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* readelf: Check there is enough data to read DWARF line opcodes arguments.Mark Wielaard2019-02-011-4/+14
| | | | | | | | | | | When reading the debug_line opcode arguments we have to make sure there is enough data to read the arguments (if there are any(. The similar code in dwarf_getsrclines already had these checks. https://sourceware.org/bugzilla/show_bug.cgi?id=24116 Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Fix check test for SHN_XINDEX symbol.Mark Wielaard2019-01-242-1/+5
| | | | | | | | | | | | | The check for whether a symbol used the extended section table was wrong causing the run-strip-test-many.sh testcase to declare the testfile was an illformed file. Fixing this exposed a strict elfutils check for the '.shstrtab' section having this exact name and a SHT_STRTAB type. This might be a little too strict, but easily worked around by changing the name of the "old" shstrtab section in the addsections program. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Don't go past end of line data reading unknown opcode parameters.Mark Wielaard2019-01-222-1/+7
| | | | | | https://sourceware.org/bugzilla/show_bug.cgi?id=24116 Signed-off-by: Mark Wielaard <mark@klomp.org>
* libdw: Check terminating NUL byte in dwarf_getsrclines for dir/file table.Mark Wielaard2019-01-222-2/+11
| | | | | | | | | | | | | For DWARF version < 5 the .debug_line directory and file tables consist of a terminating NUL byte after all strings. The code used to just skip this without checking it actually existed. This could case a spurious read past the end of data. Fix the same issue in readelf. https://sourceware.org/bugzilla/show_bug.cgi?id=24102 Signed-off-by: Mark Wielaard <mark@klomp.org>
* libebl: Check NT_PLATFORM core notes contain a zero terminated string.Mark Wielaard2019-01-162-1/+5
| | | | | | | | | | Most strings in core notes are fixed size. But NT_PLATFORM contains just a variable length string. Check that it is actually zero terminated before passing to readelf to print. https://sourceware.org/bugzilla/show_bug.cgi?id=24089 Signed-off-by: Mark Wielaard <mark@klomp.org>
* elflint: Allow PT_GNU_EH_FRAME segment to match SHT_X86_64_UNWIND section.Mark Wielaard2018-11-132-2/+9
| | | | | | | The gold linker might generate an .eh_frame_hdr with a SHT_X86_64_UNWIND type instead of a SHT_PROGBITS type. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Also handle gnu compressed debug sections with --reloc-debug-sectionsMark Wielaard2018-11-132-6/+28
| | | | | | | | | | | | | Check whether a section was gnu compressed and decompress it first before trying to resolve relocations. Recompress it afterwards. This found a bug in elf_compress_gnu which would use the "raw" file contents even if the user had just created the section (copying over the section from the original input file). Add compressed ET_REL tests to run-strip-reloc.sh testcase. Signed-off-by: Mark Wielaard <mark@klomp.org>
* Handle GNU Build Attribute ELF Notes.Mark Wielaard2018-11-133-2/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GNU Build Attribute ELF Notes are generated by the GCC annobin plugin and described at https://fedoraproject.org/wiki/Toolchain/Watermark Unfortunately the constants aren't yet described in the standard glibc elf.h so they have been added to the elfutils specific elf-knowledge.h. The notes abuse the name owner field to encode some data not in the description. This makes it a bit hard to parse. We have to match the note owner name prefix (to "GA") to be sure the type is valid. We also cannot rely on the owner name being a valid C string since the attribute name and value can contain zero (terminators). So pass around namesz to the ebl note parsing functions. eu-elflint will recognize and eu-readelf -n will now show the notes: Note section [27] '.gnu.build.attributes' of 56080 bytes at offset 0x114564: Owner Data size Type GA 16 GNU Build Attribute OPEN Address Range: 0x2f30f - 0x2f30f VERSION: "3p8" GA 0 GNU Build Attribute OPEN TOOL: "gcc 8.2.1 20180801" GA 0 GNU Build Attribute OPEN "GOW": 45 GA 0 GNU Build Attribute OPEN STACK_PROT: 0 GA 0 GNU Build Attribute OPEN "stack_clash": TRUE GA 0 GNU Build Attribute OPEN "cf_protection": 0 GA 0 GNU Build Attribute OPEN "GLIBCXX_ASSERTIONS": TRUE GA 0 GNU Build Attribute OPEN "FORTIFY": 0 GA 0 GNU Build Attribute OPEN PIC: 3 GA 0 GNU Build Attribute OPEN SHORT_ENUM: FALSE GA 0 GNU Build Attribute OPEN ABI: c001100000012 GA 0 GNU Build Attribute OPEN "stack_realign": FALSE A new test was added to run-readelf -n for the existing annobin file. Signed-off-by: Mark Wielaard <mark@klomp.org>
