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-rw-r--r--base/loader/elf_object.cc297
-rw-r--r--base/loader/elf_object.hh11
2 files changed, 237 insertions, 71 deletions
diff --git a/base/loader/elf_object.cc b/base/loader/elf_object.cc
index 30dec4c91..d43e2fe7c 100644
--- a/base/loader/elf_object.cc
+++ b/base/loader/elf_object.cc
@@ -35,21 +35,43 @@
#include "base/trace.hh" // for DPRINTF
-#include "base/loader/exec_elf.h"
using namespace std;
ObjectFile *
ElfObject::tryFile(const string &fname, int fd, size_t len, uint8_t *data)
{
- if (memcmp(((Elf64_Ehdr *)data)->e_ident, ELFMAG, SELFMAG) == 0) {
- // for now we'll assume it's a 64-bit Alpha Linux binary
+ Elf *elf;
+ GElf_Ehdr ehdr;
+
+
+ /* check that header matches library version */
+ assert(elf_version(EV_CURRENT) != EV_NONE);
+
+ /* get a pointer to elf structure */
+ elf = elf_memory((char*)data,len);
+ /* will only fail if fd is invalid */
+ assert(elf != NULL);
+
+ /* Check that we actually have a elf file */
+ if(gelf_getehdr(elf, &ehdr) ==0)
+ {
+ DPRINTFR(Loader, "Not ELF\n");
+ elf_end(elf);
+ return NULL;
+ }
+ else
+ {
+ if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
+ panic("32 bit ELF Binary, Not Supported");
+ if (ehdr.e_machine != EM_ALPHA)
+ panic("Non Alpha Binary, Not Supported");
+
+ elf_end(elf);
+
return new ElfObject(fname, fd, len, data,
ObjectFile::Alpha, ObjectFile::Linux);
}
- else {
- return NULL;
- }
}
@@ -57,71 +79,117 @@ ElfObject::ElfObject(const string &_filename, int _fd,
size_t _len, uint8_t *_data,
Arch _arch, OpSys _opSys)
: ObjectFile(_filename, _fd, _len, _data, _arch, _opSys)
+
{
- ehdr = (Elf64_Ehdr *)fileData;
-
- entry = ehdr->e_entry;
-
- phdr = (Elf64_Phdr *)(fileData + ehdr->e_phoff);
- assert(sizeof(Elf64_Phdr) == ehdr->e_phentsize);
-
- bool foundText = false;
- bool foundData = false;
- for (int i = 0; i < ehdr->e_phnum; ++i) {
- Elf64_Phdr *p = &phdr[i];
-
- // for now we don't care about non-loadable segments
- if (!(p->p_type & PT_LOAD))
- continue;
-
- if (p->p_flags & PF_X) {
- // executable: must be text
- assert(!foundText);
- foundText = true;
- textPhdrIdx = i;
- text.baseAddr = p->p_vaddr;
- text.size = p->p_filesz;
- assert(p->p_filesz == p->p_memsz);
- }
- else {
- assert(p->p_flags & PF_R);
- assert(!foundData);
- foundData = true;
- dataPhdrIdx = i;
- data.baseAddr = p->p_vaddr;
- data.size = p->p_filesz;
- bss.baseAddr = data.baseAddr + data.size;
- bss.size = p->p_memsz - p->p_filesz;
- }
+
+ Elf *elf;
+ GElf_Ehdr ehdr;
+
+ /* check that header matches library version */
+ assert(elf_version(EV_CURRENT) != EV_NONE);
+
