From 1e2c886bb2e1e48dfc592f356ecad7da0a032f0a Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Sun, 14 Jan 2018 03:22:05 +0100 Subject: [PATCH] libdw: dwarf_formsdata should return a signed value The function dwarf_formsdata is used for decoding signed values, but except for the variable-length DW_FORM_sdata, it uses unsigned primitives to decode the value. This is not a problem for 64-bit values, but the smaller values come decoded wrong. Fix by changing to signed primitives for decoding the fixed-length forms. Add a test case that uses dwarf_aggregate_size to determine an array size whose lower bound is -1, encoded using DW_FORM_data1, and upper bound 255 with DW_FORM_data2. When the -1 is decoded wrongly, it comes back as 255, and the array size is 1. The correct array size should be 257. Signed-off-by: Petr Machata --- libdw/ChangeLog | 7 ++++ libdw/dwarf_formsdata.c | 8 ++-- tests/ChangeLog | 6 +++ tests/Makefile.am | 3 +- tests/run-aggregate-size.sh | 8 +++- tests/testfile-sizes4.o.bz2 | Bin 0 -> 387 bytes tests/testfile-sizes4.s | 77 ++++++++++++++++++++++++++++++++++++ 7 files changed, 103 insertions(+), 6 deletions(-) create mode 100644 tests/testfile-sizes4.o.bz2 create mode 100644 tests/testfile-sizes4.s diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 7cfc7825b..479dd42b3 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,10 @@ +2018-01-14 Petr Machata + + * dwarf_formsdata.c (dwarf_formsdata): + : Cast to signed char. + : Use read_*sbyte_unaligned instead of + read_*ubyte_unaligned. + 2017-12-26 Mark Wielaard * libdwP.h (struct Dwarf_Abbrev): Pack struct. Remove attrcnt, diff --git a/libdw/dwarf_formsdata.c b/libdw/dwarf_formsdata.c index e7deaee10..bc2b508d8 100644 --- a/libdw/dwarf_formsdata.c +++ b/libdw/dwarf_formsdata.c @@ -53,25 +53,25 @@ dwarf_formsdata (Dwarf_Attribute *attr, Dwarf_Sword *return_sval) __libdw_seterrno (DWARF_E_INVALID_DWARF); return -1; } - *return_sval = *attr->valp; + *return_sval = (signed char) *attr->valp; break; case DW_FORM_data2: if (datap + 2 > endp) goto invalid; - *return_sval = read_2ubyte_unaligned (attr->cu->dbg, attr->valp); + *return_sval = read_2sbyte_unaligned (attr->cu->dbg, attr->valp); break; case DW_FORM_data4: if (datap + 4 > endp) goto invalid; - *return_sval = read_4ubyte_unaligned (attr->cu->dbg, attr->valp); + *return_sval = read_4sbyte_unaligned (attr->cu->dbg, attr->valp); break; case DW_FORM_data8: if (datap + 8 > endp) goto invalid; - *return_sval = read_8ubyte_unaligned (attr->cu->dbg, attr->valp); + *return_sval = read_8sbyte_unaligned (attr->cu->dbg, attr->valp); break; case DW_FORM_sdata: diff --git a/tests/ChangeLog b/tests/ChangeLog index 831532b24..758f20e6a 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,3 +1,9 @@ +2018-01-14 Petr Machata + + * testfile-sizes4.o.bz2: New test file. + * testfile-sizes4.s: New test source. + * run-aggregate-size.sh: Check testfile-sizes4.o v size 257. + 2017-12-23 Mark Wielaard * backtrace-subr.sh (check_native_core): Use a lock file and try diff --git a/tests/Makefile.am b/tests/Makefile.am index 64cb5bd90..1fce44740 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -333,7 +333,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \ run-deleted.sh run-linkmap-cut.sh linkmap-cut-lib.so.bz2 \ linkmap-cut.bz2 linkmap-cut.core.bz2 \ run-aggregate-size.sh testfile-sizes1.o.bz2 testfile-sizes2.o.bz2 \ - testfile-sizes3.o.bz2 run-peel-type.sh \ + testfile-sizes3.o.bz2 testfile-sizes4.o.bz2 testfile-sizes4.s \ + run-peel-type.sh \ run-readelf-A.sh testfileppc32attrs.o.bz2 \ testfilesparc64attrs.o.bz2 testfileppc64attrs.o.bz2 \ testfile-debug-types.bz2 \ diff --git a/tests/run-aggregate-size.sh b/tests/run-aggregate-size.sh index 6d8aa2401..08d57bbf2 100755 --- a/tests/run-aggregate-size.sh +++ b/tests/run-aggregate-size.sh @@ -63,7 +63,9 @@ # # gcc -std=c99 -g -c -o testfile-sizes3.o sizes.c -testfiles testfile-sizes1.o testfile-sizes2.o testfile-sizes3.o +# The file testfile-size4.o is hand-crafted. + +testfiles testfile-sizes1.o testfile-sizes2.o testfile-sizes3.o testfile-sizes4.o testrun_compare ${abs_builddir}/aggregate_size -e testfile-sizes1.o <<\EOF c size 1 @@ -104,4 +106,8 @@ f size 4 b size 4 EOF +testrun_compare ${abs_builddir}/aggregate_size -e testfile-sizes4.o <<\EOF +v size 257 +EOF + exit 0 diff --git a/tests/testfile-sizes4.o.bz2 b/tests/testfile-sizes4.o.bz2 new file mode 100644 index 0000000000000000000000000000000000000000..046e0a23429c166c659349f628c39170bbb4818f GIT binary patch literal 387 zc-jGj0et>KT4*^jL0KkKS*U1%zyJYNfAs(V>Th(1qytN(LIL;ppJ2d1006)MKmY&; zumMI1hJq6+dsOu{DWf1XWM}{Y05m;ErkaNtGHApxG{8W>nqZ6*6HPP#VFZaN$V1Wr zpk!zPpa99EKn(_(N{z;abVA6Etg=-jpBQVd%dq;e6Q>9sa+xWbp{9draa^JPJRNG7UMVI%lII?kh^@`&;bZ`8l9vj(N&GCdoUne%}m2_-C-sJeC$dc zRs=NKY&V)*jSAC3*!qNUJ2&v)o8u3XuT?+XU(%w3Ol_&e+S<9PJno*e2s+^yC2Wuv zYYL>0n@d&qy3D-8C5BTLMaZa%@P*vOUdIVvr$m7B7*vxZ#l?7usFf6{7O7%ox7xzP zn4E{qj4D#xi1vKslj!Or-mJ>1XagNuBz3(2vJWi57V$TVwSIoYVz!`!_C;