Commit Graph

304 Commits

Author SHA1 Message Date
John Baldwin c5d7e04052 [ASAN] Use the correct shadow offset for ASAN on FreeBSD/mips64.
Reviewed By: atanasyan

Differential Revision: https://reviews.llvm.org/D49939

llvm-svn: 338650
2018-08-01 22:51:13 +00:00
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
Evgeniy Stepanov 289a7d4c7d Revert "[asan] Instrument comdat globals on COFF targets"
Causes false positive ODR violation reports on __llvm_profile_raw_version.

llvm-svn: 335681
2018-06-26 22:43:48 +00:00
Reid Kleckner 12395b7795 [WinASan] Don't instrument globals in sections containing '$'
Such globals are very likely to be part of a sorted section array, such
the .CRT sections used for dynamic initialization. The uses its own
sorted sections called ATL$__a, ATL$__m, and ATL$__z. Instead of special
casing them, just look for the dollar sign, which is what invokes linker
section sorting for COFF.

Avoids issues with ASan and the ATL uncovered after we started
instrumenting comdat globals on COFF.

llvm-svn: 334653
2018-06-13 20:47:21 +00:00
Reid Kleckner 0bab222084 [asan] Instrument comdat globals on COFF targets
Summary:
If we can use comdats, then we can make it so that the global metadata
is thrown away if the prevailing definition of the global was
uninstrumented. I have only tested this on COFF targets, but in theory,
there is no reason that we cannot also do this for ELF.

This will allow us to re-enable string merging with ASan on Windows,
reducing the binary size cost of ASan on Windows.

Reviewers: eugenis, vitalybuka

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47841

llvm-svn: 334313
2018-06-08 18:33:16 +00:00
Walter Lee cdbb207bd1 [asan] Add instrumentation support for Myriad
1. Define Myriad-specific ASan constants.

2. Add code to generate an outer loop that checks that the address is
   in DRAM range, and strip the cache bit from the address.  The
   former is required because Myriad has no memory protection, and it
   is up to the instrumentation to range-check before using it to
   index into the shadow memory.

3. Do not add an unreachable instruction after the error reporting
   function; on Myriad such function may return if the run-time has
   not been initialized.

4. Add a test.

Differential Revision: https://reviews.llvm.org/D46451

llvm-svn: 332692
2018-05-18 04:10:38 +00:00
Shiva Chen 2c864551df [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
2018-05-09 02:40:45 +00:00
Kuba Mracek 8842da8e07 [asan] Fix a false positive ODR violation due to LTO ConstantMerge pass [llvm part, take 3]
This fixes a false positive ODR violation that is reported by ASan when using LTO. In cases, where two constant globals have the same value, LTO will merge them, which breaks ASan's ODR detection.

Differential Revision: https://reviews.llvm.org/D43959

llvm-svn: 327061
2018-03-08 21:02:18 +00:00
Kuba Mracek f0bcbfef5c Revert r327053.
llvm-svn: 327055
2018-03-08 20:13:39 +00:00
Kuba Mracek 584bd10803 [asan] Fix a false positive ODR violation due to LTO ConstantMerge pass [llvm part, take 2]
This fixes a false positive ODR violation that is reported by ASan when using LTO. In cases, where two constant globals have the same value, LTO will merge them, which breaks ASan's ODR detection.

Differential Revision: https://reviews.llvm.org/D43959

llvm-svn: 327053
2018-03-08 20:05:45 +00:00
David Zarzycki c71c9aace8 [Tests] Remove empty test file that causes the test suite to fail
This empty file was "created" by r327033, which attempted to revert
r327029, which introduced the file.

llvm-svn: 327036
2018-03-08 18:03:15 +00:00
Kuba Mracek e834b22874 Revert r327029
llvm-svn: 327033
2018-03-08 17:32:00 +00:00
Kuba Mracek 0e06d37dba [asan] Fix a false positive ODR violation due to LTO ConstantMerge pass [llvm part]
This fixes a false positive ODR violation that is reported by ASan when using LTO. In cases, where two constant globals have the same value, LTO will merge them, which breaks ASan's ODR detection.

Differential Revision: https://reviews.llvm.org/D43959

llvm-svn: 327029
2018-03-08 17:24:06 +00:00
Vedant Kumar 8a816f0c9b Revert "asan: add kernel inline instrumentation test"
This reverts commit r323451. It breaks this bot:

http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/24077

llvm-svn: 323454
2018-01-25 18:20:19 +00:00
Vedant Kumar d22f07bbbe asan: add kernel inline instrumentation test
Patch by Andrey Konovalov!

