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authorRalf Baechle <ralf@linux-mips.org>2006-10-21 23:17:35 +0100
committerRalf Baechle <ralf@linux-mips.org>2006-10-21 23:17:35 +0100
commitf8829caee311207afbc882794bdc5aa0db5caf33 (patch)
treedbadd9fa746a1a4f091bc7e240ca8d787188a913 /include/asm-mips/fixmap.h
parent224dc50ece1b40f8cff5ecadd42a6b2691e231de (diff)
[MIPS] Fix aliasing bug in copy_to_user_page / copy_from_user_page
The current implementation uses a sequence of a cacheflush and a copy. This is racy in case of a multithreaded debuggee and renders GDB virtually unusable. Aside this fixes a performance hog rendering access to /proc/cmdline very slow and resulting in a enough cache stalls for the 34K AP/SP programming model to make the bare metal code on the non-Linux VPE miss RT deadlines. The main part of this patch was originally written by Ralf Baechle; Atushi Nemoto did the the debugging. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/fixmap.h')
-rw-r--r--include/asm-mips/fixmap.h14
1 files changed, 11 insertions, 3 deletions
diff --git a/include/asm-mips/fixmap.h b/include/asm-mips/fixmap.h
index 6959bdb5931..02c8a13fc89 100644
--- a/include/asm-mips/fixmap.h
+++ b/include/asm-mips/fixmap.h
@@ -45,8 +45,16 @@
* fix-mapped?
*/
enum fixed_addresses {
+#define FIX_N_COLOURS 8
+ FIX_CMAP_BEGIN,
+#ifdef CONFIG_MIPS_MT_SMTC
+ FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS),
+#else
+ FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,
+#endif
#ifdef CONFIG_HIGHMEM
- FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
+ /* reserved pte's for temporary kernel mappings */
+ FIX_KMAP_BEGIN = FIX_CMAP_END + 1,
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
#endif
__end_of_fixed_addresses
@@ -70,9 +78,9 @@ extern void __set_fixmap (enum fixed_addresses idx,
* at the top of mem..
*/
#if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX)
-#define FIXADDR_TOP (0xff000000UL - 0x2000)
+#define FIXADDR_TOP ((unsigned long)(long)(int)(0xff000000 - 0x20000))
#else
-#define FIXADDR_TOP (0xffffe000UL)
+#define FIXADDR_TOP ((unsigned long)(long)(int)0xfffe0000)
#endif
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)