Commit Graph

16 Commits

Author SHA1 Message Date
Georgii Rymar 351f736368 [llvm-readelf] - Report unique warnings when dumping hash symbols/histogram.
This converts 2 more places to use `reportUniqueWarning` and adds tests.

Differential revision: https://reviews.llvm.org/D92551
2020-12-03 14:05:04 +03:00
Georgii Rymar a7a447be0f [yaml2obj] - ProgramHeaders: introduce FirstSec/LastSec instead of Sections list.
Imagine we have a YAML declaration of few sections: `foo1`, `<unnamed 2>`, `foo3`, `foo4`.

To put them into segment we can do (1*):

```
Sections:
 - Section: foo1
 - Section: foo4
```

or we can use (2*):

```
Sections:
 - Section: foo1
 - Section: foo3
 - Section: foo4
```

or (3*) :

```
Sections:
 - Section: foo1
## "(index 2)" here is a name that we automatically created for a unnamed section.
 - Section: (index 2)
 - Section: foo3
 - Section: foo4
```

It looks really confusing that we don't have to list all of sections.

At first I've tried to make this rule stricter and report an error when there is a gap
(i.e. when a section is included into segment, but not listed explicitly).
This did not work perfect, because such approach conflicts with unnamed sections/fills (see (3*)).

This patch drops "Sections" key and introduces 2 keys instead: `FirstSec` and `LastSec`.
Both are optional.

Differential revision: https://reviews.llvm.org/D90458
2020-11-09 13:00:50 +03:00
Georgii Rymar 80bf29f00c [llvm-readobj] - Fix possible crashes related to dumping gnu hash symbols.
It fixes possible scenarios when we crash/assert with `--hash-symbols` when
dumping an invalid GNU hash table which has a broken value in the buckets array.

This fixes a crash reported in comments for
https://bugs.llvm.org/show_bug.cgi?id=47681

Differential revision: https://reviews.llvm.org/D88561
2020-10-08 16:21:56 +03:00
Georgii Rymar 7df873f9c6 [llvm-readobj/elf] - Don't crash when the size of s dynamic symbol table, inferred from the hash table, is broken.
Currently we might derive the dynamic symbol table size from the DT_HASH hash table (using its `nchain` field).
It is possible to crash dumpers with a broken relocation that refers to a symbol with an index
that is too large. To trigger it, the inferred size of the dynamic symbol table should go past the end of the object.

This patch adds a size validation + warning.

Differential revision: https://reviews.llvm.org/D86923
2020-09-15 17:44:16 +03:00
Georgii Rymar a6436b0b3a [yaml2obj] - Make the 'Machine' key optional.
Currently we have to set 'Machine' to something in our
YAML descriptions. Usually we use 'EM_X86_64' for 64-bit targets
and 'EM_386' for 32-bit targets. At the same time, in fact, in most
cases our tests do not need a machine type and we can use
'EM_NONE'.

This is cleaner, because avoids the need of using a particular machine.

In this patch I've made the 'Machine' key optional (the default value,
when it is not specified is `EM_NONE`) and removed it (where possible)
from yaml2obj, obj2yaml and llvm-readobj tests.

There are few tests left where I decided not to remove it, because
I didn't want to touch CHECK lines or doing anything more complex
than a removing a "Machine: *" line and formatting lines around.

Differential revision: https://reviews.llvm.org/D86202
2020-08-20 11:40:51 +03:00
Georgii Rymar 917bdfaca6 [llvm-readobj] - Simplify and refine hash table tests
Now we are able to have default values for macros in YAML descriptions.
I've applied it for hash table tests and also fixed few copy-paste issues
in their comments.

Differential revision: https://reviews.llvm.org/D82870
2020-07-01 12:09:08 +03:00
Georgii Rymar c587b076a0 [llvm-readobj] - Add a validation of the GNU hash table to printGnuHashHistogram().
Similar to D81937, we might crash when printing a histogram for a GNU hash table
with a 'symndx' index that is larger than the number of dynamic symbols.

This patch adopts and reuses the `getGnuHashTableChains()` helper which performs
a validation of the table. As a side effect the warning reported for
the --gnu-hash-table was improved.

Also with this change we start to report a warning when the histogram is requested for
the GNU hash table, but the dynamic symbols table is empty (size == 0).

