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| author | Andrew Burgess <andrew.burgess@embecosm.com> | 2021-05-12 13:44:06 +0100 |
|---|---|---|
| committer | Andrew Burgess <andrew.burgess@embecosm.com> | 2021-06-07 16:45:10 +0100 |
| commit | a12a15e7c5ff9f3549dd185fa1acd5a9dddd001b (patch) | |
| tree | 71278848c6d52c54c8d85799717efcb248721df9 /gdb/amd64-tdep.c | |
| parent | ecac8d1c14acba1fd20b99c2481d0cab5887e3b7 (diff) | |
| download | fsf-binutils-gdb-a12a15e7c5ff9f3549dd185fa1acd5a9dddd001b.zip fsf-binutils-gdb-a12a15e7c5ff9f3549dd185fa1acd5a9dddd001b.tar.gz fsf-binutils-gdb-a12a15e7c5ff9f3549dd185fa1acd5a9dddd001b.tar.bz2 | |
gdb: handle case where type alignment is unknown
It was spotted that if type_align returned 0 then it was possible to
trigger a divide by zero exception within GDB. It turns out this will
only happen in an edge case where GDB is unable to figure out the
alignment of a field within a structure.
The attached test generates some non-standard, probably broken, DWARF,
that triggers this condition, and then fixes this issue by throwing an
exception when this case occurs.
gdb/ChangeLog:
PR gdb/27847
* amd64-tdep.c (amd64_has_unaligned_fields): Move call to
type_align, and spot case where the alignment is unknown.
gdb/testsuite/ChangeLog:
PR gdb/27847
* gdb.dwarf2/dw2-weird-type-len.c: New file.
* gdb.dwarf2/dw2-weird-type-len.exp: New file.
Diffstat (limited to 'gdb/amd64-tdep.c')
| -rw-r--r-- | gdb/amd64-tdep.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c index 91305dd..3afac3c 100644 --- a/gdb/amd64-tdep.c +++ b/gdb/amd64-tdep.c @@ -554,7 +554,6 @@ amd64_has_unaligned_fields (struct type *type) { struct type *subtype = check_typedef (type->field (i).type ()); int bitpos = TYPE_FIELD_BITPOS (type, i); - int align = type_align(subtype); /* Ignore static fields, empty fields (for example nested empty structures), and bitfields (these are handled by @@ -568,6 +567,10 @@ amd64_has_unaligned_fields (struct type *type) if (bitpos % 8 != 0) return true; + int align = type_align (subtype); + if (align == 0) + error (_("could not determine alignment of type")); + int bytepos = bitpos / 8; if (bytepos % align != 0) return true; |