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-rw-r--r--arch/powerpc/kernel/Makefile9
-rw-r--r--arch/powerpc/kernel/entry_64.S58
-rw-r--r--arch/powerpc/kernel/ftrace.c79
-rw-r--r--arch/powerpc/kernel/process.c16
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S1
5 files changed, 153 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d1599211908..583ba6493a6 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -18,12 +18,10 @@ CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
-
-ifdef CONFIG_DYNAMIC_FTRACE
-# dynamic ftrace setup.
+# do not trace tracer code
CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
-endif
-
+# timers used by tracing
+CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog
endif
obj-y := cputable.o ptrace.o syscalls.o \
@@ -95,6 +93,7 @@ obj-$(CONFIG_AUDIT) += audit.o
obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 383ed6eb008..a32699e74c3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -931,13 +931,65 @@ _GLOBAL(_mcount)
ld r5,0(r5)
mtctr r5
bctrl
-
nop
+
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ b ftrace_graph_caller
+#endif
ld r0, 128(r1)
mtlr r0
addi r1, r1, 112
_GLOBAL(ftrace_stub)
blr
-#endif
-#endif
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ftrace_graph_caller:
+ /* load r4 with local address */
+ ld r4, 128(r1)
+ subi r4, r4, MCOUNT_INSN_SIZE
+
+ /* get the parent address */
+ ld r11, 112(r1)
+ addi r3, r11, 16
+
+ bl .prepare_ftrace_return
+ nop
+
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+ blr
+
+_GLOBAL(return_to_handler)
+ /* need to save return values */
+ std r4, -32(r1)
+ std r3, -24(r1)
+ /* save TOC */
+ std r2, -16(r1)
+ std r31, -8(r1)
+ mr r31, r1
+ stdu r1, -112(r1)
+
+ /* update the TOC */
+ LOAD_REG_IMMEDIATE(r4,ftrace_return_to_handler)
+ ld r2, 8(r4)
+
+ bl .ftrace_return_to_handler
+ nop
+
+ /* return value has real return address */
+ mtlr r3
+
+ ld r1, 0(r1)
+ ld r4, -32(r1)
+ ld r3, -24(r1)
+ ld r2, -16(r1)
+ ld r31, -8(r1)
+
+ /* Jump back to real return address */
+ blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 4112175183d..c9b1547f65a 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -5,6 +5,9 @@
*
* Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
*
+ * Added function graph tracer code, taken from x86 that was written
+ * by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
+ *
*/
#include <linux/spinlock.h>
@@ -20,8 +23,6 @@
#include <asm/code-patching.h>
#include <asm/ftrace.h>
-static unsigned int ftrace_nop = PPC_NOP_INSTR;
-
#ifdef CONFIG_PPC32
# define GET_ADDR(addr) addr
#else
@@ -29,6 +30,8 @@ static unsigned int ftrace_nop = PPC_NOP_INSTR;
# define GET_ADDR(addr) (*(unsigned long *)addr)
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+static unsigned int ftrace_nop = PPC_NOP_INSTR;
static unsigned int ftrace_calc_offset(long ip, long addr)
{
@@ -525,3 +528,75 @@ int __init ftrace_dyn_arch_init(void *data)
return 0;
}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#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)
+{
+ unsigned long old;
+ unsigned long long calltime;
+ int faulted;
+ struct ftrace_graph_ent trace;
+ unsigned long return_hooker = (unsigned long)
+ &return_to_handler;
+
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ return;
+
+ return_hooker = GET_ADDR(return_hooker);
+
+ /*
+ * Protect against fault, even if it shouldn't
+ * happen. This tool is too much intrusive to
+ * ignore such a protection.
+ */
+ asm volatile(
+ "1: " PPC_LL "%[old], 0(%[parent])\n"
+ "2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
+ " li %[faulted], 0\n"
+ "3:"
+
+ ".section .fixup, \"ax\"\n"
+ "4: li %[faulted], 1\n"
+ " b 3b\n"
+ ".previous\n"
+
+ ".section __ex_table,\"a\"\n"
+ PPC_LONG_ALIGN "\n"
+ PPC_LONG "1b,4b\n"
+ PPC_LONG "2b,4b\n"
+ ".previous"
+
+ : [old] "=r" (old), [faulted] "=r" (faulted)
+ : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
+ : "memory"
+ );
+
+ if (unlikely(faulted)) {
+ ftrace_graph_stop();
+ WARN_ON(1);
+ return;
+ }
+
+ calltime = cpu_clock(raw_smp_processor_id());
+
+ if (ftrace_push_return_trace(old, calltime,
+ self_addr, &trace.depth) == -EBUSY) {
+ *parent = old;
+ return;
+ }
+
+ trace.func = self_addr;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ current->curr_ret_stack--;
+ *parent = old;
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index fb7049c054c..8ede428e76c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -33,6 +33,7 @@
#include <linux/mqueue.h>
#include <linux/hardirq.h>
#include <linux/utsname.h>
+#include <linux/ftrace.h>
#include <linux/kernel_stat.h>
#include <asm/pgtable.h>
@@ -1008,6 +1009,14 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
unsigned long sp, ip, lr, newsp;
int count = 0;
int firstframe = 1;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ int curr_frame = current->curr_ret_stack;
+ extern void return_to_handler(void);
+ unsigned long addr = (unsigned long)return_to_handler;
+#ifdef CONFIG_PPC64
+ addr = *(unsigned long*)addr;
+#endif
+#endif
sp = (unsigned long) stack;
if (tsk == NULL)
@@ -1030,6 +1039,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
ip = stack[STACK_FRAME_LR_SAVE];
if (!firstframe || ip != lr) {
printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ip == addr && curr_frame >= 0) {
+ printk(" (%pS)",
+ (void *)current->ret_stack[curr_frame].ret);
+ curr_frame--;
+ }
+#endif
if (firstframe)
printk(" (unreliable)");
printk("\n");
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 161b9b9691f..895af44bf1f 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -58,6 +58,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
+ IRQENTRY_TEXT
#ifdef CONFIG_PPC32
*(.got1)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-30 12:41:22 +0000