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PackVmlinuxBase::canPack(); templates are fun!

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This commit is contained in:
John Reiser
2006-12-18 22:55:38 -08:00
parent 277d862172
commit 4c068e3e00
2 changed files with 121 additions and 235 deletions
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src/p_vmlinx.cpp
+100 -227
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@@ -58,6 +58,12 @@ PackVmlinuxBase<T>::~PackVmlinuxBase()
delete [] shdri;
}
template <class T>
int PackVmlinuxBase<T>::is_valid_e_entry(Addr /*e_entry*/)
{
return 0;
}
template <class T>
int PackVmlinuxBase<T>::getStrategy(Filter &/*ft*/)
{
@@ -69,6 +75,21 @@ int PackVmlinuxBase<T>::getStrategy(Filter &/*ft*/)
return (opt->no_filter ? -3 : ((opt->filter > 0) ? -2 : 2));
};
template <class T>
int __acc_cdecl_qsort
PackVmlinuxBase<T>::compare_Phdr(void const *aa, void const *bb)
{
Phdr const *const a = (Phdr const *)aa;
Phdr const *const b = (Phdr const *)bb;
unsigned const xa = a->p_type - Phdr::PT_LOAD;
unsigned const xb = b->p_type - Phdr::PT_LOAD;
if (xa < xb) return -1; // PT_LOAD first
if (xa > xb) return 1;
if (a->p_paddr < b->p_paddr) return -1; // ascending by .p_paddr
if (a->p_paddr > b->p_paddr) return 1;
return 0;
}
template <class T>
class T::Shdr const *PackVmlinuxBase<T>::getElfSections()
{
@@ -94,7 +115,79 @@ class T::Shdr const *PackVmlinuxBase<T>::getElfSections()
}
}
return shstrsec;
};
}
template <class T>
bool PackVmlinuxBase<T>::canPack()
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
// now check the ELF header
if (memcmp(&ehdri, "\x7f\x45\x4c\x46", 4)
|| ehdri.e_ident[/*EI_CLASS*/ 4]!=my_elfclass
|| ehdri.e_ident[/*EI_DATA*/ 5]!=my_elfdata
|| ehdri.e_ident[/*EI_VERSION*/ 6]!=1 // EV_CURRENT
|| !memcmp(&ehdri.e_ident[8], "FreeBSD", 7) // branded
|| ehdri.e_version != 1 // version
|| ehdri.e_ehsize != sizeof(ehdri) // different <elf.h> ?
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Phdr)
)
return false;
// additional requirements for vmlinux
if (ehdri.e_machine != my_e_machine
|| ehdri.e_type!=Ehdr::ET_EXEC
|| !is_valid_e_entry(ehdri.e_entry)
) {
return false;
}
// A Linux kernel must have a __ksymtab section. [??]
Shdr const *p, *const shstrsec = getElfSections();
if (0==shstrsec) {
return false;
}
{
int j;
for (p = shdri, j= ehdri.e_shnum; --j>=0; ++p) {
if (Shdr::SHT_PROGBITS==p->sh_type
&& 0==strcmp("__ksymtab", p->sh_name + shstrtab)) {
break;
}
}
if (j < 0)
return false;
}
phdri = new Phdr[(unsigned) ehdri.e_phnum];
fi->seek(ehdri.e_phoff, SEEK_SET);
fi->readx(phdri, ehdri.e_phnum * sizeof(*phdri));
// Put PT_LOAD together at the beginning, ascending by .p_paddr.
qsort(phdri, ehdri.e_phnum, sizeof(*phdri), compare_Phdr);
// Check that PT_LOADs form one contiguous chunk of the file.
for (unsigned j = 0; j < ehdri.e_phnum; ++j) {
if (Phdr::PT_LOAD==phdri[j].p_type) {
if (0xfff & (phdri[j].p_offset | phdri[j].p_paddr
| phdri[j].p_align | phdri[j].p_vaddr) ) {
return false;
}
if (0 < j) {
unsigned const sz = (0u - phdri[j-1].p_align)
& (phdri[j-1].p_align -1 + phdri[j-1].p_filesz);
if ((sz + phdri[j-1].p_offset)!=phdri[j].p_offset) {
return false;
}
}
++n_ptload;
sz_ptload = phdri[j].p_filesz + phdri[j].p_offset - phdri[0].p_offset;
}
}
return 0 < n_ptload;
}
/*************************************************************************
//
@@ -126,20 +219,6 @@ const int *PackVmlinuxARM::getFilters() const
return f50;
}
static int __acc_cdecl_qsort
compare_Phdr(void const *aa, void const *bb)
{
Elf32_Phdr const *const a = (Elf32_Phdr const *)aa;
Elf32_Phdr const *const b = (Elf32_Phdr const *)bb;
unsigned const xa = a->p_type - Elf32_Phdr::PT_LOAD;
unsigned const xb = b->p_type - Elf32_Phdr::PT_LOAD;
if (xa < xb) return -1; // PT_LOAD first
if (xa > xb) return 1;
if (a->p_paddr < b->p_paddr) return -1; // ascending by .p_paddr
if (a->p_paddr > b->p_paddr) return 1;
return 0;
}
//
// Examples as of 2004-07-16 [readelf --segments vmlinux # before fiddling]:
//
@@ -165,72 +244,9 @@ compare_Phdr(void const *aa, void const *bb)
// LOAD 0x27b000 0xc067a000 0x0067a000 0x10ee64 0x1b07e8 RWE 0x1000
// NOTE 0x000000 0x00000000 0x00000000 0x00000 0x00000 R 0x4
bool PackVmlinuxI386::canPack()
int PackVmlinuxI386::is_valid_e_entry(Addr e_entry)
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
// now check the ELF header
if (memcmp(&ehdri, "\x7f\x45\x4c\x46\x01\x01\x01", 7) // ELF 32-bit LSB
|| !memcmp(&ehdri.e_ident[8], "FreeBSD", 7) // branded
|| ehdri.e_version != 1 // version
|| ehdri.e_ehsize != sizeof(ehdri) // different <elf.h> ?
