[devel] [PATCH for apt 2/2 v2] Fix pointer arithmetics
Aleksei Nikiforov
darktemplar на altlinux.org
Пн Дек 9 09:54:27 MSK 2019
07.12.2019 17:52, Andrey Savchenko пишет:
> Hi all!
>
> On Fri, 6 Dec 2019 18:36:55 +0300 Aleksei Nikiforov wrote:
>> This change should fix pointer arithmetic issues for e2k.
>
> This commit message is misleading. Pointer arithmetic is broken on
> all architectures, but by pure chance in happens to work correctly
> when gcc is used. On e2k the lcc compiler is used, so problem
> manifests itself. But this doesn't change the fact that pointer
> arithmetic was flawed on all architectures.
>
Your first sentence contradicts later ones. You just repeated my
sentence about issue manifesting on e2k, but you did it more verbosely.
Yes, there is a flaw for all architectures, but it manifests only for
e2k in practice, thus change fixes it for e2k. So, what's misleading there?
>> ---
>> apt/apt-pkg/Makefile.am | 1 +
>> apt/apt-pkg/cacheiterators.h | 26 ++++++++++++++------------
>> apt/apt-pkg/contrib/mmap.cc | 8 +++++---
>> apt/apt-pkg/pkgcachegen.cc | 29 +++++++++++++++--------------
>> apt/apt-pkg/pkgcachegen.h | 6 +++---
>> apt/apt-pkg/rebase_pointer.h | 16 ++++++++++++++++
>> apt/apt-pkg/rpm/rpmlistparser.cc | 5 +++--
>> apt/apt-pkg/rpm/rpmpackagedata.cc | 2 +-
>> 8 files changed, 58 insertions(+), 35 deletions(-)
>> create mode 100644 apt/apt-pkg/rebase_pointer.h
>>
>> diff --git a/apt/apt-pkg/Makefile.am b/apt/apt-pkg/Makefile.am
>> index 4c0d234..d038d01 100644
>> --- a/apt/apt-pkg/Makefile.am
>> +++ b/apt/apt-pkg/Makefile.am
>> @@ -94,6 +94,7 @@ libapt_pkg_la_SOURCES = \
>> pkgsystem.h \
>> policy.cc \
>> policy.h \
>> + rebase_pointer.h \
>> repository.cc \
>> repository.h \
>> scopeexit.h \
>> diff --git a/apt/apt-pkg/cacheiterators.h b/apt/apt-pkg/cacheiterators.h
>> index a4bf670..118838e 100644
>> --- a/apt/apt-pkg/cacheiterators.h
>> +++ b/apt/apt-pkg/cacheiterators.h
>> @@ -34,6 +34,8 @@
>> #pragma interface "apt-pkg/cacheiterators.h"
>> #endif
>>
>> +#include <apt-pkg/rebase_pointer.h>
>> +
>> #include <set>
>>
>> // Package Iterator
>> @@ -85,11 +87,11 @@ class pkgCache::PkgIterator
>> inline unsigned long long Index() const {return Pkg - Owner->PkgP;};
>> OkState State() const;
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || Pkg == 0)
>> return;
>> - Pkg += static_cast<Package const *>(newMap) - static_cast<Package const *>(oldMap);
>> + Pkg = RebasePointer(Pkg, oldMap, newMap);
>> }
>>
>> // Constructors
>> @@ -147,11 +149,11 @@ class pkgCache::VerIterator
>> bool Automatic() const;
>> VerFileIterator NewestFile() const;
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || Ver == 0)
>> return;
>> - Ver += static_cast<Version const *>(newMap) - static_cast<Version const *>(oldMap);
>> + Ver = RebasePointer(Ver, oldMap, newMap);
>> }
>>
>> inline VerIterator() : Ver(0), Owner(0) {};
>> @@ -220,11 +222,11 @@ class pkgCache::DepIterator
>> inline const char *CompType() {return Owner->CompType(Dep->CompareOp);};
>> inline const char *DepType() {return Owner->DepType(Dep->Type);};
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || Dep == 0)
>> return;
>> - Dep += static_cast<Dependency const *>(newMap) - static_cast<Dependency const *>(oldMap);
>> + Dep = RebasePointer(Dep, oldMap, newMap);
>> }
>>
>> inline DepIterator(pkgCache &Owner,Dependency *Trg,Version * = 0) :
