alive, either being the map for current
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* Mach error specifying why the fault is fatal is returned.
*
- * The map in question must be alive, either being the map for current
+ * The map in question must be alive, either being the map for the current
* process, or the owner process hold count incremented to prevent
alc:
* process, or the owner process hold count incremented to prevent
markjUnsubmitted
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It's not quite true that the caller may hold no locks, e.g., in the TDP_NOFAULTING case the caller may legitimately hold them.

markj: It's not quite true that the caller may hold no locks, e.g., in the TDP_NOFAULTING case the…
alcUnsubmitted
Done
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* The map in question must be alive, either being the map for current
- * process, or the owner process hold count incremented to prevent
+ * process, or the owner process hold count has been incremented to prevent
* exit().
alc:
* exit().
*
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* exit().
*
- * If the thread private TDP_NOFAULTING flag is set, any fault result
+ * If the thread private TDP_NOFAULTING flag is set, any fault results
* in immediate protection failure. Otherwise the fault is processed,
markj:
* If the thread private TDP_NOFAULTING flag is set, any fault results
* in immediate protection failure. Otherwise the fault is processed,
* and caller may hold no locks.
*/
int int
vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type, vm_fault(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
int fault_flags, vm_page_t *m_hold) int fault_flags, vm_page_t *m_hold)
{ {
struct pctrie_iter pages; struct pctrie_iter pages;
struct faultstate fs; struct faultstate fs;
int ahead, behind, faultcount, rv; int ahead, behind, faultcount, rv;
enum fault_status res; enum fault_status res;
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