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Elf32_Phdr)
)
return false;
// additional requirements for vmlinux
if (ehdri.e_machine != Elf32_Ehdr::EM_386
|| ehdri.e_type!=Elf32_Ehdr::ET_EXEC
|| 0!=(0x000fffff & ehdri.e_entry) // entry not on whole 1MB
) {
return false;
}
// A Linux kernel must have a __ksymtab section. [??]
Elf_LE32_Shdr const *p, *const shstrsec = getElfSections();
if (0==shstrsec) {
return false;
}
{
int j;
for (p = shdri, j= ehdri.e_shnum; --j>=0; ++p) {
if (Elf32_Shdr::SHT_PROGBITS==p->sh_type
&& 0==strcmp("__ksymtab", p->sh_name + shstrtab)) {
break;
}
}
if (j < 0)
return false;
}
phdri = new Elf_LE32_Phdr[(unsigned) ehdri.e_phnum];
fi->seek(ehdri.e_phoff, SEEK_SET);
fi->readx(phdri, ehdri.e_phnum * sizeof(*phdri));
// Put PT_LOAD together at the beginning, ascending by .p_paddr.
qsort(phdri, ehdri.e_phnum, sizeof(*phdri), compare_Phdr);
// Check that PT_LOADs form one contiguous chunk of the file.
for (unsigned j = 0; j < ehdri.e_phnum; ++j) {
if (Elf32_Phdr::PT_LOAD==phdri[j].p_type) {
if (0xfff & (phdri[j].p_offset | phdri[j].p_paddr
| phdri[j].p_align | phdri[j].p_vaddr) ) {
return false;
}
if (0 < j) {
unsigned const sz = (0u - phdri[j-1].p_align)
& (phdri[j-1].p_align -1 + phdri[j-1].p_filesz);
if ((sz + phdri[j-1].p_offset)!=phdri[j].p_offset) {
return false;
}
}
++n_ptload;
sz_ptload = phdri[j].p_filesz + phdri[j].p_offset - phdri[0].p_offset;
}
}
return 0 < n_ptload;
return 0==(0x000fffff & e_entry); // entry on whole 1MB
}
@@ -265,75 +281,11 @@ void PackVmlinuxI386::buildLoader(const Filter *ft)
"LINUX992,IDENTSTR,UPX1HEAD", NULL);
}
bool PackVmlinuxARM::canPack()
int PackVmlinuxARM::is_valid_e_entry(Addr e_entry)
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
// now check the ELF header
if (memcmp(&ehdri, "\x7f\x45\x4c\x46\x01\x01\x01", 7) // ELF 32-bit LSB
|| !memcmp(&ehdri.e_ident[8], "FreeBSD", 7) // branded
|| ehdri.e_version != 1 // version
|| ehdri.e_ehsize != sizeof(ehdri) // different <elf.h> ?
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Elf32_Phdr)
)
return false;
// additional requirements for vmlinux
if (ehdri.e_machine != Elf32_Ehdr::EM_ARM
|| ehdri.e_type!=Elf32_Ehdr::ET_EXEC
|| 0xc0008000!=ehdri.e_entry
) {
return false;
}
// A Linux kernel must have a __ksymtab section. [??]
