diff options
| -rw-r--r-- | arch/blackfin/Kconfig | 1 | ||||
| -rw-r--r-- | arch/blackfin/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/blackfin/kernel/ftrace-entry.S | 68 | ||||
| -rw-r--r-- | arch/blackfin/kernel/ftrace.c | 42 | ||||
| -rw-r--r-- | arch/blackfin/kernel/vmlinux.lds.S | 1 |
5 files changed, 115 insertions, 0 deletions
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index ea8d92c1d44..5bc1360de2e 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -19,6 +19,7 @@ config RWSEM_XCHGADD_ALGORITHM config BLACKFIN def_bool y + select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER select HAVE_IDE select HAVE_KERNEL_GZIP diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile index d2ae285e5b6..3731088e181 100644 --- a/arch/blackfin/kernel/Makefile +++ b/arch/blackfin/kernel/Makefile @@ -16,6 +16,9 @@ else endif obj-$(CONFIG_FUNCTION_TRACER) += ftrace-entry.o +obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o +CFLAGS_REMOVE_ftrace.o = -pg + obj-$(CONFIG_IPIPE) += ipipe.o obj-$(CONFIG_IPIPE_TRACE_MCOUNT) += mcount.o obj-$(CONFIG_BFIN_GPTIMERS) += gptimers.o diff --git a/arch/blackfin/kernel/ftrace-entry.S b/arch/blackfin/kernel/ftrace-entry.S index ce71487b515..6980b7a0615 100644 --- a/arch/blackfin/kernel/ftrace-entry.S +++ b/arch/blackfin/kernel/ftrace-entry.S @@ -35,6 +35,28 @@ ENTRY(__mcount) cc = r2 == r3; if ! cc jump .Ldo_trace; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* if the ftrace_graph_return function pointer is not set to + * the ftrace_stub entry, call prepare_ftrace_return(). + */ + p0.l = _ftrace_graph_return; + p0.h = _ftrace_graph_return; + r3 = [p0]; + cc = r2 == r3; + if ! cc jump _ftrace_graph_caller; + + /* similarly, if the ftrace_graph_entry function pointer is not + * set to the ftrace_graph_entry_stub entry, ... + */ + p0.l = _ftrace_graph_entry; + p0.h = _ftrace_graph_entry; + r2.l = _ftrace_graph_entry_stub; + r2.h = _ftrace_graph_entry_stub; + r3 = [p0]; + cc = r2 == r3; + if ! cc jump _ftrace_graph_caller; +#endif + r2 = [sp++]; rts; @@ -61,6 +83,7 @@ ENTRY(__mcount) call (p0); /* restore state and get out of dodge */ +.Lfinish_trace: rets = [sp++]; r1 = [sp++]; r0 = [sp++]; @@ -70,3 +93,48 @@ ENTRY(__mcount) _ftrace_stub: rts; ENDPROC(__mcount) + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +/* The prepare_ftrace_return() function is similar to the trace function + * except it takes a pointer to the location of the frompc. This is so + * the prepare_ftrace_return() can hijack it temporarily for probing + * purposes. + */ +ENTRY(_ftrace_graph_caller) + /* save first/second function arg and the return register */ + [--sp] = r0; + [--sp] = r1; + [--sp] = rets; + + r0 = fp; + r1 = rets; + r0 += 4; + r1 += -MCOUNT_INSN_SIZE; + call _prepare_ftrace_return; + + jump .Lfinish_trace; +ENDPROC(_ftrace_graph_caller) + +/* Undo the rewrite caused by ftrace_graph_caller(). The common function + * ftrace_return_to_handler() will return the original rets so we can + * restore it and be on our way. + */ +ENTRY(_return_to_handler) + /* make sure original return values are saved */ + [--sp] = p0; + [--sp] = r0; + [--sp] = r1; + + /* get original return address */ + call _ftrace_return_to_handler; + rets = r0; + + /* anomaly 05000371 - make sure we have at least three instructions + * between rets setting and the return + */ + r1 = [sp++]; + r0 = [sp++]; + p0 = [sp++]; + rts; +ENDPROC(_return_to_handler) +#endif diff --git a/arch/blackfin/kernel/ftrace.c b/arch/blackfin/kernel/ftrace.c new file mode 100644 index 00000000000..905bfc40a00 --- /dev/null +++ b/arch/blackfin/kernel/ftrace.c @@ -0,0 +1,42 @@ +/* + * ftrace graph code + * + * Copyright (C) 2009 Analog Devices Inc. + * Licensed under the GPL-2 or later. + */ + +#include <linux/ftrace.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <asm/atomic.h> + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + +/* + * Hook the return address and push it in the stack of return addrs + * in current thread info. + */ +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) +{ + struct ftrace_graph_ent trace; + unsigned long return_hooker = (unsigned long)&return_to_handler; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + if (ftrace_push_return_trace(*parent, self_addr, &trace.depth) == -EBUSY) + return; + + trace.func = self_addr; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) { + current->curr_ret_stack--; + return; + } + + /* all is well in the world ! hijack RETS ... */ + *parent = return_hooker; +} + +#endif diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S index 119fbdb4647..6ac307ca0d8 100644 --- a/arch/blackfin/kernel/vmlinux.lds.S +++ b/arch/blackfin/kernel/vmlinux.lds.S @@ -54,6 +54,7 @@ SECTIONS SCHED_TEXT #endif LOCK_TEXT + IRQENTRY_TEXT KPROBES_TEXT *(.text.*) *(.fixup) |