ARM: Fix ptrace accesses

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/cacheflush.h

@@ -316,12 +316,8 @@ static inline void outer_flush_range(unsigned long start, unsigned long end)
  * processes address space.  Really, we want to allow our "user
  * space" model to handle this.
  */
-#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
-	do {							\
-		memcpy(dst, src, len);				\
-		flush_ptrace_access(vma, page, vaddr, dst, len, 1);\
-	} while (0)
-
+extern void copy_to_user_page(struct vm_area_struct *, struct page *,
+	unsigned long, void *, const void *, unsigned long);
 #define copy_from_user_page(vma, page, vaddr, dst, src, len) \
 	do {							\
 		memcpy(dst, src, len);				\
@@ -355,33 +351,17 @@ vivt_flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsig
 	}
 }
 
-static inline void
-vivt_flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
-			 unsigned long uaddr, void *kaddr,
-			 unsigned long len, int write)
-{
-	if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {
-		unsigned long addr = (unsigned long)kaddr;
-		__cpuc_coherent_kern_range(addr, addr + len);
-	}
-}
-
 #ifndef CONFIG_CPU_CACHE_VIPT
 #define flush_cache_mm(mm) \
 		vivt_flush_cache_mm(mm)
 #define flush_cache_range(vma,start,end) \
 		vivt_flush_cache_range(vma,start,end)
 #define flush_cache_page(vma,addr,pfn) \
 		vivt_flush_cache_page(vma,addr,pfn)
-#define flush_ptrace_access(vma,page,ua,ka,len,write) \
-		vivt_flush_ptrace_access(vma,page,ua,ka,len,write)
 #else
 extern void flush_cache_mm(struct mm_struct *mm);
 extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
 extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn);
-extern void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
-				unsigned long uaddr, void *kaddr,
-				unsigned long len, int write);
 #endif
 
 #define flush_cache_dup_mm(mm) flush_cache_mm(mm)

arch/arm/include/asm/smp_plat.h

@@ -13,4 +13,9 @@ static inline int tlb_ops_need_broadcast(void)
 	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
 }
 
+static inline int cache_ops_need_broadcast(void)
+{
+	return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
+}
+
 #endif

arch/arm/mm/flush.c

@@ -13,6 +13,7 @@
 
 #include <asm/cacheflush.h>
 #include <asm/cachetype.h>
+#include <asm/smp_plat.h>
 #include <asm/system.h>
 #include <asm/tlbflush.h>
 
@@ -87,13 +88,26 @@ 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)
+#endif
 
+#ifdef CONFIG_SMP
+static void flush_ptrace_access_other(void *args)
+{
+	__flush_icache_all();
+}
+#endif
+
+static
 void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
-			 unsigned long uaddr, void *kaddr,
-			 unsigned long len, int write)
+			 unsigned long uaddr, void *kaddr, unsigned long len)
 {
 	if (cache_is_vivt()) {
-		vivt_flush_ptrace_access(vma, page, uaddr, kaddr, len, write);
+		if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {
+			unsigned long addr = (unsigned long)kaddr;
+			__cpuc_coherent_kern_range(addr, addr + len);
+		}
 		return;
 	}
 
@@ -104,16 +118,37 @@ void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
 	}
 
 	/* VIPT non-aliasing cache */
-	if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm)) &&
-	    vma->vm_flags & VM_EXEC) {
+	if (vma->vm_flags & VM_EXEC) {
 		unsigned long addr = (unsigned long)kaddr;
-		/* only flushing the kernel mapping on non-aliasing VIPT */
 		__cpuc_coherent_kern_range(addr, addr + len);
+#ifdef CONFIG_SMP
+		if (cache_ops_need_broadcast())
+			smp_call_function(flush_ptrace_access_other,
+					  NULL, 1);
+#endif
 	}
 }
-#else
-#define flush_pfn_alias(pfn,vaddr)	do { } while (0)
+
+/*
+ * Copy user data from/to a page which is mapped into a different
+ * processes address space.  Really, we want to allow our "user
+ * space" model to handle this.
+ *
+ * Note that this code needs to run on the current CPU.
+ */
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+		       unsigned long uaddr, void *dst, const void *src,
+		       unsigned long len)
+{
+#ifdef CONFIG_SMP
+	preempt_disable();
 #endif
+	memcpy(dst, src, len);
+	flush_ptrace_access(vma, page, uaddr, dst, len);
+#ifdef CONFIG_SMP
+	preempt_enable();
+#endif
+}
 
 void __flush_dcache_page(struct address_space *mapping, struct page *page)
 {