5 files changed, 70 insertions, 13 deletions

diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 00af9fe435e6..fd43f7f55b70 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -487,4 +487,6 @@ int set_memory_rw(unsigned long addr, int numpages);
 int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
 
+void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
+                             void *kaddr, unsigned long len);
 #endif
diff --git a/arch/arm/kernel/uprobes.c b/arch/arm/kernel/uprobes.c
index f9bacee973bf..56adf9c1fde0 100644
--- a/arch/arm/kernel/uprobes.c
+++ b/arch/arm/kernel/uprobes.c
@@ -113,6 +113,26 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
         return 0;
 }
 
+void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+                           void *src, unsigned long len)
+{
+        void *xol_page_kaddr = kmap_atomic(page);
+        void *dst = xol_page_kaddr + (vaddr & ~PAGE_MASK);
+
+        preempt_disable();
+
+        /* Initialize the slot */
+        memcpy(dst, src, len);
+
+        /* flush caches (dcache/icache) */
+        flush_uprobe_xol_access(page, vaddr, dst, len);
+
+        preempt_enable();
+
+        kunmap_atomic(xol_page_kaddr);
+}
+
+
 int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
 {
         struct uprobe_task *utask = current->utask;
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 3387e60e4ea3..43d54f5b26b9 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -104,17 +104,20 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsig
 #define flush_icache_alias(pfn,vaddr,len)       do { } while (0)
 #endif
 
+#define FLAG_PA_IS_EXEC 1
+#define FLAG_PA_CORE_IN_MM 2
+
 static void flush_ptrace_access_other(void *args)
 {
         __flush_icache_all();
 }
 
-static
-void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
-                         unsigned long uaddr, void *kaddr, unsigned long len)
+static inline
+void __flush_ptrace_access(struct page *page, unsigned long uaddr, void *kaddr,
+                           unsigned long len, unsigned int flags)
 {
         if (cache_is_vivt()) {
-                if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {
+                if (flags & FLAG_PA_CORE_IN_MM) {
                         unsigned long addr = (unsigned long)kaddr;
                         __cpuc_coherent_kern_range(addr, addr + len);
                 }
@@ -128,7 +131,7 @@ void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
         }
 
         /* VIPT non-aliasing D-cache */
-        if (vma->vm_flags & VM_EXEC) {
+        if (flags & FLAG_PA_IS_EXEC) {
                 unsigned long addr = (unsigned long)kaddr;
                 if (icache_is_vipt_aliasing())
                         flush_icache_alias(page_to_pfn(page), uaddr, len);
@@ -140,6 +143,26 @@ void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
         }
 }
 
+static
+void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
+                         unsigned long uaddr, void *kaddr, unsigned long len)
+{
+        unsigned int flags = 0;
+        if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm)))
+                flags |= FLAG_PA_CORE_IN_MM;
+        if (vma->vm_flags & VM_EXEC)
+                flags |= FLAG_PA_IS_EXEC;
+        __flush_ptrace_access(page, uaddr, kaddr, len, flags);
+}
+
+void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
+                             void *kaddr, unsigned long len)
+{
+        unsigned int flags = FLAG_PA_CORE_IN_MM|FLAG_PA_IS_EXEC;
+
+        __flush_ptrace_access(page, uaddr, kaddr, len, flags);
+}
+
 /*
  * Copy user data from/to a page which is mapped into a different
  * processes address space.  Really, we want to allow our "user
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index edff2b97b864..c52f827ba6ce 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -32,6 +32,7 @@ struct vm_area_struct;
 struct mm_struct;
 struct inode;
 struct notifier_block;
+struct page;
 
 #define UPROBE_HANDLER_REMOVE           1
 #define UPROBE_HANDLER_MASK             1
@@ -127,6 +128,8 @@ extern int  arch_uprobe_exception_notify(struct notifier_block *self, unsigned l
 extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
 extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs);
 extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs);
+extern void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+                                         void *src, unsigned long len);
 #else /* !CONFIG_UPROBES */
 struct uprobes_state {
 };
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 04709b66369d..4968213c63fa 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1296,14 +1296,8 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
         if (unlikely(!xol_vaddr))
                 return 0;
 
-        /* Initialize the slot */
-        copy_to_page(area->page, xol_vaddr,
-                        &uprobe->arch.ixol, sizeof(uprobe->arch.ixol));
-        /*
-         * We probably need flush_icache_user_range() but it needs vma.
-         * This should work on supported architectures too.
-         */
-        flush_dcache_page(area->page);
+        arch_uprobe_copy_ixol(area->page, xol_vaddr,
+                              &uprobe->arch.ixol, sizeof(uprobe->arch.ixol));
 
         return xol_vaddr;
 }
@@ -1346,6 +1340,21 @@ static void xol_free_insn_slot(struct task_struct *tsk)
         }
 }
 
+void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+                                  void *src, unsigned long len)
+{
+        /* Initialize the slot */
+        copy_to_page(page, vaddr, src, len);
+
+        /*
+         * We probably need flush_icache_user_range() but it needs vma.
+         * This should work on most of architectures by default. If
+         * architecture needs to do something different it can define
+         * its own version of the function.
+         */
+        flush_dcache_page(page);
+}
+
 /**
  * uprobe_get_swbp_addr - compute address of swbp given post-swbp regs
  * @regs: Reflects the saved state of the task after it has hit a breakpoint