Commit Graph

24 Commits

Author SHA1 Message Date
Peter Collingbourne 4a653fa7f1 Rename __asan_gen_* symbols to ___asan_gen_*.
This prevents gold from printing a warning when trying to export
these symbols via the asan dynamic list after ThinLTO promotes them
from private symbols to external symbols with hidden visibility.

Differential Revision: https://reviews.llvm.org/D49498

llvm-svn: 337428
2018-07-18 22:23:14 +00:00
Walter Lee 5a440d323a [asan] Test ASan instrumentation for shadow scale value of 5
Add additional RUN clauses to test for -asan-mapping-scale=5 in
selective tests, with special CHECK statements where needed.

Differential Revision: https://reviews.llvm.org/D39775

llvm-svn: 318493
2017-11-17 01:15:31 +00:00
Evgeniy Stepanov 964f4663c4 [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

This is a second re-land of r298158. This time, this feature is
limited to -fdata-sections builds.

llvm-svn: 301587
2017-04-27 20:27:27 +00:00
Evgeniy Stepanov 716f0ff222 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

This is a second re-land of r298756. This time with a flag to disable
the whole thing to avoid a bug in the gold linker:
  https://sourceware.org/bugzilla/show_bug.cgi?id=19002

llvm-svn: 301586
2017-04-27 20:27:23 +00:00
Evgeniy Stepanov ed7fce7c84 Revert "[asan] Put ctor/dtor in comdat."
This reverts commit r299696, which is causing mysterious test failures.

llvm-svn: 299880
2017-04-10 20:36:36 +00:00
Evgeniy Stepanov ba7c2e9661 Revert "[asan] Fix dead stripping of globals on Linux."
This reverts commit r299697, which caused a big increase in object file size.

llvm-svn: 299879
2017-04-10 20:36:30 +00:00
Evgeniy Stepanov 6c3a8cbc4d [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

This is a re-land of r298158 rebased on D31358. This time,
asan.module_ctor is put in a comdat as well to avoid quadratic
behavior in Gold.

llvm-svn: 299697
2017-04-06 19:55:17 +00:00
Evgeniy Stepanov 5dfe420d10 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

This is a rebase of r298756.

llvm-svn: 299696
2017-04-06 19:55:13 +00:00
Alex Shlyapnikov 09171aa31f Revert "[asan] Put ctor/dtor in comdat."
Speculative revert, some libfuzzer tests are affected.

This reverts commit r298756.

llvm-svn: 298889
2017-03-27 23:11:47 +00:00
Evgeniy Stepanov 71bb8f1ad0 [asan] Put ctor/dtor in comdat.
When possible, put ASan ctor/dtor in comdat.

The only reason not to is global registration, which can be
TU-specific. This is not the case when there are no instrumented
globals. This is also limited to ELF targets, because MachO does
not have comdat, and COFF linkers may GC comdat constructors.

The benefit of this is a lot less __asan_init() calls: one per DSO
instead of one per TU. It's also necessary for the upcoming
gc-sections-for-globals change on Linux, where multiple references to
section start symbols trigger quadratic behaviour in gold linker.

llvm-svn: 298756
2017-03-25 01:01:11 +00:00
Evgeniy Stepanov c440572715 Revert r298158.
Revert "[asan] Fix dead stripping of globals on Linux."

OOM in gold linker.

llvm-svn: 298288
2017-03-20 18:45:34 +00:00
Evgeniy Stepanov c5aa6b9411 [asan] Fix dead stripping of globals on Linux.
Use a combination of !associated, comdat, @llvm.compiler.used and
custom sections to allow dead stripping of globals and their asan
metadata. Sometimes.

Currently this works on LLD, which supports SHF_LINK_ORDER with
sh_link pointing to the associated section.

This also works on BFD, which seems to treat comdats as
all-or-nothing with respect to linker GC. There is a weird quirk
where the "first" global in each link is never GC-ed because of the
section symbols.

At this moment it does not work on Gold (as in the globals are never
stripped).

