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/asm-mips/cacheflush.h | |
| 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/asm-mips/cacheflush.h')
| -rw-r--r-- | include/asm-mips/cacheflush.h | 19 |
1 files changed, 4 insertions, 15 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); #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); |