Simplify code and add missing wri/rdi

Author: brenoguim

src/patchelf.cc

@@ -1892,11 +1892,11 @@ static uint32_t gnuHash(std::string_view name) {
 }
 
 template<ElfFileParams>
-auto ElfFile<ElfFileParamNames>::GnuHashTable::parse(span<char> sectionData) -> GnuHashTable
+auto ElfFile<ElfFileParamNames>::parseGnuHashTable(span<char> sectionData) -> GnuHashTable
 {
-    auto hdr = (Header*)sectionData.begin();
-    auto bloomFilters = span((BloomWord*)(hdr+1), hdr->maskwords);
-    auto buckets = span((uint32_t*)bloomFilters.end(), hdr->numBuckets);
+    auto hdr = (typename GnuHashTable::Header*)sectionData.begin();
+    auto bloomFilters = span((typename GnuHashTable::BloomWord*)(hdr+1), rdi(hdr->maskwords));
+    auto buckets = span((uint32_t*)bloomFilters.end(), rdi(hdr->numBuckets));
     auto table = span(buckets.end(), ((uint32_t*)sectionData.end()) - buckets.end());
     return GnuHashTable{*hdr, bloomFilters, buckets, table};
 }
@@ -1908,11 +1908,10 @@ void ElfFile<ElfFileParamNames>::rebuildGnuHashTable(const char* strTab, span<El
     if (!sectionData)
         return;
 
-    auto ght = GnuHashTable::parse(sectionData);
+    auto ght = parseGnuHashTable(sectionData);
 
-    // Only work with the last "m_table.size()" symbols from dynsyms which are the
-    // symbols that belong to the hash table
-    auto firstSymIdx = dynsyms.size() - ght.m_table.size();
+    // The hash table includes only a subset of dynsyms
+    auto firstSymIdx = rdi(ght.m_hdr.symndx);
     auto symsToInsert = span(dynsyms.begin() + firstSymIdx, dynsyms.end());
 
     // Only use the range of symbol versions that will be changed
@@ -1933,7 +1932,7 @@ void ElfFile<ElfFileParamNames>::rebuildGnuHashTable(const char* strTab, span<El
     {
         Entry e;
         e.hash = gnuHash(strTab + rdi(sym.st_name));
-        e.bucketIdx = e.hash % ght.m_hdr.numBuckets;
+        e.bucketIdx = e.hash % rdi(ght.m_hdr.numBuckets);
         e.originalPos = pos++;
         entries.push_back(e);
     }
@@ -1993,10 +1992,10 @@ void ElfFile<ElfFileParamNames>::rebuildGnuHashTable(const char* strTab, span<El
     for (size_t i = 0; i < entries.size(); ++i)
     {
         auto h = entries[i].hash;
-        size_t idx = (h / ElfWordSize) % ght.m_bloomFilters.size();
+        size_t idx = (h / ElfClass) % ght.m_bloomFilters.size();
         auto val = rdi(ght.m_bloomFilters[idx]);
-        val |= uint64_t(1) << (h % ElfWordSize);
-        val |= uint64_t(1) << ((h >> ght.m_hdr.shift2) % ElfWordSize);
+        val |= uint64_t(1) << (h % ElfClass);
+        val |= uint64_t(1) << ((h >> ght.m_hdr.shift2) % ElfClass);
         wri(ght.m_bloomFilters[idx], val);
     }
 
@@ -2006,7 +2005,7 @@ void ElfFile<ElfFileParamNames>::rebuildGnuHashTable(const char* strTab, span<El
     {
         auto symBucketIdx = entries[i].bucketIdx;
         if (!ght.m_buckets[symBucketIdx])
-            ght.m_buckets[symBucketIdx] = i + ght.m_hdr.symndx;
+            wri(ght.m_buckets[symBucketIdx], i + firstSymIdx);
     }
 
     // Fill hash table
@@ -2015,7 +2014,7 @@ void ElfFile<ElfFileParamNames>::rebuildGnuHashTable(const char* strTab, span<El
         auto& n = entries[i];
         bool isLast = (i == entries.size() - 1) || (n.bucketIdx != entries[i+1].bucketIdx);
         // Add hash with first bit indicating end of chain
-        ght.m_table[i] = isLast ? (n.hash | 1) : (n.hash & ~1);
+        wri(ght.m_table[i], isLast ? (n.hash | 1) : (n.hash & ~1));
     }
 }
 
@@ -2033,10 +2032,10 @@ static uint32_t sysvHash(std::string_view name) {
 }
 
 template<ElfFileParams>
-auto ElfFile<ElfFileParamNames>::HashTable::parse(span<char> sectionData) -> HashTable
+auto ElfFile<ElfFileParamNames>::parseHashTable(span<char> sectionData) -> HashTable
 {
-    auto hdr = (Header*)sectionData.begin();
-    auto buckets = span((uint32_t*)(hdr+1), hdr->numBuckets);
+    auto hdr = (typename HashTable::Header*)sectionData.begin();
+    auto buckets = span((uint32_t*)(hdr+1), rdi(hdr->numBuckets));
     auto table = span(buckets.end(), ((uint32_t*)sectionData.end()) - buckets.end());
     return HashTable{*hdr, buckets, table};
 }
@@ -2048,7 +2047,7 @@ void ElfFile<ElfFileParamNames>::rebuildHashTable(const char* strTab, span<Elf_S
     if (!sectionData)
         return;
 