Differential Revision: https://reviews.llvm.org/D30121

llvm-svn: 298158
2017-03-17 22:17:29 +00:00
David Blaikie f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +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 )
      call void @llvm.foo(metadata !{i32 7}, metadata )
      call void @llvm.foo(metadata , metadata )
      call void @llvm.foo(metadata , metadata )
      call void @llvm.foo(metadata !{metadata !3}, metadata )
      ret void, !bar 
    }
     = metadata !{metadata !2}
     = metadata !{i32* @global}
     = metadata !{metadata !3}
     = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata )
      call void @llvm.foo(metadata i32 7, metadata )
      call void @llvm.foo(metadata i32* @global, metadata )
      call void @llvm.foo(metadata , metadata )
      call void @llvm.foo(metadata !{!3}, metadata )
      ret void, !bar 
    }
     = !{!2}
     = !{i32* @global}
     = !{!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
Alexey Samsonov 15c9669615 [ASan] Collect unmangled names of global variables in Clang to print them in error reports.
Currently ASan instrumentation pass creates a string with global name
for each instrumented global (to include global names in the error report). Global
name is already mangled at this point, and we may not be able to demangle it
at runtime (e.g. there is no __cxa_demangle on Android).

Instead, create a string with fully qualified global name in Clang, and pass it
to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata
for some global, ASan will use the original algorithm.

This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264.

llvm-svn: 212872
2014-07-12 00:42:52 +00:00
Alexey Samsonov 4f319cca42 [ASan] Print exact source location of global variables in error reports.
See https://code.google.com/p/address-sanitizer/issues/detail?id=299 for the
original feature request.

Introduce llvm.asan.globals metadata, which Clang (or any other frontend)
may use to report extra information about global variables to ASan
instrumentation pass in the backend. This metadata replaces
llvm.asan.dynamically_initialized_globals that was used to detect init-order
bugs. llvm.asan.globals contains the following data for each global:
  1) source location (file/line/column info);
  2) whether it is dynamically initialized;
  3) whether it is blacklisted (shouldn't be instrumented).

Source location data is then emitted in the binary and can be picked up
by ASan runtime in case it needs to print error report involving some global.
For example:

  0x... is located 4 bytes to the right of global variable 'C::array' defined in '/path/to/file:17:8' (0x...) of size 40

These source locations are printed even if the binary doesn't have any
debug info.

This is an ABI-breaking change. ASan initialization is renamed to
__asan_init_v4(). Pre-built libraries compiled with older Clang will not work
with the fresh runtime.

llvm-svn: 212188
2014-07-02 16:54:41 +00:00
Rafael Espindola daeafb4c2a Add back r201608, r201622, r201624 and r201625
r201608 made llvm corretly handle private globals with MachO. r201622 fixed
a bug in it and r201624 and r201625 were changes for using private linkage,
assuming that llvm would do the right thing.

They all got reverted because r201608 introduced a crash in LTO. This patch
includes a fix for that. The issue was that TargetLoweringObjectFile now has
to be initialized before we can mangle names of private globals. This is
trivially true during the normal codegen pipeline (the asm printer does it),
but LTO has to do it manually.

llvm-svn: 201700
2014-02-19 17:23:20 +00:00
Rafael Espindola 2173603825 This reverts commit r201625 and r201624.
Since r201608 got reverted, it is not safe to use private linkage in these cases
until it is committed back.

llvm-svn: 201688
2014-02-19 15:49:46 +00:00
Rafael Espindola 8b27c4edc6 Now that llvm always does the right thing with private, use it.
llvm-svn: 201625
2014-02-19 02:08:39 +00:00
Kostya Serebryany d3d23bec66 [asan] Optimize accesses to global arrays with constant index
Summary:
Given a global array G[N], which is declared in this CU and has static initializer
avoid instrumenting accesses like G[i], where 'i' is a constant and 0<=i<N.
Also add a bit of stats.

This eliminates ~1% of instrumentations on SPEC2006
and also partially helps when asan is being run together with coverage.

Reviewers: samsonov

Reviewed By: samsonov

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1947

llvm-svn: 192794
2013-10-16 14:06:14 +00:00
Kostya Serebryany dfe9e7933e [asan] Split AddressSanitizer into two passes (FunctionPass, ModulePass), LLVM part. This requires a clang part which will follow.
llvm-svn: 168781
2012-11-28 10:31:36 +00:00
Kostya Serebryany 19ab3d1f6a [asan] fix a test
llvm-svn: 165938
2012-10-15 14:30:30 +00:00
Kostya Serebryany 561dade58d [asan] add a test for instrumenting globals
llvm-svn: 146718
2011-12-16 01:28:19 +00:00