- let ksym_addrs = List.filter_map (
- fun ksym -> try Some (lookup_ksym ksym) with Not_found -> None
- ) common_ksyms in
-
- (* Search for those kernel addresses in the image. We're looking
- * for the table kallsyms_addresses followed by kallsyms_num_syms
- * (number of symbols in the table).
- *)
- let ksym_addrs = List.map (MMap.find_pointer_all mem) ksym_addrs in
- let ksym_addrs = List.concat ksym_addrs in
-
- (* Test each one to see if it's a candidate list of kernel
- * addresses followed by length of list.
- *)
- let kallsymtabs = List.filter_map (
- fun addr ->
- (* Search upwards from address until we find the length field.
- * If found, jump backwards by length and check all addresses.
- *)
- if debug then
- eprintf "%s: testing candidate kallsyms at %Lx\n" name addr;
- let rec loop addr =
- let addrp = MMap.follow_pointer mem addr in
- if MMap.is_mapped mem addrp then
- loop (MMap.succ_long mem addr) (* continue up the table *)
- else
- if addrp >= min_kallsyms_tabsize &&
- addrp <= max_kallsyms_tabsize then (
- (* addrp might be the symbol count. Count backwards and
- * check the full table.
- *)
- let num_entries = Int64.to_int addrp in
- let entry_size = bytes_of_wordsize (MMap.get_wordsize mem) in
- let start_addr =
- addr -^ Int64.of_int (entry_size * num_entries) in
- let end_addr = addr in
- let rec loop2 addr =
- if addr < end_addr then (
- let addrp = MMap.follow_pointer mem addr in
- if MMap.is_mapped mem addrp then
- loop2 (MMap.succ_long mem addr)
- else
- None (* can't verify the full address table *)
- ) else
- (* ok! *)
- let names_addr = MMap.succ_long mem end_addr in
- if debug then
- eprintf "%s: candidate kallsyms found at %Lx (names_addr at %Lx, num_entries %d)\n"
- name start_addr names_addr num_entries;
- Some (start_addr, num_entries, names_addr)
- in
- loop2 start_addr
- )
- else
- None (* forget it *)
- in
- match loop addr with
- | None -> None
- | Some (start_addr, num_entries, names_addr) ->
- (* As an additional verification, check the list of
- * kallsyms_names.
- *)
- try
- (* If the first byte is '\000' and is followed by a
- * C identifier, then this is old-school list of
- * symbols with prefix compression as in 2.6.9.
- * Otherwise Huffman-compressed kallsyms as in
- * 2.6.25.
- *)
- if MMap.get_byte mem names_addr = 0 &&
- MMap.is_C_identifier mem (names_addr+^1L) then (
- let names = ref [] in
- let prev = ref "" in
- let rec loop names_addr start_addr num =
- if num > 0 then (
- let prefix = MMap.get_byte mem names_addr in
- let prefix = String.sub !prev 0 prefix in
- let name = MMap.get_string mem (names_addr+^1L) in
- let len = String.length name in
- let name = prefix ^ name in
- prev := name;
- let names_addr = names_addr +^ Int64.of_int len +^ 2L in
- let sym_value = MMap.follow_pointer mem start_addr in
- let start_addr = MMap.succ_long mem start_addr in
- (*eprintf "%S -> %Lx\n" name sym_value;*)
- names := (name, sym_value) :: !names;
- loop names_addr start_addr (num-1)
- )
- in
- loop names_addr start_addr num_entries;
- let names = List.rev !names in
-
- Some (start_addr, num_entries, names_addr,
- Uncompressed names)
- )
- else ( (* new-style "compressed" names. *)
- let compressed_names = ref [] in
- let rec loop names_addr start_addr num =
- if num > 0 then (
- let len = MMap.get_byte mem names_addr in
- let name = MMap.get_bytes mem (names_addr+^1L) len in
- let names_addr = names_addr +^ Int64.of_int len +^ 1L in
- let sym_value = MMap.follow_pointer mem start_addr in
- let start_addr = MMap.succ_long mem start_addr in
- compressed_names :=
- (name, sym_value) :: !compressed_names;
- loop names_addr start_addr (num-1)
- ) else
- names_addr
- in
- let markers_addr = loop names_addr start_addr num_entries in
- let markers_addr = MMap.align mem markers_addr in
- let compressed_names = List.rev !compressed_names in
-
- Some (start_addr, num_entries, names_addr,
- Compressed (compressed_names, markers_addr))
- )
- with
- Invalid_argument _ -> None (* bad names list *)
- ) ksym_addrs in
-
- if debug then (
- eprintf "%s: candidate kallsyms at:\n" name;
- List.iter (
- function
- | (start_addr, num_entries, names_addr, Uncompressed _) ->
- eprintf "\t%Lx %d entries names_addr=%Lx old-style\n%!"