* Recognize NT_VERSION notes.Mark Wielaard2018-11-133-6/+29
| | | | | | | | NT_VERSION notes are emitted by the gas .version directive. They have an empty description and (ab)use the owner name to store the version data string. Signed-off-by: Mark Wielaard <mark@klomp.org>
* libdwelf: New function dwelf_elf_begin.Mark Wielaard2018-11-092-5/+10
| | | | | | | | | | | | | | | | | | This introduces a new function dwelf_elf_begin which creates a (read-only) ELF handle from a possibly compressed file handle or a file that start with a linux kernel header. This can be used in eu-readelf to (re)open a (pure) ELF. eu-readelf uses libdwfl to relocate addresses in the original file in case it is ET_REL. But to show the "raw" data it might need to (re)open the file. Which could fail if the file was compressed. And produced an obscure error message: "cannot create EBL handle". This rewrites __libdw_open_file a little so that the given file handle will never be closed (whether on success or failure) and introduces a new internal function __libdw_open_elf that dwelf_elf_begin wraps. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Add --reloc-debug-sections-only option.Mark Wielaard2018-11-062-6/+160
| | | | | | | | | | | This option does the same thing as --reloc-debug-sections without doing any other strip operation. This is useful when you want to remove the debug section relocations in a separate ET_REL debug file that was created without --reloc-debug-sections, or for a file (like the linux debug vmlinux) that you don't want to strip, but for which the debug section relocations can be resolved already. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Extract code to update shdrstrndx into new common function.Mark Wielaard2018-11-062-45/+54
| | | | Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Split out debug section relocation into separate helper functions.Mark Wielaard2018-11-062-249/+299
| | | | | | | | Extract a couple of helper functions out of handle_elf (secndx_name, get_xndxdata and remove_debug_relocations) so they can be reused more easily in the future. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Always copy over any phdrs if there are any.Mark Wielaard2018-11-062-28/+48
| | | | | | | | Ignore the type of ELF file, just copy over any phdrs if the original file contained any. Also refuse to move around any allocated sections based on whether there are any phdrs instead of on ELF file type. Signed-off-by: Mark Wielaard <mark@klomp.org>
* unstrip: Add ELF_CHECK to make sure gelf_getehdr () doesn't return NULL.Mark Wielaard2018-11-022-0/+6
| | | | Signed-off-by: Mark Wielaard <mark@klomp.org>
* Recognize and parse GNU Property notes.Mark Wielaard2018-10-293-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GNU Property notes are different from normal notes because they use variable alignment/padding of their fields. They are 8 byte aligned, but use 4 byte fields. The name is aligned at 4 bytes and padded so that, the desc is aligned at 8 bytes. The whole note is padded to 8 bytes again. For normal notes all fields are both 4 bytes wide and 4 bytes aligned. To recognize these new kind of ELF Notes a new Elf_Type is introduced, ELF_T_NHDR8. This type is used in the xlate functions to determine how to align and pad the various fields. Since the fields themselves can now have different alignments we will have to keep track of the current alignement and use either NOTE_ALIGN4 or NOTE_ALIGN8 to determine the padding. To set the correct Elf_Type on the Elf_Data we use either the section sh_addralign or the segment p_align values. Assuming 8 means the section or segment contains the new style notes, otherwise normal notes. When we cannot determine the "alignment" directly, like when parsing special kernel sys files, we check the name "GNU" and type "GNU_PROPERTY_TYPE_0" fields. ebl_object_note now parses the new NT_GNU_PROPERTY_TYPE_0 and can extract the GNU_PROPERTY_STACK_SIZE, GNU_PROPERTY_NO_COPY_ON_PROTECTED and GNU_PROPERTY_X86_FEATURE_1_AND types GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK. Tests are added for extracting the note from sections or segments as set by gcc -fcf-protection. Signed-off-by: Mark Wielaard <mark@klomp.org>
