Commit Graph

558 Commits

Author SHA1 Message Date
Kazu Hirata cfeecdf7b6 [llvm] Use llvm::all_of (NFC) 2021-01-06 18:27:36 -08:00
Fangrui Song b5ad32ef5c Migrate deprecated DebugLoc::get to DILocation::get
This migrates all LLVM (except Kaleidoscope and
CodeGen/StackProtector.cpp) DebugLoc::get to DILocation::get.

The CodeGen/StackProtector.cpp usage may have a nullptr Scope
and can trigger an assertion failure, so I don't migrate it.

Reviewed By: #debug-info, dblaikie

Differential Revision: https://reviews.llvm.org/D93087
2020-12-11 12:45:22 -08:00
Marco Elver c28b18af19 [KernelAddressSanitizer] Fix globals exclusion for indirect aliases
GlobalAlias::getAliasee() may not always point directly to a
GlobalVariable. In such cases, try to find the canonical GlobalVariable
that the alias refers to.

Link: https://github.com/ClangBuiltLinux/linux/issues/1208

Reviewed By: dvyukov, nickdesaulniers

Differential Revision: https://reviews.llvm.org/D92846
2020-12-11 12:20:40 +01:00
Fangrui Song a5309438fe static const char *const foo => const char foo[]
By default, a non-template variable of non-volatile const-qualified type
having namespace-scope has internal linkage, so no need for `static`.
2020-12-01 10:33:18 -08:00
Xun Li 7f34aca083 [musttail] Unify musttail call preceding return checking
There is already an API in BasicBlock that checks and returns the musttail call if it precedes the return instruction.
Use it instead of manually checking in each place.

Differential Revision: https://reviews.llvm.org/D90693
2020-11-03 11:39:27 -08:00
Xun Li 0ccf9263cc [ASAN] Make sure we are only processing lifetime markers with offset 0 to alloca
This patch addresses https://bugs.llvm.org/show_bug.cgi?id=47787 (and hence https://bugs.llvm.org/show_bug.cgi?id=47767 as well).
In latter instrumentation code, we always use the beginning of the alloca as the base for instrumentation, ignoring any offset into the alloca.
Because of that, we should only instrument a lifetime marker if it's actually pointing to the beginning of the alloca.

Differential Revision: https://reviews.llvm.org/D89191
2020-10-13 10:21:45 -07:00
Anatoly Parshintsev a566f0525a [RISCV][ASAN] instrumentation pass now uses proper shadow offset
[10/11] patch series to port ASAN for riscv64

Depends On D87580

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D87581
2020-10-04 16:30:38 +03:00
Michał Górny 66e493f81e [asan] Stop instrumenting user-defined ELF sections
Do not instrument user-defined ELF sections (whose names resemble valid
C identifiers).  They may have special use semantics and modifying them
may break programs.  This is e.g. the case with NetBSD __link_set API
that expects these sections to store consecutive array elements.

Differential Revision: https://reviews.llvm.org/D76665
2020-10-03 19:54:38 +02:00
Dominic Chen 06e68f05da
[AddressSanitizer] Copy type metadata to prevent miscompilation
When ASan and e.g. Dead Virtual Function Elimination are enabled, the
latter will rely on type metadata to determine if certain virtual calls can be
removed. However, ASan currently does not copy type metadata, which can cause
virtual function calls to be incorrectly removed.

Differential Revision: https://reviews.llvm.org/D88368
2020-09-28 13:56:05 -04:00
Xun Li 11453740bc [ASAN] Properly deal with musttail calls in ASAN
When address sanitizing a function, stack unpinsoning code is inserted before each ret instruction. However if the ret instruciton is preceded by a musttail call, such transformation broke the musttail call contract and generates invalid IR.
This patch fixes the issue by moving the insertion point prior to the musttail call if there is one.

Differential Revision: https://reviews.llvm.org/D87777
2020-09-18 23:10:34 -07:00
Kai Nacke b3aece0531 [SystemZ/ZOS] Add binary format goff and operating system zos to the triple
Adds the binary format goff and the operating system zos to the triple
class. goff is selected as default binary format if zos is choosen as
operating system. No further functionality is added.

