Re: libsanitizer merge from upstream r191666

[Konstantin Serebryany <konstantin dot s dot serebryany at gmail dot com>]

Jakub,

Your patch seems to do what it should:

% ../gcc-inst/bin/g++ -gdwarf-2 -fsanitize=address -static-libasan
../gcc/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c && ./a.out
...
Address 0x7fffb8ec95ca is located in stack of thread T0 at offset 42 in frame
    #0 0x44bd73 in main
../gcc/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c:13

But now when I run the tests I get this:

FAIL: c-c++-common/asan/clone-test-1.c  -O2 -flto
-fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: c-c++-common/asan/clone-test-1.c  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
FAIL: c-c++-common/asan/memcmp-1.c  -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
FAIL: c-c++-common/asan/memcmp-1.c  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
FAIL: c-c++-common/asan/stack-overflow-1.c  -O2 -flto
-fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: c-c++-common/asan/stack-overflow-1.c  -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
FAIL: c-c++-common/asan/swapcontext-test-1.c  -O2 -flto
-fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: c-c++-common/asan/swapcontext-test-1.c  -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
FAIL: g++.dg/asan/deep-thread-stack-1.C  -O2 -flto
-fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: g++.dg/asan/deep-thread-stack-1.C  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)

W/o your change they pass.
Could you please remind me how to debug this (i.e. how to run the
exact test commands manually)?

