libdwfl: Handle unaligned Phdr in dwfl_segment_report_module
Commit Message
The xlate functions only handle correctly aligned buffers. But they do
handle src == dest. So if the source buffer isn't aligned correctly
just copy it first into the destination (which is already correctly
aligned).
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libdwfl/ChangeLog | 5 +++++
libdwfl/dwfl_segment_report_module.c | 12 ++++++++++++
2 files changed, 17 insertions(+)
@@ -1,3 +1,8 @@
+2021-12-19 Mark Wielaard <mark@klomp.org>
+
+ * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy
+ data and set xlatefrom.d_buf to notes when data is not aligned.
+
2021-12-19 Mark Wielaard <mark@klomp.org>
* dwfl_segment_report_module.c (dwfl_segment_report_module): Copy
@@ -573,6 +573,18 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name,
xlatefrom.d_size = filesz;
xlateto.d_buf = notes;
xlateto.d_size = filesz;
+
+ /* data may be unaligned, in which case xlatetom would not work.
+ xlatetom does work when the in and out d_buf are equal (but not
+ for any other overlap). */
+ if ((uintptr_t) data != (align == 8
+ ? NOTE_ALIGN8 ((uintptr_t) data)
+ : NOTE_ALIGN4 ((uintptr_t) data)))
+ {
+ memcpy (notes, data, filesz);
+ xlatefrom.d_buf = notes;
+ }
+
if (elf32_xlatetom (&xlateto, &xlatefrom, xencoding) == NULL)
{
free (notes);