From: Simon Marchi <simark@simark.ca>
To: Andrew Burgess <aburgess@redhat.com>,
Simon Marchi via Gdb-patches <gdb-patches@sourceware.org>
Cc: Simon Marchi <simon.marchi@efficios.com>
Subject: Re: [PATCH 2/2] gdb/dwarf: fix UBsan crash in read_subrange_type
Date: Fri, 20 Jan 2023 11:51:29 -0500 [thread overview]
Message-ID: <92b91e11-10bc-ff5a-1bde-901ae8e3388f@simark.ca> (raw)
In-Reply-To: <87fsc5e4tu.fsf@redhat.com>
>> @@ -17684,15 +17683,25 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
>> with GCC, for instance, where the ambiguous DW_FORM_dataN form
>> is used instead. To work around that ambiguity, we treat
>> the bounds as signed, and thus sign-extend their values, when
>> - the base type is signed. */
>> - negative_mask =
>> - -((ULONGEST) 1 << (base_type->length () * TARGET_CHAR_BIT - 1));
>> - if (low.kind () == PROP_CONST
>> - && !base_type->is_unsigned () && (low.const_val () & negative_mask))
>> - low.set_const_val (low.const_val () | negative_mask);
>> - if (high.kind () == PROP_CONST
>> - && !base_type->is_unsigned () && (high.const_val () & negative_mask))
>> - high.set_const_val (high.const_val () | negative_mask);
>> + the base type is signed.
>> +
>> + Skip it if the base type's length is largest than ULONGEST, to avoid
>
> s/largest/larger/
Fixed.
>> @@ -92,3 +112,5 @@ gdb_test "ptype TByteArray" \
>> "type = array \\\[0\\.\\.191\\\] of byte"
>> gdb_test "ptype subrange_with_buggy_negative_bounds_variable" \
>> "type = -16..-12"
>> +gdb_test "ptype a_16_byte_subrange_variable" \
>> + "type = -9223372036854775808..9223372036854775807"
>
> As before, I'd use "\\.\\." here.
Fixed.
> Looks good with those nits fixed.
Thanks, will push.
Simon
next prev parent reply other threads:[~2023-01-20 16:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-20 5:08 [PATCH 1/2] gdb/testsuite: add test for negative subrange bounds with unsigned form Simon Marchi
2023-01-20 5:08 ` [PATCH 2/2] gdb/dwarf: fix UBsan crash in read_subrange_type Simon Marchi
2023-01-20 13:03 ` Andrew Burgess
2023-01-20 16:51 ` Simon Marchi [this message]
2023-01-20 12:51 ` [PATCH 1/2] gdb/testsuite: add test for negative subrange bounds with unsigned form Andrew Burgess
2023-01-20 16:38 ` Simon Marchi
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