* addr2line: Use elf_getshdrstrndx not Ehdr field to print section name.Mark Wielaard2018-10-242-3/+8
| | | | | | | Using the Ehdr field directly doesn't work when there are a large number of sections. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Use shstrndx to lookup section names.Mark Wielaard2018-10-242-35/+68
| | | | | | | | The function section_name would use the Ehdr e_shstrndx field to find the index of the section index string table directly. But it should use elf_getshdrstrndx. Adjust all callers. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Make sure readp is smaller than cieend in print_debug_frame_section.Mark Wielaard2018-10-201-2/+10
| | | | | | | | We could end up with a negative length in a call to memchr. https://sourceware.org/bugzilla/show_bug.cgi?id=23782 Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Make sure readp is smaller than cieend in print_debug_frame_section.Mark Wielaard2018-10-201-0/+5
| | | | | | | | We could end up with a negative length in a call to memchr. https://sourceware.org/bugzilla/show_bug.cgi?id=23782 Signed-off-by: Mark Wielaard <mark@klomp.org>
* Check sh_entsize is not zero.Mark Wielaard2018-10-202-1/+33
| | | | | | | | | There were some recent bug reports where we trusted the ELF section header to be sane and divided the sh_size by the sh_entsize to get the number of objects in the section. This would cause a divide by zero if the file was corrupt and the sh_entsize was zero. Add checks for any such code. Signed-off-by: Mark Wielaard <mark@klomp.org>
* size: Handle recursive ELF ar files.Mark Wielaard2018-10-202-2/+8
| | | | | | | | | | eu-size didn't handle an ELF ar file that contained an ar file itself correctly. handle_ar would recursively call itself but close the ELF file before returning. Only close the ELF file at the top-level. https://sourceware.org/bugzilla/show_bug.cgi?id=23787 Signed-off-by: Mark Wielaard <mark@klomp.org>
* arlib: Check that sh_entsize isn't zero.Mark Wielaard2018-10-202-0/+7
| | | | | | | | | A bogus ELF file could have sh_entsize as zero. Don't divide by zero, but just assume there are no symbols in the section. https://sourceware.org/bugzilla/show_bug.cgi?id=23786 Signed-off-by: Mark Wielaard <mark@klomp.org>
* ar: Assume epoch if ar_date is bogus.Mark Wielaard2018-10-202-2/+12
| | | | | | | | | | If the ar header contains a bogus ar_date then in verbose mode we would get a NULL pointer from localtime. Just assume the entry was created during the epoch. https://sourceware.org/bugzilla/show_bug.cgi?id=23754 Signed-off-by: Mark Wielaard <mark@klomp.org>
* findtextrel: Check that sh_entsize isn't zero.Mark Wielaard2018-10-202-10/+17
| | | | | | | | | A bogus ELF file could have sh_entsize as zero. Don't divide by zero, but just assume there are no entries in the section. https://sourceware.org/bugzilla/show_bug.cgi?id=23755 Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Handle multiple .debug_macro sections and decode header flag.Mark Wielaard2018-10-192-3/+34
| | | | | | | | | | | | | In object files there could be multiple .debug_macro sections. These are COMDAT sections used as imports. Note that the output for DW_MACRO_import isn't ideal since the offset is printed against the start of the .debug_macro section, but it doesn't show which one. We currently don't have that information and no interface yet for libdw users. Also decode the macro header flag byte for convenience. Signed-off-by: Mark Wielaard <mark@klomp.org>
* unstrip: Renumber the group section indexes.Mark Wielaard2018-10-192-0/+18
| | | | | | | When unstripping we might need to renumber the group section indexes. Just like we do when stripping. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip, unstrip: Handle SHT_GROUP correctly.Mark Wielaard2018-10-173-8/+76
| | | | | | | | | | | | | | | | | | | | The usage of annobin in Fedora showed a couple of bugs when using eu-strip and eu-unstrip on ET_REL files that contain multiple group sections. When stripping we should not remove the SHF_GROUP flag from sections even if the group section itself might be removed. Either the section itself gets removed, and so the flag doesn't matter. Or it gets moved together with the group section into the debug file, and then it still needs to have the flag set. Also we would "renumber" the section group flag field (which isn't a section index, and so shouldn't be changed). Often the group sections have the exact same name (".group"), flags (none) and sometimes the same sizes. Which makes matching them hard. Extract the group signature and compare those when comparing two group sections. Signed-off-by: Mark Wielaard <mark@klomp.org>
