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authorWill Deacon <will.deacon@arm.com>2010-09-13 16:19:41 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-10-04 20:57:10 +0100
commitc4e259c859538e94007d1f04a488540375189551 (patch)
treedf5485bd1184c562a11a8588915539d136e8de29
parent8925ec4c530094b878e7e28a1fd78e7122afd973 (diff)
ARM: 6386/1: flush_ptrace_access: invalidate correct I-cache alias
copy_to_user_page can be used by access_process_vm to write to an executable page of a process using a mapping acquired by kmap. For systems with I-cache aliasing, flushing the I-cache using the Kernel mapping may leave stale data in the I-cache if the user mapping is of a different colour. This patch introduces a flush_icache_alias function to flush.c, which calls flush_icache_range with a mapping of the specified colour. flush_ptrace_access is then modified to call this new function instead of coherent_kern_range in the case of an aliasing I-cache and a non-aliasing D-cache. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mm/flush.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 2332b774c6b9..391ffae75098 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -40,6 +40,18 @@ static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
: "cc");
}
+static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned long len)
+{
+ unsigned long colour = CACHE_COLOUR(vaddr);
+ unsigned long offset = vaddr & (PAGE_SIZE - 1);
+ unsigned long to;
+
+ set_pte_ext(TOP_PTE(ALIAS_FLUSH_START) + colour, pfn_pte(pfn, PAGE_KERNEL), 0);
+ to = ALIAS_FLUSH_START + (colour << PAGE_SHIFT) + offset;
+ flush_tlb_kernel_page(to);
+ flush_icache_range(to, to + len);
+}
+
void flush_cache_mm(struct mm_struct *mm)
{
if (cache_is_vivt()) {
@@ -90,8 +102,10 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsig
if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged())
__flush_icache_all();
}
+
#else
-#define flush_pfn_alias(pfn,vaddr) do { } while (0)
+#define flush_pfn_alias(pfn,vaddr) do { } while (0)
+#define flush_icache_alias(pfn,vaddr,len) do { } while (0)
#endif
static void flush_ptrace_access_other(void *args)
@@ -117,10 +131,13 @@ void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
return;
}
- /* VIPT non-aliasing cache */
+ /* VIPT non-aliasing D-cache */
if (vma->vm_flags & VM_EXEC) {
unsigned long addr = (unsigned long)kaddr;
- __cpuc_coherent_kern_range(addr, addr + len);
+ if (icache_is_vipt_aliasing())
+ flush_icache_alias(page_to_pfn(page), uaddr, len);
+ else
+ __cpuc_coherent_kern_range(addr, addr + len);
if (cache_ops_need_broadcast())
smp_call_function(flush_ptrace_access_other,
NULL, 1);