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Code Issues Releases Wiki Activity

Allow any number of contiguous PT_LOAD.

Browse Source 
p_vmlinx.cpp p_vmlinx.h

committer: jreiser <jreiser> 1090040793 +0000
This commit is contained in:
John Reiser 2004-07-17 05:06:33 +00:00
parent 212b674bc2
commit ce3d3a850c
2 changed files with 67 additions and 22 deletions
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83
src/p_vmlinx.cpp
View File

@ -45,12 +45,13 @@ static const
**************************************************************************/
PackVmlinuxI386::PackVmlinuxI386(InputFile *f) :
super(f), shdri(NULL)
super(f), n_ptload(0), phdri(NULL), shdri(NULL)
{
}
PackVmlinuxI386::~PackVmlinuxI386()
{
delete [] phdri;
delete [] shdri;
}
@ -68,6 +69,36 @@ const int *PackVmlinuxI386::getFilters() const
return filters;
}
static int __acc_cdecl_qsort
compare_Phdr(void const *const aa, void const *const bb)
{
Elf_LE32_Phdr const *const a = (Elf_LE32_Phdr const *)aa;
Elf_LE32_Phdr const *const b = (Elf_LE32_Phdr const *)bb;
unsigned const xa = a->p_type - Elf_LE32_Phdr::PT_LOAD;
unsigned const xb = b->p_type - Elf_LE32_Phdr::PT_LOAD;
if (xa < xb) return -1;
if (xa > xb) return 1;
return le32_compare(&a->p_paddr, &b->p_paddr);
}
//
// Examples as of 2004-07-16 [readelf --segments vmlinux # before fiddling]:
//
//----- kernel-2.6.7 plain [defconfig?]
//Program Headers(2):
// Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
// LOAD 0x001000 0x00100000 0x00100000 0x1c7e61 0x1c7e61 R E 0x1000
// LOAD 0x1c8e64 0x002c8e64 0x002c8e64 0x00000 0x00000 RW 0x1000
//
//----- kernel-2.6.7-1.488 Fedora Core 3 test 1
//Program Headers(5):
// Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
// LOAD 0x001000 0x02100000 0x02100000 0x202246 0x202246 R E 0x1000
// LOAD 0x204000 0xffff3000 0x02303000 0x00664 0x00664 R E 0x1000
// LOAD 0x205000 0x02304000 0x02304000 0x43562 0x43562 R 0x1000
// LOAD 0x249000 0x02348000 0x02348000 0x81800 0xcb0fc RWE 0x1000
// STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4
//
bool PackVmlinuxI386::canPack()
{
@ -84,27 +115,40 @@ bool PackVmlinuxI386::canPack()
// additional requirements for vmlinux
if (ehdri.e_ehsize != sizeof(ehdri) // different <elf.h> ?
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phnum!=2 || ehdri.e_phentsize!=sizeof(Elf_LE32_Phdr)
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Elf_LE32_Phdr)
|| ehdri.e_type!=Elf_LE32_Ehdr::ET_EXEC
|| 0x00100000!=(0x001fffff & ehdri.e_entry) // entry not an odd 1MB
) {
return false;
}
phdri = new Elf_LE32_Phdr[ehdri.e_phnum];
fi->seek(ehdri.e_phoff, SEEK_SET);
fi->readx(phdri, sizeof(phdri));
if (Elf_LE32_Phdr::PT_LOAD!=phdri[0].p_type || 0!=(0xfff & phdri[0].p_offset)
|| Elf_LE32_Phdr::PT_LOAD!=phdri[1].p_type || 0!=(0xfff & phdri[1].p_offset)
|| 0!=(0xfff & phdri[0].p_paddr) || 0!=(0xfff & phdri[0].p_vaddr)
|| 0!=(0xfff & phdri[1].p_paddr) || 0!=(0xfff & phdri[1].p_vaddr)
|| 0x1000!=phdri[0].p_offset
|| phdri[1].p_offset!=(phdri[0].p_offset + (~0xfff & (0xfff + phdri[0].p_filesz)))
) {
return false;
}
fi->readx(phdri, ehdri.e_phnum * sizeof(*phdri));
return true;
// 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 (int j= 0; j < ehdri.e_phnum; ++j) {
if (Elf_LE32_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 = -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;
}
int PackVmlinuxI386::buildLoader(const Filter *ft)
@ -162,8 +206,7 @@ void PackVmlinuxI386::pack(OutputFile *fo)
ehdro.e_shstrndx = 4;
fo->write(&ehdro, sizeof(ehdro)); fo_off+= sizeof(ehdro);
// .data length + (.text length padded to PAGE_SIZE)
ph.u_len = phdri[1].p_filesz + (phdri[1].p_offset - phdri[0].p_offset);
ph.u_len = sz_ptload;
fi->seek(phdri[0].p_offset, SEEK_SET);
fi->readx(ibuf, ph.u_len);
checkAlreadyPacked(ibuf + ph.u_len - 1024, 1024);
@ -201,8 +244,8 @@ void PackVmlinuxI386::pack(OutputFile *fo)
verifyOverlappingDecompression();
// .note with 1st page --------------------------------
fi->seek(0, SEEK_SET);
ph.u_len = phdri[0].p_offset;
fi->seek(0, SEEK_SET);
fi->readx(ibuf, ph.u_len);
compress(ibuf, obuf);
@ -216,8 +259,8 @@ void PackVmlinuxI386::pack(OutputFile *fo)
fo->write(obuf, ph.c_len); fo_off += shdro[2].sh_size;
// .note with rest --------------------------------
fi->seek(phdri[1].p_offset + phdri[1].p_filesz, SEEK_SET);
ph.u_len = file_size - (phdri[1].p_offset + phdri[1].p_filesz);
ph.u_len = file_size - (sz_ptload + phdri[0].p_offset);
fi->seek(sz_ptload + phdri[0].p_offset, SEEK_SET);
fi->readx(ibuf, ph.u_len);
compress(ibuf, obuf);
@ -298,7 +341,7 @@ int PackVmlinuxI386::canUnpack()
Elf_LE32_Shdr *p, *p_shstrtab=0;
shdri = new Elf_LE32_Shdr[ehdri.e_shnum];
fi->seek(ehdri.e_shoff, SEEK_SET);
fi->readx(shdri, ehdri.e_shnum * sizeof(Elf_LE32_Shdr));
fi->readx(shdri, ehdri.e_shnum * sizeof(*shdri));
int j;
for (p = shdri, j= ehdri.e_shnum; --j>=0; ++p) {
if (Elf_LE32_Shdr::SHT_STRTAB==p->sh_type

6
src/p_vmlinx.h
View File

@ -58,12 +58,14 @@ protected:
// virtual const upx_byte *getLoader() const;
// virtual int getLoaderSize() const;
Elf_LE32_Ehdr ehdri; // from input file
Elf_LE32_Phdr phdri[2]; // from input file
int n_ptload;
unsigned sz_ptload;
Elf_LE32_Phdr *phdri; // from input file
Elf_LE32_Shdr *shdri; // from input file
Elf_LE32_Shdr *p_text;
Elf_LE32_Shdr *p_note0;
Elf_LE32_Shdr *p_note1;
Elf_LE32_Ehdr ehdri; // from input file
};