Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753339AbaBYPAt (ORCPT ); Tue, 25 Feb 2014 10:00:49 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:63216 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752595AbaBYPAr (ORCPT ); Tue, 25 Feb 2014 10:00:47 -0500 Date: Tue, 25 Feb 2014 15:00:07 +0000 From: Will Deacon To: AKASHI Takahiro Cc: "viro@zeniv.linux.org.uk" , "eparis@redhat.com" , "rgb@redhat.com" , Catalin Marinas , "dsaxena@linaro.org" , "arndb@arndb.de" , "linux-arm-kernel@lists.infradead.org" , "linaro-kernel@lists.linaro.org" , "linux-kernel@vger.kernel.org" , "linux-audit@redhat.com" Subject: Re: [PATCH v2 1/1] arm64: make a single hook to syscall_trace() for all syscall features Message-ID: <20140225150007.GB23136@mudshark.cambridge.arm.com> References: <1391767651-5296-1-git-send-email-takahiro.akashi@linaro.org> <1393319683-2707-1-git-send-email-takahiro.akashi@linaro.org> <1393319683-2707-2-git-send-email-takahiro.akashi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1393319683-2707-2-git-send-email-takahiro.akashi@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 25, 2014 at 09:14:43AM +0000, AKASHI Takahiro wrote: > Currently syscall_trace() is called only for ptrace. > With additional TIF_xx flags defined, it is now called in all the cases > of audit, ftrace and seccomp in addition to ptrace. > > Signed-off-by: AKASHI Takahiro > Acked-by: Richard Guy Briggs > --- > arch/arm64/include/asm/thread_info.h | 13 ++++++++++ > arch/arm64/kernel/entry.S | 5 ++-- > arch/arm64/kernel/ptrace.c | 45 +++++++++++++++++----------------- > 3 files changed, 38 insertions(+), 25 deletions(-) > > diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h > index 720e70b..0a8b2a9 100644 > --- a/arch/arm64/include/asm/thread_info.h > +++ b/arch/arm64/include/asm/thread_info.h > @@ -91,6 +91,9 @@ static inline struct thread_info *current_thread_info(void) > /* > * thread information flags: > * TIF_SYSCALL_TRACE - syscall trace active > + * TIF_SYSCALL_TRACEPOINT - syscall tracepoint for ftrace > + * TIF_SYSCALL_AUDIT - syscall auditing > + * TIF_SECOMP - syscall secure computing > * TIF_SIGPENDING - signal pending > * TIF_NEED_RESCHED - rescheduling necessary > * TIF_NOTIFY_RESUME - callback before returning to user > @@ -101,6 +104,9 @@ static inline struct thread_info *current_thread_info(void) > #define TIF_NEED_RESCHED 1 > #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_SECCOMP 11 > #define TIF_POLLING_NRFLAG 16 > #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ > #define TIF_FREEZE 19 > @@ -112,10 +118,17 @@ static inline struct thread_info *current_thread_info(void) > #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) > #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) > #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_SECCOMP (1 << TIF_SECCOMP) > #define _TIF_32BIT (1 << TIF_32BIT) > > #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ > _TIF_NOTIFY_RESUME) > > +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ > + _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP) > + > #endif /* __KERNEL__ */ > #endif /* __ASM_THREAD_INFO_H */ > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 0d7b789..6d613cd 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -630,8 +630,9 @@ el0_svc_naked: // compat entry point > enable_irq > > get_thread_info tsk > - ldr x16, [tsk, #TI_FLAGS] // check for syscall tracing > - tbnz x16, #TIF_SYSCALL_TRACE, __sys_trace // are we tracing syscalls? > + ldr x16, [tsk, #TI_FLAGS] // check for syscall hooks > + tst x16, #_TIF_SYSCALL_WORK > + b.ne __sys_trace > adr lr, ret_fast_syscall // return address > cmp scno, sc_nr // check upper syscall limit > b.hs ni_sys All looks fine up to here. > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index 6a8928b..c70133e 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -1062,31 +1062,30 @@ asmlinkage int syscall_trace(int dir, struct pt_regs *regs) > { > unsigned long saved_reg; > > - if (!test_thread_flag(TIF_SYSCALL_TRACE)) > - return regs->syscallno; > - > - if (is_compat_task()) { > - /* AArch32 uses ip (r12) for scratch */ > - saved_reg = regs->regs[12]; > - regs->regs[12] = dir; > - } else { > - /* > - * Save X7. X7 is used to denote syscall entry/exit: > - * X7 = 0 -> entry, = 1 -> exit > - */ > - saved_reg = regs->regs[7]; > - regs->regs[7] = dir; > - } > + if (test_thread_flag(TIF_SYSCALL_TRACE)) { > + if (is_compat_task()) { > + /* AArch32 uses ip (r12) for scratch */ > + saved_reg = regs->regs[12]; > + regs->regs[12] = dir; > + } else { > + /* > + * Save X7. X7 is used to denote syscall entry/exit: > + * X7 = 0 -> entry, = 1 -> exit > + */ > + saved_reg = regs->regs[7]; > + regs->regs[7] = dir; > + } > > - if (dir) > - tracehook_report_syscall_exit(regs, 0); > - else if (tracehook_report_syscall_entry(regs)) > - regs->syscallno = ~0UL; > + if (dir) > + tracehook_report_syscall_exit(regs, 0); > + else if (tracehook_report_syscall_entry(regs)) > + regs->syscallno = ~0UL; > > - if (is_compat_task()) > - regs->regs[12] = saved_reg; > - else > - regs->regs[7] = saved_reg; > + if (is_compat_task()) > + regs->regs[12] = saved_reg; > + else > + regs->regs[7] = saved_reg; > + } Aren't these changes (to ptrace.c) just a giant NOP? Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/