From a986cf2438303b12ba2bc7dbc59e79ef06427798 Mon Sep 17 00:00:00 2001
From: Anton Kirilov <anton.kirilov@arm.com>
Date: Thu, 7 Oct 2021 18:49:40 +0100
Subject: [PATCH] Increase the default code section alignment to 64 KB for
 AArch64 targets (#3424)

Some platforms such as AArch64 Linux support different memory page
sizes, so we need to be conservative when choosing the code section
alignment (which is equal to the page size) by using the maximum.

Copyright (c) 2021, Arm Limited.
---
 cranelift/codegen/src/isa/mod.rs | 3 +++
 crates/jit/src/code_memory.rs    | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/cranelift/codegen/src/isa/mod.rs b/cranelift/codegen/src/isa/mod.rs
index 1b6686cc71..b1ff090498 100644
--- a/cranelift/codegen/src/isa/mod.rs
+++ b/cranelift/codegen/src/isa/mod.rs
@@ -290,6 +290,9 @@ impl<'a> dyn TargetIsa + 'a {
                 | OperatingSystem::Tvos,
                 Architecture::Aarch64(..),
             ) => 0x4000,
+            // 64 KB is the maximal page size (i.e. memory translation granule size)
+            // supported by the architecture and is used on some platforms.
+            (_, Architecture::Aarch64(..)) => 0x10000,
             _ => 0x1000,
         }
     }
diff --git a/crates/jit/src/code_memory.rs b/crates/jit/src/code_memory.rs
index 2dc3d3799f..acfb5745b1 100644
--- a/crates/jit/src/code_memory.rs
+++ b/crates/jit/src/code_memory.rs
@@ -88,6 +88,7 @@ impl CodeMemory {
             mmap: &self.mmap,
             text: &[],
         };
+        let mmap_ptr = self.mmap.as_ptr() as u64;
 
         // Sanity-check that all sections are aligned correctly.
         for section in ret.obj.sections() {
@@ -98,7 +99,7 @@ impl CodeMemory {
             if section.align() == 0 || data.len() == 0 {
                 continue;
             }
-            if data.as_ptr() as u64 % section.align() != 0 {
+            if (data.as_ptr() as u64 - mmap_ptr) % section.align() != 0 {
                 bail!(
                     "section `{}` isn't aligned to {:#x}",
                     section.name().unwrap_or("ERROR"),