Reviewers: efriedma, tahonermann, hubert.reinterpertcast, MaskRay

Reviewed By: efriedma, tahonermann, hubert.reinterpertcast

Differential Revision: https://reviews.llvm.org/D82081
2020-08-11 05:26:26 -04:00
Vitaly Buka b0eb40ca39 [NFC] Remove unused GetUnderlyingObject paramenter
Depends on D84617.

Differential Revision: https://reviews.llvm.org/D84621
2020-07-31 02:10:03 -07:00
Vitaly Buka 89051ebace [NFC] GetUnderlyingObject -> getUnderlyingObject
I am going to touch them in the next patch anyway
2020-07-30 21:08:24 -07:00
Vitaly Buka b256cb88a7 [ValueTracking] Remove AllocaForValue parameter
findAllocaForValue uses AllocaForValue to cache resolved values.
The function is used only to resolve arguments of lifetime
intrinsic which usually are not fare for allocas. So result reuse
is likely unnoticeable.

In followup patches I'd like to replace the function with
GetUnderlyingObjects.

Depends on D84616.

Differential Revision: https://reviews.llvm.org/D84617
2020-07-30 18:48:34 -07:00
Kuba Mracek 176a6e7abe [asan] Use dynamic shadow memory position on Apple Silicon macOS
This is needed because macOS on Apple Silicon has some reserved pages inside the "regular" shadow memory location, and mapping over that location fails.

Differential Revision: https://reviews.llvm.org/D82912
2020-07-17 17:40:21 -07:00
Leonard Chan cf5df40c4c Revert "[AddressSanitizer] Don't use weak linkage for __{start,stop}_asan_globals"
This reverts commit d76e62fdb7.

Reverting since this can lead to linker errors:

```
ld.lld: error: undefined hidden symbol: __start_asan_globals
```

when using --gc-sections. The linker can discard __start_asan_globals
once there are no more `asan_globals` sections left, which can lead to
this error if we have external linkages to them.
2020-07-17 15:29:50 -07:00
Guillaume Chatelet 87e2751cf0 [Alignment][NFC] Use proper getter to retrieve alignment from ConstantInt and ConstantSDNode
This patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Differential Revision: https://reviews.llvm.org/D83082
2020-07-03 08:06:43 +00:00
Christopher Tetreault bdcd200629 [SVE] Remove calls to VectorType::getNumElements from Instrumentation
Reviewers: efriedma, pcc, gchatelet, kmclaughlin, sdesmalen

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82241
2020-06-29 15:20:24 -07:00
Zequan Wu 6a822e20ce [ASan][MSan] Remove EmptyAsm and set the CallInst to nomerge to avoid from merging.
Summary: `nomerge` attribute was added at D78659. So, we can remove the EmptyAsm workaround in ASan the MSan and use this attribute.

Reviewers: vitalybuka

Reviewed By: vitalybuka

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82322
2020-06-23 14:22:53 -07:00
Eric Christopher 10563e16aa [Analysis/Transforms/Sanitizers] As part of using inclusive language
within the llvm project, migrate away from the use of blacklist and
whitelist.
2020-06-20 00:42:26 -07:00
Marco Elver 8af7fa07aa [ASan][NFC] Refactor redzone size calculation
Refactor redzone size calculation. This will simplify changing the
redzone size calculation in future.

Note that AddressSanitizer.cpp violates the latest LLVM style guide in
various ways due to capitalized function names. Only code related to the
change here was changed to adhere to the style guide.

No functional change intended.

Reviewed By: andreyknvl

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81367
2020-06-12 15:33:00 +02:00
Marco Elver d3f89314ff [KernelAddressSanitizer] Make globals constructors compatible with kernel [v2]
[ v1 was reverted by c6ec352a6b due to
  modpost failing; v2 fixes this. More info:
  https://github.com/ClangBuiltLinux/linux/issues/1045#issuecomment-640381783 ]

This makes -fsanitize=kernel-address emit the correct globals
constructors for the kernel. We had to do the following:

* Disable generation of constructors that rely on linker features such
  as dead-global elimination.

* Only instrument globals *not* in explicit sections. The kernel uses
  sections for special globals, which we should not touch.