+ /* get a pointer to elf structure */
+ elf = elf_memory((char*)fileData,len);
+ /* will only fail if fd is invalid */
+ assert(elf != NULL);
+
+ /* Check that we actually have a elf file */
+ if(gelf_getehdr(elf, &ehdr) ==0)
+ {
+ panic("Not ELF, shouldn't be here");
}
- assert(foundText && foundData);
- DPRINTFR(Loader, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
- text.baseAddr, text.size, data.baseAddr, data.size,
- bss.baseAddr, bss.size);
+ entry = ehdr.e_entry;
+ elf_end(elf);
+
+ /* We will actually read the sections when we need to load them*/
}
bool
ElfObject::loadSections(FunctionalMemory *mem, bool loadPhys)
{
- Addr textAddr = text.baseAddr;
- Addr dataAddr = data.baseAddr;
+ Elf *elf;
+ int secidx = 1; /* there is a 0 but it is nothing, go figure*/
+ Elf_Scn *section;
+ GElf_Shdr shdr;
+ GElf_Ehdr ehdr;
+
+ Addr address;
+ char *secname;
+
+ /* check that header matches library version */
+ assert(elf_version(EV_CURRENT) != EV_NONE);
+
+
+ /* get a pointer to elf structure */
+ elf = elf_memory((char*)fileData,len);
+
+ assert(elf != NULL);
+
+ /* Check that we actually have a elf file */
+ if(gelf_getehdr(elf, &ehdr) ==0)
+ {
+ panic("Not ELF, shouldn't be here");
+ }
+
+
+
+ /* Get the first section */
+ section = elf_getscn(elf, secidx);
+
+ /* While there are no more sections */
+ while (section != NULL)
+ {
+ gelf_getshdr(section, &shdr);
+
+
+ if (shdr.sh_flags & SHF_ALLOC)
+ {
+ /* we should load this */
+ DPRINTF(Loader,"Name: %20s Address: 0x%016llx Size: 0x%08llx Offset: 0x%08llx Flags:0x%08llx %s\n",
+ elf_strptr(elf, ehdr.e_shstrndx, shdr.sh_name), shdr.sh_addr,
+ shdr.sh_size, shdr.sh_offset, shdr.sh_flags, shdr.sh_flags & SHF_ALLOC ? "ALLOC" : "");
+ secname = elf_strptr(elf, ehdr.e_shstrndx, shdr.sh_name);
+ if(secname)
+ {
+ if (strcmp(secname, ".text")==0)
+ {
+ text.baseAddr = shdr.sh_addr;
+ text.size = shdr.sh_size;
+ }
+ if (strcmp(secname, ".data")==0)
+ {
+ data.baseAddr = shdr.sh_addr;
+ data.size = shdr.sh_size;
+ }
+ if (strcmp(secname, ".bss")==0)
+ {
+ bss.baseAddr = shdr.sh_addr;
+ bss.size = shdr.sh_size;
+ }
+ }
+ if(shdr.sh_size != 0)
+ {
+ if (loadPhys)
+ {
+ address = shdr.sh_addr &= (ULL(1) << 40) - 1;
+ mem->prot_write(address, fileData + shdr.sh_offset, shdr.sh_size);
+ }
+ else
+ {
+ mem->prot_write(shdr.sh_addr, fileData + shdr.sh_offset, shdr.sh_size);
+ }
+ }
- if (loadPhys) {
- textAddr &= (ULL(1) << 40) - 1;
- dataAddr &= (ULL(1) << 40) - 1;
+ }
+
+ ++secidx;
+ section = elf_getscn(elf, secidx);
}
- // Since we don't really have an MMU and all memory is
- // zero-filled, there's no need to set up the BSS segment.