-    auto ht = HashTable::parse(sectionData);
+    auto ht = parseHashTable(sectionData);
 
     std::fill(ht.m_buckets.begin(), ht.m_buckets.end(), 0);
     std::fill(ht.m_chain.begin(), ht.m_chain.end(), 0);
@@ -2222,9 +2221,9 @@ static void patchElf()
         const std::string & outputFileName2 = outputFileName.empty() ? fileName : outputFileName;
 
         if (getElfType(fileContents).is32Bit)
-            patchElf2(ElfFile<Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr, Elf32_Addr, Elf32_Off, Elf32_Dyn, Elf32_Sym, Elf32_Verneed, Elf32_Versym, Elf32_Rel, Elf32_Rela>(fileContents), fileContents, outputFileName2);
+            patchElf2(ElfFile<Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr, Elf32_Addr, Elf32_Off, Elf32_Dyn, Elf32_Sym, Elf32_Verneed, Elf32_Versym, Elf32_Rel, Elf32_Rela, 32>(fileContents), fileContents, outputFileName2);
         else
-            patchElf2(ElfFile<Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr, Elf64_Addr, Elf64_Off, Elf64_Dyn, Elf64_Sym, Elf64_Verneed, Elf64_Versym, Elf64_Rel, Elf64_Rela>(fileContents), fileContents, outputFileName2);
+            patchElf2(ElfFile<Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr, Elf64_Addr, Elf64_Off, Elf64_Dyn, Elf64_Sym, Elf64_Verneed, Elf64_Versym, Elf64_Rel, Elf64_Rela, 64>(fileContents), fileContents, outputFileName2);
     }
 }
 

src/patchelf.h

@@ -1,7 +1,7 @@
 using FileContents = std::shared_ptr<std::vector<unsigned char>>;
 
-#define ElfFileParams class Elf_Ehdr, class Elf_Phdr, class Elf_Shdr, class Elf_Addr, class Elf_Off, class Elf_Dyn, class Elf_Sym, class Elf_Verneed, class Elf_Versym, class Elf_Rel, class Elf_Rela
-#define ElfFileParamNames Elf_Ehdr, Elf_Phdr, Elf_Shdr, Elf_Addr, Elf_Off, Elf_Dyn, Elf_Sym, Elf_Verneed, Elf_Versym, Elf_Rel, Elf_Rela
+#define ElfFileParams class Elf_Ehdr, class Elf_Phdr, class Elf_Shdr, class Elf_Addr, class Elf_Off, class Elf_Dyn, class Elf_Sym, class Elf_Verneed, class Elf_Versym, class Elf_Rel, class Elf_Rela, unsigned ElfClass
+#define ElfFileParamNames Elf_Ehdr, Elf_Phdr, Elf_Shdr, Elf_Addr, Elf_Off, Elf_Dyn, Elf_Sym, Elf_Verneed, Elf_Versym, Elf_Rel, Elf_Rela, ElfClass
 
 template<class T>
 struct span
@@ -158,31 +158,25 @@ class ElfFile
 
     void renameDynamicSymbols(const std::unordered_map<std::string_view, std::string>&);
 
-    static constexpr auto ElfWordSize = std::is_same_v<Elf_Sym, Elf64_Sym> ? 64 : 32;
-    struct GnuHashTable
-    {
-        using BloomWord = std::conditional_t<ElfWordSize == 32, uint32_t, uint64_t>;
-
-        static GnuHashTable parse(span<char> gh);
-
+    struct GnuHashTable {
+        using BloomWord = Elf_Addr;
         struct Header {
             uint32_t numBuckets, symndx, maskwords, shift2;
         } m_hdr;
         span<BloomWord> m_bloomFilters;
         span<uint32_t> m_buckets, m_table;
     };
+    GnuHashTable parseGnuHashTable(span<char> gh);
 
-    void rebuildGnuHashTable(const char* strTab, span<Elf_Sym> dynsyms);
-
-    struct HashTable
-    {
-        static HashTable parse(span<char> gh);
-
+    struct HashTable {
         struct Header {
             uint32_t numBuckets, nchain;
         } m_hdr;
         span<uint32_t> m_buckets, m_chain;
     };
+    HashTable parseHashTable(span<char> gh);
+
+    void rebuildGnuHashTable(const char* strTab, span<Elf_Sym> dynsyms);
     void rebuildHashTable(const char* strTab, span<Elf_Sym> dynsyms);
 
     using Elf_Rel_Info = decltype(Elf_Rel::r_info);