* Do not instrument globals that are prefixed with "__" nor that are
  aliased by a symbol that is prefixed with "__". For example, modpost
  relies on specially named aliases to find globals and checks their
  contents. Unfortunately modpost relies on size stored as ELF debug info
  and any padding of globals currently causes the debug info to cause size
  reported to be *with* redzone which throws modpost off.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203493

Tested:
* With 'clang/test/CodeGen/asan-globals.cpp'.

* With test_kasan.ko, we can see:

  	BUG: KASAN: global-out-of-bounds in kasan_global_oob+0xb3/0xba [test_kasan]

* allyesconfig, allmodconfig (x86_64)

Reviewed By: glider

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D81390
2020-06-10 15:08:42 +02:00
Marco Elver c6ec352a6b Revert "[KernelAddressSanitizer] Make globals constructors compatible with kernel"
This reverts commit 866ee2353f.

Building the kernel results in modpost failures due to modpost relying
on debug info and inspecting kernel modules' globals:
https://github.com/ClangBuiltLinux/linux/issues/1045#issuecomment-640381783
2020-06-08 10:34:03 +02:00
Marco Elver 866ee2353f [KernelAddressSanitizer] Make globals constructors compatible with kernel
Summary:
This makes -fsanitize=kernel-address emit the correct globals
constructors for the kernel. We had to do the following:

- Disable generation of constructors that rely on linker features such
  as dead-global elimination.

- Only emit constructors for globals *not* in explicit sections. The
  kernel uses sections for special globals, which we should not touch.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203493

Tested:
1. With 'clang/test/CodeGen/asan-globals.cpp'.
2. With test_kasan.ko, we can see:

  	BUG: KASAN: global-out-of-bounds in kasan_global_oob+0xb3/0xba [test_kasan]

Reviewers: glider, andreyknvl

Reviewed By: glider

Subscribers: cfe-commits, nickdesaulniers, hiraditya, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D80805
2020-06-05 20:20:46 +02:00
Arthur Eubanks 8133e289b6 Add ASan metadata globals to @llvm.compiler.used under COFF
Summary:
This matches ELF.

This makes the number of ASan failures under the new pass manager on
Windows go from 18 to 1.

Under the old pass manager, the ASan module pass was one of the very
last things run, so these globals didn't get removed due to GlobalOpt.
But with the NPM the ASan module pass that adds these globals are run
much earlier in the pipeline and GlobalOpt ends up removing them.

Reviewers: vitalybuka, hans

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81175
2020-06-05 09:04:52 -07:00
serge-sans-paille 2fc085e0e5 Fix return status of AddressSanitizer pass
Differential Revision: https://reviews.llvm.org/D81240
2020-06-05 15:44:51 +02:00
Petr Hosek d76e62fdb7 [AddressSanitizer] Don't use weak linkage for __{start,stop}_asan_globals
It should not be necessary to use weak linkage for these. Doing so
implies interposablity and thus PIC generates indirections and
dynamic relocations, which are unnecessary and suboptimal. Aside
from this, ASan instrumentation never introduces GOT indirection
relocations where there were none before--only new absolute relocs
in RELRO sections for metadata, which are less problematic for
special linkage situations that take pains to avoid GOT generation.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D80605
2020-06-04 20:18:35 -07:00
Nikita Popov 47a0e9f49b [Sanitizers] Use getParamByValType() (NFC)
Instead of fetching the pointer element type.
2020-05-18 22:06:18 +02:00
Eli Friedman 4f04db4b54 AllocaInst should store Align instead of MaybeAlign.
Along the lines of D77454 and D79968.  Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.

Differential Revision: https://reviews.llvm.org/D80044
2020-05-16 14:53:16 -07:00
Alina Sbirlea bd541b217f [NewPassManager] Add assertions when getting statefull cached analysis.
Summary:
Analyses that are statefull should not be retrieved through a proxy from
an outer IR unit, as these analyses are only invalidated at the end of
the inner IR unit manager.
This patch disallows getting the outer manager and provides an API to
get a cached analysis through the proxy. If the analysis is not
stateless, the call to getCachedResult will assert.

