From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dmitry V. Levin" Subject: [PATCH v4 1/2] ptrace: save the type of syscall-stop in ptrace_message Date: Wed, 28 Nov 2018 16:06:01 +0300 Message-ID: <20181128130601.GC28206@altlinux.org> References: <20181128130439.GB28206@altlinux.org> Reply-To: strace development discussions Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20181128130439.GB28206-u2l5PoMzF/Vg9hUCZPvPmw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: strace-devel-bounces-3+4lAyCyj6AWlMsSdNXQLw@public.gmane.org Sender: "Strace-devel" To: Oleg Nesterov , Andy Lutomirski Cc: Kees Cook , Jann Horn , Michael Ellerman , Eugene Syromyatnikov , Steven Rostedt , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ingo Molnar , strace-devel-3+4lAyCyj6AWlMsSdNXQLw@public.gmane.org List-Id: linux-api@vger.kernel.org From: Elvira Khabirova Define two constants, PTRACE_EVENTMSG_SYSCALL_ENTRY and PTRACE_EVENTMSG_SYSCALL_EXIT, and place them in ptrace_message for the duration of syscall-stops. This way ptracers can distinguish syscall-enter-stops from syscall-exit-stops using PTRACE_GETEVENTMSG request. Signed-off-by: Elvira Khabirova Signed-off-by: Dmitry V. Levin --- include/linux/tracehook.h | 9 ++++++--- include/uapi/linux/ptrace.h | 10 ++++++++++ 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 40b0b4c1bf7b..633a83fe7051 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -57,13 +57,15 @@ struct linux_binprm; /* * ptrace report for syscall entry and exit looks identical. */ -static inline int ptrace_report_syscall(struct pt_regs *regs) +static inline int ptrace_report_syscall(struct pt_regs *regs, + unsigned long message) { int ptrace = current->ptrace; if (!(ptrace & PT_PTRACED)) return 0; + current->ptrace_message = message; ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); /* @@ -76,6 +78,7 @@ static inline int ptrace_report_syscall(struct pt_regs *regs) current->exit_code = 0; } + current->ptrace_message = 0; return fatal_signal_pending(current); } @@ -101,7 +104,7 @@ static inline int ptrace_report_syscall(struct pt_regs *regs) static inline __must_check int tracehook_report_syscall_entry( struct pt_regs *regs) { - return ptrace_report_syscall(regs); + return ptrace_report_syscall(regs, PTRACE_EVENTMSG_SYSCALL_ENTRY); } /** @@ -126,7 +129,7 @@ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) if (step) user_single_step_report(regs); else - ptrace_report_syscall(regs); + ptrace_report_syscall(regs, PTRACE_EVENTMSG_SYSCALL_EXIT); } /** diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h index d5a1b8a492b9..cb138902d042 100644 --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -104,6 +104,16 @@ struct seccomp_metadata { #define PTRACE_O_MASK (\ 0x000000ff | PTRACE_O_EXITKILL | PTRACE_O_SUSPEND_SECCOMP) +/* + * These values are stored in task->ptrace_message by tracehook_report_syscall_* + * to describe current syscall-stop. + * + * Values for these constants are chosen so that they do not appear + * in task->ptrace_message by other means. + */ +#define PTRACE_EVENTMSG_SYSCALL_ENTRY 0x80000000U +#define PTRACE_EVENTMSG_SYSCALL_EXIT 0x90000000U + #include -- ldv -- Strace-devel mailing list Strace-devel-3+4lAyCyj6AWlMsSdNXQLw@public.gmane.org https://lists.strace.io/mailman/listinfo/strace-devel