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* i386 pgd_index() doesn't parenthesize its arg
@ 2003-01-17  5:51 William Lee Irwin III
  2003-01-17  6:03 ` William Lee Irwin III
  0 siblings, 1 reply; 2+ messages in thread
From: William Lee Irwin III @ 2003-01-17  5:51 UTC (permalink / raw)
  To: akpm; +Cc: linux-kernel, linux-mm

pgd_index() doesn't parenthesize its argument. This is a bad idea for
macros, since it's legitimate to pass expressions to them that will
get misinterpreted given operator precedence and the shift.

vs. 2.5.59


-- wli


===== include/asm-i386/pgtable.h 1.22 vs edited =====
--- 1.22/include/asm-i386/pgtable.h	Mon Nov 25 14:41:15 2002
+++ edited/include/asm-i386/pgtable.h	Thu Jan 16 21:08:06 2003
@@ -242,7 +242,7 @@
 	((pmd_val(pmd) & (_PAGE_PSE|_PAGE_PRESENT)) == (_PAGE_PSE|_PAGE_PRESENT))
 
 /* to find an entry in a page-table-directory. */
-#define pgd_index(address) ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 
 #define __pgd_offset(address) pgd_index(address)
 
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^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: i386 pgd_index() doesn't parenthesize its arg
  2003-01-17  5:51 i386 pgd_index() doesn't parenthesize its arg William Lee Irwin III
@ 2003-01-17  6:03 ` William Lee Irwin III
  0 siblings, 0 replies; 2+ messages in thread
From: William Lee Irwin III @ 2003-01-17  6:03 UTC (permalink / raw)
  To: akpm, linux-kernel, linux-mm

PAE's pte_none() and pte_pfn() evaluate their arguments twice;
analogous fixes have been made to other things; c.f. pgtable.h's long
list of one-line inlines with parentheses still around their args.


===== include/asm-i386/pgtable-3level.h 1.8 vs edited =====
--- 1.8/include/asm-i386/pgtable-3level.h	Fri Jul 26 06:23:51 2002
+++ edited/include/asm-i386/pgtable-3level.h	Thu Jan 16 21:59:08 2003
@@ -89,8 +89,8 @@
 }
 
 #define pte_page(x)	pfn_to_page(pte_pfn(x))
-#define pte_none(x)	(!(x).pte_low && !(x).pte_high)
-#define pte_pfn(x)	(((x).pte_low >> PAGE_SHIFT) | ((x).pte_high << (32 - PAGE_SHIFT)))
+static inline int pte_none(pte_t pte) { return !pte.pte_low && !pte.pte_high; }
+static inline unsigned long pte_pfn(pte_t pte) { return (pte.pte_low >> PAGE_SHIFT) | (pte.pte_high << (32 - PAGE_SHIFT)); }
 
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
--
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