Reviewers: chandlerc

Subscribers: mehdi_amini, eraman, hiraditya, zzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72893
2020-05-13 12:38:38 -07:00
Jann Horn a22685885d [AddressSanitizer] Instrument byval call arguments
Summary:
In the LLVM IR, "call" instructions read memory for each byval operand.
For example:

```
$ cat blah.c
struct foo { void *a, *b, *c; };
struct bar { struct foo foo; };
void func1(const struct foo);
void func2(struct bar *bar) { func1(bar->foo); }
$ [...]/bin/clang -S -flto -c blah.c -O2 ; cat blah.s
[...]
define dso_local void @func2(%struct.bar* %bar) local_unnamed_addr #0 {
entry:
  %foo = getelementptr inbounds %struct.bar, %struct.bar* %bar, i64 0, i32 0
  tail call void @func1(%struct.foo* byval(%struct.foo) align 8 %foo) #2
  ret void
}
[...]
$ [...]/bin/clang -S -c blah.c -O2 ; cat blah.s
[...]
func2:                                  # @func2
[...]
        subq    $24, %rsp
[...]
        movq    16(%rdi), %rax
        movq    %rax, 16(%rsp)
        movups  (%rdi), %xmm0
        movups  %xmm0, (%rsp)
        callq   func1
        addq    $24, %rsp
[...]
        retq
```

Let ASAN instrument these hidden memory accesses.

This is patch 4/4 of a patch series:
https://reviews.llvm.org/D77616 [PATCH 1/4] [AddressSanitizer] Refactor ClDebug{Min,Max} handling
https://reviews.llvm.org/D77617 [PATCH 2/4] [AddressSanitizer] Split out memory intrinsic handling
https://reviews.llvm.org/D77618 [PATCH 3/4] [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
https://reviews.llvm.org/D77619 [PATCH 4/4] [AddressSanitizer] Instrument byval call arguments

Reviewers: kcc, glider

Reviewed By: glider

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77619
2020-04-30 17:09:13 +02:00
Jann Horn cfe36e4c6a [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
Summary:
Refactor getInterestingMemoryOperands() so that information about the
pointer operand is returned through an array of structures instead of
passing each piece of information separately by-value.

This is in preparation for returning information about multiple pointer
operands from a single instruction.

A side effect is that, instead of repeatedly generating the same
information through isInterestingMemoryAccess(), it is now simply collected
once and then passed around; that's probably more efficient.

HWAddressSanitizer has a bunch of copypasted code from AddressSanitizer,
so these changes have to be duplicated.

This is patch 3/4 of a patch series:
https://reviews.llvm.org/D77616 [PATCH 1/4] [AddressSanitizer] Refactor ClDebug{Min,Max} handling
https://reviews.llvm.org/D77617 [PATCH 2/4] [AddressSanitizer] Split out memory intrinsic handling
https://reviews.llvm.org/D77618 [PATCH 3/4] [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
https://reviews.llvm.org/D77619 [PATCH 4/4] [AddressSanitizer] Instrument byval call arguments

[glider: renamed llvm::InterestingMemoryOperand::Type to OpType to fix
GCC compilation]

Reviewers: kcc, glider

Reviewed By: glider

Subscribers: hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77618
2020-04-30 17:09:13 +02:00
Jann Horn 223a95fdf0 [AddressSanitizer] Split out memory intrinsic handling
Summary:
In both AddressSanitizer and HWAddressSanitizer, we first collect
instructions whose operands should be instrumented and memory intrinsics,
then instrument them. Both during collection and when inserting
instrumentation, they are handled separately.

Collect them separately and instrument them separately. This is a bit
more straightforward, and prepares for collecting operands instead of
instructions in a future patch.

This is patch 2/4 of a patch series:
https://reviews.llvm.org/D77616 [PATCH 1/4] [AddressSanitizer] Refactor ClDebug{Min,Max} handling
https://reviews.llvm.org/D77617 [PATCH 2/4] [AddressSanitizer] Split out memory intrinsic handling
https://reviews.llvm.org/D77618 [PATCH 3/4] [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
https://reviews.llvm.org/D77619 [PATCH 4/4] [AddressSanitizer] Instrument byval call arguments

Reviewers: kcc, glider

Reviewed By: glider

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77617
2020-04-30 17:09:13 +02:00
Jann Horn e29996c9a2 [AddressSanitizer] Refactor ClDebug{Min,Max} handling
Summary:
A following commit will split the loop over ToInstrument into two.
To avoid having to duplicate the condition for suppressing instrumentation
sites based on ClDebug{Min,Max}, refactor it out into a new function.

