Re: [Crash-utility] [PATCH v2] GDB: fix completion related libstdc++ assert

Currently crash built with some specific flags (-D_GLIBCXX_ASSERTIONS and etc.) may abort and print the following error when running the gdb list command or tab-completion of symbols. For example: crash> l panic /usr/include/c++/11/string_view:234: ... Aborted (core dumped) crash> p "TAB completion" crash> p /usr/include/c++/11/string_view:234: ... Aborted (core dumped) When the name string is null(the length of name is zero), there are multiple places where array access is out of bounds in the gdb/ada-lang.c (see ada_fold_name() and ada_lookup_name_info()). The patch backports these gdb patches: 6a780b676637 ("Fix completion related libstdc++ assert when using -D_GLIBCXX_DEBUG") 2ccee230f830 ("Fix off-by-one error in ada_fold_name") Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- gdb-10.2.patch | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/gdb-10.2.patch b/gdb-10.2.patch index 1332b6638028..f5e4c06e6f97 100644 --- a/gdb-10.2.patch +++ b/gdb-10.2.patch @@ -1591,3 +1591,34 @@ max += 2; limit = cols / max; if (limit != 1 && (limit * max == cols)) +--- gdb-10.2/gdb/ada-lang.c.orig ++++ gdb-10.2/gdb/ada-lang.c +@@ -997,7 +997,7 @@ ada_fold_name (gdb::string_view name) + int len = name.size (); + GROW_VECT (fold_buffer, fold_buffer_size, len + 1); + +- if (name[0] == '\'') ++ if (!name.empty () && name[0] == '\'') + { + strncpy (fold_buffer, name.data () + 1, len - 2); + fold_buffer[len - 2] = '\000'; +@@ -1006,8 +1006,9 @@ ada_fold_name (gdb::string_view name) + { + int i; + +- for (i = 0; i <= len; i += 1) ++ for (i = 0; i < len; i += 1) + fold_buffer[i] = tolower (name[i]); ++ fold_buffer[i] = '\0'; + } + + return fold_buffer; +@@ -13596,7 +13597,7 @@ ada_lookup_name_info::ada_lookup_name_info (const lookup_name_info &lookup_name) + { + gdb::string_view user_name = lookup_name.name (); + +- if (user_name[0] == '<') ++ if (!user_name.empty () && user_name[0] == '<') + { + if (user_name.back () == '>') + m_encoded_name -- 2.20.1