From patchwork Sat Jul 9 10:57:26 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tixy X-Patchwork-Id: 959402 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p69BJBZM016116 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 9 Jul 2011 11:19:31 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QfVWA-0000X8-Ik; Sat, 09 Jul 2011 11:16:16 +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 1QfVVX-00007U-TI; Sat, 09 Jul 2011 11:15:35 +0000 Received: from queue01.mail.zen.net.uk ([212.23.3.234]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QfVVT-000078-L2 for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 11:15:32 +0000 Received: from [212.23.3.141] (helo=smarthost02.mail.zen.net.uk) by queue01.mail.zen.net.uk with esmtp (Exim 4.63) (envelope-from ) id 1QfVER-00006a-Hw for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:57:55 +0000 Received: from [82.69.122.217] (helo=plug1) by smarthost02.mail.zen.net.uk with esmtpsa (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from ) id 1QfVEQ-0005jB-7Y for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:57:55 +0000 Received: from [192.168.2.20] (helo=computer2) by plug1 with esmtp (Exim 4.72) (envelope-from ) id 1QfVEM-0003hg-W2 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-0005Uy-P2 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 39/51] ARM: kprobes: Decode 32-bit Thumb load/store dual and load/store exclusive instructions Date: Sat, 9 Jul 2011 11:57:26 +0100 Message-Id: <1310209058-20980-40-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-Smarthost02-IP: [82.69.122.217] X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110709_071531_941998_B3FCE1A5 X-CRM114-Status: GOOD ( 15.31 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.23.3.234 listed in list.dnswl.org] 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 (demeter1.kernel.org [140.211.167.41]); Sat, 09 Jul 2011 11:19:32 +0000 (UTC) From: Jon Medhurst We reject probing of load/store exclusive instructions because any emulation routine could never succeed in gaining exclusive access as the exception framework clears the exclusivity monitor when a probes breakpoint is hit. Signed-off-by: Jon Medhurst --- arch/arm/kernel/kprobes-thumb.c | 56 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 56 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c index d25e5cb..299dc3a 100644 --- a/arch/arm/kernel/kprobes-thumb.c +++ b/arch/arm/kernel/kprobes-thumb.c @@ -50,6 +50,33 @@ t32_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi) return ret; } +static void __kprobes +t32_emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long pc = thumb_probe_pc(p) & ~3; + int rt1 = (insn >> 12) & 0xf; + int rt2 = (insn >> 8) & 0xf; + int rn = (insn >> 16) & 0xf; + + register unsigned long rt1v asm("r0") = regs->uregs[rt1]; + register unsigned long rt2v asm("r1") = regs->uregs[rt2]; + register unsigned long rnv asm("r2") = (rn == 15) ? pc + : regs->uregs[rn]; + + __asm__ __volatile__ ( + "blx %[fn]" + : "=r" (rt1v), "=r" (rt2v), "=r" (rnv) + : "0" (rt1v), "1" (rt2v), "2" (rnv), [fn] "r" (p->ainsn.insn_fn) + : "lr", "memory", "cc" + ); + + if (rn != 15) + regs->uregs[rn] = rnv; /* Writeback base register */ + regs->uregs[rt1] = rt1v; + regs->uregs[rt2] = rt2v; +} + static const union decode_item t32_table_1110_100x_x0xx[] = { /* Load/store multiple instructions */ @@ -79,6 +106,29 @@ static const union decode_item t32_table_1110_100x_x0xx[] = { DECODE_END }; +static const union decode_item t32_table_1110_100x_x1xx[] = { + /* Load/store dual, load/store exclusive, table branch */ + + /* STRD (immediate) 1110 1000 x110 xxxx xxxx xxxx xxxx xxxx */ + /* LDRD (immediate) 1110 1000 x111 xxxx xxxx xxxx xxxx xxxx */ + DECODE_OR (0xff600000, 0xe8600000), + /* STRD (immediate) 1110 1001 x1x0 xxxx xxxx xxxx xxxx xxxx */ + /* LDRD (immediate) 1110 1001 x1x1 xxxx xxxx xxxx xxxx xxxx */ + DECODE_EMULATEX (0xff400000, 0xe9400000, t32_emulate_ldrdstrd, + REGS(NOPCWB, NOSPPC, NOSPPC, 0, 0)), + + /* STREX 1110 1000 0100 xxxx xxxx xxxx xxxx xxxx */ + /* LDREX 1110 1000 0101 xxxx xxxx xxxx xxxx xxxx */ + /* STREXB 1110 1000 1100 xxxx xxxx xxxx 0100 xxxx */ + /* STREXH 1110 1000 1100 xxxx xxxx xxxx 0101 xxxx */ + /* STREXD 1110 1000 1100 xxxx xxxx xxxx 0111 xxxx */ + /* LDREXB 1110 1000 1101 xxxx xxxx xxxx 0100 xxxx */ + /* LDREXH 1110 1000 1101 xxxx xxxx xxxx 0101 xxxx */ + /* LDREXD 1110 1000 1101 xxxx xxxx xxxx 0111 xxxx */ + /* And unallocated instructions... */ + DECODE_END +}; + static const union decode_item t32_table_1111_0xxx___1[] = { /* Branches and miscellaneous control */ @@ -103,6 +153,12 @@ const union decode_item kprobe_decode_thumb32_table[] = { DECODE_TABLE (0xfe400000, 0xe8000000, t32_table_1110_100x_x0xx), /* + * Load/store dual, load/store exclusive, table branch + * 1110 100x x1xx xxxx xxxx xxxx xxxx xxxx + */ + DECODE_TABLE (0xfe400000, 0xe8400000, t32_table_1110_100x_x1xx), + + /* * Branches and miscellaneous control * 1111 0xxx xxxx xxxx 1xxx xxxx xxxx xxxx */