Miscompilation on aarch64-apple-darwin (likely a calling convention bug) #112548

cbeuw · 2023-06-12T10:33:04Z

Fuzzer generated code:

#![feature(const_hash)]
extern crate core;
use core::ptr;

use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};

static mut H: DefaultHasher = DefaultHasher::new();

pub fn fn10() {
    let mut _11 = 0;
    let mut _29 = 0;
    let p = core::ptr::addr_of_mut!(_29);
    unsafe { fn14(_11, p) };
}

pub unsafe fn fn14(mut _2: isize, mut _3: *mut isize) {
    let r = core::ptr::addr_of_mut!(_2);
    *r = fn15(r, _3);
    fn18();
}
pub unsafe fn fn15(mut _2: *mut isize, mut _3: *mut isize) -> isize {
    let mut _4: *mut isize = ptr::null_mut();
    let mut _7: *mut *mut isize = ptr::null_mut();
    let mut _13: *mut isize = ptr::null_mut();
    let mut _16: *mut isize = ptr::null_mut();

    let mut _9: ((bool, i128), (f32, i128), [u128; 8], u32) = ((false, 0), (0., 0), [0; 8], 0);
    _4 = core::ptr::addr_of_mut!((*_3));
    fn16();
    'bb1: loop {
        let ret = *_4;
        _7 = core::ptr::addr_of_mut!(_2);
        _9.3 = 3178558635_u32 % 2879763616_u32;
        _9.0 = (false, 1);
        'bb3: loop {
            (*_7) = core::ptr::addr_of_mut!((*_2));
            _16 = core::ptr::addr_of_mut!((*_2));
            match _9.0 .1 {
                0 => continue 'bb1,
                1 => 'bb5: loop {
                    _4 = _2;
                    _9.2 = [279331277471898888451578203748788445758_u128; 8];
                    _7 = core::ptr::addr_of_mut!(_13);
                    loop {
                        _9.1 = (0., 2);
                        (*_16) = f64::NEG_INFINITY as isize;
                        match _9.1 .1 {
                            0 => continue 'bb5,
                            2 => {
                                _16 = core::ptr::addr_of_mut!((*_4));
                                match _9.3 {
                                    0 => continue 'bb5,
                                    _ => return ret,
                                }
                            }
                            _ => continue 'bb3,
                        }
                    }
                },
                _ => continue 'bb3,
            }
        }
    }
}

pub fn fn16() {
    let mut _23 = [1849_i16; 7];
    _23[2] = 13917_i16;
    let _32 = _23;
    unsafe {
        0.hash(&mut H);
        _32.hash(&mut H);
    }
}

pub fn fn18() {
    let mut _8: [i16; 8] = [0; 8];
    let _5 = -10_i128;
    let _9 = [(-1414_i16); 7];
    unsafe {
        _9[0].hash(&mut H);
        _8.hash(&mut H);
        1_i128.hash(&mut H);
    }
}

pub fn main() {
    fn10();
    unsafe {
        println!("hash: {}", H.finish());
    }
}

This should output 15917201677548574216: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=a51ce49127180037639732b4a990ddbe.

But on -Zmir-opt-level=0 -Copt-level>=1 it prints something different. -Zmir-opt-level>=1 masks the bug.

% rustc -Zmir-opt-level=0 -Copt-level=0 repro.rs && ./repro
hash: 15917201677548574216
% rustc -Zmir-opt-level=0 -Copt-level=1 repro.rs && ./repro
hash: 2617855399195014552

This is only reproducible on aarch64-apple-darwin, but not on x86_64-apple-darwin or aarch64-unknown-linux-gnu. The reproducer is very sensitive to small changes. For instance, changing the length of _23 in fn16 to 8 prevents the bug. For these reasons I suspect it's an Apple Silicon specific calling convention bug leading to some stack corruption.

The text was updated successfully, but these errors were encountered:

Jules-Bertholet · 2023-06-12T19:20:26Z

@rustbot label O-aarch64 O-macos

apiraino · 2023-06-13T09:01:15Z

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high

cbeuw · 2023-06-15T12:00:47Z

I have another reproduction of what I believe is the same bug, but this one is only 34 lines, has only safe code and doesn't need a hasher:

use std::fmt::Debug;

pub fn dump_var<T: Debug>(
    f: usize,
    var0: usize,
    val0: T,
    var1: usize,
    val1: i32,
    var2: usize,
    val2: i32,
    var3: usize,
    val3: i32,
) {
    println!(
        "fn{f}:_{var0} = {val0:?}\n_{var1} = {val1:?}\n_{var2} = {val2:?}\n_{var3} = {val3:?}"
    );
}