* Handle ADD/SUB relocationsAndreas Schwab2018-10-132-4/+23
| | | | | | This adds support for ADD and SUB relocations as seen on RISC-V. Signed-off-by: Andreas Schwab <schwab@suse.de>
* readelf: Use elf_getshdrnum in print_shdr and print_phdr.Mark Wielaard2018-09-142-5/+25
| | | | | | | | | print_shdr didn't print the correct number of sections if there were more than SHN_LORESERVE sections. print_phdr wouldn't match up the (allocated) sections and segements if there were more than SHN_LORESERVE sections in the ELF file. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip,unstrip: Use and set shdrstrndx consistently.Mark Wielaard2018-09-143-5/+66
| | | | | | | | | | | In various places in strip we used e_shstrndx instead of shdrstrndx and we didn't setup the shdrstrndx for the debug file. In unstrip we forgot to copy the shdrstrndx in case the -o output option was used. Added a new testcase that adds many sections to a testfile and runs strip, elflint, unstrip and elfcmp. Signed-off-by: Mark Wielaard <mark@klomp.org>
* elflint: Use shnum and shstrndx instead of ehdr field directly.Mark Wielaard2018-09-142-3/+10
| | | | | | | | | We already got the right shnum and shstrndx. But were still using e_shnum in one check for ELFCLASS64 (it was correct for ELFCLASS32). And when getting section names in check_symtab we still used e_shstrndx in two places. Signed-off-by: Mark Wielaard <mark@klomp.org>
* elfcmp: Get, check and shdrstrndx for section names.Mark Wielaard2018-09-132-2/+22
| | | | | | | | elfcmp would use the Ehdr e_shstrndx field to find the shdr string index table. Use elf_getshdrstrndx instead to be able to handle ELF files with more than SHN_LORESERVE sections. Signed-off-by: Mark Wielaard <mark@klomp.org>
* libebl: Use elf_getshdrstrndx in ebl_section_strip_p.Mark Wielaard2018-09-133-4/+9
| | | | | | | | | | The ebl_section_strip_p function used the Ehdr e_shstrndx field to get at the name of the (debug) sections. This is not correct if there are more than SHN_LORESERVE sections. Use elf_getshdrstrndx to get at the shstrtab section. And drop the Ehdr argument that isn't necessary anymore. Signed-off-by: Mark Wielaard <mark@klomp.org>
* backends: Always use elf_getshdrstrndx in check_special_symbol.Mark Wielaard2018-09-132-2/+7
| | | | | | | | | | The check_special_symbol backend functions used the Ehdr e_shstrndx field to get at the name of sections. This is not correct if there are more than SHN_LORESERVE sections. Always use elf_getshdrstrndx to get the shstrtab section. And drop the Ehdr argument that isn't necessary anymore. Signed-off-by: Mark Wielaard <mark@klomp.org>
* strip: Handle mixed allocated/non-allocated sections.Mark Wielaard2018-08-302-15/+71
| | | | | | | | | | | | | | | | | | Normally in non-ET_REL files all allocated sections come before all non-allocated sections. eu-strip relies on this when stripping a file and calculating the file offsets. But recently on Fedora there are non-allocated .gnu.build.attributes NOTE sections in the middle of the allocated sections, with a sh_offset field that is larger then the next section. This confuses eu-strip so much that it might corrupt the stripped file. Work around this by calculating the sh_offset fields in two phases when detecting mixed allocated/non-allocated sections. First handle the allocated ones, then use the offset after the last allocated section to calculate the offsets of the non-allocated sections left in the stripped file. Signed-off-by: Mark Wielaard <mark@klomp.org>
* libdw, readelf: Make sure there is enough data to read full aranges header.Mark Wielaard2018-08-182-0/+7
| | | | | | | | | | dwarf_getaranges didn't check if there was enough data left to read both the address and segment size. readelf didn't check there was enough data left to read the segment size. https://sourceware.org/bugzilla/show_bug.cgi?id=23541 Signed-off-by: Mark Wielaard <mark@klomp.org>
* elflint: Fix check_sysv_hash[64] sanity checks to not overflow.Mark Wielaard2018-08-182-2/+12
