[PATCH v5 24/37] rust: Add a rust helper for krealloc()

[PATCH v5 24/37] rust: Add a rust helper for krealloc()

[Suren Baghdasaryan]

From: Kent Overstreet <kent.overstreet@linux.dev>

Memory allocation profiling is turning krealloc() into a nontrivial
macro - so for now, we need a helper for it.

Until we have proper support on the rust side for memory allocation
profiling this does mean that all Rust allocations will be accounted to
the helper.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: rust-for-linux@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
---
 rust/helpers.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/rust/helpers.c b/rust/helpers.c
index 70e59efd92bc..ad62eaf604b3 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -28,6 +28,7 @@
 #include <linux/mutex.h>
 #include <linux/refcount.h>
 #include <linux/sched/signal.h>
+#include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
@@ -157,6 +158,13 @@ void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func,
 }
 EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key);
 
+void * __must_check rust_helper_krealloc(const void *objp, size_t new_size,
+					 gfp_t flags) __realloc_size(2)
+{
+	return krealloc(objp, new_size, flags);
+}
+EXPORT_SYMBOL_GPL(rust_helper_krealloc);
+
 /*
  * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
  * use it in contexts where Rust expects a `usize` like slice (array) indices.
-- 
2.44.0.278.ge034bb2e1d-goog

Re: [PATCH v5 24/37] rust: Add a rust helper for krealloc()

[Miguel Ojeda]

On Wed, Mar 6, 2024 at 7:26 PM Suren Baghdasaryan <surenb@google.com> wrote:
>
> +void * __must_check rust_helper_krealloc(const void *objp, size_t new_size,
> +                                        gfp_t flags) __realloc_size(2)

The `__realloc_size(2)` should be placed earlier, i.e. this triggers:

rust/helpers.c:162:20: error: GCC does not allow '__alloc_size__'
attribute in this position on a function definition [-Wgcc-compat]

With that fixed:

Acked-by: Miguel Ojeda <ojeda@kernel.org>

Cheers,
Miguel