Re: [PATCH] Try to fix recently introduced crashes in ggc_collect

[Richard Biener <rguenther@suse.de>]

On May 18, 2017 5:15:43 PM GMT+02:00, Bernd Edlinger <bernd.edlinger@hotmail.de> wrote:
>Hi,
>
>
>this attempts to fix occasional segmentation faults that are present in
>the current snapshot, while previous snapshot was stable.
>
>I observed numerous crashes but all were non-reproducible,
>like the following example:
>
>In file included from 
>/home/ed/gnu/gcc-build-1/x86_64-pc-linux-gnu/libstdc++-v3/include/string:52:0,
>                  from 
>/home/ed/gnu/gcc-8-20170514-1/gcc/testsuite/g++.dg/asan/asan_test_config.h:19,
>                  from 
>/home/ed/gnu/gcc-8-20170514-1/gcc/testsuite/g++.dg/asan/asan_test_utils.h:17,
>                  from 
>/home/ed/gnu/gcc-8-20170514-1/gcc/testsuite/g++.dg/asan/asan_globals_test.cc:12,
>                  from 
>/home/ed/gnu/gcc-8-20170514-1/gcc/testsuite/g++.dg/asan/asan_globals_test-wrapper.cc:2:
>/home/ed/gnu/gcc-build-1/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:6277:22:
>
>internal compiler error: Segmentation fault
>0xd7e17f crash_signal
>         ../../gcc-8-20170514-1/gcc/toplev.c:337
>0x8f23fe ggc_set_mark(void const*)
>         ../../gcc-8-20170514-1/gcc/ggc-page.c:1546
>0x7e6a5f gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:133
>0x7e8c7a gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:235
>0x7e8882 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:365
>0x81b26d gt_ggc_mx_cp_binding_level(void*)
>         ./gt-cp-name-lookup.h:72
>0x7e6d85 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:648
>0x7e8ad2 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:221
>0x7e8eeb gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:337
>0x7e8a3c gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:441
>0x7e7304 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:606
>0x81b352 gt_ggc_mx_cxx_binding(void*)
>         ./gt-cp-name-lookup.h:60
>0x7e6d85 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:648
>0x7e8ef5 gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:336
>0x7e8a3c gt_ggc_mx_lang_tree_node(void*)
>         ./gt-cp-tree.h:441
>0xb2edbe void gt_ggc_mx<tree_node*>(vec<tree_node*, va_gc, vl_embed>*)
>         ../../gcc-8-20170514-1/gcc/vec.h:1110
>0xb2edbe gt_ggc_mx_vec_tree_va_gc_(void*)
>         /home/ed/gnu/gcc-build-1/gcc/gtype-desc.c:1737
>0xac59f5 ggc_mark_root_tab
>         ../../gcc-8-20170514-1/gcc/ggc-common.c:77
>0xac5c50 ggc_mark_roots()
>         ../../gcc-8-20170514-1/gcc/ggc-common.c:94
>0x8f2de7 ggc_collect()
>         ../../gcc-8-20170514-1/gcc/ggc-page.c:2206
>Please submit a full bug report,
>with preprocessed source if appropriate.
>Please include the complete backtrace with any bug report.
>
>
>The following patch fixes one rather suspicious static tree
>object that did not have the GTY attribute, and was therefore
>apparently not in the GC root set.
>
>
>Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
>Is it OK for trunk?

OK.

Richard.

>
>Thanks
>Bernd.