| | | | | | | | | The sanity checks for how many words were needed in the section could overflow causing errors. Fix the checks. https://sourceware.org/bugzilla/show_bug.cgi?id=23542 Signed-off-by: Mark Wielaard <mark@klomp.org>
* unstrip: Also check sh_size in compare_unalloc_sections.Mark Wielaard2018-07-272-0/+10
| | | | | | | | | | | | compare_unalloc_sections only checked sh_flags and the section names. This would cause stripped/debug section mismatches when there were multiple sections with the same name and flags. Fix this by also checking the size of the section matches. Add a testcase that has two ".group" sections created on i386 with the gcc annobin plugin. Signed-off-by: Mark Wielaard <mark@klomp.org>
* unstrip: Handle SHT_GROUP sections in ET_REL files.Mark Wielaard2018-07-272-1/+9
| | | | | | | | | SHT_GROUP sections are put in both the stripped and debug file. Handle correcting the symbol table/name entry of the group only once. The testfile was generated with the gcc annobin plugin. Signed-off-by: Mark Wielaard <mark@klomp.org>
* elfcompress: Don't rewrite file if no section data needs to be updated.Mark Wielaard2018-07-242-3/+49
| | | | | | | | | | | | | | | If the input and output file are the same and no section needs to be updated we really don't need to rewrite the file. Check whether any matching section is already compressed or decompressed. Skip the section if it doesn't need to be changed. If no section data needs updating end with success without rewriting/updating file. With --force the file will still always be updated/rewritten even if no section data needs to be (de)compressed. Acked-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org> Signed-off-by: Mark Wielaard <mark@klomp.org>
* elfcompress: Swap fchmod and fchown calls on new file.Mark Wielaard2018-07-222-4/+11
| | | | | | | | | | | Calling fchmod with a suid bit on a file might silently fail or the suid bit might be slilently cleared by a call to fchown if already set. Swap the calls so that the owner is set first and then set the suid bit. https://bugzilla.redhat.com/show_bug.cgi?id=1607044 Reported-and-tested-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org> Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Don't shadow index function from string.hMark Wielaard2018-07-052-7/+13
| | | | | | | | | | | | | On some ancient GCC versions (4.4.7 at least) -Wshadow warns about local variables "shadowing" global function definitions. readelf.c: In function ‘print_debug_addr_section’: readelf.c:5265: error: declaration of ‘index’ shadows a global declaration /usr/include/string.h:489: error: shadowed declaration is here This is silly of course, but easy to work around. Signed-off-by: Mark Wielaard <mark@klomp.org>
* Consolidate error.h inclusion in system.hRoss Burton2018-07-0518-19/+24
| | | | | | | | | error.h isn't standard and so isn't part of the musl C library. To easy future porting, consolidate the inclusion of error.h into system.h. https://sourceware.org/bugzilla/show_bug.cgi?id=21008 Signed-off-by: Ross Burton <ross.burton@intel.com>
* libdw: Add dwarf_next_lines to read .debug_line tables without CUs.Mark Wielaard2018-06-292-37/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is sometimes useful to read .debug_line tables on their own without having an associated CU DIE. DWARF5 line tables are self-contained. Adjust dwarf_begin_elf to accept ELF files with just a .debug_line. Add a new function dwarf_next_lines that returns the Dwarf_Files and Dwarf_Lines while iterating over just the .debug_lines section. Since we parse and cache the information it also will try to match the CU a table is associated with. This is only necessary for DWARF4 line tables (we will need at least the compilation dir from the CU) and won't be done for DWARF5 line tables. It also isn't an error if there is no associated CU (but will mean for DWARF4 line tables the dir list and the file paths might not be complete). A typical way to call this new function is: Dwarf_Off off, next_off = 0; Dwarf_CU *cu = NULL; Dwarf_Files *files; size_t nfiles; Dwarf_Lines *lines; size_t nlines; int res; while ((res = dwarf_next_lines (dbg, off = next_off, &next_off, &cu, &files, &nfiles, &lines, &nlines)) == 0) { /* ... handle files and lines ... */ } if (res < 0) printf ("BAD dwarf_next_lines: %s\n", dwarf_errmsg (-1)); See libdw.h for the full documentation. For more examples on how to use the function see the new