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Add linked list allocator with automatic resizing

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Fix memory leaks in exec
Remove warnings
This commit is contained in:
Jeremy Soller
2018-01-29 21:29:24 -07:00
parent 015b79430e
commit 761fe30bf3
12 changed files with 255 additions and 117 deletions
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src/syscall/process.rs
+85 -69
View File
@@ -542,8 +542,14 @@ impl Drop for ExecFile {
}
}
fn exec_noreturn(elf: elf::Elf, canonical: Box<[u8]>, setuid: Option<u32>, setgid: Option<u32>, args: Box<[Box<[u8]>]>) -> ! {
let entry = elf.entry();
fn exec_noreturn(
canonical: Box<[u8]>,
setuid: Option<u32>,
setgid: Option<u32>,
data: Box<[u8]>,
args: Box<[Box<[u8]>]>
) -> ! {
let entry;
let mut sp = ::USER_STACK_OFFSET + ::USER_STACK_SIZE - 256;
{
@@ -567,69 +573,76 @@ fn exec_noreturn(elf: elf::Elf, canonical: Box<[u8]>, setuid: Option<u32>, setgi
// Map and copy new segments
let mut tls_option = None;
for segment in elf.segments() {
if segment.p_type == program_header::PT_LOAD {
let voff = segment.p_vaddr % 4096;
let vaddr = segment.p_vaddr - voff;
{
let elf = elf::Elf::from(&data).unwrap();
entry = elf.entry();
for segment in elf.segments() {
if segment.p_type == program_header::PT_LOAD {
let voff = segment.p_vaddr % 4096;
let vaddr = segment.p_vaddr - voff;
let mut memory = context::memory::Memory::new(
VirtualAddress::new(vaddr as usize),
segment.p_memsz as usize + voff as usize,
EntryFlags::NO_EXECUTE | EntryFlags::WRITABLE,
true
);
let mut memory = context::memory::Memory::new(
VirtualAddress::new(vaddr as usize),
segment.p_memsz as usize + voff as usize,
EntryFlags::NO_EXECUTE | EntryFlags::WRITABLE,
true
);
unsafe {
// Copy file data
intrinsics::copy((elf.data.as_ptr() as usize + segment.p_offset as usize) as *const u8,
segment.p_vaddr as *mut u8,
segment.p_filesz as usize);
unsafe {
// Copy file data
intrinsics::copy((elf.data.as_ptr() as usize + segment.p_offset as usize) as *const u8,
segment.p_vaddr as *mut u8,
segment.p_filesz as usize);
}
let mut flags = EntryFlags::NO_EXECUTE | EntryFlags::USER_ACCESSIBLE;
if segment.p_flags & program_header::PF_R == program_header::PF_R {
flags.insert(EntryFlags::PRESENT);
}
// W ^ X. If it is executable, do not allow it to be writable, even if requested
if segment.p_flags & program_header::PF_X == program_header::PF_X {
flags.remove(EntryFlags::NO_EXECUTE);
} else if segment.p_flags & program_header::PF_W == program_header::PF_W {
flags.insert(EntryFlags::WRITABLE);
}
memory.remap(flags);
context.image.push(memory.to_shared());
} else if segment.p_type == program_header::PT_TLS {
let memory = context::memory::Memory::new(
VirtualAddress::new(::USER_TCB_OFFSET),
4096,
EntryFlags::NO_EXECUTE | EntryFlags::WRITABLE | EntryFlags::USER_ACCESSIBLE,
true
);
let aligned_size = if segment.p_align > 0 {
((segment.p_memsz + (segment.p_align - 1))/segment.p_align) * segment.p_align
} else {
segment.p_memsz
};
let rounded_size = ((aligned_size + 4095)/4096) * 4096;
let rounded_offset = rounded_size - aligned_size;
let tcb_offset = ::USER_TLS_OFFSET + rounded_size as usize;
unsafe { *(::USER_TCB_OFFSET as *mut usize) = tcb_offset; }
context.image.push(memory.to_shared());
tls_option = Some((
VirtualAddress::new(segment.p_vaddr as usize),
segment.p_filesz as usize,
rounded_size as usize,
rounded_offset as usize,
));
}
let mut flags = EntryFlags::NO_EXECUTE | EntryFlags::USER_ACCESSIBLE;
if segment.p_flags & program_header::PF_R == program_header::PF_R {
flags.insert(EntryFlags::PRESENT);
}
// W ^ X. If it is executable, do not allow it to be writable, even if requested
if segment.p_flags & program_header::PF_X == program_header::PF_X {
flags.remove(EntryFlags::NO_EXECUTE);
} else if segment.p_flags & program_header::PF_W == program_header::PF_W {
flags.insert(EntryFlags::WRITABLE);
}
memory.remap(flags);
context.image.push(memory.to_shared());
} else if segment.p_type == program_header::PT_TLS {
let memory = context::memory::Memory::new(
VirtualAddress::new(::USER_TCB_OFFSET),
4096,
EntryFlags::NO_EXECUTE | EntryFlags::WRITABLE | EntryFlags::USER_ACCESSIBLE,
true
);
let aligned_size = if segment.p_align > 0 {
((segment.p_memsz + (segment.p_align - 1))/segment.p_align) * segment.p_align
} else {
segment.p_memsz
};
let rounded_size = ((aligned_size + 4095)/4096) * 4096;
let rounded_offset = rounded_size - aligned_size;
let tcb_offset = ::USER_TLS_OFFSET + rounded_size as usize;
unsafe { *(::USER_TCB_OFFSET as *mut usize) = tcb_offset; }
context.image.push(memory.to_shared());
tls_option = Some((
VirtualAddress::new(segment.p_vaddr as usize),
segment.p_filesz as usize,
rounded_size as usize,
rounded_offset as usize,
));
}
}
// Data no longer required, can deallocate
drop(data);
// Map heap
context.heap = Some(context::memory::Memory::new(
VirtualAddress::new(::USER_HEAP_OFFSET),
@@ -713,6 +726,9 @@ fn exec_noreturn(elf: elf::Elf, canonical: Box<[u8]>, setuid: Option<u32>, setgi
context.image.push(memory.to_shared());
}
// Args no longer required, can deallocate
drop(args);
context.actions = Arc::new(Mutex::new(vec![(
SigAction {
sa_handler: unsafe { mem::transmute(SIG_DFL) },
@@ -861,10 +877,6 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
match elf::Elf::from(&data) {
Ok(elf) => {
// Drop so that usage is not allowed after unmapping context
drop(path);
drop(arg_ptrs);
// We check the validity of all loadable sections here
for segment in elf.segments() {
if segment.p_type == program_header::PT_LOAD {
@@ -880,17 +892,21 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
}
}
}
// This is the point of no return, quite literaly. Any checks for validity need
// to be done before, and appropriate errors returned. Otherwise, we have nothing
// to return to.
exec_noreturn(elf, canonical.into_boxed_slice(), setuid, setgid, args.into_boxed_slice());
},
Err(err) => {
println!("exec: failed to execute {}: {}", unsafe { str::from_utf8_unchecked(path) }, err);
Err(Error::new(ENOEXEC))
return Err(Error::new(ENOEXEC));
}
}
// Drop so that usage is not allowed after unmapping context
drop(path);
drop(arg_ptrs);
// This is the point of no return, quite literaly. Any checks for validity need
// to be done before, and appropriate errors returned. Otherwise, we have nothing
// to return to.
exec_noreturn(canonical.into_boxed_slice(), setuid, setgid, data.into_boxed_slice(), args.into_boxed_slice());
}
pub fn exit(status: usize) -> ! {