Commit Graph

14 Commits

Author SHA1 Message Date
Rafael Espindola ce2fbddd19 Change how readobj stores info about dynamic symbols.
We used to keep both a section and a pointer to the first symbol.

The oddity of keeping a section for dynamic symbols is because there is
a DT_SYMTAB but no DT_SYMTABZ, so to print the table we have to find the
size via a section table.

The reason for still keeping a pointer to the first symbol is because we
want to be able to print relocation tables even if the section table is
missing (it is mandatory only for files used in linking).

With this patch we keep just a DynRegionInfo. This then requires
changing a few places that were asking for a Elf_Shdr but actually just
needed the first symbol.

The test change is to delete the program header pointer.
Now that we use the information of both DT_SYMTAB and .dynsym, we don't
depend on the sh_entsize of .dynsym if we see DT_SYMTAB.

Note: It is questionable if it is worth it putting the effort to report
broken sh_entsize given that in files with no section table we have to
assume it is sizeof(Elf_Sym), but that is for another change.

Extracted from r260488.

llvm-svn: 261099
2016-02-17 15:38:21 +00:00
Rafael Espindola 6009db696b This reverts commit r260488 and r260489.
Original messages:
    Revert "[readobj] Handle ELF files with no section table or with no program headers."
    Revert "[readobj] Dump DT_JMPREL relocations when outputting dynamic relocations."

r260489 depends on r260488 and among other issues r260488 deleted error
handling code.

llvm-svn: 260962
2016-02-16 14:17:48 +00:00
Michael J. Spencer 582c4d2bab [readobj] Handle ELF files with no section table or with no program headers.
This adds support for finding the dynamic table and dynamic symbol table via
the section table or the program header table. If there's no section table an
attempt is made to figure out the length of the dynamic symbol table.

llvm-svn: 260488
2016-02-11 04:59:45 +00:00
Rafael Espindola e038948166 Report an error if a SHT_SYMTAB_SHNDX section has the wrong size.
llvm-svn: 245873
2015-08-24 21:09:41 +00:00
Rafael Espindola 6565ea7299 Refactor duplicated code and check for invalid symbol table size.
llvm-svn: 242981
2015-07-23 03:24:22 +00:00
Rafael Espindola 2119a96279 Improve error message.
Thanks to Sean Silva for the suggestion.

llvm-svn: 241255
2015-07-02 11:48:48 +00:00
Rafael Espindola 6def304209 Return ErrorOr from getSection.
This also improves the logic of what is an error:

* getSection(uint_32): only return an error if the index is out of bounds. The
  index 0 corresponds to a perfectly valid entry.
* getSection(Elf_Sym): Returns null for symbols that normally don't have
  sections and error for out of bound indexes.

In many places this just moves the report_fatal_error up the stack, but those
can then be fixed in smaller patches.

llvm-svn: 241156
2015-07-01 12:56:27 +00:00
Rafael Espindola 7605cdef90 Remove Elf_Shdr_Iter. Diagnose files with invalid section header sizes.
llvm-svn: 241109
2015-06-30 19:58:10 +00:00
Rafael Espindola 0fe34f7359 Add a test of an elf file with an invalid section index.
We were already checking, but were missing a test.

llvm-svn: 241094
2015-06-30 18:23:07 +00:00
Rafael Espindola 350239c424 Report an error on invalid sh_entsize.
llvm-svn: 241070
2015-06-30 14:59:20 +00:00
Rafael Espindola 6a1bfb2f9b Factor out the checking of string tables.
This moves the error checking for string tables to getStringTable which returns
an ErrorOr<StringRef>.

This improves error checking, makes it uniform across all string tables and
makes it possible to check them once instead of once per name.

llvm-svn: 240950
2015-06-29 14:39:25 +00:00
Rafael Espindola f87b05e43b Add a testcase for an invalid file.
We were already checking this, but had no tests.

llvm-svn: 240945
2015-06-29 14:12:14 +00:00
Rafael Espindola f934a6a104 Convert an assert that can fail into error checking.
llvm-svn: 240944
2015-06-29 14:02:24 +00:00
Rafael Espindola 3dc0d05bf4 Improve error handling of getRelocationAddend.
This patch changes getRelocationAddend to use ErrorOr and considers it an error
to try to get the addend of a REL section.

If, for example, a x86_64 file has a REL section, that file is corrupted and
we should reject it.

Using ErrorOr is not ideal since we check the section type once per relocation
instead of once per section.

Checking once per section would involve getRelocationAddend just asserting and
callers checking the section before iterating over the relocations.

In any case, this is an improvement and includes a test.

llvm-svn: 240176
2015-06-19 20:58:43 +00:00