From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755807Ab2DWVp2 (ORCPT ); Mon, 23 Apr 2012 17:45:28 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:5836 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755285Ab2DWVp1 (ORCPT ); Mon, 23 Apr 2012 17:45:27 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6690"; a="184252301" From: Stephen Boyd To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: [PATCH 1/2] vsprintf: Fix %ps on non symbols when using kallsyms Date: Mon, 23 Apr 2012 14:45:24 -0700 Message-Id: <1335217525-30709-1-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.7.10.227.gd1ca7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Using %ps in a printk format will sometimes fail silently and print the empty string if the address passed in does not match a symbol that kallsyms knows about. But using %pS will fall back to printing the full address if kallsyms can't find the symbol. Make %ps act the same as %pS by falling back to printing the address. While we're here also make %ps print the module that a symbol comes from so that it matches what %pS already does. Take this simple function for example (in a module): static void test_printk(void) { int test; pr_info("with pS: %pS\n", &test); pr_info("with ps: %ps\n", &test); } Before this patch: with pS: 0xdff7df44 with ps: After this patch: with pS: 0xdff7df44 with ps: 0xdff7df44 Signed-off-by: Stephen Boyd --- The name is admittedly bad. Please suggest alternatives. include/linux/kallsyms.h | 7 +++++++ kernel/kallsyms.c | 32 ++++++++++++++++++++++++-------- lib/vsprintf.c | 2 +- 3 files changed, 32 insertions(+), 9 deletions(-) diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 3875719..6883e19 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -36,6 +36,7 @@ const char *kallsyms_lookup(unsigned long addr, /* Look up a kernel symbol and return it in a text buffer. */ extern int sprint_symbol(char *buffer, unsigned long address); +extern int sprint_symbol_no_offset(char *buffer, unsigned long address); extern int sprint_backtrace(char *buffer, unsigned long address); /* Look up a kernel symbol and print it to the kernel messages. */ @@ -80,6 +81,12 @@ static inline int sprint_symbol(char *buffer, unsigned long addr) return 0; } +static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) +{ + *buffer = '\0'; + return 0; +} + static inline int sprint_backtrace(char *buffer, unsigned long addr) { *buffer = '\0'; diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 079f1d3..2169fee 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -343,7 +343,7 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size, /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, - int symbol_offset) + int symbol_offset, int add_offset) { char *modname; const char *name; @@ -358,13 +358,13 @@ static int __sprint_symbol(char *buffer, unsigned long address, if (name != buffer) strcpy(buffer, name); len = strlen(buffer); - buffer += len; offset -= symbol_offset; + if (add_offset) + len += sprintf(buffer + len, "+%#lx/%#lx", offset, size); + if (modname) - len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname); - else - len += sprintf(buffer, "+%#lx/%#lx", offset, size); + len += sprintf(buffer + len, " [%s]", modname); return len; } @@ -382,12 +382,28 @@ static int __sprint_symbol(char *buffer, unsigned long address, */ int sprint_symbol(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, 0); + return __sprint_symbol(buffer, address, 0, 1); } - EXPORT_SYMBOL_GPL(sprint_symbol); /** + * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer + * @buffer: buffer to be stored + * @address: address to lookup + * + * This function looks up a kernel symbol with @address and stores its name + * and module name to @buffer if possible. If no symbol was found, just saves + * its @address as is. + * + * This function returns the number of bytes stored in @buffer. + */ +int sprint_symbol_no_offset(char *buffer, unsigned long address) +{ + return __sprint_symbol(buffer, address, 0, 0); +} +EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); + +/** * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer * @buffer: buffer to be stored * @address: address to lookup @@ -403,7 +419,7 @@ EXPORT_SYMBOL_GPL(sprint_symbol); */ int sprint_backtrace(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, -1); + return __sprint_symbol(buffer, address, -1, 1); } /* Look up a kernel symbol and print it to the kernel messages. */ diff --git a/lib/vsprintf.c b/lib/vsprintf.c index ba7bb1b..0b56d43 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -535,7 +535,7 @@ char *symbol_string(char *buf, char *end, void *ptr, else if (ext != 'f' && ext != 's') sprint_symbol(sym, value); else - kallsyms_lookup(value, NULL, NULL, NULL, sym); + sprint_symbol_no_offset(sym, value); return string(buf, end, sym, spec); #else -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.