diff options
Diffstat (limited to 'src/libstd/sys/unix/alloc.rs')
| -rw-r--r-- | src/libstd/sys/unix/alloc.rs | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/libstd/sys/unix/alloc.rs b/src/libstd/sys/unix/alloc.rs index 8e8f5017da7..c5b6a360dd3 100644 --- a/src/libstd/sys/unix/alloc.rs +++ b/src/libstd/sys/unix/alloc.rs @@ -1,11 +1,15 @@ use crate::ptr; use crate::sys_common::alloc::{MIN_ALIGN, realloc_fallback}; use crate::alloc::{GlobalAlloc, Layout, System}; +use crate::mem; #[stable(feature = "alloc_system_type", since = "1.28.0")] unsafe impl GlobalAlloc for System { #[inline] unsafe fn alloc(&self, layout: Layout) -> *mut u8 { + // jemalloc provides alignment less than MIN_ALIGN for small allocations. + // So only rely on MIN_ALIGN if size >= align. + // Also see <https://github.com/rust-lang/rust/issues/45955>. if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { libc::malloc(layout.size()) as *mut u8 } else { @@ -21,6 +25,9 @@ unsafe impl GlobalAlloc for System { #[inline] unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { + // jemalloc provides alignment less than MIN_ALIGN for small allocations. + // So only rely on MIN_ALIGN if size >= align. + // Also see <https://github.com/rust-lang/rust/issues/45955>. if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { libc::calloc(layout.size(), 1) as *mut u8 } else { @@ -80,7 +87,10 @@ unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { #[inline] unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { let mut out = ptr::null_mut(); - let ret = libc::posix_memalign(&mut out, layout.align(), layout.size()); + // posix_memalign requires that the alignment be a multiple of `sizeof(void*)`. + // Since these are all powers of 2, we can just use max. + let align = layout.align().max(mem::size_of::<usize>()); + let ret = libc::posix_memalign(&mut out, align, layout.size()); if ret != 0 { ptr::null_mut() } else { |