ExternalVendorCode/genode
1
0
Fork 0
mirror of https://github.com/genodelabs/genode.git synced 2025-01-31 00:24:51 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

ldso: place dynamic allocations within linker area

Browse Source 
This is needed to execute the tool-chain scenario on base-nova.
Otherwise, the fork mechanism stumbles upon a region conflict
between ldso allocations and the application heap.

Fixes #3706
This commit is contained in:
Norman Feske 2020-03-20 16:26:20 +01:00
parent 0f3ac4cb9f
commit 685bd763f9
1 changed files with 37 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
repos/base/src/lib/ldso/main.cc
View File

@ -669,6 +669,42 @@ static Genode::Constructible<Heap> &heap()
void Genode::init_ldso_phdr(Env &env)
{
/*
* Custom 'Region_map' that is used to place heap allocations of the
* dynamic linker within the linker area, keeping the rest of the
* component's virtual address space unpolluted.
*/
struct Linker_area_region_map : Region_map
{
struct Not_implemented : Exception { };
Local_addr attach(Dataspace_capability ds, size_t, off_t,
bool, Local_addr, bool, bool) override
{
size_t const size = Dataspace_client(ds).size();
Linker::Region_map &linker_area = *Linker::Region_map::r();
addr_t const at = linker_area.alloc_region_at_end(size);
(void)linker_area.attach_at(ds, at, size, 0UL);
return at;
}
void detach(Local_addr) override { throw Not_implemented(); }
void fault_handler(Signal_context_capability) override { }
State state() override { throw Not_implemented(); }
Dataspace_capability dataspace() override { throw Not_implemented(); }
Linker_area_region_map() { }
};
Linker_area_region_map &ld_rm = *unmanaged_singleton<Linker_area_region_map>();
/*
* Use a statically allocated initial block to make the first dynamic
* allocations deterministic. This assumption is required by the libc's
@ -680,7 +716,7 @@ void Genode::init_ldso_phdr(Env &env)
* must reside on the same addresses in the parent and child.
*/
static char initial_block[8*1024];
heap().construct(&env.ram(), &env.rm(), Heap::UNLIMITED,
heap().construct(&env.ram(), &ld_rm, Heap::UNLIMITED,
initial_block, sizeof(initial_block));
/* load program headers of linker now */