>> @@ -279,11 +281,11 @@ class pkgCache::PrvIterator
>> inline PkgIterator OwnerPkg() const {return PkgIterator(*Owner,Owner->PkgP + Owner->VerP[Prv->Version].ParentPkg);};
>> inline unsigned long long Index() const {return Prv - Owner->ProvideP;};
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || Prv == 0)
>> return;
>> - Prv += static_cast<Provides const *>(newMap) - static_cast<Provides const *>(oldMap);
>> + Prv = RebasePointer(Prv, oldMap, newMap);
>> }
>>
>> inline PrvIterator() : Prv(0), Type(PrvVer), Owner(0) {};
>> @@ -342,11 +344,11 @@ class pkgCache::PkgFileIterator
>> bool IsOk();
>> string RelStr();
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || File == 0)
>> return;
>> - File += static_cast<PackageFile const *>(newMap) - static_cast<PackageFile const *>(oldMap);
>> + File = RebasePointer(File, oldMap, newMap);
>> }
>>
>> // Constructors
>> @@ -383,11 +385,11 @@ class pkgCache::VerFileIterator
>> inline PkgFileIterator File() const {return PkgFileIterator(*Owner,FileP->File + Owner->PkgFileP);};
>> inline unsigned long long Index() const {return FileP - Owner->VerFileP;};
>>
>> - void ReMap(void const * const oldMap, void const * const newMap)
>> + void ReMap(void *oldMap, void *newMap)
>> {
>> if (Owner == 0 || FileP == 0)
>> return;
>> - FileP += static_cast<VerFile const *>(newMap) - static_cast<VerFile const *>(oldMap);
>> + FileP = RebasePointer(FileP, oldMap, newMap);
>> }
>>
>> inline VerFileIterator() : Owner(0), FileP(0) {};
>> diff --git a/apt/apt-pkg/contrib/mmap.cc b/apt/apt-pkg/contrib/mmap.cc
>> index cf01be9..35f1a25 100644
>> --- a/apt/apt-pkg/contrib/mmap.cc
>> +++ b/apt/apt-pkg/contrib/mmap.cc
>> @@ -30,6 +30,7 @@
>> #include <apt-pkg/configuration.h>
>> #include <apt-pkg/mmap.h>
>> #include <apt-pkg/error.h>
>> +#include <apt-pkg/rebase_pointer.h>
>>
>> #include <apti18n.h>
>>
>> @@ -301,7 +302,7 @@ std::experimental::optional<map_ptrloc> DynamicMMap::Allocate(unsigned long Item
>> Pool* oldPools = Pools;
>> auto idxResult = RawAllocate(I->Count*ItemSize,ItemSize);
>> if (Pools != oldPools)
>> - I += Pools - oldPools;
>> + I = RebasePointer(I, oldPools, Pools);
>>
>> // Does the allocation failed ?
>> if (!idxResult)
>> @@ -371,7 +372,7 @@ bool DynamicMMap::Grow(unsigned long long size)
>> Fd->Write(&C,sizeof(C));
>> }
>>
>> - unsigned long const poolOffset = Pools - ((Pool*) Base);
>> + void *old_base = Base;
>>
>> if (Fd != 0)
>> {
>> @@ -408,7 +409,8 @@ bool DynamicMMap::Grow(unsigned long long size)
>> memset((char*)Base + WorkSpace, 0, newSize - WorkSpace);
>> }
>>
>> - Pools = (Pool*) Base + poolOffset;
>> + if (Base != old_base)
>> + Pools = RebasePointer(Pools, old_base, Base);
>> WorkSpace = newSize;
>>
>> return true;
>> diff --git a/apt/apt-pkg/pkgcachegen.cc b/apt/apt-pkg/pkgcachegen.cc
>> index 654c81c..37364e9 100644
>> --- a/apt/apt-pkg/pkgcachegen.cc
>> +++ b/apt/apt-pkg/pkgcachegen.cc
>> @@ -26,6 +26,7 @@
>> #include <apt-pkg/strutl.h>
>> #include <apt-pkg/sptr.h>
>> #include <apt-pkg/pkgsystem.h>
>> +#include <apt-pkg/rebase_pointer.h>
>>
>> #include <apti18n.h>
>>
>> @@ -109,18 +110,18 @@ pkgCacheGenerator::~pkgCacheGenerator()
>> Map.Sync(0,sizeof(pkgCache::Header));
>> }
>> /*}}}*/
>> -void pkgCacheGenerator::ReMap(void const * const oldMap, void const * const newMap)
