From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wtarreau.pck.nerim.net ([62.212.114.60]:27608 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754194AbcAWOrh (ORCPT ); Sat, 23 Jan 2016 09:47:37 -0500 Message-Id: <20160123141223.463515154@1wt.eu> Date: Sat, 23 Jan 2016 15:12:55 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Holzheu , Martin Schwidefsky , Ben Hutchings , Willy Tarreau Subject: [PATCH 2.6.32 34/42] s390/dis: Fix handling of format specifiers MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Michael Holzheu commit 272fa59ccb4fc802af28b1d699c2463db6a71bf7 upstream. The print_insn() function returns strings like "lghi %r1,0". To escape the '%' character in sprintf() a second '%' is used. For example "lghi %%r1,0" is converted into "lghi %r1,0". After print_insn() the output string is passed to printk(). Because format specifiers like "%r" or "%f" are ignored by printk() this works by chance most of the time. But for instructions with control registers like "lctl %c6,%c6,780" this fails because printk() interprets "%c" as character format specifier. Fix this problem and escape the '%' characters twice. For example "lctl %%%%c6,%%%%c6,780" is then converted by sprintf() into "lctl %%c6,%%c6,780" and by printk() into "lctl %c6,%c6,780". Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky [bwh: Backported to 3.2: drop the OPERAND_VR case] Signed-off-by: Ben Hutchings (cherry picked from commit 45f32e359d36dd045e4af0d1bea8bbbafd81eeb7) Signed-off-by: Willy Tarreau --- arch/s390/kernel/dis.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/s390/kernel/dis.c b/arch/s390/kernel/dis.c index db943a7..d9dfffc 100644 --- a/arch/s390/kernel/dis.c +++ b/arch/s390/kernel/dis.c @@ -1182,14 +1182,21 @@ static int print_insn(char *buffer, unsigned char *code, unsigned long addr) } if (separator) ptr += sprintf(ptr, "%c", separator); + /* + * Use four '%' characters below because of the + * following two conversions: + * + * 1) sprintf: %%%%r -> %%r + * 2) printk : %%r -> %r + */ if (operand->flags & OPERAND_GPR) - ptr += sprintf(ptr, "%%r%i", value); + ptr += sprintf(ptr, "%%%%r%i", value); else if (operand->flags & OPERAND_FPR) - ptr += sprintf(ptr, "%%f%i", value); + ptr += sprintf(ptr, "%%%%f%i", value); else if (operand->flags & OPERAND_AR) - ptr += sprintf(ptr, "%%a%i", value); + ptr += sprintf(ptr, "%%%%a%i", value); else if (operand->flags & OPERAND_CR) - ptr += sprintf(ptr, "%%c%i", value); + ptr += sprintf(ptr, "%%%%c%i", value); else if (operand->flags & OPERAND_PCREL) ptr += sprintf(ptr, "%lx", (signed int) value + addr); -- 1.7.12.2.21.g234cd45.dirty