check before test for hardware capabilites in bits 32~63 of usize #146323

h3fang · 2025-09-08T08:43:47Z

This commit tries to fix #146230.

std::arch::is_aarch64_feature_detected panics on aarch64 ILP32 targets.

After some digging, the real problem is

rust/library/std_detect/src/detect/os/linux/aarch64.rs

Lines 210 to 241 in 91edc3e

    
           // ebf16: bit::test(auxv.hwcap2, 32), 
        
           // sveebf16: bit::test(auxv.hwcap2, 33), 
        
           cssc: bit::test(auxv.hwcap2, 34), 
        
           // rprfm: bit::test(auxv.hwcap2, 35), 
        
           sve2p1: bit::test(auxv.hwcap2, 36), 
        
           sme2: bit::test(auxv.hwcap2, 37), 
        
           sme2p1: bit::test(auxv.hwcap2, 38), 
        
           // smei16i32: bit::test(auxv.hwcap2, 39), 
        
           // smebi32i32: bit::test(auxv.hwcap2, 40), 
        
           smeb16b16: bit::test(auxv.hwcap2, 41), 
        
           smef16f16: bit::test(auxv.hwcap2, 42), 
        
           mops: bit::test(auxv.hwcap2, 43), 
        
           hbc: bit::test(auxv.hwcap2, 44), 
        
           sveb16b16: bit::test(auxv.hwcap2, 45), 
        
           lrcpc3: bit::test(auxv.hwcap2, 46), 
        
           lse128: bit::test(auxv.hwcap2, 47), 
        
           fpmr: bit::test(auxv.hwcap2, 48), 
        
           lut: bit::test(auxv.hwcap2, 49), 
        
           faminmax: bit::test(auxv.hwcap2, 50), 
        
           f8cvt: bit::test(auxv.hwcap2, 51), 
        
           f8fma: bit::test(auxv.hwcap2, 52), 
        
           f8dp4: bit::test(auxv.hwcap2, 53), 
        
           f8dp2: bit::test(auxv.hwcap2, 54), 
        
           f8e4m3: bit::test(auxv.hwcap2, 55), 
        
           f8e5m2: bit::test(auxv.hwcap2, 56), 
        
           smelutv2: bit::test(auxv.hwcap2, 57), 
        
           smef8f16: bit::test(auxv.hwcap2, 58), 
        
           smef8f32: bit::test(auxv.hwcap2, 59), 
        
           smesf8fma: bit::test(auxv.hwcap2, 60), 
        
           smesf8dp4: bit::test(auxv.hwcap2, 61), 
        
           smesf8dp2: bit::test(auxv.hwcap2, 62), 
        
           // pauthlr: bit::test(auxv.hwcap2, ??),

checks bits 32~63 of usize unconditionally on normal aarch64 LP64 target and aarch64 ILP32 target.

Here I propose to move these to a block guarded by #[cfg(target_pointer_width="64")].

See #146230 for more detailed analysis.

r? @Amanieu

folkertdev

Could you add a bit more to the PR description: a short summary of the problem, and of the solution.

Also, does this change actually fix the issue you're observing?

View changes since this review

folkertdev · 2025-09-08T08:49:21Z

library/std_detect/src/detect/os/linux/aarch64.rs

+        #[cfg(target_pointer_width = "64")]
+        {


This should at least get a comment, because I think it's quite reasonable to assume that aarch64 implies 64-bit pointers.

also now you're basically saying that the features in this block cannot be queried for on ilp32, is that correct?

Ok, I will add some comment to clarify it.

also now you're basically saying that the features in this block cannot be queried for on ilp32, is that correct?

Yes, the libc::getauxval returns 32 bit c_ulong for aarch64 ILP32 target.

also now you're basically saying that the features in this block cannot be queried for on ilp32, is that correct?

Well, to be more accurate, they can be queried, but the values will all be false.

This should at least get a comment, because I think it's quite reasonable to assume that aarch64 implies 64-bit pointers.

I have added some comments to clarify it.

h3fang · 2025-09-08T08:56:33Z

Could you add a bit more to the PR description: a short summary of the problem, and of the solution.

