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authorRalf Baechle <ralf@linux-mips.org>2006-10-21 18:17:35 -0400
committerRalf Baechle <ralf@linux-mips.org>2006-10-21 18:17:35 -0400
commitf8829caee311207afbc882794bdc5aa0db5caf33 (patch)
treedbadd9fa746a1a4f091bc7e240ca8d787188a913 /include/asm-mips
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')
-rw-r--r--include/asm-mips/cacheflush.h19
-rw-r--r--include/asm-mips/fixmap.h14
2 files changed, 15 insertions, 18 deletions
diff --git a/include/asm-mips/cacheflush.h b/include/asm-mips/cacheflush.h
index 9ab59e2bb233..e3c9925876a3 100644
--- a/include/asm-mips/cacheflush.h
+++ b/include/asm-mips/cacheflush.h
@@ -55,24 +55,13 @@ extern void (*flush_icache_range)(unsigned long start, unsigned long end);
55#define flush_cache_vmap(start, end) flush_cache_all() 55#define flush_cache_vmap(start, end) flush_cache_all()
56#define flush_cache_vunmap(start, end) flush_cache_all() 56#define flush_cache_vunmap(start, end) flush_cache_all()
57 57
58static inline void copy_to_user_page(struct vm_area_struct *vma, 58extern void copy_to_user_page(struct vm_area_struct *vma,
59 struct page *page, unsigned long vaddr, void *dst, const void *src, 59 struct page *page, unsigned long vaddr, void *dst, const void *src,
60 unsigned long len) 60 unsigned long len);
61{
62 if (cpu_has_dc_aliases)
63 flush_cache_page(vma, vaddr, page_to_pfn(page));
64 memcpy(dst, src, len);
65 __flush_icache_page(vma, page);
66}
67 61
68static inline void copy_from_user_page(struct vm_area_struct *vma, 62extern void copy_from_user_page(struct vm_area_struct *vma,
69 struct page *page, unsigned long vaddr, void *dst, const void *src, 63 struct page *page, unsigned long vaddr, void *dst, const void *src,
70 unsigned long len) 64 unsigned long len);
71{
72 if (cpu_has_dc_aliases)
73 flush_cache_page(vma, vaddr, page_to_pfn(page));
74 memcpy(dst, src, len);
75}
76 65
77extern void (*flush_cache_sigtramp)(unsigned long addr); 66extern void (*flush_cache_sigtramp)(unsigned long addr);
78extern void (*flush_icache_all)(void); 67extern void (*flush_icache_all)(void);
diff --git a/include/asm-mips/fixmap.h b/include/asm-mips/fixmap.h
index 6959bdb59310..02c8a13fc894 100644
--- a/include/asm-mips/fixmap.h
+++ b/include/asm-mips/fixmap.h
@@ -45,8 +45,16 @@
45 * fix-mapped? 45 * fix-mapped?
46 */ 46 */
47enum fixed_addresses { 47enum fixed_addresses {
48#define FIX_N_COLOURS 8
49 FIX_CMAP_BEGIN,
50#ifdef CONFIG_MIPS_MT_SMTC
51 FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS),
52#else
53 FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,
54#endif
48#ifdef CONFIG_HIGHMEM 55#ifdef CONFIG_HIGHMEM
49 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 56 /* reserved pte's for temporary kernel mappings */
57 FIX_KMAP_BEGIN = FIX_CMAP_END + 1,
50 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 58 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
51#endif 59#endif
52 __end_of_fixed_addresses 60 __end_of_fixed_addresses
@@ -70,9 +78,9 @@ extern void __set_fixmap (enum fixed_addresses idx,
70 * at the top of mem.. 78 * at the top of mem..
71 */ 79 */
72#if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX) 80#if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX)
73#define FIXADDR_TOP (0xff000000UL - 0x2000) 81#define FIXADDR_TOP ((unsigned long)(long)(int)(0xff000000 - 0x20000))
74#else 82#else
75#define FIXADDR_TOP (0xffffe000UL) 83#define FIXADDR_TOP ((unsigned long)(long)(int)0xfffe0000)
76#endif 84#endif
77#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 85#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
78#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 86#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)