From patchwork Wed Apr 12 10:58:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Naveen N. Rao" X-Patchwork-Id: 749920 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3w31J91cq7z9s8N for ; Wed, 12 Apr 2017 21:03:53 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3w31J90qJRzDqNQ for ; Wed, 12 Apr 2017 21:03:53 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w31CZ5MH1zDqHK for ; Wed, 12 Apr 2017 20:59:54 +1000 (AEST) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3CAwfQb071267 for ; Wed, 12 Apr 2017 06:59:44 -0400 Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) by mx0a-001b2d01.pphosted.com with ESMTP id 29sb7cadct-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 12 Apr 2017 06:59:44 -0400 Received: from localhost by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 12 Apr 2017 20:59:41 +1000 Received: from d23relay07.au.ibm.com (202.81.31.226) by e23smtp03.au.ibm.com (202.81.31.209) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 12 Apr 2017 20:59:39 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v3CAxVwM23527574 for ; Wed, 12 Apr 2017 20:59:39 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v3CAx2Ea019172 for ; Wed, 12 Apr 2017 20:59:02 +1000 Received: from naverao1-tp.ibm.com ([9.84.217.62]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v3CAwqIK018997; Wed, 12 Apr 2017 20:59:00 +1000 From: "Naveen N. Rao" To: Michael Ellerman Subject: [PATCH v2 1/5] kprobes: convert kprobe_lookup_name() to a function Date: Wed, 12 Apr 2017 16:28:24 +0530 X-Mailer: git-send-email 2.12.1 In-Reply-To: References: In-Reply-To: References: X-TM-AS-MML: disable x-cbid: 17041210-0008-0000-0000-0000011F0078 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17041210-0009-0000-0000-0000094BC602 Message-Id: <2780c632bc2c6e39f27920f8cc98e17430189e27.1491991939.git.naveen.n.rao@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-04-12_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1704120093 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Masami Hiramatsu , Ingo Molnar Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The macro is now pretty long and ugly on powerpc. In the light of further changes needed here, convert it to a __weak variant to be over-ridden with a nicer looking function. Suggested-by: Masami Hiramatsu Signed-off-by: Naveen N. Rao Acked-by: Masami Hiramatsu --- arch/powerpc/include/asm/kprobes.h | 53 ---------------------------------- arch/powerpc/kernel/kprobes.c | 58 ++++++++++++++++++++++++++++++++++++++ arch/powerpc/kernel/optprobes.c | 4 +-- include/linux/kprobes.h | 1 + kernel/kprobes.c | 20 ++++++------- 5 files changed, 69 insertions(+), 67 deletions(-) diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h index 0503c98b2117..a843884aafaf 100644 --- a/arch/powerpc/include/asm/kprobes.h +++ b/arch/powerpc/include/asm/kprobes.h @@ -61,59 +61,6 @@ extern kprobe_opcode_t optprobe_template_end[]; #define MAX_OPTINSN_SIZE (optprobe_template_end - optprobe_template_entry) #define RELATIVEJUMP_SIZE sizeof(kprobe_opcode_t) /* 4 bytes */ -#ifdef PPC64_ELF_ABI_v2 -/* PPC64 ABIv2 needs local entry point */ -#define kprobe_lookup_name(name, addr) \ -{ \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); \ - if (addr) \ - addr = (kprobe_opcode_t *)ppc_function_entry(addr); \ -} -#elif defined(PPC64_ELF_ABI_v1) -/* - * 64bit powerpc ABIv1 uses function descriptors: - * - Check for the dot variant of the symbol first. - * - If that fails, try looking up the symbol provided. - * - * This ensures we always get to the actual symbol and not the descriptor. - * Also handle format. - */ -#define kprobe_lookup_name(name, addr) \ -{ \ - char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN]; \ - const char *modsym; \ - bool dot_appended = false; \ - if ((modsym = strchr(name, ':')) != NULL) { \ - modsym++; \ - if (*modsym != '\0' && *modsym != '.') { \ - /* Convert to */ \ - strncpy(dot_name, name, modsym - name); \ - dot_name[modsym - name] = '.'; \ - dot_name[modsym - name + 1] = '\0'; \ - strncat(dot_name, modsym, \ - sizeof(dot_name) - (modsym - name) - 2);\ - dot_appended = true; \ - } else { \ - dot_name[0] = '\0'; \ - strncat(dot_name, name, sizeof(dot_name) - 1); \ - } \ - } else if (name[0] != '.') { \ - dot_name[0] = '.'; \ - dot_name[1] = '\0'; \ - strncat(dot_name, name, KSYM_NAME_LEN - 2); \ - dot_appended = true; \ - } else { \ - dot_name[0] = '\0'; \ - strncat(dot_name, name, KSYM_NAME_LEN - 1); \ - } \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \ - if (!addr && dot_appended) { \ - /* Let's try the original non-dot symbol lookup */ \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); \ - } \ -} -#endif - #define