I have updated the PR description.

Also, does this change actually fix the issue you're observing?

It should. I will test it on the real hardware soon.

h3fang · 2025-09-08T10:19:23Z

Also, does this change actually fix the issue you're observing?

It should. I will test it on the real hardware soon.

Yes, it does fix the issue. I have verified that on the real hardware.

The following code ran and printed true without panic in debug build.

fn main() {
    println!("{:?}", std::arch::is_aarch64_feature_detected!("lse"));
}

Amanieu · 2025-09-11T18:39:46Z

library/std_detect/src/detect/os/linux/aarch64.rs

+
+        // Hardware capabilities from bits 32 to 63 should only
+        // be tested on LP64 targets with 64 bits `usize`.
+        // On ILP32 targets like `aarch64-unknown-linux-gun_ilp32`,


Suggested change

// On ILP32 targets like `aarch64-unknown-linux-gun_ilp32`,

// On ILP32 targets like `aarch64-unknown-linux-gnu_ilp32`,

Fixed, thanks!

Amanieu · 2025-09-12T00:19:59Z

@bors r+

bors · 2025-09-12T00:20:01Z

📌 Commit 4c849c7 has been approved by Amanieu

It is now in the queue for this repository.

check before test for hardware capabilites in bits 32~63 of usize This commit tries to fix rust-lang#146230. `std::arch::is_aarch64_feature_detected` panics on aarch64 ILP32 targets. After some digging, the real problem is https://github.com/rust-lang/rust/blob/91edc3ebccc4daa46c20a93f4709862376da1fdd/library/std_detect/src/detect/os/linux/aarch64.rs#L210-L241 checks bits 32~63 of usize unconditionally on normal aarch64 LP64 target and aarch64 ILP32 target. Here I propose to move these to a block guarded by `#[cfg(target_pointer_width="64")]`. See rust-lang#146230 for more detailed analysis. r? `@Amanieu`

Rollup of 16 pull requests Successful merges: - #145660 (initial implementation of the darwin_objc unstable feature) - #145895 (thread parking: fix docs and examples) - #146308 (support integer literals in `${concat()}`) - #146323 (check before test for hardware capabilites in bits 32~63 of usize) - #146332 (tidy: make behavior of extra-checks more uniform) - #146338 (Extends AArch64 branch protection support to include GCS) - #146374 (Update `browser-ui-test` version to `0.22.2`) - #146413 (Improve suggestion in case a bare URL is surrounded by brackets) - #146426 (Bump miow to 0.60.1) - #146432 (Implement `Socket::take_error` for Hermit) - #146433 (rwlock tests: fix miri macos test regression) - #146435 (Change the default value of `gcc.download-ci-gcc` to `true`) - #146439 (fix cfg for poison test macro) - #146448 ([rustdoc] Correctly handle literal search on paths) - #146449 (Fix `libgccjit` symlink when we build GCC locally) - #146455 (test: remove an outdated normalization for rustc versions) Failed merges: - #146389 (Convert `no_std` and `no_core` to the new attribute infrastructure) r? `@ghost` `@rustbot` modify labels: rollup

check before test for hardware capabilites in bits 32~63 of usize This commit tries to fix rust-lang#146230. `std::arch::is_aarch64_feature_detected` panics on aarch64 ILP32 targets. After some digging, the real problem is https://github.com/rust-lang/rust/blob/91edc3ebccc4daa46c20a93f4709862376da1fdd/library/std_detect/src/detect/os/linux/aarch64.rs#L210-L241 checks bits 32~63 of usize unconditionally on normal aarch64 LP64 target and aarch64 ILP32 target. Here I propose to move these to a block guarded by `#[cfg(target_pointer_width="64")]`. See rust-lang#146230 for more detailed analysis. r? ``@Amanieu``

