Brad Bishop | 6e60e8b | 2018-02-01 10:27:11 -0500 | [diff] [blame] | 1 | From 3239a4231ff79bf8b67b8faaf414b1667486167c Mon Sep 17 00:00:00 2001 |
| 2 | From: Andrew Burgess <andrew.burgess@embecosm.com> |
| 3 | Date: Mon, 19 Dec 2016 15:27:59 +0000 |
| 4 | Subject: [PATCH] bfd: Improve lookup of file / line information for errors |
| 5 | |
| 6 | When looking up file and line information (used from the linker to |
| 7 | report error messages) if no symbol is passed in, then use the symbol |
| 8 | list to look for a matching symbol. |
| 9 | |
| 10 | If a matching symbol is found then use this to look up the file / line |
| 11 | information. |
| 12 | |
| 13 | This should improve errors when looking up file / line information for |
| 14 | data sections. Hopefully we should find a matching data symbol, which |
| 15 | should, in turn (we hope) match a DW_TAG_variable in the DWARF, this |
| 16 | should allow us to give accurate file / line errors for data symbols. |
| 17 | |
| 18 | As the hope is to find a matching DW_TAG_variable in the DWARF then we |
| 19 | ignore section symbols, and prefer global symbols to locals. |
| 20 | |
| 21 | CVE: CVE-2017-8392 |
| 22 | Upstream-Status: Accepted |
| 23 | |
| 24 | Signed-off-by: Fan Xin <fan.xin@jp.fujitsu.com> |
| 25 | --- |
| 26 | bfd/dwarf2.c | 32 ++++++++++++++++++++++++++++++++ |
| 27 | 1 files changed, 32 insertions(+) |
| 28 | |
| 29 | |
| 30 | diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c |
| 31 | index 03447a9..9bb8126 100644 |
| 32 | --- a/bfd/dwarf2.c |
| 33 | +++ b/bfd/dwarf2.c |
| 34 | @@ -4155,6 +4155,38 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd, |
| 35 | { |
| 36 | BFD_ASSERT (section != NULL && functionname_ptr != NULL); |
| 37 | addr = offset; |
| 38 | + |
| 39 | + /* If we have no SYMBOL but the section we're looking at is not a |
| 40 | + code section, then take a look through the list of symbols to see |
| 41 | + if we have a symbol at the address we're looking for. If we do |
| 42 | + then use this to look up line information. This will allow us to |
| 43 | + give file and line results for data symbols. We exclude code |
| 44 | + symbols here, if we look up a function symbol and then look up the |
| 45 | + line information we'll actually return the line number for the |
| 46 | + opening '{' rather than the function definition line. This is |
| 47 | + because looking up by symbol uses the line table, in which the |
| 48 | + first line for a function is usually the opening '{', while |
| 49 | + looking up the function by section + offset uses the |
| 50 | + DW_AT_decl_line from the function DW_TAG_subprogram for the line, |
| 51 | + which will be the line of the function name. */ |
| 52 | + if ((section->flags & SEC_CODE) == 0) |
| 53 | + { |
| 54 | + asymbol **tmp; |
| 55 | + |
| 56 | + for (tmp = symbols; (*tmp) != NULL; ++tmp) |
| 57 | + if ((*tmp)->the_bfd == abfd |
| 58 | + && (*tmp)->section == section |
| 59 | + && (*tmp)->value == offset |
| 60 | + && ((*tmp)->flags & BSF_SECTION_SYM) == 0) |
| 61 | + { |
| 62 | + symbol = *tmp; |
| 63 | + do_line = TRUE; |
| 64 | + /* For local symbols, keep going in the hope we find a |
| 65 | + global. */ |
| 66 | + if ((symbol->flags & BSF_GLOBAL) != 0) |
| 67 | + break; |
| 68 | + } |
| 69 | + } |
| 70 | } |
| 71 | |
| 72 | if (section->output_section) |
| 73 | -- |
| 74 | 1.9.1 |
| 75 | |