While we're at it, we can also avoid the indirection through
NumInstrumented for setting FunctionModified.

This is patch 1/4 of a patch series:
https://reviews.llvm.org/D77616 [PATCH 1/4] [AddressSanitizer] Refactor ClDebug{Min,Max} handling
https://reviews.llvm.org/D77617 [PATCH 2/4] [AddressSanitizer] Split out memory intrinsic handling
https://reviews.llvm.org/D77618 [PATCH 3/4] [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
https://reviews.llvm.org/D77619 [PATCH 4/4] [AddressSanitizer] Instrument byval call arguments

Reviewers: kcc, glider

Reviewed By: glider

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77616
2020-04-30 17:09:13 +02:00
Alexander Potapenko 7e7754df32 Revert an accidental commit of four AddressSanitizer refactor CLs
I couldn't make arc land the changes properly, for some reason they all got
squashed. Reverting them now to land cleanly.

Summary: This reverts commit cfb5f89b62.

Reviewers: kcc, thejh

Subscribers:
2020-04-30 16:15:43 +02:00
Jann Horn cfb5f89b62 [AddressSanitizer] Refactor ClDebug{Min,Max} handling
Summary:
A following commit will split the loop over ToInstrument into two.
To avoid having to duplicate the condition for suppressing instrumentation
sites based on ClDebug{Min,Max}, refactor it out into a new function.

While we're at it, we can also avoid the indirection through
NumInstrumented for setting FunctionModified.

This is patch 1/4 of a patch series:
https://reviews.llvm.org/D77616 [PATCH 1/4] [AddressSanitizer] Refactor ClDebug{Min,Max} handling
https://reviews.llvm.org/D77617 [PATCH 2/4] [AddressSanitizer] Split out memory intrinsic handling
https://reviews.llvm.org/D77618 [PATCH 3/4] [AddressSanitizer] Refactor: Permit >1 interesting operands per instruction
https://reviews.llvm.org/D77619 [PATCH 4/4] [AddressSanitizer] Instrument byval call arguments

Reviewers: kcc, glider

Reviewed By: glider

Subscribers: jfb, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77616
2020-04-30 15:30:46 +02:00
Craig Topper a58b62b4a2 [IR] Replace all uses of CallBase::getCalledValue() with getCalledOperand().
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().

I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.

Differential Revision: https://reviews.llvm.org/D78882
2020-04-27 22:17:03 -07:00
Craig Topper 6235951ec0 [CallSite removal][Instrumentation] Use CallBase instead of CallSite in AddressSanitizer/DataFlowSanitizer/MemorySanitizer. NFC
Differential Revision: https://reviews.llvm.org/D78524
2020-04-20 22:39:14 -07:00
Christopher Tetreault 3bebf02861 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: sdesmalen, rriddle, efriedma

Reviewed By: sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77262
2020-04-10 07:47:19 -07:00
Vedant Kumar 5f185a8999 [AddressSanitizer] Fix for wrong argument values appearing in backtraces
Summary:
In some cases, ASan may insert instrumentation before function arguments
have been stored into their allocas. This causes two issues:

1) The argument value must be spilled until it can be stored into the
   reserved alloca, wasting a stack slot.

2) Until the store occurs in a later basic block, the debug location
   will point to the wrong frame offset, and backtraces will show an
   uninitialized value.

The proposed solution is to move instructions which initialize allocas
for arguments up into the entry block, before the position where ASan
starts inserting its instrumentation.

For the motivating test case, before the patch we see:

```
 | 0033: movq %rdi, 0x68(%rbx)  |   | DW_TAG_formal_parameter     |
 | ...                          |   |   DW_AT_name ("a")          |
 | 00d1: movq 0x68(%rbx), %rsi  |   |   DW_AT_location (RBX+0x90) |
 | 00d5: movq %rsi, 0x90(%rbx)  |   |       ^ not correct ...     |
```

and after the patch we see:

```
 | 002f: movq %rdi, 0x70(%rbx)  |   | DW_TAG_formal_parameter     |
 |                              |   |   DW_AT_name ("a")          |
 |                              |   |   DW_AT_location (RBX+0x70) |
```

rdar://61122691

Reviewers: aprantl, eugenis

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77182
2020-04-06 15:59:25 -07:00
Nikita Popov 80397d2d12 [IRBuilder] Delete copy constructor
D73835 will make IRBuilder no longer trivially copyable. This patch
deletes the copy constructor in advance, to separate out the breakage.

