diff options
Diffstat (limited to 'arch/parisc/kernel/ftrace.c')
| -rw-r--r-- | arch/parisc/kernel/ftrace.c | 146 |
1 files changed, 23 insertions, 123 deletions
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 559d400f9385..b13f9ec6f294 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -1,6 +1,6 @@ /* * Code for tracing calls in Linux kernel. - * Copyright (C) 2009 Helge Deller <deller@gmx.de> + * 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> @@ -13,104 +13,21 @@ #include <linux/init.h> #include <linux/ftrace.h> +#include <asm/assembly.h> #include <asm/sections.h> #include <asm/ftrace.h> - #ifdef CONFIG_FUNCTION_GRAPH_TRACER - -/* Add a function return address to the trace stack on thread info.*/ -static int push_return_trace(unsigned long ret, unsigned long long time, - unsigned long func, int *depth) -{ - int index; - - if (!current->ret_stack) - return -EBUSY; - - /* The return trace stack is full */ - if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) { - atomic_inc(¤t->trace_overrun); - return -EBUSY; - } - - index = ++current->curr_ret_stack; - barrier(); - current->ret_stack[index].ret = ret; - current->ret_stack[index].func = func; - current->ret_stack[index].calltime = time; - *depth = index; - - return 0; -} - -/* Retrieve a function return address to the trace stack on thread info.*/ -static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) -{ - int index; - - index = current->curr_ret_stack; - - if (unlikely(index < 0)) { - ftrace_graph_stop(); - WARN_ON(1); - /* Might as well panic, otherwise we have no where to go */ - *ret = (unsigned long) - dereference_function_descriptor(&panic); - return; - } - - *ret = current->ret_stack[index].ret; - trace->func = current->ret_stack[index].func; - trace->calltime = current->ret_stack[index].calltime; - trace->overrun = atomic_read(¤t->trace_overrun); - trace->depth = index; - barrier(); - current->curr_ret_stack--; - -} - -/* - * Send the trace to the ring-buffer. - * @return the original return address. - */ -unsigned long ftrace_return_to_handler(unsigned long retval0, - unsigned long retval1) -{ - struct ftrace_graph_ret trace; - unsigned long ret; - - pop_return_trace(&trace, &ret); - trace.rettime = local_clock(); - ftrace_graph_return(&trace); - - if (unlikely(!ret)) { - ftrace_graph_stop(); - WARN_ON(1); - /* Might as well panic. What else to do? */ - ret = (unsigned long) - dereference_function_descriptor(&panic); - } - - /* HACK: we hand over the old functions' return values - in %r23 and %r24. Assembly in entry.S will take care - and move those to their final registers %ret0 and %ret1 */ - asm( "copy %0, %%r23 \n\t" - "copy %1, %%r24 \n" : : "r" (retval0), "r" (retval1) ); - - return ret; -} - /* * 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) +static void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) { unsigned long old; - unsigned long long calltime; struct ftrace_graph_ent trace; + extern int parisc_return_to_handler; if (unlikely(ftrace_graph_is_dead())) return; @@ -119,64 +36,47 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) return; old = *parent; - *parent = (unsigned long) - dereference_function_descriptor(&return_to_handler); - if (unlikely(!__kernel_text_address(old))) { - ftrace_graph_stop(); - *parent = old; - WARN_ON(1); - return; - } - - calltime = local_clock(); + trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; - if (push_return_trace(old, calltime, - self_addr, &trace.depth) == -EBUSY) { - *parent = old; + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) return; - } - trace.func = self_addr; + if (ftrace_push_return_trace(old, self_addr, &trace.depth, + 0 ) == -EBUSY) + return; - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) { - current->curr_ret_stack--; - *parent = old; - } + /* activate parisc_return_to_handler() as return point */ + *parent = (unsigned long) &parisc_return_to_handler; } - #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ - -void ftrace_function_trampoline(unsigned long parent, +void notrace ftrace_function_trampoline(unsigned long parent, unsigned long self_addr, unsigned long org_sp_gr3) { - extern ftrace_func_t ftrace_trace_function; + 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) { - ftrace_trace_function(parent, self_addr); + /* 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_entry && ftrace_graph_return) { - unsigned long sp; + if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub || + ftrace_graph_entry != ftrace_graph_entry_stub) { unsigned long *parent_rp; - asm volatile ("copy %%r30, %0" : "=r"(sp)); - /* sanity check: is stack pointer which we got from - assembler function in entry.S in a reasonable - range compared to current stack pointer? */ - if ((sp - org_sp_gr3) > 0x400) - return; - /* calculate pointer to %rp in stack */ - parent_rp = (unsigned long *) org_sp_gr3 - 0x10; + 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; } |