x86/ftrace: Fix compiler warning in ftrace.c

 Due to commit dc326fca2b64 (x86, cpu: Clean up and unify the NOP selection infrastructure), we get the following warning:

arch/x86/kernel/ftrace.c: In function ‘ftrace_make_nop’:
arch/x86/kernel/ftrace.c:308:6: warning: assignment discards qualifiers from pointer target type
arch/x86/kernel/ftrace.c: In function ‘ftrace_make_call’:
arch/x86/kernel/ftrace.c:318:6: warning: assignment discards qualifiers from pointer target type

ftrace_nop_replace() now returns const unsigned char *, so change its associated function/variable to its compatible type to keep compiler clam.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Link: http://lkml.kernel.org/r/1305221620.7986.4.camel@localhost.localdomain
[ updated for change of const void *src in probe_kernel_write() ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 0ba15a6..c9a281f 100644 (file)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -123,7 +123,7 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
 static atomic_t nmi_running = ATOMIC_INIT(0);
 static int mod_code_status;            /* holds return value of text write */
 static void *mod_code_ip;              /* holds the IP to write to */
-static void *mod_code_newcode;         /* holds the text to write to the IP */
+static const void *mod_code_newcode;   /* holds the text to write to the IP */
 
 static unsigned nmi_wait_count;
 static atomic_t nmi_update_count = ATOMIC_INIT(0);
@@ -225,7 +225,7 @@ within(unsigned long addr, unsigned long start, unsigned long end)
 }
 
 static int
-do_ftrace_mod_code(unsigned long ip, void *new_code)
+do_ftrace_mod_code(unsigned long ip, const void *new_code)
 {
        /*
         * On x86_64, kernel text mappings are mapped read-only with
@@ -266,8 +266,8 @@ static const unsigned char *ftrace_nop_replace(void)
 }
 
 static int
-ftrace_modify_code(unsigned long ip, unsigned char *old_code,
-                  unsigned char *new_code)
+ftrace_modify_code(unsigned long ip, unsigned const char *old_code,
+                  unsigned const char *new_code)
 {
        unsigned char replaced[MCOUNT_INSN_SIZE];
 
@@ -301,7 +301,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
 int ftrace_make_nop(struct module *mod,
                    struct dyn_ftrace *rec, unsigned long addr)
 {
-       unsigned char *new, *old;
+       unsigned const char *new, *old;
        unsigned long ip = rec->ip;
 
        old = ftrace_call_replace(ip, addr);
@@ -312,7 +312,7 @@ int ftrace_make_nop(struct module *mod,
 
 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
-       unsigned char *new, *old;
+       unsigned const char *new, *old;
        unsigned long ip = rec->ip;
 
        old = ftrace_nop_replace();