testcases next-files and next-lines. Also adjust the file paths for line tables missing a comp_dir. They are no longer made "absolute" by prepending a slash '/' in front of them. This really was not useful and didn't happen in any of the testcases. They are now just kept relative. Make eu-readelf --debug-dump=decodedline use dwarf_next_lines instead of iterating over the CUs to show the (decoded) line tables. This allows it to show decoded line tables even if there is no .debug_info section. New tests have been added that mimic the get-files and get-lines tests but use dwarf_next_lines instead of iterating over all CUs. They produce identical output (modulo the CU information). Also add a new test file that contains only a .debug_line section. Signed-off-by: Mark Wielaard <mark@klomp.org>
* libdw, readelf: Don't handle DW_FORM_data16 as expression block/location.Mark Wielaard2018-06-172-5/+15
| | | | | | | | | | | Also found by afl-fuzz on the varlocs testcase. DW_FORM_data16 is constant form according to the DWARF5 spec. But since it is 128bits it isn't really representable as Dwarf_Word. So we treat it as block form. But we cannot treat it as an expression block. Make sure readelf prints it as a regular block and that dwarf_getlocation[s|_addr] doesn't treat it as location expression. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Check there are at least 4 bytes available for DWARF_FORM_block4.Mark Wielaard2018-06-172-1/+6
| | | | | | | | | Found by afl-fuzz. When printing a DWARF_FORM_block4 we checked there were only 2 bytes available (copy/paste from DW_FORM_block2 right before). Obviously we need at least 4 bytes to read the length of a DW_FORM_block4. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Make sure print_form_data always consumes DW_FORM_strx[1234] data.Mark Wielaard2018-06-172-6/+11
| | | | | | | | | | Found by afl-fuzz. When printing DW_FORM_strx[1234] data eu-readelf didn't increase readp which meant eu-readelf would keep printing the same line dirs or files encoded with strx[1234] names. This meant that for insane large dir or file counts eu-readelf would just keep printing endlessly because we never reached and of the .debug_line buffer. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: While printing .debug_loc make sure that next_off doesn't overflow.Mark Wielaard2018-06-162-1/+8
| | | | | | | | Found by the afl fuzzer. The next offset (after a locview) comes from a DIE loclist attribute. This could be a bogus value so large it overflows the buffer and makes us print past the end of buffer. Signed-off-by: Mark Wielaard <mark@klomp.org>
* readelf: Handle signedness of DW_FORM_implicit_const and DW_AT_const_value.Mark Wielaard2018-06-152-21/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We only handles DW_FORM_sdata as a signed form, but DW_FORM_implicit_const is also signed by default. For DW_AT_const_value we can do a little better. GCC encodes some const_values with signed forms, even though the type is unsigned. Lookup the (base) type of the DIE and display the const value as their (signed) type/size (if we can determine that). Add a new testcase run-readelf-const-values.sh that shows that. With the new testcase the const values would come out as follows: name (string) "i" const_value (implicit_const) 18446744073709551615 name (string) "j" const_value (implicit_const) 18446744073709551615 name (string) "sc" const_value (sdata) -2 name (string) "uc" const_value (sdata) -2 name (string) "ss" const_value (sdata) -16 name (string) "us" const_value (sdata) -16 name (string) "si" const_value (sdata) -3 name (string) "ui" const_value (sdata) -94967296 name (string) "sl" const_value (sdata) -1 name (string) "ul" const_value (sdata) -1 With this patch they show up as: name (string) "i" const_value (implicit_const) -1 name (string) "j" const_value (implicit_const) -1 name (string) "sc" const_value (sdata) -2 name (string) "uc" const_value (sdata) 254 (-2) name (string) "ss" const_value (sdata) -16 name (string) "us" const_value (sdata) 65520 (-16) name (string) "si" const_value (sdata) -3 name (string) "ui" const_value (sdata) 4200000000 (-94967296) name (string) "sl" const_value (sdata) -1 name (string) "ul" const_value (sdata) 18446744073709551615 (-1) (for signed/unsigned int char, short and long) Signed-off-by: Mark Wielaard <mark@klomp.org>
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