Thanks!
--kcc

On Tue, Oct 29, 2013 at 6:49 AM, Konstantin Serebryany
<konstantin.s.serebryany@gmail.com> wrote:
> Thanks!
> (At this time I will be slow with response due to travel)
>
> --kcc
>
>
> On Tue, Oct 29, 2013 at 5:13 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>
>> > On Wed, Oct 2, 2013 at 12:51 PM, Konstantin Serebryany
>> > > 2013-10-XX  Kostya Serebryany  <kcc@google.com>
>> > >
>> > >         * g++.dg/asan/asan_test.cc: Update the test
>> > >         to match the fresh asan run-time.
>> > >         * c-c++-common/asan/stack-overflow-1.c: Ditto.
>> > >
>> > > =========== gcc/ChangeLog
>> > >
>> > > 2013-10-XX  Kostya Serebryany  <kcc@google.com>
>> > >
>> > >         * asan.c: Update to match the changed asan API.
>> > >         (asan_emit_stack_protection): update the string stored in the
>> > >         stack red zone to match new API. Store the PC of the current
>> > >         function in the red zone.
>> > >         (asan_global_struct): update the __asan_global definition to
>> > > match
>> > >         the new API.
>> > >         (asan_add_global): Ditto.
>> > >         * sanitizer.def: rename __asan_init_v1 to __asan_init_v3
>>
>> The "Update to match the changed asan API." should either be
>> dropped, or come on a line before the * asan.c
>> (asan_emit_stack_protection):
>> line.  All descriptions should start with capital letters, end with ., two
>> spaces after . if followed by another sentence.
>>
>> Besides that, here is (completely untested) attempt to give you
>> the pc of the first instruction of the function and two minor changes
>> (pp_string (something, "") is useless and in two spots I've noticed
>> you didn't add space before ( in function call).
>>
>> Finally, if the new libasan is ABI incompatible with the old one, which
>> seems it is, then libsanitizer/asan/libtool-version (and perhaps also
>> libsanitizer/tsan/libtool-version, haven't looked if that one is ABI
>> compatible or not) needs to be bumped (to 1:0:0 ?).
>>
>> --- gcc/asan.c.jj       2013-10-29 11:58:30.000000000 +0100
>> +++ gcc/asan.c  2013-10-29 13:04:07.709667677 +0100
>> @@ -921,6 +921,15 @@ asan_clear_shadow (rtx shadow_mem, HOST_
>>    add_int_reg_note (jump, REG_BR_PROB, REG_BR_PROB_BASE * 80 / 100);
>>  }
>>
>> +void
>> +asan_function_start (void)
>> +{
>> +  section *fnsec = function_section (current_function_decl);
>> +  switch_to_section (fnsec);
>> +  ASM_OUTPUT_DEBUG_LABEL (asm_out_file, "LASANPC",
>> +                         current_function_funcdef_no);
>> +}
>> +
>>  /* Insert code to protect stack vars.  The prologue sequence should be
>> emitted
>>     directly, epilogue sequence returned.  BASE is the register holding
>> the
>>     stack base, against which OFFSETS array offsets are relative to,
>> OFFSETS
>> @@ -936,12 +945,13 @@ asan_emit_stack_protection (rtx base, HO
>>                             int length)
>>  {
>>    rtx shadow_base, shadow_mem, ret, mem;
>> +  char buf[30];
>>    unsigned char shadow_bytes[4];
>>    HOST_WIDE_INT base_offset = offsets[length - 1], offset, prev_offset;
>>    HOST_WIDE_INT last_offset, last_size;
>>    int l;
>>    unsigned char cur_shadow_byte = ASAN_STACK_MAGIC_LEFT;
>> -  tree str_cst;
>> +  tree str_cst, decl;
>>
>>    if (shadow_ptr_types[0] == NULL_TREE)
>>      asan_init_shadow_ptr_types ();
>> @@ -949,7 +959,6 @@ asan_emit_stack_protection (rtx base, HO
>>    /* First of all, prepare the description string.  */
>>    pretty_printer asan_pp;
>>
>> -  pp_string (&asan_pp, "");
>>    pp_decimal_int (&asan_pp, length / 2 - 1);
>>    pp_space (&asan_pp);
>>    for (l = length - 2; l; l -= 2)
>> @@ -980,7 +989,17 @@ asan_emit_stack_protection (rtx base, HO
>>    mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
>>    emit_move_insn (mem, expand_normal (str_cst));
>>    mem = adjust_address (mem, VOIDmode, GET_MODE_SIZE (ptr_mode));
>> -  emit_move_insn (mem, expand_normal (str_cst));  // FIXME: should be
>> cur_pc.
>> +  ASM_GENERATE_INTERNAL_LABEL (buf, "LASANPC",
>> current_function_funcdef_no);
>> +  decl = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
>> +                    VAR_DECL, get_identifier (buf), char_type_node);
>> +  TREE_ADDRESSABLE (decl) = 1;
>> +  TREE_READONLY (decl) = 1;
>> +  DECL_ARTIFICIAL (decl) = 1;
>> +  DECL_IGNORED_P (decl) = 1;
>> +  TREE_STATIC (decl) = 1;
>> +  TREE_PUBLIC (decl) = 0;
>> +  TREE_USED (decl) = 1;
>> +  emit_move_insn (mem, expand_normal (build_fold_addr_expr (decl)));
>>    shadow_base = expand_binop (Pmode, lshr_optab, base,
>>                               GEN_INT (ASAN_SHADOW_SHIFT),
>>                               NULL_RTX, 1, OPTAB_DIRECT);
>> @@ -1979,8 +1998,8 @@ asan_add_global (tree decl, tree type, v
>>      pp_string (&asan_pp, "<unknown>");
>>    str_cst = asan_pp_string (&asan_pp);
>>
>> -  pp_string(&module_name_pp, main_input_filename);
>> -  module_name_cst = asan_pp_string(&module_name_pp);
>> +  pp_string (&module_name_pp, main_input_filename);
>> +  module_name_cst = asan_pp_string (&module_name_pp);
>>
>>    if (asan_needs_local_alias (decl))
>>      {
>> --- gcc/asan.h.jj       2013-01-11 09:02:50.000000000 +0100
>> +++ gcc/asan.h  2013-10-29 12:37:54.190798947 +0100
>> @@ -21,6 +21,7 @@ along with GCC; see the file COPYING3.
>>  #ifndef TREE_ASAN
>>  #define TREE_ASAN
>>
>> +extern void asan_function_start (void);
>>  extern void asan_finish_file (void);
>>  extern rtx asan_emit_stack_protection (rtx, HOST_WIDE_INT *, tree *,
>> int);
>>  extern bool asan_protect_global (tree);
>> --- gcc/final.c.jj      2013-10-23 14:43:12.000000000 +0200
>> +++ gcc/final.c 2013-10-29 12:49:33.609176613 +0100
>> @@ -78,6 +78,7 @@ along with GCC; see the file COPYING3.
>>  #include "cfgloop.h"
>>  #include "params.h"
>>  #include "tree-pretty-print.h" /* for dump_function_header */
>> +#include "asan.h"
>>
>>  #ifdef XCOFF_DEBUGGING_INFO
>>  #include "xcoffout.h"          /* Needed for external data
>> @@ -1738,6 +1739,9 @@ final_start_function (rtx first, FILE *f
>>
>>    high_block_linenum = high_function_linenum = last_linenum;
>>
>> +  if (flag_sanitize & SANITIZE_ADDRESS)
>> +    asan_function_start ();
>> +
>>    if (!DECL_IGNORED_P (current_function_decl))
>>      debug_hooks->begin_prologue (last_linenum, last_filename);
>>
>>
>>
>>         Jakub
>
>