From c3a6a9dfc6ed0c24ab2d11b2d71f425b479575c9 Mon Sep 17 00:00:00 2001 From: Mark Wielaard Date: Wed, 6 Oct 2021 22:41:29 +0200 Subject: [PATCH] libdw: Use signedness of subrange type to determine array bounds When calculating the array size check if the subrange has an associate type, if it does then check the type to determine whether the upper and lower values need to be interpreted as signed of unsigned values. We default to signed because that is what the testcase run-aggregate-size.sh testfile-size4 expects (this is an hardwritten testcase, we could have chosen a different default). https://sourceware.org/bugzilla/show_bug.cgi?id=28294 Signed-off-by: Mark Wielaard --- libdw/ChangeLog | 6 +++++ libdw/dwarf_aggregate_size.c | 44 +++++++++++++++++++++++++++++++----- 2 files changed, 44 insertions(+), 6 deletions(-) diff --git a/libdw/ChangeLog b/libdw/ChangeLog index b707bbfe6..4275b830f 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,9 @@ +2021-10-06 Mark Wielaard + + * dwarf_aggregate_size.c (array_size): Check signedness of child DIE + type. Use dwarf_formsdata or dwarf_formudata to get the lower and + upper bounds. + 2021-09-08 Mark Wielaard * dwarf_begin_elf.c (valid_p): Identify ELF class and use this to set diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c index 75105e4d1..96023d69d 100644 --- a/libdw/dwarf_aggregate_size.c +++ b/libdw/dwarf_aggregate_size.c @@ -83,19 +83,51 @@ array_size (Dwarf_Die *die, Dwarf_Word *size, } else { + bool is_signed = true; + if (INTUSE(dwarf_attr) (get_type (&child, attr_mem, &type_mem), + DW_AT_encoding, attr_mem) != NULL) + { + Dwarf_Word encoding; + if (INTUSE(dwarf_formudata) (attr_mem, &encoding) == 0) + is_signed = (encoding == DW_ATE_signed + || encoding == DW_ATE_signed_char); + } + Dwarf_Sword upper; Dwarf_Sword lower; - if (INTUSE(dwarf_formsdata) (INTUSE(dwarf_attr_integrate) - (&child, DW_AT_upper_bound, - attr_mem), &upper) != 0) - return -1; + if (is_signed) + { + if (INTUSE(dwarf_formsdata) (INTUSE(dwarf_attr_integrate) + (&child, DW_AT_upper_bound, + attr_mem), &upper) != 0) + return -1; + } + else + { + Dwarf_Word unsigned_upper; + if (INTUSE(dwarf_formudata) (INTUSE(dwarf_attr_integrate) + (&child, DW_AT_upper_bound, + attr_mem), &unsigned_upper) != 0) + return -1; + upper = unsigned_upper; + } /* Having DW_AT_lower_bound is optional. */ if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_lower_bound, attr_mem) != NULL) { - if (INTUSE(dwarf_formsdata) (attr_mem, &lower) != 0) - return -1; + if (is_signed) + { + if (INTUSE(dwarf_formsdata) (attr_mem, &lower) != 0) + return -1; + } + else + { + Dwarf_Word unsigned_lower; + if (INTUSE(dwarf_formudata) (attr_mem, &unsigned_lower) != 0) + return -1; + lower = unsigned_lower; + } } else { -- 2.39.5