diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2006-10-21 23:17:35 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2006-10-21 23:17:35 +0100 |
| commit | f8829caee311207afbc882794bdc5aa0db5caf33 (patch) | |
| tree | dbadd9fa746a1a4f091bc7e240ca8d787188a913 /include | |
| parent | 224dc50ece1b40f8cff5ecadd42a6b2691e231de (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')
| -rw-r--r-- | include/asm-mips/cacheflush.h | 19 | ||||
| -rw-r--r-- | include/asm-mips/fixmap.h | 14 |
2 files changed, 15 insertions, 18 deletions
diff --git a/include/asm-mips/cacheflush.h b/include/asm-mips/cacheflush.h index 9ab59e2bb23..e3c9925876a 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); #define flush_cache_vmap(start, end) flush_cache_all() #define flush_cache_vunmap(start, end) flush_cache_all() -static inline void copy_to_user_page(struct vm_area_struct *vma, +extern void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, - unsigned long len) -{ - if (cpu_has_dc_aliases) - flush_cache_page(vma, vaddr, page_to_pfn(page)); - memcpy(dst, src, len); - __flush_icache_page(vma, page); -} + unsigned long len); -static inline void copy_from_user_page(struct vm_area_struct *vma, +extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, - unsigned long len) -{ - if (cpu_has_dc_aliases) - flush_cache_page(vma, vaddr, page_to_pfn(page)); - memcpy(dst, src, len); -} + unsigned long len); extern void (*flush_cache_sigtramp)(unsigned long addr); extern void (*flush_icache_all)(void); 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) |