Differential Revision: https://reviews.llvm.org/D42473

llvm-svn: 323451
2018-01-25 18:05:44 +00:00
Daniel Neilson 1e68724d24 Remove alignment argument from memcpy/memmove/memset in favour of alignment attributes (Step 1)
Summary:
 This is a resurrection of work first proposed and discussed in Aug 2015:
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
and initially landed (but then backed out) in Nov 2015:
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

 The @llvm.memcpy/memmove/memset intrinsics currently have an explicit argument
which is required to be a constant integer. It represents the alignment of the
dest (and source), and so must be the minimum of the actual alignment of the
two.

 This change is the first in a series that allows source and dest to each
have their own alignments by using the alignment attribute on their arguments.

 In this change we:
1) Remove the alignment argument.
2) Add alignment attributes to the source & dest arguments. We, temporarily,
   require that the alignments for source & dest be equal.

 For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 100, i32 4, i1 false)
will now read
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dest, i8* align 4 %src, i32 100, i1 false)

 Downstream users may have to update their lit tests that check for
@llvm.memcpy/memmove/memset call/declaration patterns. The following extended sed script
may help with updating the majority of your tests, but it does not catch all possible
patterns so some manual checking and updating will be required.

s~declare void @llvm\.mem(set|cpy|move)\.p([^(]*)\((.*), i32, i1\)~declare void @llvm.mem\1.p\2(\3, i1)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* \3, i8 \4, i8 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* \3, i8 \4, i16 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* \3, i8 \4, i32 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* \3, i8 \4, i64 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* \3, i8 \4, i128 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* align \6 \3, i8 \4, i8 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* align \6 \3, i8 \4, i16 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* align \6 \3, i8 \4, i32 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* align \6 \3, i8 \4, i64 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* align \6 \3, i8 \4, i128 \5, i1 \7)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* \4, i8\5* \6, i8 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* \4, i8\5* \6, i16 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* \4, i8\5* \6, i32 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* \4, i8\5* \6, i64 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* \4, i8\5* \6, i128 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* align \8 \4, i8\5* align \8 \6, i8 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* align \8 \4, i8\5* align \8 \6, i16 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* align \8 \4, i8\5* align \8 \6, i32 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* align \8 \4, i8\5* align \8 \6, i64 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* align \8 \4, i8\5* align \8 \6, i128 \7, i1 \9)~g

 The remaining changes in the series will:
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
   source and dest alignments.
Step 3) Update Clang to use the new IRBuilder API.
Step 4) Update Polly to use the new IRBuilder API.
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
        and those that use use MemIntrinsicInst::[get|set]Alignment() to use
        getDestAlignment() and getSourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
        MemIntrinsicInst::[get|set]Alignment() methods.

Reviewers: pete, hfinkel, lhames, reames, bollu

Reviewed By: reames

Subscribers: niosHD, reames, jholewinski, qcolombet, jfb, sanjoy, arsenm, dschuff, dylanmckay, mehdi_amini, sdardis, nemanjai, david2050, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, llvm-commits

Differential Revision: https://reviews.llvm.org/D41675

llvm-svn: 322965
2018-01-19 17:13:12 +00:00
Adrian Prantl 3c6c14d14b ASAN: Provide reliable debug info for local variables at -O0.
The function stack poisioner conditionally stores local variables
either in an alloca or in malloc'ated memory, which has the
unfortunate side-effect, that the actual address of the variable is
only materialized when the variable is accessed, which means that
those variables are mostly invisible to the debugger even when
compiling without optimizations.

This patch stores the address of the local stack base into an alloca,
which can be referred to by the debug info and is available throughout
the function. This adds one extra pointer-sized alloca to each stack
frame (but mem2reg can optimize it away again when optimizations are
enabled, yielding roughly the same debug info quality as before in
optimized code).

rdar://problem/30433661

Differential Revision: https://reviews.llvm.org/D41034

llvm-svn: 320415
2017-12-11 20:43:21 +00:00
Bill Seurer 957a076cce [PowerPC][asan] Update asan to handle changed memory layouts in newer kernels
In more recent Linux kernels with 47 bit VMAs the layout of virtual memory
for powerpc64 changed causing the address sanitizer to not work properly. This
patch adds support for 47 bit VMA kernels for powerpc64 and fixes up test
cases.

https://reviews.llvm.org/D40907

There is an associated patch for compiler-rt.

Tested on several 4.x and 3.x kernel releases.

llvm-svn: 320109
2017-12-07 22:53:33 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Evgeniy Stepanov 8e7018d92f [asan] Use dynamic shadow on 32-bit Android, try 2.
Summary:
This change reverts r318575 and changes FindDynamicShadowStart() to
keep the memory range it found mapped PROT_NONE to make sure it is
not reused. We also skip MemoryRangeIsAvailable() check, because it
is (a) unnecessary, and (b) would fail anyway.

