Commit Graph

29 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith 9885469922 IR: Move MDLocation into place
This commit moves `MDLocation`, finishing off PR21433.  There's an
accompanying clang commit for frontend testcases.  I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.

This changes the schema for `DebugLoc` and `DILocation` from:

    !{i32 3, i32 7, !7, !8}

to:

    !MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)

Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.

llvm-svn: 226048
2015-01-14 22:27:36 +00:00
Duncan P. N. Exon Smith be7ea19b58 IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

llvm-svn: 224257
2014-12-15 19:07:53 +00:00
Peter Collingbourne e67e4e821d Add target triples to all dfsan tests.
llvm-svn: 223536
2014-12-05 22:32:30 +00:00
Peter Collingbourne a1099840ff [dfsan] Abort at runtime on indirect calls to uninstrumented vararg functions.
We currently have no infrastructure to support these correctly.

This is accomplished by generating a call to a runtime library function that
aborts at runtime in place of the regular wrapper for such functions. Direct
calls are rewritten in the usual way during traversal of the caller's IR.

We also remove the "split-stack" attribute from such wrappers, as the code
generator cannot currently handle split-stack vararg functions.

llvm-svn: 221360
2014-11-05 17:21:00 +00:00
Peter Collingbourne dd3486ece1 [dfsan] New calling convention for custom functions with variadic arguments.
Summary:
The previous calling convention prevented custom functions from being able
to access argument labels unless it knew how many variadic arguments there
were, and of which type. This restriction made it impossible to correctly
model functions in the printf family, as it is legal to pass more arguments
than required to those functions. We now pass arguments in the following order:

non-vararg arguments
labels for non-vararg arguments
[if vararg function, pointer to array of labels for vararg arguments]
[if non-void function, pointer to label for return value]
vararg arguments

Differential Revision: http://reviews.llvm.org/D6028

llvm-svn: 220906
2014-10-30 13:22:57 +00:00
David Blaikie c6c6c7b177 DebugInfo+DFSan: Ensure that debug info references to llvm::Functions remain pointing to the underlying function when wrappers are created
This is somewhat the inverse of how similar bugs in DAE and ArgPromo
manifested and were addressed. In those passes, individual call sites
were visited explicitly, and then the old function was deleted. This
left the debug info with a null llvm::Function* that needed to be
updated to point to the new function.

In the case of DFSan, it RAUWs the old function with the wrapper, which
includes debug info. So now the debug info refers to the wrapper, which
doesn't actually have any instructions with debug info in it, so it is
ignored entirely - resulting in a DW_TAG_subprogram with no high/low pc,
etc. Instead, fix up the debug info to refer to the original function
after the RAUW messed it up.

Reviewed/discussed with Peter Collingbourne on the llvm-dev mailing
list.

llvm-svn: 219249
2014-10-07 22:59:46 +00:00
Lorenzo Martignoni 40d3deeb7d Introduce support for custom wrappers for vararg functions.
Differential Revision: http://reviews.llvm.org/D5412

llvm-svn: 218671
2014-09-30 12:33:16 +00:00
Peter Collingbourne fab565a56b [dfsan] Fix non-determinism bug in non-zero label check annotator.
We now use a std::vector instead of a DenseSet to store the list of
label checks so that we can iterate over it deterministically.

llvm-svn: 216255
2014-08-22 01:18:18 +00:00
Peter Collingbourne f39430bd4a [dfsan] Treat vararg custom functions like unimplemented functions.
Because declarations of these functions can appear in places like autoconf
checks, they have to be handled somehow, even though we do not support
vararg custom functions. We do so by printing a warning and calling the
uninstrumented function, as we do for unimplemented functions.

llvm-svn: 216042
2014-08-20 01:40:23 +00:00
Peter Collingbourne df240b252a [dfsan] Try not to create too many additional basic blocks in functions which
already have a large number of blocks. Works around a performance issue with
the greedy register allocator.

llvm-svn: 214944
2014-08-06 00:33:40 +00:00
Peter Collingbourne 142fdff0d5 [dfsan] Correctly handle loads and stores of zero size.
llvm-svn: 214561
2014-08-01 21:18:18 +00:00
Peter Collingbourne 9947c49812 [dfsan] Introduce further optimization to reduce the number of union queries.
Specifically, do not compute a union if it is statically known that one
shadow set subsumes the other.

llvm-svn: 213100
2014-07-15 22:13:19 +00:00
Peter Collingbourne 705a1ae3c8 [dfsan] Introduce an optimization to reduce the number of union queries.
Specifically, when building a union query, if we are dominated by an identical
query then use the result of that query instead.

llvm-svn: 213047
2014-07-15 04:41:17 +00:00
Peter Collingbourne 2e28edf8e1 [dfsan] Handle bitcast aliases.
llvm-svn: 212668
2014-07-10 01:30:39 +00:00
Peter Collingbourne 0be79e1ade Introduce two command-line flags for the instrumentation pass to control whether the labels of pointers should be ignored in load and store instructions
The new command line flags are -dfsan-ignore-pointer-label-on-store and -dfsan-ignore-pointer-label-on-load. Their default value matches the current labelling scheme.

Additionally, the function __dfsan_union_load is marked as readonly.

Patch by Lorenzo Martignoni!

