Replace mimalloc patch with stubs (envoyproxy#112)

buildtools/mimalloc/Dockerfile

@@ -5,10 +5,12 @@ FROM ghcr.io/corazawaf/coraza-proxy-wasm/buildtools-wasi-sdk:main
 
 RUN apt-get install -y cmake patch
 
+# Enables export of aligned_alloc
+# TODO(anuraaga): It seems like this should be set automatically, consider debugging further.
+ENV CFLAGS -D__USE_ISOC11 ${CFLAGS}
+
 RUN mkdir -p /mimalloc && curl -L https://github.com/microsoft/mimalloc/archive/refs/tags/v2.0.6.tar.gz | tar -xz --strip-components 1 -C /mimalloc
 WORKDIR /mimalloc
-ADD mimalloc.patch mimalloc.patch
-RUN patch -p1 < mimalloc.patch
 RUN mkdir -p out/release && cd out/release && cmake ../.. -DMI_BUILD_SHARED=off -DMI_BUILD_TESTS=off && make && ${RANLIB} libmimalloc.a
 
 CMD ["cp", "./out/release/libmimalloc.a", "/out/libmimalloc.a"]

internal/gc/mem.go

@@ -9,3 +9,43 @@ import "unsafe"
 
 //go:linkname memzero runtime.memzero
 func memzero(ptr unsafe.Pointer, size uintptr)
+
+//export mi_aligned_alloc
+func mi_aligned_alloc(alignment uintptr, size uintptr) unsafe.Pointer
+
+//export mi_zalloc_aligned
+func mi_zalloc_aligned(size uintptr, alignment uintptr) unsafe.Pointer
+
+//export mi_malloc
+func mi_malloc(size uintptr) unsafe.Pointer
+
+//export mi_calloc
+func mi_calloc(count uintptr, size uintptr) unsafe.Pointer
+
+//export mi_free
+func mi_free(ptr unsafe.Pointer)
+
+// Not exported by mimalloc on __wasi__ by default so we implement here.
+
+//export __libc_malloc
+func __libc_malloc(size uintptr) unsafe.Pointer {
+	return mi_malloc(size)
+}
+
+//export __libc_calloc
+func __libc_calloc(count uintptr, size uintptr) unsafe.Pointer {
+	return mi_calloc(count, size)
+}
+
+//export __libc_free
+func __libc_free(ptr unsafe.Pointer) {
+	mi_free(ptr)
+}
+
+// Used by mimalloc for delayed free but Envoy doesn't stub it yet.
+// We don't use delayed free, so it's fine to stub it out.
+
+//export sched_yield
+func sched_yield() int32 {
+	return 0
+}

internal/gc/mmap.go

@@ -19,12 +19,6 @@ import "C"
 // Must match bdwgc value of HBLKSIZE
 const hBlkSize = 4096
 
-//export mi_zalloc_aligned
-func mi_zalloc_aligned(size uintptr, alignment uintptr) unsafe.Pointer
-
-//export mi_free
-func mi_free(ptr unsafe.Pointer)
-
 //export mmap
 func mmap(_ unsafe.Pointer, length uintptr, _ int32, _ int32, _ int32, _ uint64) unsafe.Pointer {
 	buf := mi_zalloc_aligned(length, hBlkSize)