From patchwork Sat Jul 9 10:57:22 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tixy X-Patchwork-Id: 959232 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p69B8JVJ027658 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 9 Jul 2011 11:08:40 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QfVKy-0005vy-N6; Sat, 09 Jul 2011 11:04:42 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QfVKu-0006BC-IA; Sat, 09 Jul 2011 11:04:36 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QfVEY-0004Pn-H8 for linux-arm-kernel@canuck.infradead.org; Sat, 09 Jul 2011 10:58:02 +0000 Received: from smarthost03.mail.zen.net.uk ([212.23.3.142]) by casper.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QfVEQ-0006EP-Sx for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:58:00 +0000 Received: from [82.69.122.217] (helo=plug1) by smarthost03.mail.zen.net.uk with esmtpsa (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from ) id 1QfVEQ-0005gh-6o for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:57:54 +0000 Received: from [192.168.2.20] (helo=computer2) by plug1 with esmtp (Exim 4.72) (envelope-from ) id 1QfVEM-0003hc-QC for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 11:57:51 +0100 Received: from tixy by computer2 with local (Exim 4.72) (envelope-from ) id 1QfVEM-0005Um-Iw for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 11:57:50 +0100 From: Tixy To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 35/51] ARM: kprobes: Add load_write_pc() Date: Sat, 9 Jul 2011 11:57:22 +0100 Message-Id: <1310209058-20980-36-git-send-email-tixy@yxit.co.uk> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1310209058-20980-1-git-send-email-tixy@yxit.co.uk> References: <1310209058-20980-1-git-send-email-tixy@yxit.co.uk> X-Originating-Smarthost03-IP: [82.69.122.217] X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110709_115755_676018_56169BB4 X-CRM114-Status: GOOD ( 15.79 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2-r929478 on casper.infradead.org summary: Content analysis details: (-1.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.23.3.142 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Sat, 09 Jul 2011 11:08:40 +0000 (UTC) From: Jon Medhurst This writes a value to PC which was obtained as the result of a LDR or LDM instruction. For ARMv5T and later this must perform interworking. Signed-off-by: Jon Medhurst --- arch/arm/kernel/kprobes.h | 24 ++++++++++++++++++++++++ arch/arm/kernel/kprobes-common.c | 15 +++++++++++++++ 2 files changed, 39 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h index 12627a3..5d6bf0d 100644 --- a/arch/arm/kernel/kprobes.h +++ b/arch/arm/kernel/kprobes.h @@ -109,6 +109,30 @@ static inline void __kprobes bx_write_pc(long pcv, struct pt_regs *regs) regs->ARM_pc = pcv; } + +#if __LINUX_ARM_ARCH__ >= 6 + +/* Kernels built for >= ARMv6 should never run on <= ARMv5 hardware, so... */ +#define load_write_pc_interworks true +#define test_load_write_pc_interworking() + +#else /* __LINUX_ARM_ARCH__ < 6 */ + +/* We need run-time testing to determine if load_write_pc() should interwork. */ +extern bool load_write_pc_interworks; +void __init test_load_write_pc_interworking(void); + +#endif + +static inline void __kprobes load_write_pc(long pcv, struct pt_regs *regs) +{ + if (load_write_pc_interworks) + bx_write_pc(pcv, regs); + else + regs->ARM_pc = pcv; +} + + void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs); void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs); diff --git a/arch/arm/kernel/kprobes-common.c b/arch/arm/kernel/kprobes-common.c index 84c0c74..41e8218 100644 --- a/arch/arm/kernel/kprobes-common.c +++ b/arch/arm/kernel/kprobes-common.c @@ -45,9 +45,24 @@ void __init find_str_pc_offset(void) #endif /* !find_str_pc_offset */ +#ifndef test_load_write_pc_interworking + +bool load_write_pc_interworks; + +void __init test_load_write_pc_interworking(void) +{ + int arch = cpu_architecture(); + BUG_ON(arch == CPU_ARCH_UNKNOWN); + load_write_pc_interworks = arch >= CPU_ARCH_ARMv5T; +} + +#endif /* !test_load_write_pc_interworking */ + + void __init arm_kprobe_decode_init(void) { find_str_pc_offset(); + test_load_write_pc_interworking(); }