From af62665e1339d970ab8ea3e3260dbdbde0009c2d Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Tue, 31 Mar 2020 07:29:53 -0600 Subject: [PATCH] Don't pass NULL to memcpy in gdb I compiled gdb with -fsanitize=undefined and ran the test suite. A couple of reports came from passing NULL to memcpy, e.g.: [...]btrace-common.cc:176:13: runtime error: null pointer passed as argument 2, which is declared to never be null While it would be better to fix this in the standard, in the meantime it seems easy to avoid this error. gdb/ChangeLog 2020-03-31 Tom Tromey * dwarf2/abbrev.c (abbrev_table::read): Conditionally call memcpy. gdbsupport/ChangeLog 2020-03-31 Tom Tromey * btrace-common.cc (btrace_data_append): Conditionally call memcpy. --- gdb/ChangeLog | 5 +++++ gdb/dwarf2/abbrev.c | 5 +++-- gdbsupport/ChangeLog | 5 +++++ gdbsupport/btrace-common.cc | 3 ++- 4 files changed, 15 insertions(+), 3 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 67aa8721421..d3873da04b4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2020-03-31 Tom Tromey + + * dwarf2/abbrev.c (abbrev_table::read): Conditionally call + memcpy. + 2020-03-30 Nelson Chu * features/riscv/32bit-csr.xml: Regenerated. diff --git a/gdb/dwarf2/abbrev.c b/gdb/dwarf2/abbrev.c index 59ff138b33d..b85018060fa 100644 --- a/gdb/dwarf2/abbrev.c +++ b/gdb/dwarf2/abbrev.c @@ -168,8 +168,9 @@ abbrev_table::read (struct objfile *objfile, cur_abbrev->attrs = XOBNEWVEC (&abbrev_table->m_abbrev_obstack, struct attr_abbrev, cur_abbrev->num_attrs); - memcpy (cur_abbrev->attrs, cur_attrs.data (), - cur_abbrev->num_attrs * sizeof (struct attr_abbrev)); + if (!cur_attrs.empty ()) + memcpy (cur_abbrev->attrs, cur_attrs.data (), + cur_abbrev->num_attrs * sizeof (struct attr_abbrev)); abbrev_table->add_abbrev (abbrev_number, cur_abbrev); diff --git a/gdbsupport/ChangeLog b/gdbsupport/ChangeLog index 1d27971f5cc..86233e8d0ef 100644 --- a/gdbsupport/ChangeLog +++ b/gdbsupport/ChangeLog @@ -1,3 +1,8 @@ +2020-03-31 Tom Tromey + + * btrace-common.cc (btrace_data_append): Conditionally call + memcpy. + 2020-03-27 Andrew Burgess * create-version.sh: Resolve issues highlighted by shellcheck. diff --git a/gdbsupport/btrace-common.cc b/gdbsupport/btrace-common.cc index 7d4f6424c82..e8b24db7d53 100644 --- a/gdbsupport/btrace-common.cc +++ b/gdbsupport/btrace-common.cc @@ -173,7 +173,8 @@ btrace_data_append (struct btrace_data *dst, size = src->variant.pt.size + dst->variant.pt.size; data = (gdb_byte *) xmalloc (size); - memcpy (data, dst->variant.pt.data, dst->variant.pt.size); + if (dst->variant.pt.size > 0) + memcpy (data, dst->variant.pt.data, dst->variant.pt.size); memcpy (data + dst->variant.pt.size, src->variant.pt.data, src->variant.pt.size); -- 2.30.2