87352d621b
commit a87532c78d291265efadc4b20a8c7a70cd59ea29 upstream.
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have parisc use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
78 lines
2 KiB
C
78 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Code for tracing calls in Linux kernel.
|
|
* Copyright (C) 2009-2016 Helge Deller <deller@gmx.de>
|
|
*
|
|
* based on code for x86 which is:
|
|
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
|
|
*
|
|
* future possible enhancements:
|
|
* - add CONFIG_DYNAMIC_FTRACE
|
|
* - add CONFIG_STACK_TRACER
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/ftrace.h>
|
|
|
|
#include <asm/assembly.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/ftrace.h>
|
|
|
|
|
|
#define __hot __attribute__ ((__section__ (".text.hot")))
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/*
|
|
* Hook the return address and push it in the stack of return addrs
|
|
* in current thread info.
|
|
*/
|
|
static void __hot prepare_ftrace_return(unsigned long *parent,
|
|
unsigned long self_addr)
|
|
{
|
|
unsigned long old;
|
|
extern int parisc_return_to_handler;
|
|
|
|
if (unlikely(ftrace_graph_is_dead()))
|
|
return;
|
|
|
|
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
|
|
return;
|
|
|
|
old = *parent;
|
|
|
|
if (!function_graph_enter(old, self_addr, 0, NULL))
|
|
/* activate parisc_return_to_handler() as return point */
|
|
*parent = (unsigned long) &parisc_return_to_handler;
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
void notrace __hot ftrace_function_trampoline(unsigned long parent,
|
|
unsigned long self_addr,
|
|
unsigned long org_sp_gr3)
|
|
{
|
|
extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */
|
|
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
|
|
|
|
if (ftrace_trace_function != ftrace_stub) {
|
|
/* struct ftrace_ops *op, struct pt_regs *regs); */
|
|
ftrace_trace_function(parent, self_addr, NULL, NULL);
|
|
return;
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
|
|
ftrace_graph_entry != ftrace_graph_entry_stub) {
|
|
unsigned long *parent_rp;
|
|
|
|
/* calculate pointer to %rp in stack */
|
|
parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET);
|
|
/* sanity check: parent_rp should hold parent */
|
|
if (*parent_rp != parent)
|
|
return;
|
|
|
|
prepare_ftrace_return(parent_rp, self_addr);
|
|
return;
|
|
}
|
|
#endif
|
|
}
|
|
|