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Adding support for overlapping ranges to RangeMap.

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When enabled, adding of a new range that overlaps with an existing one can be a successful operation.  The range which ends at the higher address will be shrunk down by moving its start position to a higher address so that it does not overlap anymore.

This change is required to fix http://crbug/611824.  The actual fix will come in a separate CL.

R=mmandlis@chromium.org

Review URL: https://codereview.chromium.org/2029953003 .
This commit is contained in:
Ivan Penkov 2016-06-05 22:41:10 -07:00
parent 8b7b28663f
commit 240ed57ee1
12 changed files with 598 additions and 89 deletions
Download patch file Download diff file Expand all files Collapse all files

123
src/processor/range_map-inl.h
View file

@ -40,16 +40,29 @@
#include <assert.h>
#include "processor/range_map.h"
#include "processor/linked_ptr.h"
#include "processor/logging.h"
namespace google_breakpad {
template<typename AddressType, typename EntryType>
void RangeMap<AddressType, EntryType>::SetEnableShrinkDown(
bool enable_shrink_down) {
enable_shrink_down_ = enable_shrink_down;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::StoreRange(const AddressType &base,
const AddressType &size,
const EntryType &entry) {
return StoreRangeInternal(base, 0 /* delta */, size, entry);
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::StoreRangeInternal(
const AddressType &base, const AddressType &delta,
const AddressType &size, const EntryType &entry) {
AddressType high = base + (size - 1);
// Check for undersize or overflow.
@ -57,9 +70,10 @@ bool RangeMap<AddressType, EntryType>::StoreRange(const AddressType &base,
// The processor will hit this case too frequently with common symbol
// files in the size == 0 case, which is more suited to a DEBUG channel.
// Filter those out since there's no DEBUG channel at the moment.
BPLOG_IF(INFO, size != 0) << "StoreRange failed, " << HexString(base) <<
"+" << HexString(size) << ", " <<
HexString(high);
BPLOG_IF(INFO, size != 0) << "StoreRangeInternal failed, "
<< HexString(base) << "+" << HexString(size)
<< ", " << HexString(high)
<< ", delta: " << HexString(delta);
return false;
}
@ -71,53 +85,80 @@ bool RangeMap<AddressType, EntryType>::StoreRange(const AddressType &base,
if (iterator_base != iterator_high) {
// Some other range begins in the space used by this range. It may be
// contained within the space used by this range, or it may extend lower.
// Regardless, it is an error.
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists now
// simply comment out this logging.
//
// AddressType other_base = iterator_base->second.base();
// AddressType other_size = iterator_base->first - other_base + 1;
// BPLOG(INFO) << "StoreRange failed, an existing range is contained by or "
// "extends lower than the new range: new " <<
// HexString(base) << "+" << HexString(size) <<
// ", existing " << HexString(other_base) << "+" <<
// HexString(other_size);
return false;
// If enable_shrink_down_ is true, shrink the current range down, otherwise
// this is an error.
if (enable_shrink_down_) {
AddressType additional_delta = iterator_base->first - base + 1;
return StoreRangeInternal(base + additional_delta,
delta + additional_delta,
size - additional_delta, entry);
} else {
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists
// now simply comment out this logging.
// AddressType other_base = iterator_base->second.base();
// AddressType other_size = iterator_base->first - other_base + 1;
// BPLOG(INFO) << "StoreRangeInternal failed, an existing range is "
// << "overlapping with the new range: new "
// << HexString(base) << "+" << HexString(size)
// << ", existing " << HexString(other_base) << "+"
// << HexString(other_size);
return false;
}
}
if (iterator_high != map_.end()) {
if (iterator_high->second.base() <= high) {
// The range above this one overlaps with this one. It may fully
// contain this range, or it may begin within this range and extend
// higher. Regardless, it's an error.
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists now
// simply comment out this logging.
//
// AddressType other_base = iterator_high->second.base();
// AddressType other_size = iterator_high->first - other_base + 1;
// BPLOG(INFO) << "StoreRange failed, an existing range contains or "
// "extends higher than the new range: new " <<
// HexString(base) << "+" << HexString(size) <<
// ", existing " << HexString(other_base) << "+" <<
// HexString(other_size);
return false;
// higher. If enable_shrink_down_ is true, shrink the other range down,
// otherwise this is an error.
if (enable_shrink_down_ && iterator_high->first > high) {
// Shrink the other range down.
AddressType other_high = iterator_high->first;
AddressType additional_delta =
high - iterator_high->second.base() + 1;
EntryType other_entry;
AddressType other_base = AddressType();
AddressType other_size = AddressType();
AddressType other_delta = AddressType();
RetrieveRange(other_high, &other_entry, &other_base, &other_delta,
&other_size);
map_.erase(iterator_high);
map_.insert(MapValue(other_high,
Range(other_base + additional_delta,
other_delta + additional_delta,
other_entry)));
// Retry to store this range.
return StoreRangeInternal(base, delta, size, entry);
} else {
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists
// now simply comment out this logging.
//
// AddressType other_base = iterator_high->second.base();
// AddressType other_size = iterator_high->first - other_base + 1;
// BPLOG(INFO) << "StoreRangeInternal failed, an existing range "
// << "contains or extends higher than the new range: new "
// << HexString(base) << "+" << HexString(size)
// << ", existing " << HexString(other_base) << "+"
// << HexString(other_size);
return false;
}
}
}
// Store the range in the map by its high address, so that lower_bound can
// be used to quickly locate a range by address.
map_.insert(MapValue(high, Range(base, entry)));
map_.insert(MapValue(high, Range(base, delta, entry)));
return true;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveRange(
const AddressType &address, EntryType *entry,
AddressType *entry_base, AddressType *entry_size) const {
const AddressType &address, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveRange requires |entry|";
assert(entry);
@ -136,6 +177,8 @@ bool RangeMap<AddressType, EntryType>::RetrieveRange(
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;
@ -145,13 +188,13 @@ bool RangeMap<AddressType, EntryType>::RetrieveRange(
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveNearestRange(
const AddressType &address, EntryType *entry,
AddressType *entry_base, AddressType *entry_size) const {
const AddressType &address, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveNearestRange requires |entry|";
assert(entry);
// If address is within a range, RetrieveRange can handle it.
if (RetrieveRange(address, entry, entry_base, entry_size))
if (RetrieveRange(address, entry, entry_base, entry_delta, entry_size))
return true;
// upper_bound gives the first element whose key is greater than address,
@ -167,6 +210,8 @@ bool RangeMap<AddressType, EntryType>::RetrieveNearestRange(
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;
@ -176,8 +221,8 @@ bool RangeMap<AddressType, EntryType>::RetrieveNearestRange(
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveRangeAtIndex(
int index, EntryType *entry,
AddressType *entry_base, AddressType *entry_size) const {
int index, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveRangeAtIndex requires |entry|";
assert(entry);
@ -195,6 +240,8 @@ bool RangeMap<AddressType, EntryType>::RetrieveRangeAtIndex(
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;