#include <linux/string.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/kernel.h>
#include <asm/ftrace.h>
#include <asm/cacheflush.h>
#include <asm/unistd.h>
#include <trace/syscall.h>
+#ifdef CONFIG_DYNAMIC_FTRACE
static unsigned char ftrace_replaced_code[MCOUNT_INSN_SIZE];
static unsigned char ftrace_nop[4];
return 0;
}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+
+static int ftrace_mod(unsigned long ip, unsigned long old_addr,
+ unsigned long new_addr)
+{
+ unsigned char code[MCOUNT_INSN_SIZE];
+
+ if (probe_kernel_read(code, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (old_addr != __raw_readl((unsigned long *)code))
+ return -EINVAL;
+
+ __raw_writel(new_addr, ip);
+ return 0;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip, old_addr, new_addr;
+
+ ip = (unsigned long)(&ftrace_graph_call) + GRAPH_INSN_OFFSET;
+ old_addr = (unsigned long)(&skip_trace);
+ new_addr = (unsigned long)(&ftrace_graph_caller);
+
+ return ftrace_mod(ip, old_addr, new_addr);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip, old_addr, new_addr;
+
+ ip = (unsigned long)(&ftrace_graph_call) + GRAPH_INSN_OFFSET;
+ old_addr = (unsigned long)(&ftrace_graph_caller);
+ new_addr = (unsigned long)(&skip_trace);
+
+ return ftrace_mod(ip, old_addr, new_addr);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in the current thread info.
+ *
+ * This is the main routine for the function graph tracer. The function
+ * graph tracer essentially works like this:
+ *
+ * parent is the stack address containing self_addr's return address.
+ * We pull the real return address out of parent and store it in
+ * current's ret_stack. Then, we replace the return address on the stack
+ * with the address of return_to_handler. self_addr is the function that
+ * called mcount.
+ *
+ * When self_addr returns, it will jump to return_to_handler which calls
+ * ftrace_return_to_handler. ftrace_return_to_handler will pull the real
+ * return address off of current's ret_stack and jump to it.
+ */
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+{
+ unsigned long old;
+ int faulted, err;
+ struct ftrace_graph_ent trace;
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ /*
+ * Protect against fault, even if it shouldn't
+ * happen. This tool is too much intrusive to
+ * ignore such a protection.
+ */
+ __asm__ __volatile__(
+ "1: \n\t"
+ "mov.l @%2, %0 \n\t"
+ "2: \n\t"
+ "mov.l %3, @%2 \n\t"
+ "mov #0, %1 \n\t"
+ "3: \n\t"
+ ".section .fixup, \"ax\" \n\t"
+ "4: \n\t"
+ "mov.l 5f, %0 \n\t"
+ "jmp @%0 \n\t"
+ " mov #1, %1 \n\t"
+ ".balign 4 \n\t"
+ "5: .long 3b \n\t"
+ ".previous \n\t"
+ ".section __ex_table,\"a\" \n\t"
+ ".long 1b, 4b \n\t"
+ ".long 2b, 4b \n\t"
+ ".previous \n\t"
+ : "=&r" (old), "=r" (faulted)
+ : "r" (parent), "r" (return_hooker)
+ );
+
+ if (unlikely(faulted)) {
+ ftrace_graph_stop();
+ WARN_ON(1);
+ return;
+ }
+
+ err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
+ if (err == -EBUSY) {
+ __raw_writel(old, parent);
+ return;
+ }
+
+ trace.func = self_addr;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ current->curr_ret_stack--;
+ __raw_writel(old, parent);
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#ifdef CONFIG_FTRACE_SYSCALLS
jsr @r6
nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ mov.l .Lftrace_graph_return, r6
+ mov.l .Lftrace_stub, r7
+ cmp/eq r6, r7
+ bt 1f
+
+ mov.l .Lftrace_graph_caller, r0
+ jmp @r0
+ nop
+
+1:
+ mov.l .Lftrace_graph_entry, r6
+ mov.l .Lftrace_graph_entry_stub, r7
+ cmp/eq r6, r7
+ bt skip_trace
+
+ mov.l .Lftrace_graph_caller, r0
+ jmp @r0
+ nop
+
+ .align 2
+.Lftrace_graph_return:
+ .long ftrace_graph_return
+.Lftrace_graph_entry:
+ .long ftrace_graph_entry
+.Lftrace_graph_entry_stub:
+ .long ftrace_graph_entry_stub
+.Lftrace_graph_caller:
+ .long ftrace_graph_caller
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ .globl skip_trace
skip_trace:
MCOUNT_LEAVE()
.align 2
.Lftrace_trace_function:
- .long ftrace_trace_function
+ .long ftrace_trace_function
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/*
+ * NOTE: Do not move either ftrace_graph_call or ftrace_caller
+ * as this will affect the calculation of GRAPH_INSN_OFFSET.
+ */
+ .globl ftrace_graph_call
+ftrace_graph_call:
+ mov.l .Lskip_trace, r0
+ jmp @r0
+ nop
+
+ .align 2
+.Lskip_trace:
+ .long skip_trace
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
.globl ftrace_caller
ftrace_caller:
mov.l .Lfunction_trace_stop, r0
jsr @r6
nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ bra ftrace_graph_call
+ nop
+#else
MCOUNT_LEAVE()
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_DYNAMIC_FTRACE */
/*
.Lpanic_str:
.string "Stack error"
#endif /* CONFIG_STACK_DEBUG */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl ftrace_graph_caller
+ftrace_graph_caller:
+ mov.l 2f, r0
+ mov.l @r0, r0
+ tst r0, r0
+ bt 1f
+
+ mov.l 3f, r1
+ jmp @r1
+ nop
+1:
+ /*
+ * MCOUNT_ENTER() pushed 5 registers onto the stack, so
+ * the stack address containing our return address is
+ * r15 + 20.
+ */
+ mov #20, r0
+ add r15, r0
+ mov r0, r4
+
+ mov.l .Lprepare_ftrace_return, r0
+ jsr @r0
+ nop
+
+ MCOUNT_LEAVE()
+
+ .align 2
+2: .long function_trace_stop
+3: .long skip_trace
+.Lprepare_ftrace_return:
+ .long prepare_ftrace_return
+
+ .globl return_to_handler
+return_to_handler:
+ /*
+ * Save the return values.
+ */
+ mov.l r0, @-r15
+ mov.l r1, @-r15
+
+ mov #0, r4
+
+ mov.l .Lftrace_return_to_handler, r0
+ jsr @r0
+ nop
+
+ /*
+ * The return value from ftrace_return_handler has the real
+ * address that we should return to.
+ */
+ lds r0, pr
+ mov.l @r15+, r1
+ rts
+ mov.l @r15+, r0
+
+
+ .align 2
+.Lftrace_return_to_handler:
+ .long ftrace_return_to_handler
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff