summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--arch/x86/include/asm/ftrace.h8
-rw-r--r--arch/x86/kernel/ftrace.c29
-rw-r--r--include/linux/ftrace.h53
-rw-r--r--kernel/module.c2
-rw-r--r--kernel/trace/ftrace.c62
5 files changed, 100 insertions, 54 deletions
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 9b6a1fa19e70..2bb43b433e07 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -17,6 +17,14 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
*/
return addr - 1;
}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+struct dyn_arch_ftrace {
+ /* No extra data needed for x86 */
+};
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index fe832738e1e2..762222ad1387 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -166,7 +166,7 @@ static int ftrace_calc_offset(long ip, long addr)
return (int)(addr - ip);
}
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
{
static union ftrace_code_union calc;
@@ -311,12 +311,12 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
-unsigned char *ftrace_nop_replace(void)
+static unsigned char *ftrace_nop_replace(void)
{
return ftrace_nop;
}
-int
+static int
ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code)
{
@@ -349,6 +349,29 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
return 0;
}
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *new, *old;
+ unsigned long ip = rec->ip;
+
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace();
+
+ return ftrace_modify_code(rec->ip, old, new);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *new, *old;
+ unsigned long ip = rec->ip;
+
+ old = ftrace_nop_replace();
+ new = ftrace_call_replace(ip, addr);
+
+ return ftrace_modify_code(rec->ip, old, new);
+}
+
int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 4fbc4a8b86a5..166a2070ef65 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -74,6 +74,9 @@ static inline void ftrace_start(void) { }
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_DYNAMIC_FTRACE
+/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
+#include <asm/ftrace.h>
+
enum {
FTRACE_FL_FREE = (1 << 0),
FTRACE_FL_FAILED = (1 << 1),
@@ -88,6 +91,7 @@ struct dyn_ftrace {
struct list_head list;
unsigned long ip; /* address of mcount call-site */
unsigned long flags;
+ struct dyn_arch_ftrace arch;
};
int ftrace_force_update(void);
@@ -95,22 +99,40 @@ void ftrace_set_filter(unsigned char *buf, int len, int reset);
/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
-extern unsigned char *ftrace_nop_replace(void);
-extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
extern int ftrace_dyn_arch_init(void *data);
extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_call(void);
extern void mcount_call(void);
-/* May be defined in arch */
-extern int ftrace_arch_read_dyn_info(char *buf, int size);
+/**
+ * ftrace_make_nop - convert code into top
+ * @mod: module structure if called by module load initialization
+ * @rec: the mcount call site record
+ * @addr: the address that the call site should be calling
+ *
+ * This is a very sensitive operation and great care needs
+ * to be taken by the arch. The operation should carefully
+ * read the location, check to see if what is read is indeed
+ * what we expect it to be, and then on success of the compare,
+ * it should write to the location.
+ *
+ * The code segment at @rec->ip should be a caller to @addr
+ *
+ * Return must be:
+ * 0 on success
+ * -EFAULT on error reading the location
+ * -EINVAL on a failed compare of the contents
+ * -EPERM on error writing to the location
+ * Any other value will be considered a failure.
+ */
+extern int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr);
/**
- * ftrace_modify_code - modify code segment
- * @ip: the address of the code segment
- * @old_code: the contents of what is expected to be there
- * @new_code: the code to patch in
+ * ftrace_make_call - convert a nop call site into a call to addr
+ * @rec: the mcount call site record
+ * @addr: the address that the call site should call
*
* This is a very sensitive operation and great care needs
* to be taken by the arch. The operation should carefully
@@ -118,6 +140,8 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size);
* what we expect it to be, and then on success of the compare,
* it should write to the location.
*
+ * The code segment at @rec->ip should be a nop
+ *
* Return must be:
* 0 on success
* -EFAULT on error reading the location
@@ -125,8 +149,11 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size);
* -EPERM on error writing to the location
* Any other value will be considered a failure.
*/
-extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
- unsigned char *new_code);
+extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
+
+
+/* May be defined in arch */
+extern int ftrace_arch_read_dyn_info(char *buf, int size);
extern int skip_trace(unsigned long ip);
@@ -259,11 +286,13 @@ static inline void ftrace_dump(void) { }
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
-extern void ftrace_init_module(unsigned long *start, unsigned long *end);
+extern void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end);
#else
static inline void ftrace_init(void) { }
static inline void
-ftrace_init_module(unsigned long *start, unsigned long *end) { }
+ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end) { }
#endif
diff --git a/kernel/module.c b/kernel/module.c
index 1f4cc00e0c20..69791274e899 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2201,7 +2201,7 @@ static noinline struct module *load_module(void __user *umod,
/* sechdrs[0].sh_size is always zero */
mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
sizeof(*mseg), &num_mcount);
- ftrace_init_module(mseg, mseg + num_mcount);
+ ftrace_init_module(mod, mseg, mseg + num_mcount);
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3940c71ac2a2..e9a5fbfce08e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -358,9 +358,7 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
}
-static void ftrace_bug(int failed, unsigned long ip,
- unsigned char *expected,
- unsigned char *replace)
+static void ftrace_bug(int failed, unsigned long ip)
{
switch (failed) {
case -EFAULT:
@@ -372,9 +370,7 @@ static void ftrace_bug(int failed, unsigned long ip,
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
- print_ip_ins(" expected: ", expected);
print_ip_ins(" actual: ", (unsigned char *)ip);
- print_ip_ins(" replace: ", replace);
printk(KERN_CONT "\n");
break;
case -EPERM:
@@ -392,8 +388,7 @@ static void ftrace_bug(int failed, unsigned long ip,
#define FTRACE_ADDR ((long)(ftrace_caller))
static int
-__ftrace_replace_code(struct dyn_ftrace *rec,
- unsigned char *old, unsigned char *new, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ip, fl;
@@ -435,12 +430,10 @@ __ftrace_replace_code(struct dyn_ftrace *rec,
* otherwise enable it!
