Commit Graph

14 Commits

Author SHA1 Message Date
Sanjay Patel 88fc5fdef6 [InstCombine] remove uses before deleting instructions (PR43723)
This is a less ambitious alternative to previous attempts to fix
this bug with:
rG56b2aee1875a
rGef02831f0a4e
rG56b2aee1875a
...because those all failed bot testing with use-after-free or
other problems.

The original crashing/assert problem is still showing up on
various fuzzers, so I've added a new minimal test based on
another one of those failures.

Instead of trying to manage and coordinate the logic in
isAllocSiteRemovable() with the deletion loops, just loosen
the existing code that handles casts and GEP by replacing
with undef to allow other opcodes. That means that no
instructions with uses should assert on deletion, and there
are hopefully no non-obvious sanitizer bugs induced.
2020-01-02 09:47:36 -05:00
Sanjay Patel 29f5d1670c Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (3rd try)"
This reverts commit 3db8a3ef86.
This caused a different memory-sanitizer failure than earlier attempts,
but it's still not right.
2019-11-11 09:56:03 -05:00
Sanjay Patel 3db8a3ef86 [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (3rd try)
Re-try because earlier attempts were reverted due to use-after-free.
Hopefully, diagnosed correctly this time - we replace/remove the
invariant.start first rather than the invariant.end to avoid angering
worklist-based iteration.

We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.start.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-11 09:29:40 -05:00
Sanjay Patel d115b9fd4a Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (2nd try)"
This reverts commit 56b2aee187.
Still causes a use-after-free on sanitizer bots.
2019-11-10 18:47:49 -05:00
Sanjay Patel 56b2aee187 [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723) (2nd try)
Re-try rGef02831f0a4e (reverted due to use-after-free), but bail out completely
if we encounter an unexpected llvm.invariant.start.

We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.end.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-10 17:26:36 -05:00
Sanjay Patel b0ac26a632 Revert "[InstCombine] avoid crash from deleting an instruction that still has uses (PR43723)"
This reverts commit ef02831f0a.
Sanitizer bots fail with this change.
2019-11-10 11:18:05 -05:00
Sanjay Patel ef02831f0a [InstCombine] avoid crash from deleting an instruction that still has uses (PR43723)
We gather a set of white-listed instructions in isAllocSiteRemovable() and then
replace/erase them. But we don't know in general if the instructions in the set
have uses amongst themselves, so order of deletion makes a difference.

There's already a special-case for the llvm.objectsize intrinsic, so add another
for llvm.invariant.end.

Should fix:
https://bugs.llvm.org/show_bug.cgi?id=43723

Differential Revision: https://reviews.llvm.org/D69977
2019-11-10 09:18:11 -05:00
Sanjay Patel 2f32da3da1 [InstCombine] auto-generate complete checks; NFC 2019-11-07 18:07:04 -05:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +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
Petar Jovanovic 921c2b4eb3 Reland r262337 "calculate builtin_object_size if arg is a removable pointer"
Original commit message:
 calculate builtin_object_size if argument is a removable pointer

 This patch fixes calculating correct value for builtin_object_size function
 when pointer is used only in builtin_object_size function call and never
 after that.

 Patch by Strahinja Petrovic.

 Differential Revision: http://reviews.llvm.org/D17337

Reland the original change with a small modification (first do a null check
and then do the cast) to satisfy ubsan.

llvm-svn: 263011
2016-03-09 14:12:47 +00:00
Petar Jovanovic 6315f3f9b7 Revert "calculate builtin_object_size if argument is a removable pointer"
Revert r262337 as "check-llvm ubsan" step failed on
sanitizer-x86_64-linux-fast buildbot.

llvm-svn: 262349
2016-03-01 16:50:08 +00:00
Petar Jovanovic 8aef99aa86 calculate builtin_object_size if argument is a removable pointer
This patch fixes calculating correct value for builtin_object_size function
when pointer is used only in builtin_object_size function call and never
after that.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D17337

llvm-svn: 262337
2016-03-01 14:39:55 +00:00