# HG changeset patch
# Parent  d30cb471a35b400d3db84e24b0d653b82fedd458
Bug 1542958 - avoid malloc/delete[] mismatches in elfhack; r=glandium

We were allocating ElfSection's data with `new[]` and modifying it with
`realloc` in some places, which causes allocator mismatches.
Consistently manage the data with `malloc`, `realloc`, and `free` instead.

Differential Revision: https://phabricator.services.mozilla.com/D27327

diff --git a/build/unix/elfhack/elf.cpp b/build/unix/elfhack/elf.cpp
--- a/build/unix/elfhack/elf.cpp
+++ b/build/unix/elfhack/elf.cpp
@@ -492,17 +492,20 @@ ElfSection::ElfSection(Elf_Shdr &s, std:
                                      : parent->getSection(shdr.sh_link)),
       next(nullptr),
       previous(nullptr),
       index(-1) {
   if ((file == nullptr) || (shdr.sh_type == SHT_NULL) ||
       (shdr.sh_type == SHT_NOBITS))
     data = nullptr;
   else {
-    data = new char[shdr.sh_size];
+    data = static_cast<char *>(malloc(shdr.sh_size));
+    if (!data) {
+      throw std::runtime_error("Could not malloc ElfSection data");
+    }
     int pos = file->tellg();
     file->seekg(shdr.sh_offset);
     file->read(data, shdr.sh_size);
     file->seekg(pos);
   }
   if (shdr.sh_name == 0)
     name = nullptr;
   else {
diff --git a/build/unix/elfhack/elfhack.cpp b/build/unix/elfhack/elfhack.cpp
--- a/build/unix/elfhack/elfhack.cpp
+++ b/build/unix/elfhack/elfhack.cpp
@@ -174,17 +174,20 @@ class ElfRelHackCode_Section : public El
         addr = (addr | ((*c)->getAddrAlign() - 1)) + 1;
       (*c)->getShdr().sh_addr = addr;
       // We need to align this section depending on the greater
       // alignment required by code sections.
       if (shdr.sh_addralign < (*c)->getAddrAlign())
         shdr.sh_addralign = (*c)->getAddrAlign();
     }
     shdr.sh_size = code.back()->getAddr() + code.back()->getSize();
-    data = new char[shdr.sh_size];
+    data = static_cast<char *>(malloc(shdr.sh_size));
+    if (!data) {
+      throw std::runtime_error("Could not malloc ElfSection data");
+    }
     char *buf = data;
     for (c = code.begin(); c != code.end(); ++c) {
       memcpy(buf, (*c)->getData(), (*c)->getSize());
       buf += (*c)->getSize();
     }
     name = elfhack_text;
   }
 
diff --git a/build/unix/elfhack/elfxx.h b/build/unix/elfhack/elfxx.h
--- a/build/unix/elfhack/elfxx.h
+++ b/build/unix/elfhack/elfxx.h
@@ -320,17 +320,17 @@ class ElfSection {
  public:
   typedef union {
     ElfSection *section;
     int index;
   } SectionInfo;
 
   ElfSection(Elf_Shdr &s, std::ifstream *file, Elf *parent);
 
-  virtual ~ElfSection() { delete[] data; }
+  virtual ~ElfSection() { free(data); }
 
   const char *getName() { return name; }
   unsigned int getType() { return shdr.sh_type; }
   unsigned int getFlags() { return shdr.sh_flags; }
   unsigned int getAddr();
   unsigned int getSize() { return shdr.sh_size; }
   unsigned int getAddrAlign() { return shdr.sh_addralign; }
   unsigned int getEntSize() { return shdr.sh_entsize; }