From 8a1f801e7806b30e9df2ebec706c97b8e60f0d9c Mon Sep 17 00:00:00 2001
From: "henthe-5@student.ltu.se" <henthe-5@student.ltu.se>
Date: Fri, 22 Feb 2019 08:13:03 +0100
Subject: [PATCH] bare4_2
---
examples/bare4.rs | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/examples/bare4.rs b/examples/bare4.rs
index bdfd2f7..81f7d26 100644
--- a/examples/bare4.rs
+++ b/examples/bare4.rs
@@ -39,8 +39,8 @@ use address::*;
#[inline(always)]
fn read_u32(addr: u32) -> u32 {
- unsafe { core::ptr::read_volatile(addr as *const _) }
- //core::ptr::read_volatile(addr as *const _)
+ //unsafe { core::ptr::read_volatile(addr as *const _) }
+ core::ptr::read_volatile(addr as *const _)
}
#[inline(always)]
@@ -108,12 +108,14 @@ fn main() -> ! {
//
// What was the error message and explain why.
//
-// ** your answer here **
+// ** "call to unsafe function is unsafe and requires unsafe function or block"
+// The read_volatile takes a raw pointer as parameter, dereferencing a raw pointer is always considered unsafe
+// **
//
// Digging a bit deeper, why do you think `read_volatile` is declared `unsafe`.
// (https://doc.rust-lang.org/core/ptr/fn.read_volatile.html, for some food for thought )
//
-// ** your answer here **
+// ** It's not certain that the memory address is readable or that the memory is aligned thus may result in undefined behavior **
//
// Commit your answers (bare4_2)
//
--
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