Elf_LE32_Shdr const *p, *const shstrsec = getElfSections();
if (0==shstrsec) {
return false;
}
{
int j;
for (p = shdri, j= ehdri.e_shnum; --j>=0; ++p) {
if (Elf32_Shdr::SHT_PROGBITS==p->sh_type
&& 0==strcmp("__ksymtab", p->sh_name + shstrtab)) {
break;
}
}
if (j < 0)
return false;
}
phdri = new Elf_LE32_Phdr[(unsigned) ehdri.e_phnum];
fi->seek(ehdri.e_phoff, SEEK_SET);
fi->readx(phdri, ehdri.e_phnum * sizeof(*phdri));
// Put PT_LOAD together at the beginning, ascending by .p_paddr.
qsort(phdri, ehdri.e_phnum, sizeof(*phdri), compare_Phdr);
// Check that PT_LOADs form one contiguous chunk of the file.
for (unsigned j = 0; j < ehdri.e_phnum; ++j) {
if (Elf32_Phdr::PT_LOAD==phdri[j].p_type) {
if (0xfff & (phdri[j].p_offset | phdri[j].p_paddr
| phdri[j].p_align | phdri[j].p_vaddr) ) {
return false;
}
if (0 < j) {
unsigned const sz = (0u - phdri[j-1].p_align)
& (phdri[j-1].p_align -1 + phdri[j-1].p_filesz);
if ((sz + phdri[j-1].p_offset)!=phdri[j].p_offset) {
return false;
}
}
++n_ptload;
sz_ptload = phdri[j].p_filesz + phdri[j].p_offset - phdri[0].p_offset;
}
}
return 0 < n_ptload;
return 0xc0008000==e_entry;
}
Linker* PackVmlinuxARM::newLinker() const
{
return new ElfLinkerArmLE;
@@ -1215,90 +1167,11 @@ const int *PackVmlinuxAMD64::getFilters() const
return filters;
}
static int __acc_cdecl_qsort
compare_Phdr64(void const *aa, void const *bb)
int PackVmlinuxAMD64::is_valid_e_entry(Addr e_entry)
{
Elf64_Phdr const *const a = (Elf64_Phdr const *)aa;
Elf64_Phdr const *const b = (Elf64_Phdr const *)bb;
unsigned const xa = a->p_type - Elf64_Phdr::PT_LOAD;
unsigned const xb = b->p_type - Elf64_Phdr::PT_LOAD;
if (xa < xb) return -1; // PT_LOAD first
if (xa > xb) return 1;
if (a->p_paddr < b->p_paddr) return -1; // ascending by .p_paddr
if (a->p_paddr > b->p_paddr) return 1;
return 0;
return 0x200000<=e_entry; // 2MB
}
bool PackVmlinuxAMD64::canPack()
{
fi->seek(0, SEEK_SET);
fi->readx(&ehdri, sizeof(ehdri));
// now check the ELF header
if (memcmp(&ehdri, "\x7f\x45\x4c\x46\x02\x01\x01", 7) // ELF 64-bit LSB
|| ehdri.e_version != 1 // version
|| ehdri.e_ehsize != sizeof(ehdri) // different <elf.h> ?
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Elf64_Phdr)
)
return false;
// additional requirements for vmlinux
if (ehdri.e_machine != Elf64_Ehdr::EM_X86_64
|| ehdri.e_type!=Elf64_Ehdr::ET_EXEC
|| ehdri.e_entry < 0x200000 // entry below 2MB
) {
return false;
}
// A Linux kernel must have a __ksymtab section. [??]
Elf_LE64_Shdr const *p, *const shstrsec = getElfSections();
if (0==shstrsec) {
return false;
}
int j;
for (p = shdri, j= ehdri.e_shnum; --j>=0; ++p) {
if (Elf64_Shdr::SHT_PROGBITS==p->sh_type
&& 0==strcmp("__ksymtab", p->sh_name + shstrtab)) {
break;
}
}
if (j < 0) {
return false;
}
phdri = new Elf_LE64_Phdr[(unsigned) ehdri.e_phnum];
fi->seek(ehdri.e_phoff, SEEK_SET);
fi->readx(phdri, ehdri.e_phnum * sizeof(*phdri));
// Put PT_LOAD together at the beginning, ascending by .p_paddr.
qsort(phdri, ehdri.e_phnum, sizeof(*phdri), compare_Phdr64);
// Check that PT_LOADs form one contiguous chunk of the file.
for (unsigned j = 0; j < ehdri.e_phnum; ++j) {
if (Elf64_Phdr::PT_LOAD==phdri[j].p_type) {
if (0xfff & (phdri[j].p_offset | phdri[j].p_paddr
| phdri[j].p_align | phdri[j].p_vaddr) ) {
return false;
}
if (0 < j) {
unsigned const org = (0u - phdri[j].p_align) &
(-1 + phdri[j].p_align +
phdri[j-1].p_filesz + phdri[j-1].p_offset);
unsigned const loc = (0u - phdri[j].p_align) &
(-1 + phdri[j].p_align + phdri[j].p_offset);
if (org!=loc) {
return false;
}
}
++n_ptload;
sz_ptload = phdri[j].p_filesz + phdri[j].p_offset - phdri[0].p_offset;
}
}
return 0 < n_ptload;
}
Linker* PackVmlinuxAMD64::newLinker() const
{
return new ElfLinkerX86;