From mboxrd@z Thu Jan 1 00:00:00 1970 From: wade_farnsworth@mentor.com (Wade Farnsworth) Date: Wed, 15 Aug 2012 08:14:20 -0700 Subject: [PATCH v2] ARM: support syscall tracing Message-ID: <502BBCCC.1020006@mentor.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org As specified by ftrace-design.txt, TIF_SYSCALL_TRACEPOINT was added, as well as NR_syscalls in asm/unistd.h. Additionally, __sys_trace was modified to call trace_sys_enter and trace_sys_exit when appropriate. Tests #2 - #4 of "perf test" now complete successfully. Signed-off-by: Steven Walter Signed-off-by: Wade Farnsworth --- This patch is an update of one I posted some months ago. It has been rebased to Linus's current master branch. - v2: Implemented changes suggested by Will: - Folded _TIF_SYSCALL_TRACEPOINT into _TIF_SYSCALL_WORK to save an instruction in entry-common.S. - Moved calls to trace_sys_{enter,exit} to syscall_trace_{enter,exit}. arch/arm/Kconfig | 1 + arch/arm/include/asm/syscall.h | 4 ++++ arch/arm/include/asm/thread_info.h | 4 +++- arch/arm/include/asm/unistd.h | 8 ++++++++ arch/arm/kernel/entry-common.S | 11 ++++++++++- arch/arm/kernel/ptrace.c | 20 +++++++++++++++----- 6 files changed, 41 insertions(+), 7 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e91c7cd..983e9eb 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -16,6 +16,7 @@ config ARM select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_KGDB select HAVE_ARCH_TRACEHOOK + select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES if !XIP_KERNEL select HAVE_KRETPROBES if (HAVE_KPROBES) select HAVE_FUNCTION_TRACER if (!XIP_KERNEL) diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h index c334a23..47486a4 100644 --- a/arch/arm/include/asm/syscall.h +++ b/arch/arm/include/asm/syscall.h @@ -9,6 +9,10 @@ #include +#include + +#define NR_syscalls (__NR_syscalls) + extern const unsigned long sys_call_table[]; static inline int syscall_get_nr(struct task_struct *task, diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index af7b0bd..5ded667 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -148,6 +148,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, #define TIF_NOTIFY_RESUME 2 /* callback before returning to user */ #define TIF_SYSCALL_TRACE 8 #define TIF_SYSCALL_AUDIT 9 +#define TIF_SYSCALL_TRACEPOINT 10 #define TIF_POLLING_NRFLAG 16 #define TIF_USING_IWMMXT 17 #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ @@ -160,12 +161,13 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *, #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) +#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) /* Checks for any syscall work in entry-common.S */ -#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT) +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT) /* * Change these and you break ASM code in entry-common.S diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 0cab47d..a566ec2 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -406,6 +406,14 @@ #define __NR_process_vm_writev (__NR_SYSCALL_BASE+377) /* + * This may need to be greater than __NR_last_syscall+1 in order to + * account for the padding in the syscall table + */ +#ifdef __KERNEL__ +#define __NR_syscalls (380) +#endif /* __KERNEL__ */ + +/* * The following SWIs are ARM private. */ #define __ARM_NR_BASE (__NR_SYSCALL_BASE+0x0f0000) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 978eac5..b032c94 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -94,6 +94,15 @@ ENDPROC(ret_from_fork) .equ NR_syscalls,0 #define CALL(x) .equ NR_syscalls,NR_syscalls+1 #include "calls.S" + +/* + * Ensure that the system call table is equal to __NR_syscalls, + * which is the value the rest of the system sees + */ +.ifne NR_syscalls - __NR_syscalls +.error "__NR_syscalls is not equal to the size of the syscall table" +.endif + #undef CALL #define CALL(x) .long x @@ -415,7 +424,7 @@ local_restart: 1: #endif - tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? + tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? bne __sys_trace cmp scno, #NR_syscalls @ check upper syscall limit diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 3e0fc5f..4e82fc1 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -30,6 +30,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + #define REG_PC 15 #define REG_PSR 16 /* @@ -918,7 +921,8 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, { unsigned long ip; - if (!test_thread_flag(TIF_SYSCALL_TRACE)) + if (!test_thread_flag(TIF_SYSCALL_TRACE) && + !test_thread_flag(TIF_SYSCALL_TRACEPOINT)) return scno; current_thread_info()->syscall = scno; @@ -930,10 +934,12 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, ip = regs->ARM_ip; regs->ARM_ip = dir; - if (dir == PTRACE_SYSCALL_EXIT) - tracehook_report_syscall_exit(regs, 0); - else if (tracehook_report_syscall_entry(regs)) - current_thread_info()->syscall = -1; + if (test_thread_flag(TIF_SYSCALL_TRACE)) { + if (dir == PTRACE_SYSCALL_EXIT) + tracehook_report_syscall_exit(regs, 0); + else if (tracehook_report_syscall_entry(regs)) + current_thread_info()->syscall = -1; + } regs->ARM_ip = ip; return current_thread_info()->syscall; @@ -942,6 +948,8 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno, asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) { int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER); + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_enter(regs, ret); audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3); return ret; @@ -950,6 +958,8 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) asmlinkage int syscall_trace_exit(struct pt_regs *regs, int scno) { int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_EXIT); + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) + trace_sys_exit(regs, ret); audit_syscall_exit(regs); return ret; } -- 1.7.0.4