*/
if (fl & FTRACE_FL_ENABLED) {
- /* swap new and old */
- new = old;
- old = ftrace_call_replace(ip, FTRACE_ADDR);
+ enable = 0;
rec->flags &= ~FTRACE_FL_ENABLED;
} else {
- new = ftrace_call_replace(ip, FTRACE_ADDR);
+ enable = 1;
rec->flags |= FTRACE_FL_ENABLED;
}
} else {
@@ -453,10 +446,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec,
fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
if (fl == FTRACE_FL_NOTRACE)
return 0;
-
- new = ftrace_call_replace(ip, FTRACE_ADDR);
- } else
- old = ftrace_call_replace(ip, FTRACE_ADDR);
+ }
if (enable) {
if (rec->flags & FTRACE_FL_ENABLED)
@@ -469,21 +459,18 @@ __ftrace_replace_code(struct dyn_ftrace *rec,
}
}
- return ftrace_modify_code(ip, old, new);
+ if (enable)
+ return ftrace_make_call(rec, FTRACE_ADDR);
+ else
+ return ftrace_make_nop(NULL, rec, FTRACE_ADDR);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
- unsigned char *new = NULL, *old = NULL;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- if (enable)
- old = ftrace_nop_replace();
- else
- new = ftrace_nop_replace();
-
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
rec = &pg->records[i];
@@ -504,34 +491,30 @@ static void ftrace_replace_code(int enable)
unfreeze_record(rec);
}
- failed = __ftrace_replace_code(rec, old, new, enable);
+ failed = __ftrace_replace_code(rec, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
if ((system_state == SYSTEM_BOOTING) ||
!core_kernel_text(rec->ip)) {
ftrace_free_rec(rec);
} else
- ftrace_bug(failed, rec->ip, old, new);
+ ftrace_bug(failed, rec->ip);
}
}
}
}
static int
-ftrace_code_disable(struct dyn_ftrace *rec)
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
{
unsigned long ip;
- unsigned char *nop, *call;
int ret;
ip = rec->ip;
- nop = ftrace_nop_replace();
- call = ftrace_call_replace(ip, mcount_addr);
-
- ret = ftrace_modify_code(ip, call, nop);
+ ret = ftrace_make_nop(mod, rec, mcount_addr);
if (ret) {
- ftrace_bug(ret, ip, call, nop);
+ ftrace_bug(ret, ip);
rec->flags |= FTRACE_FL_FAILED;
return 0;
}
@@ -650,7 +633,7 @@ static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int ftrace_update_code(void)
+static int ftrace_update_code(struct module *mod)
{
struct dyn_ftrace *p, *t;
cycle_t start, stop;
@@ -667,7 +650,7 @@ static int ftrace_update_code(void)
list_del_init(&p->list);
/* convert record (i.e, patch mcount-call with NOP) */
- if (ftrace_code_disable(p)) {
+ if (ftrace_code_disable(mod, p)) {
p->flags |= FTRACE_FL_CONVERTED;
ftrace_update_cnt++;
} else
@@ -1309,7 +1292,8 @@ static __init int ftrace_init_debugfs(void)
fs_initcall(ftrace_init_debugfs);
-static int ftrace_convert_nops(unsigned long *start,
+static int ftrace_convert_nops(struct module *mod,
+ unsigned long *start,
unsigned long *end)
{
unsigned long *p;
@@ -1325,18 +1309,19 @@ static int ftrace_convert_nops(unsigned long *start,
/* disable interrupts to prevent kstop machine */
local_irq_save(flags);
- ftrace_update_code();
+ ftrace_update_code(mod);
local_irq_restore(flags);
mutex_unlock(&ftrace_start_lock);
return 0;
}
-void ftrace_init_module(unsigned long *start, unsigned long *end)
+void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end)
{
if (ftrace_disabled || start == end)
return;
- ftrace_convert_nops(start, end);
+ ftrace_convert_nops(mod, start, end);
}
extern unsigned long __start_mcount_loc[];
@@ -1366,7 +1351,8 @@ void __init ftrace_init(void)
last_ftrace_enabled = ftrace_enabled = 1;
- ret = ftrace_convert_nops(__start_mcount_loc,
+ ret = ftrace_convert_nops(NULL,
+ __start_mcount_loc,
__stop_mcount_loc);
return;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 04:22:02 +0100