Bananymous
/
banan-os
1
1
Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

DynamicLoader: Don't do file backed mapping over file bounds

This commit is contained in:
Bananymous 2024-09-11 19:30:35 +03:00
parent 4189a1c729
commit 4006a04817
1 changed files with 35 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
userspace/programs/DynamicLoader/main.cpp
View File

@ -622,9 +622,34 @@ static void load_program_header(const ElfNativeProgramHeader& program_header, in
return result;
}();
if ((program_header.p_vaddr & 0xFFF) || (program_header.p_offset & 0xFFF) || program_header.p_filesz == 0)
const size_t file_backed_size =
[&program_header]() -> size_t
{
const uintptr_t aligned_addr = program_header.p_vaddr & ~(uintptr_t)0xFFF;
if ((program_header.p_vaddr & 0xFFF) || (program_header.p_offset & 0xFFF))
return 0;
if (program_header.p_filesz == program_header.p_memsz)
return program_header.p_filesz;
return program_header.p_filesz & ~(uintptr_t)0xFFF;
}();
if (file_backed_size)
{
// aligned addresses, use file mmap
sys_mmap_t mmap_args;
mmap_args.addr = reinterpret_cast<void*>(program_header.p_vaddr);
mmap_args.fildes = fd;
mmap_args.flags = MAP_PRIVATE | MAP_FIXED;
mmap_args.len = file_backed_size;
mmap_args.off = program_header.p_offset;
mmap_args.prot = prot | PROT_WRITE;
if (auto ret = syscall(SYS_MMAP, &mmap_args); ret != static_cast<long>(program_header.p_vaddr))
print_error_and_exit("could not load program header", ret);
}
if (file_backed_size < program_header.p_memsz)
{
const uintptr_t aligned_addr = (program_header.p_vaddr + file_backed_size) & ~(uintptr_t)0xFFF;
// unaligned addresses, cannot use file mmap
sys_mmap_t mmap_args;
@ -638,29 +663,15 @@ static void load_program_header(const ElfNativeProgramHeader& program_header, in
if (auto ret = syscall(SYS_MMAP, &mmap_args); ret != static_cast<long>(aligned_addr))
print_error_and_exit("could not load program header", ret);
const uintptr_t addr = program_header.p_vaddr;
const uintptr_t size = program_header.p_filesz;
const size_t offset = program_header.p_offset;
if (file_backed_size < program_header.p_filesz)
{
const uintptr_t addr = program_header.p_vaddr + file_backed_size;
const uintptr_t size = program_header.p_filesz - file_backed_size;
const size_t offset = program_header.p_offset + file_backed_size;
if (auto ret = syscall(SYS_PREAD, fd, addr, size, offset); ret != static_cast<long>(size))
print_error_and_exit("could not load program header", ret);
}
else
{
// aligned addresses, use file mmap
sys_mmap_t mmap_args;
mmap_args.addr = reinterpret_cast<void*>(program_header.p_vaddr);
mmap_args.fildes = fd;
mmap_args.flags = MAP_PRIVATE | MAP_FIXED;
mmap_args.len = program_header.p_memsz;
mmap_args.off = program_header.p_offset;
mmap_args.prot = prot | PROT_WRITE;
if (auto ret = syscall(SYS_MMAP, &mmap_args); ret != static_cast<long>(program_header.p_vaddr))
print_error_and_exit("could not load program header", ret);
}
if (program_header.p_filesz != program_header.p_memsz)
{
memset(
reinterpret_cast<void*>(program_header.p_vaddr + program_header.p_filesz),
0x00,