From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753343Ab0FWKNB (ORCPT ); Wed, 23 Jun 2010 06:13:01 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:55499 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752263Ab0FWKEO (ORCPT ); Wed, 23 Jun 2010 06:04:14 -0400 From: "Ian Munsie" To: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Cc: Jason Baron , Frederic Weisbecker , Steven Rostedt , Ingo Molnar , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Ian Munsie , Ian Munsie , FUJITA Tomonori , Grant Likely , Andrew Morton , Anton Blanchard , Nathan Lynch , Andreas Schwab , Matt Mackall , Jiri Kosina , Kumar Gala , Scott Wood , Dave Kleikamp , David Gibson , Mahesh Salgaonkar , Masami Hiramatsu Subject: [PATCH 04/40] trace, powerpc: Implement raw syscall tracepoints on PowerPC Date: Wed, 23 Jun 2010 20:02:45 +1000 Message-Id: <1277287401-28571-5-git-send-email-imunsie@au1.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> References: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Munsie 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 --- arch/powerpc/Kconfig | 1 + 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 | 19 +++++++++++++++++++ arch/powerpc/kernel/ptrace.c | 10 ++++++++++ 6 files changed, 41 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 328774b..0d5c28d 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -141,6 +141,7 @@ config PPC select GENERIC_ATOMIC64 if PPC32 select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_SYSCALL_TRACEPOINTS config EARLY_PRINTK bool 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 +/* 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< #include #include +#include #ifdef CONFIG_DYNAMIC_FTRACE @@ -600,3 +601,21 @@ 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]; +} + +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. 32bit can use the generic + * function since their symbol names don't start with a period. + */ + return (!strcmp(sym + 4, name + 3)); +} +#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 */ diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 7a0c019..eb7eeb8 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -29,6 +29,7 @@ #include #include #include +#include #ifdef CONFIG_PPC32 #include #endif @@ -38,6 +39,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + /* * 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. @@ -1615,6 +1619,9 @@ 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 (!test_thread_flag(TIF_32BIT)) @@ -1643,6 +1650,9 @@ 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); -- 1.7.1