Currently, the IRBuilder copy constructor is usually used by accident,
not by intention.  In rG7c362b25d7a9 I've fixed a number of cases where
functions accepted IRBuilder rather than IRBuilder &, thus performing
an unnecessary copy. In rG5f7b92b1b4d6 I've fixed cases where an
IRBuilder was copied, while an InsertPointGuard should have been used
instead.

The only non-trivial use of the copy constructor is the
getIRBForDbgInsertion() helper, for which I separated construction and
setting of the insertion point in this patch.

Differential Revision: https://reviews.llvm.org/D74693
2020-02-17 18:14:48 +01:00
Vedant Kumar 8e77b33b3c [Local] Do not move around dbg.declares during replaceDbgDeclare
replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.

Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.

However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.

Testing: stage2 RelWithDebInfo sanitized build, check-llvm

rdar://59397340

Differential Revision: https://reviews.llvm.org/D74517
2020-02-13 14:35:02 -08:00
Vedant Kumar 34d9f93977 [AddressSanitizer] Ensure only AllocaInst is passed to dbg.declare
Various parts of the LLVM code generator assume that the address
argument of a dbg.declare is not a `ptrtoint`-of-alloca. ASan breaks
this assumption, and this results in local variables sometimes being
unavailable at -O0.

GlobalISel, SelectionDAG, and FastISel all do not appear to expect
dbg.declares to have a `ptrtoint` as an operand. This means that they do
not place entry block allocas in the usual side table reserved for local
variables available in the whole function scope. This isn't always a
problem, as LLVM can try to lower the dbg.declare to a DBG_VALUE, but
those DBG_VALUEs can get dropped for all the usual reasons DBG_VALUEs
get dropped. In the ObjC test case I'm looking at, the cause happens to
be that `replaceDbgDeclare` has hoisted dbg.declares into the entry
block, causing LiveDebugValues to "kill" the DBG_VALUEs because the
lexical dominance check fails.

To address this, I propose:

1) Have ASan (always) pass an alloca to dbg.declares (this patch). This
   is a narrow bugfix for -O0 debugging.

2) Make replaceDbgDeclare not move dbg.declares around. This should be a
   generic improvement for optimized debug info, as it would prevent the
   lexical dominance check in LiveDebugValues from killing as many
   variables.

   This means reverting llvm/r227544, which fixed an assertion failure
   (llvm.org/PR22386) but no longer seems to be necessary. I was able to
   complete a stage2 build with the revert in place.

rdar://54688991

Differential Revision: https://reviews.llvm.org/D74369
2020-02-12 11:24:02 -08:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Guillaume Chatelet 805c157e8a [Alignment][NFC] Deprecate Align::None()
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.

Reviewers: xbolva00, courbet, bollu

Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73099
2020-01-24 12:53:58 +01:00
Guillaume Chatelet 59f95222d4 [Alignment][NFC] Use Align with CreateAlignedStore
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, bollu

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73274
2020-01-23 17:34:32 +01:00
Guillaume Chatelet 531c1161b9 Resubmit "[Alignment][NFC] Deprecate CreateMemCpy/CreateMemMove"
Summary:
This is a resubmit of D71473.

This patch introduces a set of functions to enable deprecation of IRBuilder functions without breaking out of tree clients.
Functions will be deprecated one by one and as in tree code is cleaned up.

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: aaron.ballman, courbet

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71547
2019-12-17 10:07:46 +01:00
Guillaume Chatelet 4658da10e4 Revert "[Alignment][NFC] Deprecate CreateMemCpy/CreateMemMove"
This reverts commit 181ab91efc.
2019-12-16 15:19:49 +01:00
Guillaume Chatelet 181ab91efc [Alignment][NFC] Deprecate CreateMemCpy/CreateMemMove
Summary:
This patch introduces a set of functions to enable deprecation of IRBuilder functions without breaking out of tree clients.
Functions will be deprecated one by one and as in tree code is cleaned up.

