On Mon, 2011-02-07 at 21:10 -0500, Steven Rostedt wrote:
> Ben,
>
> How do you want to work this? Do you want to ack it and I take this
> patch with the others through the tracing tree, or do you want to wait
> till the tracing tree gets updated into mainline and then pull this in
> though the ppc tree. As this touches a bit of the ppc side.
I was waiting to see what you were up to vs. the rest of the series :-)
I still need to review that one closely, at which point I'm happy for
you to take it.
Cheers,
Ben.
> -- Steve
>
>
> On Thu, 2011-02-03 at 14:27 +1100, Ian Munsie wrote:
> > From: Ian Munsie <imun...@au.ibm.com>
> >
> > This patch implements the raw syscall tracepoints on PowerPC and exports
> > them for ftrace syscalls to use.
> >
> > To minimise reworking existing code, I slightly re-ordered the thread
> > info flags such that the new TIF_SYSCALL_TRACEPOINT bit would still fit
> > within the 16 bits of the andi. instruction's UI field. The instructions
> > in question are in /arch/powerpc/kernel/entry_{32,64}.S to and the
> > _TIF_SYSCALL_T_OR_A with the thread flags to see if system call tracing
> > is enabled.
> >
> > In the case of 64bit PowerPC, arch_syscall_addr and
> > arch_syscall_match_sym_name are overridden to allow ftrace syscalls to
> > work given the unusual system call table structure and symbol names that
> > start with a period.
> >
> > Signed-off-by: Ian Munsie <imun...@au1.ibm.com>
> > ---
> > arch/powerpc/Kconfig | 1 +
> > arch/powerpc/include/asm/ftrace.h | 14 ++++++++++++++
> > arch/powerpc/include/asm/syscall.h | 5 +++++
> > arch/powerpc/include/asm/thread_info.h | 7 +++++--
> > arch/powerpc/kernel/Makefile | 1 +
> > arch/powerpc/kernel/ftrace.c | 8 ++++++++
> > arch/powerpc/kernel/ptrace.c | 10 ++++++++++
> > 7 files changed, 44 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 7d69e9b..a0e8e02 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -134,6 +134,7 @@ config PPC
> > select HAVE_GENERIC_HARDIRQS
> > select HAVE_SPARSE_IRQ
> > select IRQ_PER_CPU
> > + select HAVE_SYSCALL_TRACEPOINTS
> >
> > config EARLY_PRINTK
> > bool
> > diff --git a/arch/powerpc/include/asm/ftrace.h
> > b/arch/powerpc/include/asm/ftrace.h
> > index dde1296..169d039 100644
> > --- a/arch/powerpc/include/asm/ftrace.h
> > +++ b/arch/powerpc/include/asm/ftrace.h
> > @@ -60,4 +60,18 @@ struct dyn_arch_ftrace {
> >
> > #endif
> >
> > +#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) &&
> > !defined(__ASSEMBLY__)
> > +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
> > +static inline bool arch_syscall_match_sym_name(const char *sym, const char
> > *name)
> > +{
> > + /*
> > + * Compare the symbol name with the system call name. Skip the .sys or
> > .SyS
> > + * prefix from the symbol name and the sys prefix from the system call
> > name and
> > + * just match the rest. This is only needed on ppc64 since symbol names
> > on
> > + * 32bit do not start with a period so the generic function will work.