Rollup of 16 pull requests Successful merges: - #144549 (match clang's `va_arg` assembly on arm targets) - #145660 (initial implementation of the darwin_objc unstable feature) - #145895 (thread parking: fix docs and examples) - #146308 (support integer literals in `${concat()}`) - #146323 (check before test for hardware capabilites in bits 32~63 of usize) - #146332 (tidy: make behavior of extra-checks more uniform) - #146374 (Update `browser-ui-test` version to `0.22.2`) - #146413 (Improve suggestion in case a bare URL is surrounded by brackets) - #146426 (Bump miow to 0.60.1) - #146432 (Implement `Socket::take_error` for Hermit) - #146433 (rwlock tests: fix miri macos test regression) - #146435 (Change the default value of `gcc.download-ci-gcc` to `true`) - #146439 (fix cfg for poison test macro) - #146448 ([rustdoc] Correctly handle literal search on paths) - #146449 (Fix `libgccjit` symlink when we build GCC locally) - #146455 (test: remove an outdated normalization for rustc versions) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 15 pull requests Successful merges: - #144549 (match clang's `va_arg` assembly on arm targets) - #145895 (thread parking: fix docs and examples) - #146308 (support integer literals in `${concat()}`) - #146323 (check before test for hardware capabilites in bits 32~63 of usize) - #146332 (tidy: make behavior of extra-checks more uniform) - #146374 (Update `browser-ui-test` version to `0.22.2`) - #146413 (Improve suggestion in case a bare URL is surrounded by brackets) - #146426 (Bump miow to 0.60.1) - #146432 (Implement `Socket::take_error` for Hermit) - #146433 (rwlock tests: fix miri macos test regression) - #146435 (Change the default value of `gcc.download-ci-gcc` to `true`) - #146439 (fix cfg for poison test macro) - #146448 ([rustdoc] Correctly handle literal search on paths) - #146449 (Fix `libgccjit` symlink when we build GCC locally) - #146455 (test: remove an outdated normalization for rustc versions) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #146323 - h3fang:issue-146230-fix, r=Amanieu check before test for hardware capabilites in bits 32~63 of usize This commit tries to fix #146230. `std::arch::is_aarch64_feature_detected` panics on aarch64 ILP32 targets. After some digging, the real problem is https://github.com/rust-lang/rust/blob/91edc3ebccc4daa46c20a93f4709862376da1fdd/library/std_detect/src/detect/os/linux/aarch64.rs#L210-L241 checks bits 32~63 of usize unconditionally on normal aarch64 LP64 target and aarch64 ILP32 target. Here I propose to move these to a block guarded by `#[cfg(target_pointer_width="64")]`. See #146230 for more detailed analysis. r? ```@Amanieu```

check before test for hardware capabilites in bits 32~63 of usize

c776fbf

rustbot assigned Amanieu Sep 8, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Sep 8, 2025

h3fang mentioned this pull request Sep 8, 2025

std::arch::is_aarch64_feature_detected panics on aarch64 ilp32 targets #146230

Closed

folkertdev reviewed Sep 8, 2025

View reviewed changes

add some comments to clarify the fix

be284b6

This comment has been minimized.

Sign in to view

fix typos in comment

de359c5

Amanieu reviewed Sep 11, 2025

View reviewed changes

fix typo in comment

4c849c7

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 12, 2025

Zalathar mentioned this pull request Sep 12, 2025

Rollup of 16 pull requests #146461

Closed

Zalathar mentioned this pull request Sep 12, 2025

Rollup of 16 pull requests #146462

Closed

Zalathar mentioned this pull request Sep 12, 2025

Rollup of 15 pull requests #146468

Merged

bors merged commit 7429420 into rust-lang:master Sep 12, 2025
10 checks passed

rustbot added this to the 1.91.0 milestone Sep 12, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

check before test for hardware capabilites in bits 32~63 of usize #146323

check before test for hardware capabilites in bits 32~63 of usize #146323

h3fang commented Sep 8, 2025 •

edited

Loading

Uh oh!

folkertdev left a comment •

edited by rustbot

Loading

Uh oh!

folkertdev Sep 8, 2025

Uh oh!

folkertdev Sep 8, 2025

Uh oh!

h3fang Sep 8, 2025

Uh oh!

h3fang Sep 8, 2025

Uh oh!

h3fang Sep 8, 2025 •

edited

Loading

Uh oh!

h3fang Sep 8, 2025

Uh oh!

h3fang commented Sep 8, 2025 •

edited

Loading

Uh oh!

h3fang commented Sep 8, 2025

Uh oh!