- if (text.size != 0)
- mem->prot_write(textAddr, fileData + phdr[textPhdrIdx].p_offset,
- text.size);
- if (data.size != 0)
- mem->prot_write(dataAddr, fileData + phdr[dataPhdrIdx].p_offset,
- data.size);
+ elf_end(elf);
return true;
}
@@ -130,13 +198,118 @@ ElfObject::loadSections(FunctionalMemory *mem, bool loadPhys)
bool
ElfObject::loadGlobalSymbols(SymbolTable *symtab)
{
- // symbols not supported yet
- return false;
+ Elf *elf;
+ int secidx = 1; /* there is a 0 but it is nothing, go figure*/
+ Elf_Scn *section;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ int count, ii;
+ bool found = false;
+ GElf_Sym sym;
+
+ if (!symtab)
+ return false;
+
+ /* check that header matches library version */
+ assert(elf_version(EV_CURRENT) != EV_NONE);
+
+ /* get a pointer to elf structure */
+ elf = elf_memory((char*)fileData,len);
+
+ assert(elf != NULL);
+
+
+ /* Get the first section */
+ section = elf_getscn(elf, secidx);
+
+ /* While there are no more sections */
+ while (section != NULL)
+ {
+ gelf_getshdr(section, &shdr);
+
+
+ if(shdr.sh_type == SHT_SYMTAB)
+ {
+ found = true;
+ data = elf_getdata(section, NULL);
+ count = shdr.sh_size / shdr.sh_entsize;
+ DPRINTF(Loader, "Found Symbol Table, %d symbols present\n", count);
+
+ /* loop through all the symbols, only loading global ones*/
+ for (ii = 0; ii < count; ++ii)
+ {
+ gelf_getsym(data, ii, &sym);
+ if (GELF_ST_BIND(sym.st_info) & STB_GLOBAL)
+ {
+ symtab->insert(sym.st_value, elf_strptr(elf, shdr.sh_link, sym.st_name));
+ }
+ }
+ }
+ ++secidx;
+ section = elf_getscn(elf, secidx);
+ }
+
+ elf_end(elf);
+
+ return found;
}
bool
ElfObject::loadLocalSymbols(SymbolTable *symtab)
{
- // symbols not supported yet
- return false;
+
+ Elf *elf;
+ int secidx = 1; /* there is a 0 but it is nothing, go figure*/
+ Elf_Scn *section;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ int count, ii;
+ bool found = false;
+ GElf_Sym sym;
+
+ if (!symtab)
+ return false;
+
+ /* check that header matches library version */
+ assert(elf_version(EV_CURRENT) != EV_NONE);
+
+ /* get a pointer to elf structure */
+ elf = elf_memory((char*)fileData,len);
+
+ assert(elf != NULL);
+
+
+ /* Get the first section */
+ section = elf_getscn(elf, secidx);
+
+ /* While there are no more sections */
+ while (section != NULL)
+ {
+ gelf_getshdr(section, &shdr);
+
+
+ if(shdr.sh_type == SHT_SYMTAB)
+ {
+ found = true;
+ data = elf_getdata(section, NULL);
+ count = shdr.sh_size / shdr.sh_entsize;
+ DPRINTF(Loader, "Found Symbol Table, %d symbols present\n", count);
+
+ /* loop through all the symbols, only loading global ones*/
+ for (ii = 0; ii < count; ++ii)
+ {
+ gelf_getsym(data, ii, &sym);
+ if (GELF_ST_BIND(sym.st_info) & STB_LOCAL)
+ {
+ symtab->insert(sym.st_value, elf_strptr(elf, shdr.sh_link, sym.st_name));
+ }
+ }
+ }
+ ++secidx;
+ section = elf_getscn(elf, secidx);
+ }
+
+ elf_end(elf);
+
+ return found;
}
diff --git a/base/loader/elf_object.hh b/base/loader/elf_object.hh
index 10d97d089..afd4cd62b 100644
--- a/base/loader/elf_object.hh
+++ b/base/loader/elf_object.hh
@@ -29,20 +29,13 @@
#ifndef __ELF_OBJECT_HH__
#define __ELF_OBJECT_HH__
+#include <libelf/gelf.h>
+#include <libelf/libelf.h>
#include "base/loader/object_file.hh"
-// forward decls: avoid including exec_elf.hh here
-struct Elf64_Ehdr;
-struct Elf64_Phdr;
-
class ElfObject : public ObjectFile
{
protected:
- Elf64_Ehdr *ehdr;
- Elf64_Phdr *phdr;
-
- int textPhdrIdx;
- int dataPhdrIdx;
ElfObject(const std::string &_filename, int _fd,
size_t _len, uint8_t *_data,
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 13:36:02 +0000