From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755436Ab1IGEr1 (ORCPT ); Wed, 7 Sep 2011 00:47:27 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:38461 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752321Ab1IGErX (ORCPT ); Wed, 7 Sep 2011 00:47:23 -0400 From: Denys Vlasenko To: Oleg Nesterov Subject: [PATCH v3] Fix clearing of task->ptrace if PTRACE_SETOPTIONS fails Date: Wed, 7 Sep 2011 06:45:00 +0200 User-Agent: KMail/1.8.2 Cc: Denys Vlasenko , Tejun Heo , linux-kernel@vger.kernel.org References: <201109042311.18793.vda.linux@googlemail.com> <1315327963.29637.1.camel@dhcp-25-63.brq.redhat.com> <20110906184346.GA25904@redhat.com> In-Reply-To: <20110906184346.GA25904@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201109070645.00481.vda.linux@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix clearing of task->ptrace if PTRACE_SETOPTIONS fails. If PTRACE_SETOPTIONS fails, options should not be affected. This patch makes it so. Every PTRACE_O_TRACEevent is defined to (1 << PTRACE_EVENT_event) instead of using explicit numeric constants, to ensure we don't mess up relationship between bit positions and event ids. While at it, simplify a few things: Exchange PT_TRACESYSGOOD and PT_PTRACE_CAP bit positions, which makes PT_option bits contiguous and therefore makes code in ptrace_setoptions() much simpler. PT_EVENT_FLAG_SHIFT was not particularly useful, PT_OPT_FLAG_SHIFT with value of PT_EVENT_FLAG_SHIFT-1 is easier to use. PT_TRACE_MASK constant is nuked, the only its use is replaced by (PTRACE_O_MASK << PT_OPT_FLAG_SHIFT). Signed-off-by: Denys Vlasenko diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 800f113..0911100 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -54,17 +54,6 @@ /* flags in @data for PTRACE_SEIZE */ #define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */ -/* options set using PTRACE_SETOPTIONS */ -#define PTRACE_O_TRACESYSGOOD 0x00000001 -#define PTRACE_O_TRACEFORK 0x00000002 -#define PTRACE_O_TRACEVFORK 0x00000004 -#define PTRACE_O_TRACECLONE 0x00000008 -#define PTRACE_O_TRACEEXEC 0x00000010 -#define PTRACE_O_TRACEVFORKDONE 0x00000020 -#define PTRACE_O_TRACEEXIT 0x00000040 - -#define PTRACE_O_MASK 0x0000007f - /* Wait extended result codes for the above trace options. */ #define PTRACE_EVENT_FORK 1 #define PTRACE_EVENT_VFORK 2 @@ -74,6 +63,17 @@ #define PTRACE_EVENT_EXIT 6 #define PTRACE_EVENT_STOP 7 +/* options set using PTRACE_SETOPTIONS */ +#define PTRACE_O_TRACESYSGOOD 1 +#define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK) +#define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK) +#define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE) +#define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC) +#define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE) +#define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT) + +#define PTRACE_O_MASK 0x0000007f + #include #ifdef __KERNEL__ @@ -88,13 +88,12 @@ #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ -#define PT_TRACESYSGOOD 0x00000004 -#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */ +#define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ +#define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */ -#define PT_EVENT_FLAG_SHIFT 4 -#define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1)) - +#define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) +#define PT_TRACESYSGOOD PT_EVENT_FLAG(0) #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) @@ -102,8 +101,6 @@ #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) -#define PT_TRACE_MASK 0x000003f4 - /* single stepping state bits (used on ARM and PA-RISC) */ #define PT_SINGLESTEP_BIT 31 #define PT_SINGLESTEP (1<ptrace &= ~PT_TRACE_MASK; - - if (data & PTRACE_O_TRACESYSGOOD) - child->ptrace |= PT_TRACESYSGOOD; - - if (data & PTRACE_O_TRACEFORK) - child->ptrace |= PT_TRACE_FORK; - - if (data & PTRACE_O_TRACEVFORK) - child->ptrace |= PT_TRACE_VFORK; - - if (data & PTRACE_O_TRACECLONE) - child->ptrace |= PT_TRACE_CLONE; - - if (data & PTRACE_O_TRACEEXEC) - child->ptrace |= PT_TRACE_EXEC; - - if (data & PTRACE_O_TRACEVFORKDONE) - child->ptrace |= PT_TRACE_VFORK_DONE; + if (data & ~(long)PTRACE_O_MASK) + return -EINVAL; - if (data & PTRACE_O_TRACEEXIT) - child->ptrace |= PT_TRACE_EXIT; + child->ptrace &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT); + child->ptrace |= (data << PT_OPT_FLAG_SHIFT); - return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; + return 0; } static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)