[FIX] using functions set_memory_[ro\rw]()

because those functions may be not exported

Change-Id: I07c8917eb2c326d0a04a8f2007829e0dd77d20f4
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/kprobe/arch/asm-arm/memory_rwx.c b/kprobe/arch/asm-arm/memory_rwx.c
index d120872..bb751a6 100644 (file)
--- a/kprobe/arch/asm-arm/memory_rwx.c
+++ b/kprobe/arch/asm-arm/memory_rwx.c
@@ -31,15 +31,10 @@
 #include <ksyms/ksyms.h>
 
 
-static unsigned long get_init_mm(void)
-{
-       static unsigned long addr = 0;
-
-       if (addr == 0)
-               addr = swap_ksyms("init_mm");
+static struct mm_struct *swap_init_mm = NULL;
+static int (*swap_set_memory_ro)(unsigned long addr, int numpages) = NULL;
+static int (*swap_set_memory_rw)(unsigned long addr, int numpages) = NULL;
 
-       return addr;
-}
 
 static int get_pte_cb(pte_t *ptep, pgtable_t token,
                      unsigned long addr, void *data)
@@ -51,10 +46,10 @@ static int get_pte_cb(pte_t *ptep, pgtable_t token,
 
 static pte_t get_pte(unsigned long page_addr)
 {
-       struct mm_struct *mm = (struct mm_struct *)get_init_mm();
        pte_t pte = 0;
 
-       apply_to_page_range(mm, page_addr, PAGE_SIZE, get_pte_cb, &pte);
+       apply_to_page_range(swap_init_mm, page_addr,
+                           PAGE_SIZE, get_pte_cb, &pte);
 
        return pte;
 }
@@ -71,9 +66,13 @@ static void write_to_module(unsigned long addr, unsigned long val)
                DEFINE_SPINLOCK(mem_lock);
 
                spin_lock_irqsave(&mem_lock, flags);
-               set_memory_rw(page_addr, 1);
-               *maddr = val;
-               set_memory_ro(page_addr, 1);
+               if (swap_set_memory_rw(page_addr, 1) == 0) {
+                       *maddr = val;
+                       swap_set_memory_ro(page_addr, 1);
+               } else {
+                       printk("RWX: failed to write memory %08lx (%08lx)\n",
+                              addr, val);
+               }
                spin_unlock_irqrestore(&mem_lock, flags);
        } else {
                *maddr = val;
@@ -94,3 +93,29 @@ void mem_rwx_write_u32(unsigned long addr, unsigned long val)
                write_to_module(addr, val);
        }
 }
+
+int mem_rwx_init(void)
+{
+       const char *sym;
+
+       sym = "set_memory_ro";
+       swap_set_memory_ro = (void *)swap_ksyms(sym);
+       if (swap_set_memory_ro == NULL)
+               goto not_found;
+
+       sym = "set_memory_rw";
+       swap_set_memory_rw = (void *)swap_ksyms(sym);
+       if (swap_set_memory_rw == NULL)
+               goto not_found;
+
+       sym = "init_mm";
+       swap_init_mm = (void *)swap_ksyms(sym);
+       if (swap_init_mm == NULL)
+               goto not_found;
+
+       return 0;
+
+not_found:
+       printk("ERROR: symbol '%s' not found\n", sym);
+       return -ESRCH;
+}

diff --git a/kprobe/arch/asm-arm/memory_rwx.h b/kprobe/arch/asm-arm/memory_rwx.h
index a083a3b..97879bb 100644 (file)
--- a/kprobe/arch/asm-arm/memory_rwx.h
+++ b/kprobe/arch/asm-arm/memory_rwx.h
@@ -29,6 +29,8 @@
 #define _MEMORY_RWX_H
 
 
+int mem_rwx_init(void);
+void mem_rwx_exit(void) {};
 void mem_rwx_write_u32(unsigned long addr, unsigned long val);
 
 

diff --git a/kprobe/arch/asm-arm/swap_kprobes.c b/kprobe/arch/asm-arm/swap_kprobes.c
index 396bd14..e0b989b 100644 (file)
--- a/kprobe/arch/asm-arm/swap_kprobes.c
+++ b/kprobe/arch/asm-arm/swap_kprobes.c
@@ -870,6 +870,12 @@ int swap_arch_init_kprobes(void)
 {
        int ret;
 
+#ifdef CONFIG_STRICT_MEMORY_RWX
+       ret = mem_rwx_init();
+       if (ret)
+               return ret;
+#endif /* CONFIG_STRICT_MEMORY_RWX */
+
        // Register hooks (kprobe_handler)
        __swap_register_undef_hook = (void *)swap_ksyms("register_undef_hook");
        if (__swap_register_undef_hook == NULL) {
@@ -904,6 +910,10 @@ void swap_arch_exit_kprobes(void)
 {
        kjump_exit();
        swap_unregister_undef_hook(&undef_ho_k);
+
+#ifdef CONFIG_STRICT_MEMORY_RWX
+       mem_rwx_exit();
+#endif /* CONFIG_STRICT_MEMORY_RWX */
 }
 
 /* export symbol for trampoline_arm.h */