>> +void pkgCacheGenerator::ReMap(void *oldMap, void *newMap)
>> {
>> if (oldMap == newMap)
>> return;
>>
>> Cache.ReMap(false);
>>
>> - CurrentFile += (pkgCache::PackageFile*) newMap - (pkgCache::PackageFile*) oldMap;
>> + CurrentFile = RebasePointer(CurrentFile, oldMap, newMap);
>>
>> for (size_t i = 0; i < _count(UniqHash); ++i)
>> if (UniqHash[i] != 0)
>> - UniqHash[i] += (pkgCache::StringItem*) newMap - (pkgCache::StringItem*) oldMap;
>> + UniqHash[i] = RebasePointer(UniqHash[i], oldMap, newMap);
>>
>> for (auto i = Dynamic<pkgCache::PkgIterator>::toReMap.begin();
>> i != Dynamic<pkgCache::PkgIterator>::toReMap.end(); ++i)
>> @@ -147,7 +148,7 @@ void pkgCacheGenerator::ReMap(void const * const oldMap, void const * const newM
>> // CacheGenerator::WriteStringInMap /*{{{*/
>> std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(const char *String,
>> unsigned long Len) {
>> - void const * const oldMap = Map.Data();
>> + void *oldMap = Map.Data();
>> const auto index = Map.WriteString(String, Len);
>> if (index)
>> ReMap(oldMap, Map.Data());
>> @@ -156,7 +157,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(cons
>> /*}}}*/
>> // CacheGenerator::WriteStringInMap /*{{{*/
>> std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(const char *String) {
>> - void const * const oldMap = Map.Data();
>> + void *oldMap = Map.Data();
>> const auto index = Map.WriteString(String);
>> if (index)
>> ReMap(oldMap, Map.Data());
>> @@ -164,7 +165,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(cons
>> }
>> /*}}}*/
>> std::experimental::optional<map_ptrloc> pkgCacheGenerator::AllocateInMap(unsigned long size) {/*{{{*/
>> - void const * const oldMap = Map.Data();
>> + void *oldMap = Map.Data();
>> const auto index = Map.Allocate(size);
>> if (index)
>> ReMap(oldMap, Map.Data());
>> @@ -229,7 +230,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
>> pkgCache::VerIterator Ver = Pkg.VersionList();
>> Dynamic<pkgCache::VerIterator> DynVer(Ver);
>> map_ptrloc *Last = &Pkg->VersionList;
>> - const void * oldMap = Map.Data();
>> + void *oldMap = Map.Data();
>> int Res = 1;
>> for (; Ver.end() == false; Last = &Ver->NextVer, Ver++)
>> {
>> @@ -271,7 +272,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
>>
>> if (oldMap != Map.Data())
>> {
>> - Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
>> + Last = RebasePointer(Last, oldMap, Map.Data());
>> oldMap = Map.Data();
>> }
>>
>> @@ -297,7 +298,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
>> PackageName.c_str(), 1);
>>
>> if (oldMap != Map.Data())
>> - Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
>> + Last = RebasePointer(Last, oldMap, Map.Data());
>> *Last = *verindex;
>>
>> Ver->ParentPkg = Pkg.Index();
>> @@ -553,7 +554,7 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator &Ver,
>> unsigned int Op,
>> unsigned int Type)
>> {
>> - void const * const oldMap = Owner->Map.Data();
>> + void *oldMap = Owner->Map.Data();
>> pkgCache &Cache = Owner->Cache;
>>
>> // Get a structure
>> @@ -605,7 +606,7 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator &Ver,
>> OldDepLast = &D->NextDepends;
>> OldDepVer = Ver;
>> } else if (oldMap != Owner->Map.Data())
>> - OldDepLast += (map_ptrloc*) Owner->Map.Data() - (map_ptrloc*) oldMap;
>> + OldDepLast = RebasePointer(OldDepLast, oldMap, Owner->Map.Data());
>>
>> // Is it a file dependency?
