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yaml --- r: 209184 b: refs/heads/master c: 8fd4993 h: refs/heads/master v: v3
git-mirror · Aug 11, 2010 · 42120e1 · 42120e1
1 parent ae1ff8a
commit 42120e1
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5989cd6a1cbf86587edcc856791f960978087311
+refs/heads/master: 8fd49936a8cac246fc9ed85508556c82cd44cf68
diff --git a/trunk/arch/x86/include/asm/page.h b/trunk/arch/x86/include/asm/page.h
@@ -37,6 +37,13 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
 #define __pa_nodebug(x)	__phys_addr_nodebug((unsigned long)(x))
 /* __pa_symbol should be used for C visible symbols.
    This seems to be the official gcc blessed way to do such arithmetic. */
+/*
+ * We need __phys_reloc_hide() here because gcc may assume that there is no
+ * overflow during __pa() calculation and can optimize it unexpectedly.
+ * Newer versions of gcc provide -fno-strict-overflow switch to handle this
+ * case properly. Once all supported versions of gcc understand it, we can
+ * remove this Voodoo magic stuff. (i.e. once gcc3.x is deprecated)
+ */
 #define __pa_symbol(x)	__pa(__phys_reloc_hide((unsigned long)(x)))
 
 #define __va(x)			((void *)((unsigned long)(x)+PAGE_OFFSET))