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71473
2019-12-16 13:35:55 +01:00
Johannes Altmanninger 09667bc192 [asan] Remove debug locations from alloca prologue instrumentation
Summary:
This fixes https://llvm.org/PR26673
"Wrong debugging information with -fsanitize=address"
where asan instrumentation causes the prologue end to be computed
incorrectly: findPrologueEndLoc, looks for the first instruction
with a debug location to determine the prologue end.  Since the asan
instrumentation instructions had debug locations, that prologue end was
at some instruction, where the stack frame is still being set up.

There seems to be no good reason for extra debug locations for the
asan instrumentations that set up the frame; they don't have a natural
source location.  In the debugger they are simply located at the start
of the function.

For certain other instrumentations like -fsanitize-coverage=trace-pc-guard
the same problem persists - that might be more work to fix, since it
looks like they rely on locations of the tracee functions.

This partly reverts aaf4bb2394
"[asan] Set debug location in ASan function prologue"
whose motivation was to give debug location info to the coverage callback.
Its test only ensures that the call to @__sanitizer_cov_trace_pc_guard is
given the correct source location; as the debug location is still set in
ModuleSanitizerCoverage::InjectCoverageAtBlock, the test does not break.
So -fsanitize-coverage is hopefully unaffected - I don't think it should
rely on the debug locations of asan-generated allocas.

Related revision: 3c6c14d14b
"ASAN: Provide reliable debug info for local variables at -O0."

Below is how the X86 assembly version of the added test case changes.
We get rid of some .loc lines and put prologue_end where the user code starts.

```diff
--- 2.master.s	2019-12-02 12:32:38.982959053 +0100
+++ 2.patch.s	2019-12-02 12:32:41.106246674 +0100
@@ -45,8 +45,6 @@
 	.cfi_offset %rbx, -24
 	xorl	%eax, %eax
 	movl	%eax, %ecx
- .Ltmp2:
- 	.loc	1 3 0 prologue_end      # 2.c:3:0
 	cmpl	$0, __asan_option_detect_stack_use_after_return
 	movl	%edi, 92(%rbx)          # 4-byte Spill
 	movq	%rsi, 80(%rbx)          # 8-byte Spill
@@ -57,9 +55,7 @@
 	callq	__asan_stack_malloc_0
 	movq	%rax, 72(%rbx)          # 8-byte Spill
 .LBB1_2:
- 	.loc	1 0 0 is_stmt 0         # 2.c:0:0
 	movq	72(%rbx), %rax          # 8-byte Reload
- 	.loc	1 3 0                   # 2.c:3:0
 	cmpq	$0, %rax
 	movq	%rax, %rcx
 	movq	%rax, 64(%rbx)          # 8-byte Spill
@@ -72,9 +68,7 @@
 	movq	%rax, %rsp
 	movq	%rax, 56(%rbx)          # 8-byte Spill
 .LBB1_4:
- 	.loc	1 0 0                   # 2.c:0:0
 	movq	56(%rbx), %rax          # 8-byte Reload
- 	.loc	1 3 0                   # 2.c:3:0
 	movq	%rax, 120(%rbx)
 	movq	%rax, %rcx
 	addq	$32, %rcx
@@ -99,7 +93,6 @@
 	movb	%r8b, 31(%rbx)          # 1-byte Spill
 	je	.LBB1_7
 # %bb.5:
- 	.loc	1 0 0                   # 2.c:0:0
 	movq	40(%rbx), %rax          # 8-byte Reload
 	andq	$7, %rax
 	addq	$3, %rax
@@ -118,7 +111,8 @@
 	movl	%ecx, (%rax)
 	movq	80(%rbx), %rdx          # 8-byte Reload
 	movq	%rdx, 128(%rbx)
-	.loc	1 4 3 is_stmt 1         # 2.c:4:3
+.Ltmp2:
+	.loc	1 4 3 prologue_end      # 2.c:4:3
 	movq	%rax, %rdi
 	callq	f
 	movq	48(%rbx), %rax          # 8-byte Reload
```

Reviewers: eugenis, aprantl

Reviewed By: eugenis

Subscribers: ormris, aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70894
2019-12-03 11:24:17 +01:00