[Bug debug/41307] New: Valgrind failures / illegal reads with VTA turned on.

[ramana at gcc dot gnu dot org]

Hi, 

I'm seeing some valgrind warnings about illegal reads from addresses if I use
VTA. While compiling newlib I intermittently get segfaults in the compiler for
the attached testcase , but it seems to go away when I run this through a
debugger. 

This is with revision r151500.

Configuring a compiler with valgrind checks turned on I get the following
messages from valgrind for the attached testcase with the following options.
These warnings seem to go away if I use -fno-var-tracking. 


==29394== Invalid read of size 2
==29394==    at 0x552887: loc_descriptor (dwarf2out.c:11671)
==29394==    by 0x552980: loc_descriptor (dwarf2out.c:11688)
==29394==    by 0x552A7E: loc_descriptor (dwarf2out.c:11711)
==29394==    by 0x5578BB: add_location_or_const_value_attribute
(dwarf2out.c:13439)
==29394==    by 0x558467: gen_variable_die (dwarf2out.c:15810)
==29394==    by 0x559B0D: gen_decl_die (dwarf2out.c:17071)
==29394==    by 0x562630: decls_for_scope (dwarf2out.c:16693)
==29394==    by 0x55A785: gen_subprogram_die (dwarf2out.c:15533)
==29394==    by 0x55975D: gen_decl_die (dwarf2out.c:17004)
==29394==    by 0x595375: rest_of_handle_final (final.c:4264)
==29394==    by 0x63C323: execute_one_pass (passes.c:1292)
==29394==    by 0x63C520: execute_pass_list (passes.c:1341)
==29394==  Address 0x5004d08 is 120 bytes inside a block of size 1,608 free'd
==29394==    at 0x4A05D82: free (vg_replace_malloc.c:325)
==29394==    by 0x4E446E: empty_alloc_pool (alloc-pool.c:210)
==29394==    by 0x4E44D8: free_alloc_pool (alloc-pool.c:230)
==29394==    by 0x52203E: cselib_finish (cselib.c:2038)
==29394==    by 0x7D7E3B: vt_finalize (var-tracking.c:7425)
==29394==    by 0x7E420B: variable_tracking_main (var-tracking.c:7475)
==29394==    by 0x63C323: execute_one_pass (passes.c:1292)
==29394==    by 0x63C520: execute_pass_list (passes.c:1341)
==29394==    by 0x63C534: execute_pass_list (passes.c:1342)
==29394==    by 0x63C534: execute_pass_list (passes.c:1342)
==29394==    by 0x7041B7: tree_rest_of_compilation (tree-optimize.c:390)
==29394==    by 0x813A95: cgraph_expand_function (cgraphunit.c:1147)
==29394== 
==29394== Invalid read of size 1
==29394==    at 0x5528E3: loc_descriptor (dwarf2out.c:11934)
==29394==    by 0x552980: loc_descriptor (dwarf2out.c:11688)
==29394==    by 0x552A7E: loc_descriptor (dwarf2out.c:11711)
==29394==    by 0x5578BB: add_location_or_const_value_attribute
(dwarf2out.c:13439)
==29394==    by 0x558467: gen_variable_die (dwarf2out.c:15810)
==29394==    by 0x559B0D: gen_decl_die (dwarf2out.c:17071)
==29394==    by 0x562630: decls_for_scope (dwarf2out.c:16693)
==29394==    by 0x55A785: gen_subprogram_die (dwarf2out.c:15533)
==29394==    by 0x55975D: gen_decl_die (dwarf2out.c:17004)
==29394==    by 0x595375: rest_of_handle_final (final.c:4264)
==29394==    by 0x63C323: execute_one_pass (passes.c:1292)
==29394==    by 0x63C520: execute_pass_list (passes.c:1341)
==29394==  Address 0x5004d0a is 122 bytes inside a block of size 1,608 free'd
==29394==    at 0x4A05D82: free (vg_replace_malloc.c:325)
==29394==    by 0x4E446E: empty_alloc_pool (alloc-pool.c:210)
==29394==    by 0x4E44D8: free_alloc_pool (alloc-pool.c:230)
==29394==    by 0x52203E: cselib_finish (cselib.c:2038)
==29394==    by 0x7D7E3B: vt_finalize (var-tracking.c:7425)
==29394==    by 0x7E420B: variable_tracking_main (var-tracking.c:7475)
==29394==    by 0x63C323: execute_one_pass (passes.c:1292)
==29394==    by 0x63C520: execute_pass_list (passes.c:1341)
==29394==    by 0x63C534: execute_pass_list (passes.c:1342)
==29394==    by 0x63C534: execute_pass_list (passes.c:1342)
==29394==    by 0x7041B7: tree_rest_of_compilation (tree-optimize.c:390)
==29394==    by 0x813A95: cgraph_expand_function (cgraphunit.c:1147)
==29394== 

The command line options used to generate these warnings are : 
 -O2 -g -mcpu=cortex-a8 -mfpu=neon -mfloat-abi=hard 

and the compiler was configured with 

--target=arm-none-eabi --with-float-abi=softfp --with-fpu=neon
--with-cpu=cortex-a8 --enable-checking=valgrind
--with-mpfr=/projects/pl802_weddell/tools/linux_x86_64/ --enable-languages=c
--with-valgrind=/arm/tools/gnu/valgrind/3.5.0/rhe5-x86_64/


-- 
           Summary: Valgrind failures / illegal reads with VTA turned on.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ramana at gcc dot gnu dot org
 GCC build triplet: x86_64-linux-gnu
  GCC host triplet: x86_64-linux-gnu
GCC target triplet: arm-none-eabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41307