Wasmtime GitHub notifications bot (Jul 15 2022 at 14:37): Wasmtime GitHub notifications bot (Jul 15 2022 at 14:37):github-actions[bot] commented on issue #4453:
Subscribe to Label Action
cc @fitzgen
<details>
This issue or pull request has been labeled: "cranelift", "fuzzing"Thus the following users have been cc'd because of the following labels:
- fitzgen: fuzzing
To subscribe or unsubscribe from this label, edit the <code>.github/subscribe-to-label.json</code> configuration file.
Learn more.
</details>
Wasmtime GitHub notifications bot (Aug 08 2022 at 20:24):afonso360 commented on issue #4453:
With the CRT issue resolved I think this is ready to merge.
The only changes since the last review were a rebase and enabling the FMA tests that we couldn't enable in #4460.
Thanks for reviewing!
Wasmtime GitHub notifications bot (Aug 09 2022 at 20:38):afonso360 commented on issue #4453:
@jameysharp I agree with your comments, however this is sort of an intermediate PR with the follow up cleaning pretty much all of it.
See #4667, we do away with SingleFunctionCompiler and link the entire test file at once, so the repeated compilation issue goes away.
Wasmtime GitHub notifications bot (Aug 09 2022 at 20:39):afonso360 edited a comment on issue #4453:
@jameysharp I agree with your comments, however this is sort of an intermediate PR with the follow up cleaning pretty much all of it.
See #4667, we do away with SingleFunctionCompiler and link the entire test file at once, so the repeated compilation issue goes away.
I'd prefer not to have to clean this up, since it's going away as soon as that is done. But let me know if this is a blocker.
Wasmtime GitHub notifications bot (Aug 09 2022 at 21:55):jameysharp commented on issue #4453:
I hadn't looked at 4667 yet, and that resolves my concerns. Thanks!
Wasmtime GitHub notifications bot (Nov 04 2022 at 15:59):uweigand commented on issue #4453:
As of this commit, I'm now seeing test failures on s390x (Ubuntu 20.04), specifically when running
cargo test --docin the filetests directory. The symptom is:Test executable failed (exit status: 101). stderr: thread 'main' panicked at 'unable to make memory readable+executable: SystemCall(Os { code: 13, kind: PermissionDenied, message: "Permission denied" })', cranelift/jit/src/memory.rs:178:30when running the sample code in
src/function_runner.rs. A backtrace shows that the failing call is:#0 0x000003fffdc8cce0 in mprotect () from /lib64/libc.so.6 #1 0x000002aa0008ee96 in region::os::unix::set_protection (base=0x2aa00847000, size=4096, protection=...) at src/os/unix.rs:30 #2 0x000002aa0008e880 in region::protect::protect (address=0x2aa00847000, size=4096, protection=...) at src/protect.rs:48 #3 0x000002aa00072f6e in cranelift_jit::memory::{impl#2}::set_readable_and_executable::{closure#0} (ptr=0x2aa00847000, len=4096) at cranelift/jit/src/memory.rs:211 #4 0x000002aa00086824 in cranelift_jit::memory::Memory::set_readable_and_executable (self=0x3ffffffd2d0) at cranelift/jit/src/memory.rs:221 #5 0x000002aa00068332 in cranelift_jit::backend::JITModule::finalize_definitions (self=0x3ffffffd260) at cranelift/jit/src/backend.rs:461 #6 0x000002aa00045ae0 in cranelift_filetests::function_runner::TestFileCompiler::compile (self=<error reading variable: value has been optimized out>) at cranelift/filetests/src/function_runner.rs:247Note that this attempts to use
mprotectto grant execute permission to memory allocated on the heap. This is not supported everywhere, and will in particular be prevented by various security hardening settings on Linux.Instead, you should use separate
mmapallocations if you need to grant execute permissions.
Wasmtime GitHub notifications bot (Nov 04 2022 at 16:59):afonso360 commented on issue #4453:
:wave: Hey,
Do the regular filetests pass for you on
main? We still usemprotect, so I'm surprised as to how we haven't detected this sooner.
cranelift-jithas theselinux-fixfeature that switches tommapbased allocations, if you try to use that, does that make it pass?If so, that might be related to: https://github.com/bytecodealliance/wasmtime/issues/4986
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:00):afonso360 edited a comment on issue #4453:
:wave: Hey,
Do the regular filetests pass for you on
main? We still usemprotect, so I'm surprised as to how we haven't detected this sooner.
cranelift-jithas theselinux-fixfeature that switches tommapbased allocations, if you try to use that, does that make it pass?If so, this might be related to: https://github.com/bytecodealliance/wasmtime/issues/4986
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:06):afonso360 edited a comment on issue #4453:
:wave: Hey,
~Do the regular filetests pass for you on
main? We still usemprotect, so I'm surprised as to how we haven't detected this sooner.~Edit: Ignore that I misread your comment and thought that only the doc tests were failing.
cranelift-jithas theselinux-fixfeature that switches tommapbased allocations, if you try to use that, does that make it pass?If so, this might be related to: https://github.com/bytecodealliance/wasmtime/issues/4986
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:07):afonso360 edited a comment on issue #4453:
:wave: Hey,
~Do the regular filetests pass for you on
main? We still usemprotect, so I'm surprised as to how we haven't detected this sooner.~Edit: Ignore that, I misread your comment and thought that only the doc tests were failing.
cranelift-jithas theselinux-fixfeature that switches tommapbased allocations, if you try to use that, does that make it pass?If so, this might be related to: https://github.com/bytecodealliance/wasmtime/issues/4986
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:27):uweigand commented on issue #4453:
No, only the doc tests are indeed failing. I've been debugging this right now, and the difference is that doc test sample program is single-threaded and uses the main heap, where
mprotectPROT_EXECfails. However, when running the main filetests, theclif-utilprogram is multi-threaded and glibc uses per-thread heaps, which are separately created viammap, and therefore themprotecthappens to work ...How would I use the
selinux-fixfeature with a doc test?
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:38):afonso360 commented on issue #4453:
No, only the doc tests are indeed failing. I've been debugging this right now, and the difference is that doc test sample program is single-threaded and uses the main heap, where mprotect PROT_EXEC fails. However, when running the main filetests, the clif-util program is multi-threaded and glibc uses per-thread heaps, which are separately created via mmap, and therefore the mprotect happens to work ...
That's interesting, and weird!
How would I use the selinux-fix feature with a doc test?
This should do it.
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:39):afonso360 edited a comment on issue #4453:
No, only the doc tests are indeed failing. I've been debugging this right now, and the difference is that doc test sample program is single-threaded and uses the main heap, where mprotect PROT_EXEC fails. However, when running the main filetests, the clif-util program is multi-threaded and glibc uses per-thread heaps, which are separately created via mmap, and therefore the mprotect happens to work ...
That's interesting, and weird!
How would I use the selinux-fix feature with a doc test?
This should do it.
However I think that we probably should switch to a mmap allocator since that apparently can solve a bunch of other issues with cranelift-jit.
Wasmtime GitHub notifications bot (Nov 04 2022 at 17:59):uweigand commented on issue #4453:
How would I use the selinux-fix feature with a doc test?
This should do it.
This fixes the problem for me. Submitted as https://github.com/bytecodealliance/wasmtime/pull/5204
However I think that we probably should switch to a mmap allocator since that apparently can solve a bunch of other issues with cranelift-jit.
Agreed!
Last updated: Oct 23 2024 at 20:03 UTC