Differential Revision: http://llvm-reviews.chandlerc.com/D2187

llvm-svn: 195382
2013-11-21 23:20:54 +00:00
Peter Collingbourne 28a10aff48 DataFlowSanitizer: Implement trampolines for function pointers passed to custom functions.
Differential Revision: http://llvm-reviews.chandlerc.com/D1503

llvm-svn: 189408
2013-08-27 22:09:06 +00:00
Peter Collingbourne a96296f3ab DataFlowSanitizer: correctly combine labels in the case where they are equal.
llvm-svn: 189133
2013-08-23 18:45:06 +00:00
Peter Collingbourne 34f0c313e2 DataFlowSanitizer: Replace non-instrumented aliases of instrumented functions, and vice versa, with wrappers.
Differential Revision: http://llvm-reviews.chandlerc.com/D1442

llvm-svn: 189054
2013-08-22 20:08:15 +00:00
Peter Collingbourne 59b1262d01 DataFlowSanitizer: Prefix the name of each instrumented function with "dfs$".
DFSan changes the ABI of each function in the module.  This makes it possible
for a function with the native ABI to be called with the instrumented ABI,
or vice versa, thus possibly invoking undefined behavior.  A simple way
of statically detecting instances of this problem is to prepend the prefix
"dfs$" to the name of each instrumented-ABI function.

This will not catch every such problem; in particular function pointers passed
across the instrumented-native barrier cannot be used on the other side.
These problems could potentially be caught dynamically.

Differential Revision: http://llvm-reviews.chandlerc.com/D1373

llvm-svn: 189052
2013-08-22 20:08:08 +00:00
Daniel Dunbar 9efbedfd35 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

llvm-svn: 188513
2013-08-16 00:37:11 +00:00
Peter Collingbourne 444c59e270 DataFlowSanitizer: Add a debugging feature to help us track nonzero labels.
Summary:
When the -dfsan-debug-nonzero-labels parameter is supplied, the code
is instrumented such that when a call parameter, return value or load
produces a nonzero label, the function __dfsan_nonzero_label is called.
The idea is that a debugger breakpoint can be set on this function
in a nominally label-free program to help identify any bugs in the
instrumentation pass causing labels to be introduced.

Reviewers: eugenis

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1405

llvm-svn: 188472
2013-08-15 18:51:12 +00:00
Peter Collingbourne cdc97373f8 DataFlowSanitizer: move abilist input file to Inputs.
llvm-svn: 188423
2013-08-14 22:28:36 +00:00
Peter Collingbourne 9d31d6f329 DataFlowSanitizer: Instrumentation for memset.
Differential Revision: http://llvm-reviews.chandlerc.com/D1395

llvm-svn: 188412
2013-08-14 20:51:38 +00:00
Peter Collingbourne 68162e7512 DataFlowSanitizer: greylist is now ABI list.
This replaces the old incomplete greylist functionality with an ABI
list, which can provide more detailed information about the ABI and
semantics of specific functions.  The pass treats every function in
the "uninstrumented" category in the ABI list file as conforming to
the "native" (i.e. unsanitized) ABI.  Unless the ABI list contains
additional categories for those functions, a call to one of those
functions will produce a warning message, as the labelling behaviour
of the function is unknown.  The other supported categories are
"functional", "discard" and "custom".

- "discard" -- This function does not write to (user-accessible) memory,
  and its return value is unlabelled.
- "functional" -- This function does not write to (user-accessible)
  memory, and the label of its return value is the union of the label of
  its arguments.
- "custom" -- Instead of calling the function, a custom wrapper __dfsw_F
  is called, where F is the name of the function.  This function may wrap
  the original function or provide its own implementation.

Differential Revision: http://llvm-reviews.chandlerc.com/D1345

llvm-svn: 188402
2013-08-14 18:54:12 +00:00
Peter Collingbourne 8d642de169 Reapply r188119 now that the bug it exposed is fixed.
llvm-svn: 188217
2013-08-12 22:38:43 +00:00
Arnold Schwaighofer 3dcdb89d69 Revert r188119 "Kill some duplicated code for removing unreachable BBs."
It is breaking builbots with libgmalloc enabled on Mac OS X.

$ cd llvm ; mkdir release ; cd release
$ ../configure --enable-optimized —prefix=$PWD/install
$ make
$ make check
$ Release+Asserts/bin/llvm-lit -v --param use_gmalloc=1 --param \
  gmalloc_path=/usr/lib/libgmalloc.dylib \
  ../test/Instrumentation/DataFlowSanitizer/args-unreachable-bb.ll

llvm-svn: 188142
2013-08-10 20:16:06 +00:00
Peter Collingbourne 32090aba06 Kill some duplicated code for removing unreachable BBs.
This moves removeUnreachableBlocksFromFn from SimplifyCFGPass.cpp
to Utils/Local.cpp and uses it to replace the implementation of
llvm::removeUnreachableBlocks, which appears to do a strict subset
of what removeUnreachableBlocksFromFn does.

Differential Revision: http://llvm-reviews.chandlerc.com/D1334

llvm-svn: 188119
2013-08-09 22:47:24 +00:00
Peter Collingbourne ae66d57bcf DataFlowSanitizer: Remove unreachable BBs so IR continues to verify
under the args ABI.

Differential Revision: http://llvm-reviews.chandlerc.com/D1316

llvm-svn: 188113
2013-08-09 21:42:53 +00:00
Peter Collingbourne e5d5b0c71e DataFlowSanitizer; LLVM changes.
DataFlowSanitizer is a generalised dynamic data flow analysis.

Unlike other Sanitizer tools, this tool is not designed to detect a
specific class of bugs on its own.  Instead, it provides a generic
dynamic data flow analysis framework to be used by clients to help
detect application-specific issues within their own code.

Differential Revision: http://llvm-reviews.chandlerc.com/D965

llvm-svn: 187923
2013-08-07 22:47:18 +00:00