flush_insn_slot(p) do { } while (0) #define kretprobe_blacklist_size 0 diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 331751701fed..a7aa7394954d 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -42,6 +42,64 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}}; +kprobe_opcode_t *kprobe_lookup_name(const char *name) +{ + kprobe_opcode_t *addr; + +#ifdef PPC64_ELF_ABI_v2 + /* PPC64 ABIv2 needs local entry point */ + addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); + if (addr) + addr = (kprobe_opcode_t *)ppc_function_entry(addr); +#elif defined(PPC64_ELF_ABI_v1) + /* + * 64bit powerpc ABIv1 uses function descriptors: + * - Check for the dot variant of the symbol first. + * - If that fails, try looking up the symbol provided. + * + * This ensures we always get to the actual symbol and not + * the descriptor. + * + * Also handle format. + */ + char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN]; + const char *modsym; + bool dot_appended = false; + if ((modsym = strchr(name, ':')) != NULL) { + modsym++; + if (*modsym != '\0' && *modsym != '.') { + /* Convert to */ + strncpy(dot_name, name, modsym - name); + dot_name[modsym - name] = '.'; + dot_name[modsym - name + 1] = '\0'; + strncat(dot_name, modsym, + sizeof(dot_name) - (modsym - name) - 2); + dot_appended = true; + } else { + dot_name[0] = '\0'; + strncat(dot_name, name, sizeof(dot_name) - 1); + } + } else if (name[0] != '.') { + dot_name[0] = '.'; + dot_name[1] = '\0'; + strncat(dot_name, name, KSYM_NAME_LEN - 2); + dot_appended = true; + } else { + dot_name[0] = '\0'; + strncat(dot_name, name, KSYM_NAME_LEN - 1); + } + addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); + if (!addr && dot_appended) { + /* Let's try the original non-dot symbol lookup */ + addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); + } +#else + addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); +#endif + + return addr; +} + int __kprobes arch_prepare_kprobe(struct kprobe *p) { int ret = 0; diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index 2282bf4e63cd..aefe076d00e0 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -243,8 +243,8 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) /* * 2. branch to optimized_callback() and emulate_step() */ - kprobe_lookup_name("optimized_callback", op_callback_addr); - kprobe_lookup_name("emulate_step", emulate_step_addr); + op_callback_addr = kprobe_lookup_name("optimized_callback"); + emulate_step_addr = kprobe_lookup_name("emulate_step"); if (!op_callback_addr || !emulate_step_addr) { WARN(1, "kprobe_lookup_name() failed\n"); goto error; diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index c328e4f7dcad..16f153c84646 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -379,6 +379,7 @@ static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) return this_cpu_ptr(&kprobe_ctlblk); } +kprobe_opcode_t *kprobe_lookup_name(const char *name); int register_kprobe(struct kprobe *p); void unregister_kprobe(struct kprobe *p); int register_kprobes(struct kprobe **kps, int num); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 699c5bc51a92..f3421b6b47a3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -58,15 +58,6 @@ #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) -/* - * Some oddball architectures like 64bit powerpc have function descriptors - * so this must be overridable. - */ -#ifndef kprobe_lookup_name -#define kprobe_lookup_name(name, addr) \ - addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) -#endif - static int kprobes_initialized; static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; @@ -81,6 +72,11 @@ static struct { raw_spinlock_t lock ____cacheline_aligned_in_smp; } kretprobe_table_locks[KPROBE_TABLE_SIZE]; +kprobe_opcode_t * __weak kprobe_lookup_name(const char *name) +{ + return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); +} + static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) { return &(kretprobe_table_locks[hash].lock); @@ -1400,7 +1396,7 @@ static kprobe_opcode_t *kprobe_addr(struct kprobe *p) goto invalid; if (p->symbol_name) { - kprobe_lookup_name(p->symbol_name, addr); + addr = kprobe_lookup_name(p->symbol_name); if (!addr) return ERR_PTR(-ENOENT); } @@ -2192,8 +2188,8 @@ static int __init init_kprobes(void) if (kretprobe_blacklist_size) { /* lookup the function address from its name */ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { - kprobe_lookup_name(kretprobe_blacklist[i].name, - kretprobe_blacklist[i].addr); + kretprobe_blacklist[i].addr = + kprobe_lookup_name(kretprobe_blacklist[i].name); if (!kretprobe_blacklist[i].addr) printk("kretprobe: lookup failed: %s\n", kretprobe_blacklist[i].name);