From 55ada9157de78b614f56169643942f31d36b0035 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Mon, 8 Aug 2022 09:22:44 +0100 Subject: cheri: elf: add an RW capability to link_map For each module keep an RX and an RW root capability. Use the existing l_map_start for RX (covering all load segments) and add l_rw_start for RW (covering all writable load segments). For relocation processing, we also need individual RW ranges to decide which objects need to be derived from RW and RX capabilities. In practice most modules have exactly one RW segment and it's unlikely that any module needs more than four distinct ranges to tightly cover the RW mappings. Only added on CHERI targets so always has to be used behind ifdef. --- include/link.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/link.h b/include/link.h index 6dd8e712c4..e1dca89762 100644 --- a/include/link.h +++ b/include/link.h @@ -257,6 +257,18 @@ struct link_map ElfW(Addr) l_map_end; /* End of the executable part of the mapping. */ ElfW(Addr) l_text_end; +#ifdef __CHERI_PURE_CAPABILITY__ + /* Writable part of the mapping (may have non-writable holes). */ + elfptr_t l_rw_start; +# define DL_MAX_RW_COUNT 4 + /* Writable ranges: objects are writable in these ranges. */ + int l_rw_count; + struct rw_range + { + ElfW(Addr) start; + ElfW(Addr) end; + } l_rw_range[DL_MAX_RW_COUNT]; +#endif /* Default array for 'l_scope'. */ struct r_scope_elem *l_scope_mem[4]; -- cgit 1.4.1