From: Marc-André Lureau <marcandre.lur...@redhat.com>
The global allocator has always been disabled. There is no clear reason
Rust and C should use the same allocator. Allocations made from Rust
must be freed by Rust, and same for C, otherwise we head into troubles.
Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
meson.build | 4 --
rust/Cargo.toml | 2 +-
rust/qemu-api/Cargo.toml | 1 -
rust/qemu-api/meson.build | 1 -
rust/qemu-api/src/lib.rs | 135 --------------------------------------
5 files changed, 1 insertion(+), 142 deletions(-)
diff --git a/meson.build b/meson.build
index 50c774a195..ebbe9f8785 100644
--- a/meson.build
+++ b/meson.build
@@ -1090,9 +1090,6 @@ glib = declare_dependency(dependencies: [glib_pc,
gmodule],
# TODO: remove this check and the corresponding workaround (qtree) when
# the minimum supported glib is >= 2.75.3
glib_has_gslice = glib.version().version_compare('<2.75.3')
-# Check whether glib has the aligned_alloc family of functions.
-# <https://docs.gtk.org/glib/func.aligned_alloc.html>
-glib_has_aligned_alloc = glib.version().version_compare('>=2.72.0')
# override glib dep to include the above refinements
meson.override_dependency('glib-2.0', glib)
@@ -2706,7 +2703,6 @@ config_host_data.set('CONFIG_GETLOADAVG',
cc.has_function('getloadavg'))
config_host_data.set('HAVE_COPY_FILE_RANGE',
cc.has_function('copy_file_range'))
config_host_data.set('HAVE_GETIFADDRS', cc.has_function('getifaddrs'))
config_host_data.set('HAVE_GLIB_WITH_SLICE_ALLOCATOR', glib_has_gslice)
-config_host_data.set('HAVE_GLIB_WITH_ALIGNED_ALLOC', glib_has_aligned_alloc)
config_host_data.set('HAVE_OPENPTY', cc.has_function('openpty', dependencies:
util))
config_host_data.set('HAVE_STRCHRNUL', cc.has_function('strchrnul', prefix:
osdep_prefix))
config_host_data.set('HAVE_SYSTEM_FUNCTION', cc.has_function('system', prefix:
'#include <stdlib.h>'))
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 0868e1b426..1a24859cd7 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -17,7 +17,7 @@ rust-version = "1.77.0"
[workspace.lints.rust]
unexpected_cfgs = { level = "deny", check-cfg = [
- 'cfg(MESON)', 'cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)',
+ 'cfg(MESON)',
] }
# Occasionally, we may need to silence warnings and clippy lints that
diff --git a/rust/qemu-api/Cargo.toml b/rust/qemu-api/Cargo.toml
index db7000dee4..603327945f 100644
--- a/rust/qemu-api/Cargo.toml
+++ b/rust/qemu-api/Cargo.toml
@@ -21,7 +21,6 @@ foreign = "~0.3.1"
[features]
default = ["debug_cell"]
-allocator = []
debug_cell = []
[lints]
diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build
index a090297c45..062009f161 100644
--- a/rust/qemu-api/meson.build
+++ b/rust/qemu-api/meson.build
@@ -2,7 +2,6 @@ _qemu_api_cfg = run_command(rustc_args,
'--config-headers', config_host_h, '--features', files('Cargo.toml'),
capture: true, check: true).stdout().strip().splitlines()
-# _qemu_api_cfg += ['--cfg', 'feature="allocator"']
if get_option('debug_mutex')
_qemu_api_cfg += ['--cfg', 'feature="debug_cell"']
endif
diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs
index 86dcd8ef17..0f9231f398 100644
--- a/rust/qemu-api/src/lib.rs
+++ b/rust/qemu-api/src/lib.rs
@@ -32,139 +32,4 @@
pub mod vmstate;
pub mod zeroable;
-use std::{
- alloc::{GlobalAlloc, Layout},
- ffi::c_void,
-};
-
pub use error::{Error, Result};
-
-#[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)]
-extern "C" {
- fn g_aligned_alloc0(
- n_blocks: bindings::gsize,
- n_block_bytes: bindings::gsize,
- alignment: bindings::gsize,
- ) -> bindings::gpointer;
- fn g_aligned_free(mem: bindings::gpointer);
-}
-
-#[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))]
-extern "C" {
- fn qemu_memalign(alignment: usize, size: usize) -> *mut c_void;
- fn qemu_vfree(ptr: *mut c_void);
-}
-
-extern "C" {
- fn g_malloc0(n_bytes: bindings::gsize) -> bindings::gpointer;
- fn g_free(mem: bindings::gpointer);
-}
-
-/// An allocator that uses the same allocator as QEMU in C.