- start_addr num_entries names_addr
- | (start_addr, num_entries, names_addr,
- Compressed (_, markers_addr)) ->
- eprintf "\t%Lx %d entries names_addr=%Lx markers_addr=%Lx\n%!"
- start_addr num_entries names_addr markers_addr
- ) kallsymtabs
- );
-
- (* Vote for the most popular symbol table candidate and
- * enhance the function for looking up ksyms.
- *)
- let lookup_ksym =
- let freqs = frequency kallsymtabs in
- match freqs with
- | [] ->
- (* Can't find any kallsymtabs, just return the lookup_ksym
- * function generated previously from the exported symbols.
- *)
- lookup_ksym
-
- | (_, (_, _, _, Uncompressed names)) :: _ ->
- let lookup_ksym name =
- try (* first look it up in kallsyms table. *)
- List.assoc name names
- with Not_found -> (* try the old exports table instead *)
- lookup_ksym name
- in
- lookup_ksym
-
- | (_, (start_addr, num_entries, names_addr,
- Compressed (compressed_names, markers_addr))) :: _ ->
- (* Skip the markers and look for the token table. *)
- let num_markers = Int64.of_int ((num_entries + 255) / 256) in
- let marker_size =
- Int64.of_int (bytes_of_wordsize (MMap.get_wordsize mem)) in
- let tokens_addr = markers_addr +^ marker_size *^ num_markers in
-
- (* Now read out the compression tokens, which are just
- * 256 ASCIIZ strings that map bytes in the compression
- * names to substrings.
- *)
- let tokens = Array.make 256 "" in
- let rec loop i addr =
- if i < 256 then (
- let str = MMap.get_string mem addr in
- let len = String.length str in
- let addr = addr +^ Int64.of_int (len+1) in
- tokens.(i) <- str;
- loop (i+1) addr
- )
- in
- loop 0 tokens_addr;
-
- (* Expand the compressed names using the tokens. *)
- let names = List.filter_map (
- fun (name, sym_value) ->
- let f c = tokens.(Char.code c) in
- let name = String.replace_chars f name in
- (* First character in uncompressed output is the symbol
- * type, eg. 'T'/'t' for text etc.
- *)
- (* NOTE: Symbol names are NOT unique
- * (eg. 'con_start' is both a function and data in
- * some kernels). XXX We need to handle this situation
- * better.
- *)
- (*let typ = name.[0] in*)
- let name = String.sub name 1 (String.length name - 1) in
- (*eprintf "%S -> %Lx\n" name sym_value;*)
- Some (name, sym_value)
- ) compressed_names in
-
- let lookup_ksym name =
- try (* first look it up in kallsyms table. *)
- List.assoc name names
- with Not_found -> (* try the old exports table instead *)
- lookup_ksym name
- in
-
- lookup_ksym in
-
- if debug then (
- let end_t = gettimeofday () in
- eprintf "timing: searching for kallsyms took %f seconds\n%!"
- (end_t -. start_t)
- );
-
- (* Just wrap the lookup_ksym call in something which prints
- * the query when debug is set.
- *)
- let lookup_ksym =