Commit fb0b5490 authored by Sergey Matyukevich's avatar Sergey Matyukevich Committed by Vineet Gupta
Browse files

ARC: implement syscall tracepoints 



Implement all the bits required to support HAVE_SYSCALL_TRACEPOINTS
according to Documentation/trace/ftrace-design.rst.

Signed-off-by: default avatarSergey Matyukevich <sergey.matyukevich@synopsys.com>
Signed-off-by: default avatarVineet Gupta <vgupta@kernel.org>
parent b3bbf6a7

arch/arc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ config ARC 
	select HAVE_REGS_AND_STACK_ACCESS_API

	select HAVE_MOD_ARCH_SPECIFIC

	select HAVE_PERF_EVENTS

	select HAVE_SYSCALL_TRACEPOINTS

	select IRQ_DOMAIN

	select MODULES_USE_ELF_RELA

	select OF

arch/arc/include/asm/syscall.h

+2 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 
#include <asm/unistd.h>

#include <asm/ptrace.h>		/* in_syscall() */



extern void *sys_call_table[];



static inline long

syscall_get_nr(struct task_struct *task, struct pt_regs *regs)

{

arch/arc/include/asm/thread_info.h

+4 −1
Original line number Diff line number Diff line
@@ -78,9 +78,9 @@ static inline __attribute_const__ struct thread_info *current_thread_info(void) 
#define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */

#define TIF_NOTIFY_SIGNAL	5	/* signal notifications exist */

#define TIF_SYSCALL_TRACE	15	/* syscall trace active */



/* true if poll_idle() is polling TIF_NEED_RESCHED */

#define TIF_MEMDIE		16

#define TIF_SYSCALL_TRACEPOINT	17	/* syscall tracepoint instrumentation */



#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)

#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
@@ -89,11 +89,14 @@ static inline __attribute_const__ struct thread_info *current_thread_info(void) 
#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)

#define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)

#define _TIF_MEMDIE		(1<<TIF_MEMDIE)

#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)



/* work to do on interrupt/exception return */

#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \

				 _TIF_NOTIFY_RESUME | _TIF_NOTIFY_SIGNAL)



#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)



/*

 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.

 * SYSCALL_TRACE is anyway separately/unconditionally tested right after a

arch/arc/kernel/entry.S

+6 −6
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ ENTRY(sys_clone_wrapper) 
	DISCARD_CALLEE_SAVED_USER



	GET_CURR_THR_INFO_FLAGS   r10

	btst r10, TIF_SYSCALL_TRACE

	and.f 0, r10, _TIF_SYSCALL_WORK

	bnz   tracesys_exit



	b .Lret_from_system_call
@@ -41,7 +41,7 @@ ENTRY(sys_clone3_wrapper) 
	DISCARD_CALLEE_SAVED_USER



	GET_CURR_THR_INFO_FLAGS   r10

	btst r10, TIF_SYSCALL_TRACE

	and.f 0, r10, _TIF_SYSCALL_WORK

	bnz   tracesys_exit



	b .Lret_from_system_call
@@ -247,7 +247,7 @@ ENTRY(EV_Trap) 


	; If syscall tracing ongoing, invoke pre-post-hooks

	GET_CURR_THR_INFO_FLAGS   r10

	btst r10, TIF_SYSCALL_TRACE

	and.f 0, r10, _TIF_SYSCALL_WORK

	bnz   tracesys  ; this never comes back



	;============ Normal syscall case

arch/arc/kernel/ptrace.c

+18 −3
Original line number Diff line number Diff line
@@ -9,6 +9,9 @@ 
#include <linux/unistd.h>

#include <linux/elf.h>



#define CREATE_TRACE_POINTS

#include <trace/events/syscalls.h>



struct pt_regs_offset {

	const char *name;

	int offset;
@@ -340,15 +343,27 @@ long arch_ptrace(struct task_struct *child, long request, 


asmlinkage int syscall_trace_entry(struct pt_regs *regs)

{

	if (test_thread_flag(TIF_SYSCALL_TRACE))

		if (ptrace_report_syscall_entry(regs))

			return ULONG_MAX;



#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS

	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))

		trace_sys_enter(regs, syscall_get_nr(current, regs));

#endif



	return regs->r8;

}



asmlinkage void syscall_trace_exit(struct pt_regs *regs)

{

	if (test_thread_flag(TIF_SYSCALL_TRACE))

		ptrace_report_syscall_exit(regs, 0);



#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS

	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))

		trace_sys_exit(regs, regs_return_value(regs));

#endif

}



int regs_query_register_offset(const char *name)