From 7d1a572d6b5194d36a96f36b3d28ce591341deb6 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Thu, 14 Jul 2022 20:47:54 +0200 Subject: [gdb/symtab] Fix data race in cooked_index_functions::expand_symtabs_matching When building gdb with -fsanitize-threads and running test-case gdb.ada/char_enum_unicode.exp, I run into: ... WARNING: ThreadSanitizer: data race (pid=21301)^M Write of size 8 at 0x7b2000008080 by main thread:^M #0 free (libtsan.so.2+0x4c5e2)^M #1 _dl_close_worker (ld-linux-x86-64.so.2+0x4b7b)^M #2 convert_between_encodings() charset.c:584^M ... #21 cooked_index_functions::expand_symtabs_matching() read.c:18606 ... This is fixed by making cooked_index_functions::expand_symtabs_matching wait for the cooked index finalization to be done. Tested on x86_64-linux. https://sourceware.org/bugzilla/show_bug.cgi?id=29311 https://sourceware.org/bugzilla/show_bug.cgi?id=29286 --- gdb/dwarf2/cooked-index.h | 11 +++++++++-- gdb/dwarf2/read.c | 8 +++++--- 2 files changed, 14 insertions(+), 5 deletions(-) (limited to 'gdb') diff --git a/gdb/dwarf2/cooked-index.h b/gdb/dwarf2/cooked-index.h index 439cbb1..f3c2648 100644 --- a/gdb/dwarf2/cooked-index.h +++ b/gdb/dwarf2/cooked-index.h @@ -295,6 +295,14 @@ public: explicit cooked_index_vector (vec_type &&vec); DISABLE_COPY_AND_ASSIGN (cooked_index_vector); + /* Wait until the finalization of the entire cooked_index_vector is + done. */ + void wait () + { + for (auto &item : m_vector) + item->wait (); + } + ~cooked_index_vector () { /* The 'finalize' methods may be run in a different thread. If @@ -303,8 +311,7 @@ public: complete avoids this problem; and the cost seems ignorable because creating and immediately destroying the debug info is a relatively rare thing to do. */ - for (auto &item : m_vector) - item->wait (); + wait (); } /* A range over a vector of subranges. */ diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 5ca787c..bcd0110 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -18569,6 +18569,11 @@ cooked_index_functions::expand_symtabs_matching if (per_objfile->per_bfd->index_table == nullptr) return true; + cooked_index_vector *table + = (static_cast + (per_objfile->per_bfd->index_table.get ())); + table->wait (); + dw_expand_symtabs_matching_file_matcher (per_objfile, file_matcher); /* This invariant is documented in quick-functions.h. */ @@ -18604,9 +18609,6 @@ cooked_index_functions::expand_symtabs_matching language_ada }; - cooked_index_vector *table - = (static_cast - (per_objfile->per_bfd->index_table.get ())); for (enum language lang : unique_styles) { std::vector name_vec -- cgit v1.1