Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753108AbcJNIiq (ORCPT ); Fri, 14 Oct 2016 04:38:46 -0400 Received: from mailapp02.imgtec.com ([217.156.133.132]:38842 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751790AbcJNIfa (ORCPT ); Fri, 14 Oct 2016 04:35:30 -0400 From: Marcin Nowakowski To: CC: , , , Marcin Nowakowski , Michael Ellerman Subject: [PATCH v4 03/12] tracing/syscalls: drop arch_syscall_match_sym_name Date: Fri, 14 Oct 2016 10:35:05 +0200 Message-ID: <1476434115-25428-4-git-send-email-marcin.nowakowski@imgtec.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1476434115-25428-1-git-send-email-marcin.nowakowski@imgtec.com> References: <1476434115-25428-1-git-send-email-marcin.nowakowski@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.80.2.5] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4200 Lines: 104 arch_syscall_match_sym_name has been previously added to allow arch to override syscall_match_sym_name method, but only ppc arch implements it and the only difference made is that a prefix is longer. This can be simplified by using a #define specifying the prefix length difference for a given arch. Next commit will make syscall_match_sym_name implementation a bit larger, so clean it up now to avoid further patching arch code whenever the core method changes. Signed-off-by: Marcin Nowakowski Signed-off-by: Michael Ellerman --- Documentation/trace/ftrace-design.txt | 4 ---- arch/powerpc/include/asm/ftrace.h | 15 ++------------- kernel/trace/trace_syscalls.c | 14 ++++++++------ 3 files changed, 10 insertions(+), 23 deletions(-) diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index a273dd0..c30608e 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -237,10 +237,6 @@ You need very few things to get the syscalls tracing in an arch. - If the system call table on this arch is more complicated than a simple array of addresses of the system calls, implement an arch_syscall_addr to return the address of a given system call. -- If the symbol names of the system calls do not match the function names on - this arch, define ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and - implement arch_syscall_match_sym_name with the appropriate logic to return - true if the function name corresponds with the symbol name. - Tag this arch as HAVE_SYSCALL_TRACEPOINTS. diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index 686c5f7..f266051 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -67,20 +67,9 @@ struct dyn_arch_ftrace { #endif #endif -#if defined(CONFIG_FTRACE_SYSCALLS) && !defined(__ASSEMBLY__) #ifdef PPC64_ELF_ABI_v1 -#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME -static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) -{ - /* - * Compare the symbol name with the system call name. Skip the .sys or .SyS - * prefix from the symbol name and the sys prefix from the system call name and - * just match the rest. This is only needed on ppc64 since symbol names on - * 32bit do not start with a period so the generic function will work. - */ - return !strcmp(sym + 4, name + 3); -} +/* On ppc64 ABIv1 (BE) we have to skip the leading '.' in the symbol name */ +#define ARCH_SYM_NAME_SKIP_CHARS 1 #endif -#endif /* CONFIG_FTRACE_SYSCALLS && !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_FTRACE */ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 9065db3..707a57c 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -31,8 +31,11 @@ extern struct syscall_metadata *__stop_syscalls_metadata[]; static struct syscall_metadata **syscalls_metadata; -#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME -static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) +#ifndef ARCH_SYM_NAME_SKIP_CHARS +#define ARCH_SYM_NAME_SKIP_CHARS 0 +#endif + +static inline bool syscall_match_sym_name(const char *sym, const char *name) { /* * Only compare after the "sys" prefix. Archs that use @@ -40,9 +43,8 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name * with ".SyS" or ".sys" instead of "sys", leading to an unwanted * mismatch. */ - return !strcmp(sym + 3, name + 3); + return !strcmp(sym + 3 + ARCH_SYM_NAME_SKIP_CHARS, name + 3); } -#endif #ifdef ARCH_COMPAT_SYSCALL_NUMBERS_OVERLAP /* @@ -86,11 +88,11 @@ find_syscall_meta(unsigned long syscall) stop = __stop_syscalls_metadata; kallsyms_lookup(syscall, NULL, NULL, NULL, str); - if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) + if (syscall_match_sym_name(str, "sys_ni_syscall")) return NULL; for ( ; start < stop; start++) { - if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) + if ((*start)->name && syscall_match_sym_name(str, (*start)->name)) return *start; } return NULL; -- 2.7.4