This comment has been minimized.

Amanieu Sep 11, 2025

Uh oh!

h3fang Sep 12, 2025

Uh oh!

Amanieu commented Sep 12, 2025

Uh oh!

bors commented Sep 12, 2025

Uh oh!

Uh oh!

Uh oh!

	// ebf16: bit::test(auxv.hwcap2, 32),
	// sveebf16: bit::test(auxv.hwcap2, 33),
	cssc: bit::test(auxv.hwcap2, 34),
	// rprfm: bit::test(auxv.hwcap2, 35),
	sve2p1: bit::test(auxv.hwcap2, 36),
	sme2: bit::test(auxv.hwcap2, 37),
	sme2p1: bit::test(auxv.hwcap2, 38),
	// smei16i32: bit::test(auxv.hwcap2, 39),
	// smebi32i32: bit::test(auxv.hwcap2, 40),
	smeb16b16: bit::test(auxv.hwcap2, 41),
	smef16f16: bit::test(auxv.hwcap2, 42),
	mops: bit::test(auxv.hwcap2, 43),
	hbc: bit::test(auxv.hwcap2, 44),
	sveb16b16: bit::test(auxv.hwcap2, 45),
	lrcpc3: bit::test(auxv.hwcap2, 46),
	lse128: bit::test(auxv.hwcap2, 47),
	fpmr: bit::test(auxv.hwcap2, 48),
	lut: bit::test(auxv.hwcap2, 49),
	faminmax: bit::test(auxv.hwcap2, 50),
	f8cvt: bit::test(auxv.hwcap2, 51),
	f8fma: bit::test(auxv.hwcap2, 52),
	f8dp4: bit::test(auxv.hwcap2, 53),
	f8dp2: bit::test(auxv.hwcap2, 54),
	f8e4m3: bit::test(auxv.hwcap2, 55),
	f8e5m2: bit::test(auxv.hwcap2, 56),
	smelutv2: bit::test(auxv.hwcap2, 57),
	smef8f16: bit::test(auxv.hwcap2, 58),
	smef8f32: bit::test(auxv.hwcap2, 59),
	smesf8fma: bit::test(auxv.hwcap2, 60),
	smesf8dp4: bit::test(auxv.hwcap2, 61),
	smesf8dp2: bit::test(auxv.hwcap2, 62),
	// pauthlr: bit::test(auxv.hwcap2, ??),

	// On ILP32 targets like `aarch64-unknown-linux-gun_ilp32`,
	// On ILP32 targets like `aarch64-unknown-linux-gnu_ilp32`,

check before test for hardware capabilites in bits 32~63 of usize #146323

check before test for hardware capabilites in bits 32~63 of usize #146323

Conversation

h3fang commented Sep 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

folkertdev left a comment • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

folkertdev Sep 8, 2025

Choose a reason for hiding this comment

Uh oh!

folkertdev Sep 8, 2025

Choose a reason for hiding this comment

Uh oh!

h3fang Sep 8, 2025

Choose a reason for hiding this comment

Uh oh!

h3fang Sep 8, 2025

Choose a reason for hiding this comment

Uh oh!

h3fang Sep 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

h3fang Sep 8, 2025

Choose a reason for hiding this comment

Uh oh!

h3fang commented Sep 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

h3fang commented Sep 8, 2025

Uh oh!

This comment has been minimized.

Amanieu Sep 11, 2025

Choose a reason for hiding this comment

Uh oh!

h3fang Sep 12, 2025

Choose a reason for hiding this comment

Uh oh!

Amanieu commented Sep 12, 2025

Uh oh!

bors commented Sep 12, 2025

Uh oh!

Uh oh!

Uh oh!

h3fang commented Sep 8, 2025 •

edited

Loading

folkertdev left a comment •

edited by rustbot

Loading

h3fang Sep 8, 2025 •

edited

Loading

h3fang commented Sep 8, 2025 •

edited

Loading