/*
Processes a LC_UNIXTHREAD command.
Returns 0 on success, -1 on any failure.
The stack is mapped in and returned in *out_stack.
The thread's entry point is returned in *out_entry.
*/
static int
load_unixthread(vki_uint8_t **out_stack_start, vki_uint8_t **out_stack_end,
vki_uint8_t **out_entry, struct thread_command *threadcmd)
{
int err;
vki_uint8_t *stack_end;
int customstack;
err = load_genericthread(&stack_end, &customstack, out_entry, threadcmd);
if (err) return -1;
if (!stack_end) {
print("bad executable (no thread stack)\n");
return -1;
}
if (!customstack) {
// Map the stack
vki_size_t stacksize = VG_PGROUNDUP(default_stack_size());
vm_address_t stackbase = VG_PGROUNDDN(stack_end-stacksize);
SysRes res;
res = VG_(am_mmap_anon_fixed_client)(stackbase, stacksize, VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC);
check_mmap(res, stackbase, stacksize, "load_unixthread1");
if (out_stack_start) *out_stack_start = (vki_uint8_t *)stackbase;
} else {
// custom stack - mapped via __UNIXTHREAD segment
}
if (out_stack_end) *out_stack_end = stack_end;
return 0;
}
static int
handle_lcmain ( vki_uint8_t **out_stack_start,
vki_uint8_t **out_stack_end,
vki_size_t requested_size )
{
if (requested_size == 0) {
requested_size = default_stack_size();
}
requested_size = VG_PGROUNDUP(requested_size);
const vki_size_t HACK = 64 * 1024 * 1024;
requested_size += HACK;
SysRes res = VG_(am_mmap_anon_float_client)(requested_size,
VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC);
check_mmap_float(res, requested_size, "handle_lcmain");
vg_assert(!sr_isError(res));
*out_stack_start = (vki_uint8_t*)sr_Res(res);
*out_stack_end = *out_stack_start + requested_size - 1;
Bool need_discard = False;
res = VG_(am_munmap_client)(&need_discard, (Addr)*out_stack_start, HACK);
if (sr_isError(res)) return -1;
vg_assert(!need_discard); // True == wtf?
*out_stack_start += HACK;
return 0;
}