fn fn10() {
    let _2 = 302053680377554952743809083898710279615_u128;
    let mut _5 = _2.wrapping_shl(_2 as u32);
    let mut _18: (u128, [isize; 3]) = (0, [0; 3]);
    _18.1 = [9223372036854775807_isize; 3];
    dump_var(11, 0, 0, 0, 0, 0, 0, 0, 0);
    dump_var(11, 0, 0, 0, 0, 0, 0, /* addend */ 1, 0);
    let _1 = _5 | _18.0;
    let _11 = _5.wrapping_mul(_1);
    _5 = _11;
    dump_var(10, 5, _5, 0, 0, 0, 0, 0, 0);
}

pub fn main() {
    fn10();
}

This should print

fn11:_0 = 0
_0 = 0
_0 = 0
_0 = 0
fn11:_0 = 0
_0 = 0
_0 = 0
_1 = 0
fn10:_5 = 85070591730234615865843651857942052864
_0 = 0
_0 = 0
_0 = 0

but with -Zmir-opt-level=0 -Copt-level=3

% rustc -Zmir-opt-level=0 -Copt-level=3 repro.rs && ./repro
fn11:_0 = 0
_0 = 0
_0 = 0
_0 = 0
fn11:_0 = 0
_0 = 0
_0 = 0
_1 = 0
fn10:_5 = 85070591730234615865843651857942052865
_0 = 0
_0 = 0
_0 = 0

The value of _5 is different. In fact, the number commented "addend" in the original code gets added to _5 in the miscompiled result. If you change it to e.g. 42 you get _5 = 85070591730234615865843651857942052906

nikic · 2023-06-23T13:00:08Z

Any chance that the fix for #112767 also fixes this one? Looks kinda similar to me.

cbeuw · 2023-06-23T17:18:40Z

No it fixes neither program in this issue.

llvm/llvm-project#63475 might be related, since it also passes a vector on the stack

nikic · 2024-06-21T18:55:04Z

Does this issue still reproduce?

alex · 2024-06-21T18:57:42Z

Running on an MBP M1, with rustc 1.81.0-nightly (8337ba9 2024-06-12), I get the same hash output for both of the executions listed:

/tmp ❯❯❯ rustc +nightly -Zmir-opt-level=0 -Copt-level=0 repro.rs && ./repro
warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:72:16
   |
72 |         0.hash(&mut H);
   |                ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
   = note: `#[warn(static_mut_refs)]` on by default
help: use `addr_of_mut!` instead to create a raw pointer
   |
72 |         0.hash(addr_of_mut!(H));
   |                ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:73:18
   |
73 |         _32.hash(&mut H);
   |                  ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
73 |         _32.hash(addr_of_mut!(H));
   |                  ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:82:20
   |
82 |         _9[0].hash(&mut H);
   |                    ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
82 |         _9[0].hash(addr_of_mut!(H));
   |                    ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:83:17
   |
83 |         _8.hash(&mut H);
   |                 ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
83 |         _8.hash(addr_of_mut!(H));
   |                 ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:84:21
   |
84 |         1_i128.hash(&mut H);
   |                     ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
84 |         1_i128.hash(addr_of_mut!(H));
   |                     ~~~~~~~~~~~~~~~

warning: 5 warnings emitted

hash: 15917201677548574216
/tmp ❯❯❯ rustc +nightly -Zmir-opt-level=0 -Copt-level=1 repro.rs && ./repro
warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:72:16
   |
72 |         0.hash(&mut H);
   |                ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
   = note: `#[warn(static_mut_refs)]` on by default
help: use `addr_of_mut!` instead to create a raw pointer
   |
72 |         0.hash(addr_of_mut!(H));
   |                ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:73:18
   |
73 |         _32.hash(&mut H);
   |                  ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
73 |         _32.hash(addr_of_mut!(H));
   |                  ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:82:20
   |
82 |         _9[0].hash(&mut H);
   |                    ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
82 |         _9[0].hash(addr_of_mut!(H));
   |                    ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:83:17
   |
83 |         _8.hash(&mut H);
   |                 ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
83 |         _8.hash(addr_of_mut!(H));
   |                 ~~~~~~~~~~~~~~~

warning: creating a mutable reference to mutable static is discouraged
  --> repro.rs:84:21
   |
84 |         1_i128.hash(&mut H);
   |                     ^^^^^^ mutable reference to mutable static
   |
   = note: for more information, see issue #114447 <https://github.com/rust-lang/rust/issues/114447>
   = note: this will be a hard error in the 2024 edition
   = note: this mutable reference has lifetime `'static`, but if the static gets accessed (read or written) by any other means, or any other reference is created, then any further use of this mutable reference is Undefined Behavior
help: use `addr_of_mut!` instead to create a raw pointer
   |
84 |         1_i128.hash(addr_of_mut!(H));
   |                     ~~~~~~~~~~~~~~~

warning: 5 warnings emitted

hash: 15917201677548574216

nikic · 2024-06-21T18:59:37Z

@alex Thanks! Would you mind also trying the other test case in #112548 (comment)?