Reviewers: pcc, vitalybuka, kcc

Subscribers: srhines, kubamracek, mgorny, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40203

llvm-svn: 318666
2017-11-20 17:41:57 +00:00
Evgeniy Stepanov 9d564cdcb0 Revert "[asan] Use dynamic shadow on 32-bit Android" and 3 more.
Revert the following commits:
  r318369 [asan] Fallback to non-ifunc dynamic shadow on android<22.
  r318235 [asan] Prevent rematerialization of &__asan_shadow.
  r317948 [sanitizer] Remove unnecessary attribute hidden.
  r317943 [asan] Use dynamic shadow on 32-bit Android.

MemoryRangeIsAvailable() reads /proc/$PID/maps into an mmap-ed buffer
that may overlap with the address range that we plan to use for the
dynamic shadow mapping. This is causing random startup crashes.

llvm-svn: 318575
2017-11-18 00:22:34 +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
Walter Lee 2a2b69e9c7 [asan] Fix size/alignment issues with non-default shadow scale
Fix a couple places where the minimum alignment/size should be a
function of the shadow granularity:
- alignment of AllGlobals
- the minimum left redzone size on the stack

Added a test to verify that the metadata_array is properly aligned
for shadow scale of 5, to be enabled when we add build support
for testing shadow scale of 5.

Differential Revision: https://reviews.llvm.org/D39470

llvm-svn: 318395
2017-11-16 12:57:19 +00:00
Evgeniy Stepanov 396ed67950 [asan] Fallback to non-ifunc dynamic shadow on android<22.
Summary: Android < 22 does not support ifunc.

Reviewers: pcc

Subscribers: srhines, kubamracek, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D40116

llvm-svn: 318369
2017-11-16 02:52:19 +00:00
Evgeniy Stepanov cff19ee233 [asan] Prevent rematerialization of &__asan_shadow.
Summary:
In the mode when ASan shadow base is computed as the address of an
external global (__asan_shadow, currently on android/arm32 only),
regalloc prefers to rematerialize this value to save register spills.
Even in -Os. On arm32 it is rather expensive (2 loads + 1 constant
pool entry).

This changes adds an inline asm in the function prologue to suppress
this behavior. It reduces AsanTest binary size by 7%.

Reviewers: pcc, vitalybuka

Subscribers: aemerson, kristof.beyls, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D40048

llvm-svn: 318235
2017-11-15 00:11:51 +00:00
Hans Wennborg 08b34a017a Update some code.google.com links
llvm-svn: 318115
2017-11-13 23:47:58 +00:00
Evgeniy Stepanov 989299c42b [asan] Use dynamic shadow on 32-bit Android.
Summary:
The following kernel change has moved ET_DYN base to 0x4000000 on arm32:
https://marc.info/?l=linux-kernel&m=149825162606848&w=2

Switch to dynamic shadow base to avoid such conflicts in the future.

Reserve shadow memory in an ifunc resolver, but don't use it in the instrumentation
until PR35221 is fixed. This will eventually let use save one load per function.

Reviewers: kcc

Subscribers: aemerson, srhines, kubamracek, kristof.beyls, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D39393

llvm-svn: 317943
2017-11-10 22:27:48 +00:00
Andrew V. Tischenko 0916c6b654 Fix for Bug 34475 - LOCK/REP/REPNE prefixes emitted as instruction on their own.
Differential Revision: https://reviews.llvm.org/D39546

llvm-svn: 317330
2017-11-03 15:25:13 +00:00
Reid Kleckner c212cc88e2 [asan] Upgrade private linkage globals to internal linkage on COFF
COFF comdats require symbol table entries, which means the comdat leader
cannot have private linkage.

llvm-svn: 317009
2017-10-31 16:16:08 +00:00
Adrian Prantl 05782218ab Canonicalize the representation of empty an expression in DIGlobalVariableExpression
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().

If someone needs to upgrade out-of-tree testcases:
  perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.

llvm-svn: 312144
2017-08-30 18:06:51 +00:00
Reid Kleckner 6d353348e5 Parse and print DIExpressions inline to ease IR and MIR testing
Summary:
Most DIExpressions are empty or very simple. When they are complex, they
tend to be unique, so checking them inline is reasonable.

This also avoids the need for CodeGen passes to append to the
llvm.dbg.mir named md node.

See also PR22780, for making DIExpression not be an MDNode.

Reviewers: aprantl, dexonsmith, dblaikie

Subscribers: qcolombet, javed.absar, eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D37075

llvm-svn: 311594
2017-08-23 20:31:27 +00:00
Matt Morehouse 49e5acab33 [asan] Fix instruction emission ordering with dynamic shadow.
Summary:
Instrumentation to copy byval arguments is now correctly inserted
after the dynamic shadow base is loaded.

