Fixing volatile and memory attributes for assembly.

For volatile:
You can prevent an asm instruction from being deleted by writing the
keyword volatile after the asm. [...] The volatile keyword indicates
that the instruction has important side-effects. GCC will not
delete a volatile asm if it is reachable.
and
An asm instruction without any output operands will be treated
identically to a volatile asm instruction.

And for memory:
This will cause GCC to not keep memory values cached in
registers across the assembler instruction and not optimize
stores or loads to that memory.

See also:
https://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Extended-Asm.html
http://stackoverflow.com/questions/14449141/the-difference-between-asm-asm-volatile-and-clobbering-memory

1 files changed, 1 insertions, 1 deletions

diff --git a/src/tlb.rs b/src/tlb.rs
index f20e37e..ec39e3e 100644
--- a/src/tlb.rs
+++ b/src/tlb.rs
@@ -6,7 +6,7 @@
 /// This function is unsafe as it causes a general protection fault (GP) if the current privilege
 /// level is not 0.
 pub unsafe fn flush(addr: usize) {
-    asm!("invlpg ($0)" :: "r" (addr) : "memory" : "volatile");
+    asm!("invlpg ($0)" :: "r" (addr) : "memory");
 }
 
 /// Invalidate the TLB completely by reloading the CR3 register.