From patchwork Fri Jan 12 17:55:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 860118 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zJ9R10W2Gz9sNx for ; Sat, 13 Jan 2018 04:56:13 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965088AbeALR4C (ORCPT ); Fri, 12 Jan 2018 12:56:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:48400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964844AbeALRz6 (ORCPT ); Fri, 12 Jan 2018 12:55:58 -0500 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 832732175D; Fri, 12 Jan 2018 17:55:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 832732175D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mhiramat@kernel.org From: Masami Hiramatsu To: Alexei Starovoitov , Josef Bacik Cc: rostedt@goodmis.org, mingo@redhat.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ast@kernel.org, kernel-team@fb.com, daniel@iogearbox.net, linux-btrfs@vger.kernel.org, darrick.wong@oracle.com, mhiramat@kernel.org, Josef Bacik , Akinobu Mita Subject: [PATCH bpf-next v5 4/5] error-injection: Add injectable error types Date: Sat, 13 Jan 2018 02:55:33 +0900 Message-Id: <151577973343.17713.10284074283632340039.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <151577961239.17713.16735014086815016675.stgit@devbox> References: <151577961239.17713.16735014086815016675.stgit@devbox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add injectable error types for each error-injectable function. One motivation of error injection test is to find software flaws, mistakes or mis-handlings of expectable errors. If we find such flaws by the test, that is a program bug, so we need to fix it. But if the tester miss input the error (e.g. just return success code without processing anything), it causes unexpected behavior even if the caller is correctly programmed to handle any errors. That is not what we want to test by error injection. To clarify what type of errors the caller must expect for each injectable function, this introduces injectable error types: - EI_ETYPE_NULL : means the function will return NULL if it fails. No ERR_PTR, just a NULL. - EI_ETYPE_ERRNO : means the function will return -ERRNO if it fails. - EI_ETYPE_ERRNO_NULL : means the function will return -ERRNO (ERR_PTR) or NULL. ALLOW_ERROR_INJECTION() macro is expanded to get one of NULL, ERRNO, ERRNO_NULL to record the error type for each function. e.g. ALLOW_ERROR_INJECTION(open_ctree, ERRNO) This error types are shown in debugfs as below. ==== / # cat /sys/kernel/debug/error_injection/list open_ctree [btrfs] ERRNO io_ctl_init [btrfs] ERRNO ==== Signed-off-by: Masami Hiramatsu Reviewed-by: Josef Bacik --- fs/btrfs/disk-io.c | 2 +- fs/btrfs/free-space-cache.c | 2 +- include/asm-generic/error-injection.h | 23 +++++++++++++++--- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/error-injection.h | 6 +++++ include/linux/module.h | 3 ++ lib/error-inject.c | 43 ++++++++++++++++++++++++++++----- 7 files changed, 66 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 9798e21ebe9d..83e2349e1362 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3124,7 +3124,7 @@ int open_ctree(struct super_block *sb, goto fail_block_groups; goto retry_root_backup; } -ALLOW_ERROR_INJECTION(open_ctree); +ALLOW_ERROR_INJECTION(open_ctree, ERRNO); static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) { diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index ef847699031a..586bb06472bb 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -333,7 +333,7 @@ static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode, return 0; } -ALLOW_ERROR_INJECTION(io_ctl_init); +ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO); static void io_ctl_free(struct btrfs_io_ctl *io_ctl) { diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h index 08352c9d9f97..296c65442f00 100644 --- a/include/asm-generic/error-injection.h +++ b/include/asm-generic/error-injection.h @@ -3,17 +3,32 @@ #define _ASM_GENERIC_ERROR_INJECTION_H #if defined(__KERNEL__) && !defined(__ASSEMBLY__) +enum { + EI_ETYPE_NONE, /* Dummy value for undefined case */ + EI_ETYPE_NULL, /* Return NULL if failure */ + EI_ETYPE_ERRNO, /* Return -ERRNO if failure */ + EI_ETYPE_ERRNO_NULL, /* Return -ERRNO or NULL if failure */ +}; + +struct error_injection_entry { + unsigned long addr; + int etype; +}; + #ifdef CONFIG_FUNCTION_ERROR_INJECTION /* * Whitelist ganerating macro. Specify functions which can be * error-injectable using this macro. */ -#define ALLOW_ERROR_INJECTION(fname) \ -static unsigned long __used \ +#define ALLOW_ERROR_INJECTION(fname, _etype) \ +static struct error_injection_entry __used \ __attribute__((__section__("_error_injection_whitelist"))) \ - _eil_addr_##fname = (unsigned long)fname; + _eil_addr_##fname = { \ + .addr = (unsigned long)fname, \ + .etype = EI_ETYPE_##_etype, \ + }; #else -#define ALLOW_ERROR_INJECTION(fname) +#define ALLOW_ERROR_INJECTION(fname, _etype) #endif #endif diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index f2068cca5206..ebe544e048cd 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -137,7 +137,7 @@ #endif #ifdef CONFIG_FUNCTION_ERROR_INJECTION -#define ERROR_INJECT_WHITELIST() . = ALIGN(8); \ +#define ERROR_INJECT_WHITELIST() STRUCT_ALIGN(); \ VMLINUX_SYMBOL(__start_error_injection_whitelist) = .;\ KEEP(*(_error_injection_whitelist)) \ VMLINUX_SYMBOL(__stop_error_injection_whitelist) = .; diff --git a/include/linux/error-injection.h b/include/linux/error-injection.h index 130a67c50dac..280c61ecbf20 100644 --- a/include/linux/error-injection.h +++ b/include/linux/error-injection.h @@ -7,6 +7,7 @@ #include extern bool within_error_injection_list(unsigned long addr); +extern int get_injectable_error_type(unsigned long addr); #else /* !CONFIG_FUNCTION_ERROR_INJECTION */ @@ -16,6 +17,11 @@ static inline bool within_error_injection_list(unsigned long addr) return false; } +static inline int get_injectable_error_type(unsigned long addr) +{ + return EI_ETYPE_NONE; +} + #endif #endif /* _LINUX_ERROR_INJECTION_H */ diff --git a/include/linux/module.h b/include/linux/module.h index 792e51d83bda..9642d3116718 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -477,8 +478,8 @@ struct module { #endif #ifdef CONFIG_FUNCTION_ERROR_INJECTION + struct error_injection_entry *ei_funcs; unsigned int num_ei_funcs; - unsigned long *ei_funcs; #endif } ____cacheline_aligned __randomize_layout; #ifndef MODULE_ARCH_INIT diff --git a/lib/error-inject.c b/lib/error-inject.c index bccadcf3c981..c0d4600f4896 100644 --- a/lib/error-inject.c +++ b/lib/error-inject.c @@ -16,6 +16,7 @@ struct ei_entry { struct list_head list; unsigned long start_addr; unsigned long end_addr; + int etype; void *priv; }; @@ -35,6 +36,17 @@ bool within_error_injection_list(unsigned long addr) return ret; } +int get_injectable_error_type(unsigned long addr) +{ + struct ei_entry *ent; + + list_for_each_entry(ent, &error_injection_list, list) { + if (addr >= ent->start_addr && addr < ent->end_addr) + return ent->etype; + } + return EI_ETYPE_NONE; +} + /* * Lookup and populate the error_injection_list. * @@ -42,16 +54,17 @@ bool within_error_injection_list(unsigned long addr) * bpf_error_injection, so we need to populate the list of the symbols that have * been marked as safe for overriding. */ -static void populate_error_injection_list(unsigned long *start, - unsigned long *end, void *priv) +static void populate_error_injection_list(struct error_injection_entry *start, + struct error_injection_entry *end, + void *priv) { - unsigned long *iter; + struct error_injection_entry *iter; struct ei_entry *ent; unsigned long entry, offset = 0, size = 0; mutex_lock(&ei_mutex); for (iter = start; iter < end; iter++) { - entry = arch_deref_entry_point((void *)*iter); + entry = arch_deref_entry_point((void *)iter->addr); if (!kernel_text_address(entry) || !kallsyms_lookup_size_offset(entry, &size, &offset)) { @@ -65,6 +78,7 @@ static void populate_error_injection_list(unsigned long *start, break; ent->start_addr = entry; ent->end_addr = entry + size; + ent->etype = iter->etype; ent->priv = priv; INIT_LIST_HEAD(&ent->list); list_add_tail(&ent->list, &error_injection_list); @@ -73,8 +87,8 @@ static void populate_error_injection_list(unsigned long *start, } /* Markers of the _error_inject_whitelist section */ -extern unsigned long __start_error_injection_whitelist[]; -extern unsigned long __stop_error_injection_whitelist[]; +extern struct error_injection_entry __start_error_injection_whitelist[]; +extern struct error_injection_entry __stop_error_injection_whitelist[]; static void __init populate_kernel_ei_list(void) { @@ -157,11 +171,26 @@ static void *ei_seq_next(struct seq_file *m, void *v, loff_t *pos) return seq_list_next(v, &error_injection_list, pos); } +static const char *error_type_string(int etype) +{ + switch (etype) { + case EI_ETYPE_NULL: + return "NULL"; + case EI_ETYPE_ERRNO: + return "ERRNO"; + case EI_ETYPE_ERRNO_NULL: + return "ERRNO_NULL"; + default: + return "(unknown)"; + } +} + static int ei_seq_show(struct seq_file *m, void *v) { struct ei_entry *ent = list_entry(v, struct ei_entry, list); - seq_printf(m, "%pf\n", (void *)ent->start_addr); + seq_printf(m, "%pf\t%s\n", (void *)ent->start_addr, + error_type_string(ent->etype)); return 0; }