| From 3239a4231ff79bf8b67b8faaf414b1667486167c Mon Sep 17 00:00:00 2001 |
| From: Andrew Burgess <andrew.burgess@embecosm.com> |
| Date: Mon, 19 Dec 2016 15:27:59 +0000 |
| Subject: [PATCH] bfd: Improve lookup of file / line information for errors |
| |
| When looking up file and line information (used from the linker to |
| report error messages) if no symbol is passed in, then use the symbol |
| list to look for a matching symbol. |
| |
| If a matching symbol is found then use this to look up the file / line |
| information. |
| |
| This should improve errors when looking up file / line information for |
| data sections. Hopefully we should find a matching data symbol, which |
| should, in turn (we hope) match a DW_TAG_variable in the DWARF, this |
| should allow us to give accurate file / line errors for data symbols. |
| |
| As the hope is to find a matching DW_TAG_variable in the DWARF then we |
| ignore section symbols, and prefer global symbols to locals. |
| |
| CVE: CVE-2017-8392 |
| Upstream-Status: Accepted |
| |
| Signed-off-by: Fan Xin <fan.xin@jp.fujitsu.com> |
| --- |
| bfd/dwarf2.c | 32 ++++++++++++++++++++++++++++++++ |
| 1 files changed, 32 insertions(+) |
| |
| |
| diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c |
| index 03447a9..9bb8126 100644 |
| --- a/bfd/dwarf2.c |
| +++ b/bfd/dwarf2.c |
| @@ -4155,6 +4155,38 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd, |
| { |
| BFD_ASSERT (section != NULL && functionname_ptr != NULL); |
| addr = offset; |
| + |
| + /* If we have no SYMBOL but the section we're looking at is not a |
| + code section, then take a look through the list of symbols to see |
| + if we have a symbol at the address we're looking for. If we do |
| + then use this to look up line information. This will allow us to |
| + give file and line results for data symbols. We exclude code |
| + symbols here, if we look up a function symbol and then look up the |
| + line information we'll actually return the line number for the |
| + opening '{' rather than the function definition line. This is |
| + because looking up by symbol uses the line table, in which the |
| + first line for a function is usually the opening '{', while |
| + looking up the function by section + offset uses the |
| + DW_AT_decl_line from the function DW_TAG_subprogram for the line, |
| + which will be the line of the function name. */ |
| + if ((section->flags & SEC_CODE) == 0) |
| + { |
| + asymbol **tmp; |
| + |
| + for (tmp = symbols; (*tmp) != NULL; ++tmp) |
| + if ((*tmp)->the_bfd == abfd |
| + && (*tmp)->section == section |
| + && (*tmp)->value == offset |
| + && ((*tmp)->flags & BSF_SECTION_SYM) == 0) |
| + { |
| + symbol = *tmp; |
| + do_line = TRUE; |
| + /* For local symbols, keep going in the hope we find a |
| + global. */ |
| + if ((symbol->flags & BSF_GLOBAL) != 0) |
| + break; |
| + } |
| + } |
| } |
| |
| if (section->output_section) |
| -- |
| 1.9.1 |
| |