Reviewers: vitalybuka, eugenis

Reviewed By: vitalybuka

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36533

llvm-svn: 310503
2017-08-09 17:59:43 +00:00
Vitaly Buka 629047de8e [asan] Disable checking of arguments passed by value for --asan-force-dynamic-shadow
Fails with "Instruction does not dominate all uses!"

llvm-svn: 310241
2017-08-07 07:12:34 +00:00
Vitaly Buka f20b9bc218 Add -asan-force-dynamic-shadow test
llvm-svn: 310240
2017-08-07 07:12:33 +00:00
Vitaly Buka 74443f0778 [asan] Copy arguments passed by value into explicit allocas for ASan
Summary:
  ASan determines the stack layout from alloca instructions. Since
arguments marked as "byval" do not have an explicit alloca instruction, ASan
does not produce red zones for them. This commit produces an explicit alloca
instruction and copies the byval argument into the allocated memory so that red
zones are produced.

  Submitted on behalf of @morehouse (Matt Morehouse)

  Reviewers: eugenis, vitalybuka

  Reviewed By: eugenis

  Subscribers: hiraditya, llvm-commits

  Differential Revision: https://reviews.llvm.org/D34789

llvm-svn: 308387
2017-07-18 22:28:03 +00:00
Daniel Neilson 5fc2ee7fab Add element-atomic mem intrinsic canary tests for Address Sanitizer.
Summary:
Add canary tests to verify that ASAN currently does nothing with the element atomic memory intrinsics for memcpy, memmove, and memset.

Placeholder tests that will fail once element atomic @llvm.mem[cpy|move|set] instrinsics have been added to the MemIntrinsic class hierarchy. These will act as a reminder to verify that ASAN handles these intrinsics properly once they have been added to that class hierarchy.

Reviewers: reames

Reviewed By: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35505

llvm-svn: 308248
2017-07-18 01:06:52 +00:00
Evgeniy Stepanov 7d3eeaaa96 Revert r307342, r307343.
Revert "Copy arguments passed by value into explicit allocas for ASan."
Revert "[asan] Add end-to-end tests for overflows of byval arguments."

Build failure on lldb-x86_64-ubuntu-14.04-buildserver.
Test failure on clang-cmake-aarch64-42vma and sanitizer-x86_64-linux-android.

llvm-svn: 307345
2017-07-07 01:31:23 +00:00
Evgeniy Stepanov 2a7a4bc1c9 Copy arguments passed by value into explicit allocas for ASan.
ASan determines the stack layout from alloca instructions. Since
arguments marked as "byval" do not have an explicit alloca instruction, ASan
does not produce red zones for them. This commit produces an explicit alloca
instruction and copies the byval argument into the allocated memory so that red
zones are produced.

Patch by Matt Morehouse.

Differential revision: https://reviews.llvm.org/D34789

llvm-svn: 307342
2017-07-07 00:48:25 +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 9e536081fe [asan] Let the frontend disable gc-sections optimization for asan globals.
Also extend -asan-globals-live-support flag to all binary formats.

llvm-svn: 301226
2017-04-24 19:34:13 +00:00
Adrian Prantl 6825fb64e9 PR32382: Fix emitting complex DWARF expressions.
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
  - describe a variable in a register
  - consist of only a DW_OP_reg
2. Memory location descriptions
  - describe the address of a variable
3. Implicit location descriptions
  - describe the value of a variable
  - end with DW_OP_stack_value & friends

The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident.  This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.

This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.

There are two major changes in this patch:

I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.

When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
  DBG_VALUE, [RBP-8]                        --> DW_OP_fbreg -8
  DBG_VALUE, RAX                            --> DW_OP_reg0 +0
  DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0

All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.

https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>

Differential Revision: https://reviews.llvm.org/D31439

llvm-svn: 300522
2017-04-18 01:21:53 +00:00
Evgeniy Stepanov 90fd87303c [asan] Give global metadata private linkage.
Internal linkage preserves names like "__asan_global_foo" which may
account to 2% of unstripped binary size.

llvm-svn: 299995
2017-04-11 22:28:13 +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
Matt Arsenault f10061ec70 Add address space mangling to lifetime intrinsics
In preparation for allowing allocas to have non-0 addrspace.

llvm-svn: 299876
2017-04-10 20:18:21 +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
Evgeniy Stepanov 039af609f1 [asan] Delay creation of asan ctor.
Create the constructor in the module pass.
This in needed for the GC-friendly globals change, where the constructor can be
put in a comdat  in some cases, but we don't know about that in the function
pass.

This is a rebase of r298731 which was reverted due to a false alarm.

llvm-svn: 299695
2017-04-06 19:55:09 +00:00
Alex Shlyapnikov bbd5cc63d7 Revert "[asan] Delay creation of asan ctor."
Speculative revert. Some libfuzzer tests are affected.

This reverts commit r298731.

llvm-svn: 298890
2017-03-27 23:11:50 +00:00