Differential revision: https://reviews.llvm.org/D82010
2020-06-19 14:24:51 +03:00
Georgii Rymar 88c8581d9f [llvm-readobj] - Do not crash when GnuHashTable->symndx is greater than the dynamic symbols count.
`Elf_GnuHash_Impl` has the following method:

```
ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const {
  return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx);
}
```

When DynamicSymCount is less than symndx we return an array with the huge broken size.
This patch fixes the issue and adds an assert. This assert helped to fix an issue
in one of the test cases.

Differential revision: https://reviews.llvm.org/D81937
2020-06-17 14:26:36 +03:00
Georgii Rymar 2ad0ef6ef1 [llvm-readelf] - Do not try to read past the end of the file when dumping the the SHT_GNU_HASH.
We have unobvious issue in the condition that is used to check
that we do not read past the EOF.

The problem is that the result of "GnuHashTable->nbuckets * 4" expression is uint32.
Because of that it was still possible to overflow it and pass the check.

There was no such problem with the "GnuHashTable->maskwords * sizeof(typename ELFT::Off)"
condition, because of `sizeof` on the right (which gives 64-bits value on x64),
but I've added an explicit conversion to 64-bit value for `GnuHashTable->maskwords` too.

Differential revision: https://reviews.llvm.org/D81103
2020-06-04 12:00:44 +03:00
Georgii Rymar c68ee6da28 [llvm-readelf] - --elf-hash-histogram: do not crash when the .gnu.hash goes past the EOF.
llvm-readelf might crash when the .gnu.hash table goes past the EOF.

This patch splits and updates the code of a helper function `checkGNUHashTable`,
which is similar to `checkHashTable` and fixes the issue.

Differential revision: https://reviews.llvm.org/D80215
2020-05-29 13:29:48 +03:00
Georgii Rymar fc98447af6 [llvm-readobj] - Do not skip building of the GNU hash table histogram.
When the `--elf-hash-histogram` is used, the code first tries to build
a histogram for the .hash table and then for the .gnu.hash table.

The problem is that dumper might return early when unable or do not need to
build a histogram for the .hash.

This patch reorders the code slightly to fix the issue and adds a test case.

Differential revision: https://reviews.llvm.org/D80204
2020-05-27 13:46:41 +03:00
Georgii Rymar f527e6f2e1 [llvm-readobj] - Do not crash when SHT_HASH table is broken.
We have scenarios when the logic of --elf-hash-histogram/--hash-symbols/--hash-table
options might crash when given a broken hash table.

This patch adds pre-checks for tables for these 3 options
and provides test cases.

Differential revision: https://reviews.llvm.org/D77147
2020-04-01 18:03:02 +03:00
Georgii Rymar 4cbfb98eb3 [llvm-readobj] - Improve test of --elf-hash-histogram option.
This test missed the check of histograms printed for .hash sections.
It was removed by mistake in D71606 where I tried to get rid of precompiled objects
and did not realize that time that both SHT_GNU_HASH and SHT_HASH sections
were tested and not just GNU version.

Also it never tested aliases for the --elf-hash-histogram option.

Differential revision: https://reviews.llvm.org/D76920
2020-03-30 15:46:45 +03:00
Fangrui Song e2d7c5b2b6 [yaml2obj][test] Simplify some e_machine EI_CLASS EI_DATA tests
When both little-endian and big-endian are tested, or both 32-bit and 64-bit are tested, use a template like the following with `-D BITS=32 -D ENCODE=LSB`

```
--- !ELF
FileHeader:
 Class:   ELFCLASS[[BITS]]
 Data:    ELFDATA2[[ENCODE]]
 Type:    ET_DYN
 Machine: EM_X86_64
```

Reviewed By: grimar, jhenderson

Differential Revision: https://reviews.llvm.org/D73828
2020-02-07 09:35:26 -08:00
Georgii Rymar f31fa4f898 [llvm-readobj][test] - Cleanup hash-histogram.test
In this test case we use 3 precompiled objects to
test how we print a histogram for an GNU hash section.
It does not make sense to use precompiled objects
for that. Also we could have 2 tests: one for 32 and
another for 64 bits target.

This patch does this change. It is not possible to remove
these precompiled objects because they are used elsewhere.

Differential revision: https://reviews.llvm.org/D71606
2019-12-18 11:36:49 +03:00
Georgii Rymar dbf520f617 [llvm-readobj][test] - Move platform specific test cases and their inputs to separate folders.
This creates the next subfolders in the test directory:
"COFF", "ELF", "MachO", "wasm".

I've also removed platform specific prefixes, like "coff-*".
One unused binary was removed as well: `Inputs/relocs.obj.elf-mips`

Differential revision: https://reviews.llvm.org/D71203
2019-12-10 11:36:23 +03:00