Merge git://git.infradead.org/ubifs-2.6

[cascardo/linux.git] / arch / x86 / kernel / ftrace.c

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 25e6f5f..3096892 100644 (file)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -189,9 +189,26 @@ static void wait_for_nmi(void)
        nmi_wait_count++;
 }
 
+static inline int
+within(unsigned long addr, unsigned long start, unsigned long end)
+{
+       return addr >= start && addr < end;
+}
+
 static int
 do_ftrace_mod_code(unsigned long ip, void *new_code)
 {
+       /*
+        * On x86_64, kernel text mappings are mapped read-only with
+        * CONFIG_DEBUG_RODATA. So we use the kernel identity mapping instead
+        * of the kernel text mapping to modify the kernel text.
+        *
+        * For 32bit kernels, these mappings are same and we can use
+        * kernel identity mapping to modify code.
+        */
+       if (within(ip, (unsigned long)_text, (unsigned long)_etext))
+               ip = (unsigned long)__va(__pa(ip));
+
        mod_code_ip = (void *)ip;
        mod_code_newcode = new_code;
 
@@ -470,82 +487,10 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 
-extern unsigned long __start_syscalls_metadata[];
-extern unsigned long __stop_syscalls_metadata[];
 extern unsigned long *sys_call_table;
 
-static struct syscall_metadata **syscalls_metadata;
-
-static struct syscall_metadata *find_syscall_meta(unsigned long *syscall)
-{
-       struct syscall_metadata *start;
-       struct syscall_metadata *stop;
-       char str[KSYM_SYMBOL_LEN];
-
-
-       start = (struct syscall_metadata *)__start_syscalls_metadata;
-       stop = (struct syscall_metadata *)__stop_syscalls_metadata;
-       kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str);
-
-       for ( ; start < stop; start++) {
-               if (start->name && !strcmp(start->name, str))
-                       return start;
-       }
-       return NULL;
-}
-
-struct syscall_metadata *syscall_nr_to_meta(int nr)
-{
-       if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
-               return NULL;
-
-       return syscalls_metadata[nr];
-}
-
-int syscall_name_to_nr(char *name)
+unsigned long __init arch_syscall_addr(int nr)
 {
-       int i;
-
-       if (!syscalls_metadata)
-               return -1;
-
-       for (i = 0; i < NR_syscalls; i++) {
-               if (syscalls_metadata[i]) {
-                       if (!strcmp(syscalls_metadata[i]->name, name))
-                               return i;
-               }
-       }
-       return -1;
-}
-
-void set_syscall_enter_id(int num, int id)
-{
-       syscalls_metadata[num]->enter_id = id;
-}
-
-void set_syscall_exit_id(int num, int id)
-{
-       syscalls_metadata[num]->exit_id = id;
-}
-
-static int __init arch_init_ftrace_syscalls(void)
-{
-       int i;
-       struct syscall_metadata *meta;
-       unsigned long **psys_syscall_table = &sys_call_table;
-
-       syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
-                                       NR_syscalls, GFP_KERNEL);
-       if (!syscalls_metadata) {
-               WARN_ON(1);
-               return -ENOMEM;
-       }
-
-       for (i = 0; i < NR_syscalls; i++) {
-               meta = find_syscall_meta(psys_syscall_table[i]);
-               syscalls_metadata[i] = meta;
-       }
-       return 0;
+       return (unsigned long)(&sys_call_table)[nr];
 }
-arch_initcall(arch_init_ftrace_syscalls);
 #endif