-///
-/// It is enabled by default with the `allocator` feature.
-///
-/// To set it up manually as a global allocator in your crate:
-///
-/// ```ignore
-/// use qemu_api::QemuAllocator;
-///
-/// #[global_allocator]
-/// static GLOBAL: QemuAllocator = QemuAllocator::new();
-/// ```
-#[derive(Clone, Copy, Debug)]
-#[repr(C)]
-pub struct QemuAllocator {
- _unused: [u8; 0],
-}
-
-#[cfg_attr(all(feature = "allocator", not(test)), global_allocator)]
-pub static GLOBAL: QemuAllocator = QemuAllocator::new();
-
-impl QemuAllocator {
- // From the glibc documentation, on GNU systems, malloc guarantees 16-byte
- // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See
- // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html.
- // This alignment guarantee also applies to Windows and Android. On Darwin
- // and OpenBSD, the alignment is 16 bytes on both 64-bit and 32-bit
systems.
- #[cfg(all(
- target_pointer_width = "32",
- not(any(target_os = "macos", target_os = "openbsd"))
- ))]
- pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(8);
- #[cfg(all(
- target_pointer_width = "64",
- not(any(target_os = "macos", target_os = "openbsd"))
- ))]
- pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16);
- #[cfg(all(
- any(target_pointer_width = "32", target_pointer_width = "64"),
- any(target_os = "macos", target_os = "openbsd")
- ))]
- pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16);
- #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
- pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = None;
-
- pub const fn new() -> Self {
- Self { _unused: [] }
- }
-}
-
-impl Default for QemuAllocator {
- fn default() -> Self {
- Self::new()
- }
-}
-
-// Sanity check.
-const _: [(); 8] = [(); ::core::mem::size_of::<*mut c_void>()];
-
-unsafe impl GlobalAlloc for QemuAllocator {
- unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
- if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if
default.checked_rem(layout.align()) == Some(0))
- {
- // SAFETY: g_malloc0() is safe to call.
- unsafe { g_malloc0(layout.size().try_into().unwrap()).cast::<u8>()
}
- } else {
- #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)]
- {
- // SAFETY: g_aligned_alloc0() is safe to call.
- unsafe {
- g_aligned_alloc0(
- layout.size().try_into().unwrap(),
- 1,
- layout.align().try_into().unwrap(),
- )
- .cast::<u8>()
- }
- }
- #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))]
- {
- // SAFETY: qemu_memalign() is safe to call.
- unsafe { qemu_memalign(layout.align(),
layout.size()).cast::<u8>() }
- }
- }
- }
-
- unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
- if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if
default.checked_rem(layout.align()) == Some(0))
- {
- // SAFETY: `ptr` must have been allocated by Self::alloc thus a
valid
- // glib-allocated pointer, so `g_free`ing is safe.
- unsafe { g_free(ptr.cast::<_>()) }
- } else {
- #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)]
- {
- // SAFETY: `ptr` must have been allocated by Self::alloc thus
a valid aligned
- // glib-allocated pointer, so `g_aligned_free`ing is safe.
- unsafe { g_aligned_free(ptr.cast::<_>()) }
- }
- #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))]
- {
- // SAFETY: `ptr` must have been allocated by Self::alloc thus
a valid aligned
- // glib-allocated pointer, so `qemu_vfree`ing is safe.
- unsafe { qemu_vfree(ptr.cast::<_>()) }
- }
- }
- }
-}
--
2.50.1
