@@ -53,11 +53,6 @@ config ARM_UNWIND
config FRAME_POINTER
bool
-config OLD_MCOUNT
- bool
- depends on FUNCTION_TRACER && FRAME_POINTER
- default y
-
config DEBUG_USER
bool "Verbose user fault messages"
help
@@ -16,9 +16,6 @@ extern void __gnu_mcount_nc(void);
#ifdef CONFIG_DYNAMIC_FTRACE
struct dyn_arch_ftrace {
-#ifdef CONFIG_OLD_MCOUNT
- bool old_mcount;
-#endif
#ifdef CONFIG_ARM_MODULE_PLTS
struct module *mod;
#endif
@@ -168,9 +168,6 @@ EXPORT_SYMBOL(_find_next_bit_be);
#endif
#ifdef CONFIG_FUNCTION_TRACER
-#ifdef CONFIG_OLD_MCOUNT
-EXPORT_SYMBOL(mcount);
-#endif
EXPORT_SYMBOL(__gnu_mcount_nc);
#endif
@@ -15,23 +15,8 @@
* start of every function. In mcount, apart from the function's address (in
* lr), we need to get hold of the function's caller's address.
*
- * Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
- *
- * bl mcount
- *
- * These versions have the limitation that in order for the mcount routine to
- * be able to determine the function's caller's address, an APCS-style frame
- * pointer (which is set up with something like the code below) is required.
- *
- * mov ip, sp
- * push {fp, ip, lr, pc}
- * sub fp, ip, #4
- *
- * With EABI, these frame pointers are not available unless -mapcs-frame is
- * specified, and if building as Thumb-2, not even then.
- *
- * Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
- * with call sites like:
+ * Newer GCCs (4.4+) solve this problem by using a version of mcount with call
+ * sites like:
*
* push {lr}
* bl __gnu_mcount_nc
@@ -46,17 +31,10 @@
* allows it to be clobbered in subroutines and doesn't use it to hold
* parameters.)
*
- * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
- * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
- * arch/arm/kernel/ftrace.c).
+ * When using dynamic ftrace, we patch out the mcount call by a "pop {lr}"
+ * instead of the __gnu_mcount_nc call (see arch/arm/kernel/ftrace.c).
*/
-#ifndef CONFIG_OLD_MCOUNT
-#if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
-#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
-#endif
-#endif
-
.macro mcount_adjust_addr rd, rn
bic \rd, \rn, #1 @ clear the Thumb bit if present
sub \rd, \rd, #MCOUNT_INSN_SIZE
@@ -209,51 +187,6 @@ ftrace_graph_call\suffix:
mcount_exit
.endm
-#ifdef CONFIG_OLD_MCOUNT
-/*
- * mcount
- */
-
-.macro mcount_enter
- stmdb sp!, {r0-r3, lr}
-.endm
-
-.macro mcount_get_lr reg
- ldr \reg, [fp, #-4]
-.endm
-
-.macro mcount_exit
- ldr lr, [fp, #-4]
- ldmia sp!, {r0-r3, pc}
-.endm
-
-ENTRY(mcount)
-#ifdef CONFIG_DYNAMIC_FTRACE
- stmdb sp!, {lr}
- ldr lr, [fp, #-4]
- ldmia sp!, {pc}
-#else
- __mcount _old
-#endif
-ENDPROC(mcount)
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-ENTRY(ftrace_caller_old)
- __ftrace_caller _old
-ENDPROC(ftrace_caller_old)
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-ENTRY(ftrace_graph_caller_old)
- __ftrace_graph_caller
-ENDPROC(ftrace_graph_caller_old)
-#endif
-
-.purgem mcount_enter
-.purgem mcount_get_lr
-.purgem mcount_exit
-#endif
-
/*
* __gnu_mcount_nc
*/
@@ -47,30 +47,6 @@ void arch_ftrace_update_code(int command)
stop_machine(__ftrace_modify_code, &command, NULL);
}
-#ifdef CONFIG_OLD_MCOUNT
-#define OLD_MCOUNT_ADDR ((unsigned long) mcount)
-#define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old)
-
-#define OLD_NOP 0xe1a00000 /* mov r0, r0 */
-
-static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec)
-{
- return rec->arch.old_mcount ? OLD_NOP : NOP;
-}
-
-static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
-{
- if (!rec->arch.old_mcount)
- return addr;
-
- if (addr == MCOUNT_ADDR)
- addr = OLD_MCOUNT_ADDR;
- else if (addr == FTRACE_ADDR)
- addr = OLD_FTRACE_ADDR;
-
- return addr;
-}
-#else
static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec)
{
return NOP;
@@ -80,7 +56,6 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
{
return addr;
}
-#endif
int ftrace_arch_code_modify_prepare(void)
{
@@ -151,15 +126,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
}
#endif
-#ifdef CONFIG_OLD_MCOUNT
- if (!ret) {
- pc = (unsigned long)&ftrace_call_old;
- new = ftrace_call_replace(pc, (unsigned long)func, true);
-
- ret = ftrace_modify_code(pc, 0, new, false);
- }
-#endif
-
return ret;
}
@@ -233,16 +199,6 @@ int ftrace_make_nop(struct module *mod,
new = ftrace_nop_replace(rec);
ret = ftrace_modify_code(ip, old, new, true);
-#ifdef CONFIG_OLD_MCOUNT
- if (ret == -EINVAL && addr == MCOUNT_ADDR) {
- rec->arch.old_mcount = true;
-
- old = ftrace_call_replace(ip, adjust_address(rec, addr), true);
- new = ftrace_nop_replace(rec);
- ret = ftrace_modify_code(ip, old, new, true);
- }
-#endif
-
return ret;
}
@@ -320,13 +276,6 @@ static int ftrace_modify_graph_caller(bool enable)
#endif
-#ifdef CONFIG_OLD_MCOUNT
- if (!ret)
- ret = __ftrace_modify_caller(&ftrace_graph_call_old,
- ftrace_graph_caller_old,
- enable);
-#endif
-
return ret;
}