> > + */
> > + return !strcmp(sym + 4, name + 3);
> > +}
> > +#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 && !__ASSEMBLY__ */
> > +
> > #endif /* _ASM_POWERPC_FTRACE */
> > diff --git a/arch/powerpc/include/asm/syscall.h
> > b/arch/powerpc/include/asm/syscall.h
> > index 23913e9..b54b2ad 100644
> > --- a/arch/powerpc/include/asm/syscall.h
> > +++ b/arch/powerpc/include/asm/syscall.h
> > @@ -15,6 +15,11 @@
> >
> > #include <linux/sched.h>
> >
> > +/* ftrace syscalls requires exporting the sys_call_table */
> > +#ifdef CONFIG_FTRACE_SYSCALLS
> > +extern const unsigned long *sys_call_table;
> > +#endif /* CONFIG_FTRACE_SYSCALLS */
> > +
> > static inline long syscall_get_nr(struct task_struct *task,
> > struct pt_regs *regs)
> > {
> > diff --git a/arch/powerpc/include/asm/thread_info.h
> > b/arch/powerpc/include/asm/thread_info.h
> > index 65eb859..4403f09 100644
> > --- a/arch/powerpc/include/asm/thread_info.h
> > +++ b/arch/powerpc/include/asm/thread_info.h
> > @@ -110,7 +110,8 @@ static inline struct thread_info
> > *current_thread_info(void)
> > #define TIF_NOERROR 12 /* Force successful syscall
> > return */
> > #define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
> > #define TIF_FREEZE 14 /* Freezing for suspend */
> > -#define TIF_RUNLATCH 15 /* Is the runlatch enabled? */
> > +#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint
> > instrumentation */
> > +#define TIF_RUNLATCH 16 /* Is the runlatch enabled? */
> >
> > /* as above, but as bit values */
> > #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
> > @@ -127,8 +128,10 @@ static inline struct thread_info
> > *current_thread_info(void)
> > #define _TIF_NOERROR (1<<TIF_NOERROR)
> > #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
> > #define _TIF_FREEZE (1<<TIF_FREEZE)
> > +#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
> > #define _TIF_RUNLATCH (1<<TIF_RUNLATCH)
> > -#define _TIF_SYSCALL_T_OR_A
> > (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
> > +#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE |
> > _TIF_SYSCALL_AUDIT | \
> > + _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)
> >
> > #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
> > _TIF_NOTIFY_RESUME)
> > diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> > index 3bb2a3e..fe1ac47 100644
> > --- a/arch/powerpc/kernel/Makefile
> > +++ b/arch/powerpc/kernel/Makefile
> > @@ -105,6 +105,7 @@ obj64-$(CONFIG_AUDIT) += compat_audit.o
> >
> > obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
> > obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
> > +obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
> > obj-$(CONFIG_PERF_EVENTS) += perf_callchain.o
> >
> > obj-$(CONFIG_PPC_PERF_CTRS) += perf_event.o
> > diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
> > index ce1f3e4..bf99cfa 100644
> > --- a/arch/powerpc/kernel/ftrace.c
> > +++ b/arch/powerpc/kernel/ftrace.c
> > @@ -22,6 +22,7 @@
> > #include <asm/cacheflush.h>
> > #include <asm/code-patching.h>
> > #include <asm/ftrace.h>
> > +#include <asm/syscall.h>
> >
> >
> > #ifdef CONFIG_DYNAMIC_FTRACE
> > @@ -600,3 +601,10 @@ void prepare_ftrace_return(unsigned long *parent,
> > unsigned long self_addr)
> > }
> > }
> > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
> > +
> > +#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64)
> > +unsigned long __init arch_syscall_addr(int nr)
> > +{
> > + return sys_call_table[nr*2];
> > +}
> > +#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 */
> > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> > index 9065369..b6ff0cb 100644
> > --- a/arch/powerpc/kernel/ptrace.c
> > +++ b/arch/powerpc/kernel/ptrace.c
> > @@ -29,6 +29,7 @@
> > #include <linux/signal.h>
> > #include <linux/seccomp.h>
> > #include <linux/audit.h>
> > +#include <trace/syscall.h>
> > #ifdef CONFIG_PPC32
> > #include <linux/module.h>
> > #endif
> > @@ -40,6 +41,9 @@
> > #include <asm/pgtable.h>
> > #include <asm/system.h>
> >
> > +#define CREATE_TRACE_POINTS
> > +#include <trace/events/syscalls.h>
> > +
> > /*
> > * The parameter save area on the stack is used to store arguments being
> > passed
> > * to callee function and is located at fixed offset from stack pointer.
> > @@ -1691,6 +1695,9 @@ long do_syscall_trace_enter(struct pt_regs *regs)
> > */
> > ret = -1L;
> >
> > + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> > + trace_sys_enter(regs, regs->gpr[0]);
> > +
> > if (unlikely(current->audit_context)) {
> > #ifdef CONFIG_PPC64
> > if (!is_32bit_task())
> > @@ -1719,6 +1726,9 @@ void do_syscall_trace_leave(struct pt_regs *regs)
> >
> > audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
> > regs->result);
> >
> > + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> > + trace_sys_exit(regs, regs->result);
> > +
> > step = test_thread_flag(TIF_SINGLESTEP);
> > if (step || test_thread_flag(TIF_SYSCALL_TRACE))
> > tracehook_report_syscall_exit(regs, step);
>
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