>> if (PackageName[0] == '/')
>> @@ -739,7 +740,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteUniqString(const
>> }
>>
>> // Get a structure
>> - void const * const oldMap = Map.Data();
>> + void *oldMap = Map.Data();
>> const auto Item = AllocateInMap(sizeof(pkgCache::StringItem));
>> const auto idxString = WriteStringInMap(S, Size);
>> if ((!Item) || (!idxString))
>> @@ -747,8 +748,8 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteUniqString(const
>>
>> if (oldMap != Map.Data())
>> {
>> - Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
>> - I += (pkgCache::StringItem*) Map.Data() - (pkgCache::StringItem*) oldMap;
>> + Last = RebasePointer(Last, oldMap, Map.Data());
>> + I = RebasePointer(I, oldMap, Map.Data());
>> }
>>
>> *Last = *Item;
>> diff --git a/apt/apt-pkg/pkgcachegen.h b/apt/apt-pkg/pkgcachegen.h
>> index 77075a6..0faf6e1 100644
>> --- a/apt/apt-pkg/pkgcachegen.h
>> +++ b/apt/apt-pkg/pkgcachegen.h
>> @@ -72,7 +72,7 @@ class pkgCacheGenerator
>> class DynamicFunction
>> {
>> public:
>> - typedef std::function<void(const void *, const void *)> function;
>> + typedef std::function<void(void *, void *)> function;
>>
>> static std::set<DynamicFunction*> toReMap;
>>
>> @@ -93,7 +93,7 @@ class pkgCacheGenerator
>> toReMap.erase(this);
>> }
>>
>> - void call(const void *oldMap, const void *newMap)
>> + void call(void *oldMap, void *newMap)
>> {
>> if (m_function)
>> m_function(oldMap, newMap);
>> @@ -140,7 +140,7 @@ class pkgCacheGenerator
>> // CNC:2003-03-18
>> inline void ResetFileDeps() {FoundFileDeps = false;};
>>
>> - void ReMap(void const * const oldMap, void const * const newMap);
>> + void ReMap(void *oldMap, void *newMap);
>>
>> pkgCacheGenerator(DynamicMMap *Map,OpProgress *Progress);
>> ~pkgCacheGenerator();
>> diff --git a/apt/apt-pkg/rebase_pointer.h b/apt/apt-pkg/rebase_pointer.h
>> new file mode 100644
>> index 0000000..f6b3c15
>> --- /dev/null
>> +++ b/apt/apt-pkg/rebase_pointer.h
>> @@ -0,0 +1,16 @@
>> +#ifndef PKGLIB_REBASE_POINTER_H
>> +#define PKGLIB_REBASE_POINTER_H
>> +
>> +template <typename T>
>> +static inline T* RebasePointer(T *ptr, void *old_base, void *new_base)
>> +{
>> + return reinterpret_cast<T*>(reinterpret_cast<char*>(new_base) + (reinterpret_cast<char*>(ptr) - reinterpret_cast<char*>(old_base)));
>> +}
>> +
>> +template <typename T>
>> +static inline const T* RebasePointer(const T *ptr, void *old_base, void *new_base)
>> +{
>> + return reinterpret_cast<const T*>(reinterpret_cast<char*>(new_base) + (reinterpret_cast<const char*>(ptr) - reinterpret_cast<char*>(old_base)));
>> +}
>> +
>> +#endif
>> diff --git a/apt/apt-pkg/rpm/rpmlistparser.cc b/apt/apt-pkg/rpm/rpmlistparser.cc
>> index 9b2e9ad..bd13b99 100644
>> --- a/apt/apt-pkg/rpm/rpmlistparser.cc
>> +++ b/apt/apt-pkg/rpm/rpmlistparser.cc
>> @@ -25,6 +25,7 @@
>> #include <apt-pkg/strutl.h>
>> #include <apt-pkg/crc-16.h>
>> #include <apt-pkg/tagfile.h>
>> +#include <apt-pkg/rebase_pointer.h>
>>
>> #include <apti18n.h>
>>
>> @@ -50,13 +51,13 @@ rpmListParser::rpmListParser(RPMHandler *Handler)
>> {
>> SeenPackages.reset(new SeenPackagesType);
>> m_SeenPackagesRealloc.reset(new pkgCacheGenerator::DynamicFunction(
>> - [this] (void const *oldMap, void const *newMap)
>> + [this] (void *oldMap, void *newMap)
>> {
>> SeenPackagesType tmp;
>>
>> for (auto iter: *SeenPackages)
>> {
>> - tmp.insert(iter + (static_cast<const char *>(newMap) - static_cast<const char *>(oldMap)));
>> + tmp.insert(RebasePointer(iter, oldMap, newMap));
>> }
>>
>> SeenPackages->swap(tmp);
>> diff --git a/apt/apt-pkg/rpm/rpmpackagedata.cc b/apt/apt-pkg/rpm/rpmpackagedata.cc
>> index 61c15d5..d6c677b 100644
>> --- a/apt/apt-pkg/rpm/rpmpackagedata.cc
>> +++ b/apt/apt-pkg/rpm/rpmpackagedata.cc
>> @@ -23,7 +23,7 @@ RPMPackageData::RPMPackageData()
>> #endif
>> {
>> m_VerMapRealloc.reset(new pkgCacheGenerator::DynamicFunction(
>> - [this] (void const *oldMap, void const *newMap)
>> + [this] (void *oldMap, void *newMap)
>> {
>> for (auto iter1 = VerMap.begin(); iter1 != VerMap.end(); ++iter1)
>> {
>
>
> Best regards,
> Andrew Savchenko
>
>
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