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Fix next_instr_graph out-of-subroutine pointers

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The disasm-based next_instr_graph would introduce next instructions out
of the current subroutine for eg. calls, jmp to plts, etc.
This commit is contained in:
Théophile Bastian 2019-04-04 19:47:36 +02:00
parent 5f7dfb6f5f
commit 29ab916c55
1 changed files with 64 additions and 20 deletions
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54
DwarfSynth/Simplest.ml
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@ -120,7 +120,9 @@ let map_option f = function
| None -> None
| Some x -> Some (f x)
let build_next_instr (disasm: BStd.disasm): AddrSet.t AddrMap.t =
exception Block_not_in_subroutine
let build_next_instr sub_ranges (disasm: BStd.disasm): AddrSet.t AddrMap.t =
(** Build a map of memory_address -> AddrSet.t holding, for each address, the
set of instructions coming right after the instruction at given address.
There might be multiple such addresses, if the current instruction is at
@ -138,8 +140,9 @@ let build_next_instr (disasm: BStd.disasm): AddrSet.t AddrMap.t =
with _ -> cur_map)
in
build_of_instr_list new_map (elt2 :: tl)
| (cur_mem, _) :: [] ->
let last_addr = (try Some (to_int64_addr @@ BStd.Memory.min_addr cur_mem)
| (cur_mem, cur_insn) :: [] ->
let last_addr =
(try Some (to_int64_addr @@ BStd.Memory.min_addr cur_mem)
with _ -> None) in
cur_map, last_addr
@ -165,8 +168,24 @@ let build_next_instr (disasm: BStd.disasm): AddrSet.t AddrMap.t =
in
let build_of_block cur_map block =
(try
(* First, check that this block belongs to a subroutine *)
let block_first_address = (
try
to_int64_addr @@ BStd.Block.addr block
with _ -> raise Block_not_in_subroutine) in
let sub_first_addr, sub_last_addr = (
try AddrMap.find_last
(fun start_addr -> start_addr <= block_first_address) sub_ranges
with Not_found ->
raise Block_not_in_subroutine
) in
(* Add the sequence of instuctions inside the block itself *)
let cur_map, last_addr =
build_of_instr_list cur_map (BStd.Block.insns block) in
(* Then the set of possible destinations for the block terminator *)
(match last_addr with
| Some last_addr ->
let following_set = BStd.Graphs.Cfg.Node.outputs block cfg
@ -176,17 +195,24 @@ let build_next_instr (disasm: BStd.disasm): AddrSet.t AddrMap.t =
(block_addresses
(BStd.Graphs.Cfg.Edge.dst edge))
set)
|> AddrSet.filter (fun addr ->
sub_first_addr <= addr
&& addr <= sub_last_addr)
(* ^ We must ensure the landing address belongs
to the current subroutine for our purpose *)
in
AddrMap.add last_addr following_set cur_map
| None -> cur_map
)
with Block_not_in_subroutine ->
cur_map
)
in
BStd.Seq.fold (BStd.Graphs.Cfg.nodes cfg)
~init:AddrMap.empty
~f:build_of_block
let find_rbp_pop_set cfg entry =
(** Returns a BStd.Tid.Set.t of the terms actually "popping" %rbp, that is,
the terms that should trigger a change to RbpUndef of the %rbp register.
@ -701,11 +727,29 @@ let of_prog prog next_instr_graph : subroutine_cfa_map =
~init:StrMap.empty
~f:fold_step
let build_sub_ranges prog: (memory_address) AddrMap.t =
(** Builds a map mapping the first address of each subroutine to its last
address. This map can be interpreted as a list of address ranges with
easy fast access to a member (cf Map.S.find_first) *)
let fold_subroutine accu sub =
let first_addr = int64_addr_of sub in
let last_addr = find_last_addr sub in
AddrMap.add first_addr (last_addr) accu
in
let subroutines = BStd.Term.enum BStd.sub_t prog in
BStd.Seq.fold subroutines
~init:AddrMap.empty
~f:fold_subroutine
let of_proj no_rbp_undef proj : subroutine_cfa_map =
(** Extracts the `cfa_changes` of a project *)
__settings.no_rbp_undef <- no_rbp_undef ;
let next_instr_graph = build_next_instr (BStd.Project.disasm proj) in
let prog = BStd.Project.program proj in
let sub_ranges = build_sub_ranges prog in
let next_instr_graph =
build_next_instr sub_ranges (BStd.Project.disasm proj) in
of_prog prog next_instr_graph
let clean_lost_track_subs pre_dwarf : subroutine_cfa_map =