alex · 2024-06-21T19:01:50Z

That version does reproduce the issue:

/tmp ❯❯❯ rustc +nightly repro.rs && ./repro
fn11:_0 = 0
_0 = 0
_0 = 0
_0 = 0
fn11:_0 = 0
_0 = 0
_0 = 0
_1 = 0
fn10:_5 = 85070591730234615865843651857942052864
_0 = 0
_0 = 0
_0 = 0
/tmp ❯❯❯ rustc +nightly -Zmir-opt-level=0 -Copt-level=3 repro.rs && ./repro
fn11:_0 = 0
_0 = 0
_0 = 0
_0 = 0
fn11:_0 = 0
_0 = 0
_0 = 0
_1 = 0
fn10:_5 = 85070591730234615865843651857942052865
_0 = 0
_0 = 0
_0 = 0

nikic · 2024-06-21T19:06:03Z

Thanks!

dianqk · 2024-06-28T10:19:32Z

I can reproduce this.
@rustbot claim

dianqk · 2024-06-29T07:31:30Z

Upstream issue: llvm/llvm-project#97147.

dianqk · 2024-06-30T14:08:07Z

@rustbot label +llvm-fixed-upstream

Update LLVM submodule Fixes rust-lang#112548 and unlock rust-lang#125642. r? `@cuviper` or `@nikic`

Rollup merge of rust-lang#127190 - DianQK:llvm-backport, r=nikic Update LLVM submodule Fixes rust-lang#112548 and unlock rust-lang#125642. r? ``@cuviper`` or ``@nikic``

Noratrieb added T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. I-unsound Issue: A soundness hole (worst kind of bug), see: https://en.wikipedia.org/wiki/Soundness C-bug Category: This is a bug. labels Jun 12, 2023

rustbot added the I-prioritize Issue: Indicates that prioritization has been requested for this issue. label Jun 12, 2023

rustbot added O-AArch64 Armv8-A or later processors in AArch64 mode O-macos Operating system: macOS labels Jun 12, 2023

rustbot added P-high High priority and removed I-prioritize Issue: Indicates that prioritization has been requested for this issue. labels Jun 13, 2023

apiraino added the A-LLVM Area: Code generation parts specific to LLVM. Both correctness bugs and optimization-related issues. label Jun 13, 2023

IceTDrinker mentioned this issue Oct 23, 2023

lto = "fat" causes doctest to generate invalid code for Apple M1 (and potentially x86) #116941

Closed

wesleywiser added the WG-llvm Working group: LLVM backend code generation label Jun 21, 2024

rustbot assigned dianqk Jun 28, 2024

rustbot added the llvm-fixed-upstream Issue expected to be fixed by the next major LLVM upgrade, or backported fixes label Jun 30, 2024

This was referenced Jun 30, 2024

[Backport llvm-project#97148][AArch64] Avoid overflow when using shl lower mul rust-lang/llvm-project#174

Merged

Update LLVM submodule #127190

Merged

bors added a commit to rust-lang-ci/rust that referenced this issue Jul 2, 2024

Auto merge of rust-lang#127190 - DianQK:llvm-backport, r=nikic

847e087

Update LLVM submodule Fixes rust-lang#112548 and unlock rust-lang#125642. r? `@cuviper` or `@nikic`

bors closed this as completed in 77fa597 Jul 4, 2024

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Miscompilation on aarch64-apple-darwin (likely a calling convention bug) #112548

Miscompilation on aarch64-apple-darwin (likely a calling convention bug) #112548

cbeuw commented Jun 12, 2023 •

edited by rustbot

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Jules-Bertholet commented Jun 12, 2023

apiraino commented Jun 13, 2023

cbeuw commented Jun 15, 2023

nikic commented Jun 23, 2023

cbeuw commented Jun 23, 2023 •

edited

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nikic commented Jun 21, 2024

alex commented Jun 21, 2024

nikic commented Jun 21, 2024

alex commented Jun 21, 2024

nikic commented Jun 21, 2024

dianqk commented Jun 28, 2024

dianqk commented Jun 29, 2024

dianqk commented Jun 30, 2024

Miscompilation on aarch64-apple-darwin (likely a calling convention bug) #112548

Miscompilation on aarch64-apple-darwin (likely a calling convention bug) #112548

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cbeuw commented Jun 12, 2023 • edited by rustbot Loading

Jules-Bertholet commented Jun 12, 2023

apiraino commented Jun 13, 2023

cbeuw commented Jun 15, 2023

nikic commented Jun 23, 2023

cbeuw commented Jun 23, 2023 • edited Loading

nikic commented Jun 21, 2024

alex commented Jun 21, 2024

nikic commented Jun 21, 2024

alex commented Jun 21, 2024

nikic commented Jun 21, 2024

dianqk commented Jun 28, 2024

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cbeuw commented Jun 12, 2023 •

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