Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759885AbZFBHBB (ORCPT ); Tue, 2 Jun 2009 03:01:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754897AbZFBHAx (ORCPT ); Tue, 2 Jun 2009 03:00:53 -0400 Received: from smtp.gentoo.org ([140.211.166.183]:40167 "EHLO smtp.gentoo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753780AbZFBHAx (ORCPT ); Tue, 2 Jun 2009 03:00:53 -0400 From: Mike Frysinger To: linux-kernel@vger.kernel.org Cc: Greg KH , Robin Getz , Bryan Wu Subject: [PATCH] debugfs: use specified mode to possibly mark files read/write only Date: Tue, 2 Jun 2009 03:00:47 -0400 Message-Id: <1243926047-29704-1-git-send-email-vapier@gentoo.org> X-Mailer: git-send-email 1.6.3.1 In-Reply-To: <20090125213403.GB3600@kroah.com> References: <20090125213403.GB3600@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7995 Lines: 179 From: Robin Getz In many SoC implementations there are hardware registers can be read or write only. This extends the debugfs to enforce the file permissions for these types of registers by providing a set of fops which are read or write only. This assumes that the kernel developer knows more about the hardware than the user (even root users) -- which is normally true. Signed-off-by: Robin Getz Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu --- you mention debugfs header file changes, but i don't see what would need changing ? the mode checking is all done internally ... fs/debugfs/file.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 63 insertions(+), 0 deletions(-) diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 33a9012..f10091f 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -67,6 +67,8 @@ static int debugfs_u8_get(void *data, u64 *val) return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); /** * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value @@ -95,6 +97,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); struct dentry *debugfs_create_u8(const char *name, mode_t mode, struct dentry *parent, u8 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u8_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u8_wo); + return debugfs_create_file(name, mode, parent, value, &fops_u8); } EXPORT_SYMBOL_GPL(debugfs_create_u8); @@ -110,6 +119,8 @@ static int debugfs_u16_get(void *data, u64 *val) return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); /** * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value @@ -138,6 +149,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); struct dentry *debugfs_create_u16(const char *name, mode_t mode, struct dentry *parent, u16 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u16_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u16_wo); + return debugfs_create_file(name, mode, parent, value, &fops_u16); } EXPORT_SYMBOL_GPL(debugfs_create_u16); @@ -153,6 +171,8 @@ static int debugfs_u32_get(void *data, u64 *val) return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); /** * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value @@ -181,6 +201,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); struct dentry *debugfs_create_u32(const char *name, mode_t mode, struct dentry *parent, u32 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u32_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u32_wo); + return debugfs_create_file(name, mode, parent, value, &fops_u32); } EXPORT_SYMBOL_GPL(debugfs_create_u32); @@ -197,6 +224,8 @@ static int debugfs_u64_get(void *data, u64 *val) return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); /** * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value @@ -225,15 +254,28 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); struct dentry *debugfs_create_u64(const char *name, mode_t mode, struct dentry *parent, u64 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u64_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_u64_wo); + return debugfs_create_file(name, mode, parent, value, &fops_u64); } EXPORT_SYMBOL_GPL(debugfs_create_u64); DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); /* * debugfs_create_x{8,16,32} - create a debugfs file that is used to read and write an unsigned {8,16,32}-bit value @@ -256,6 +298,13 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n" struct dentry *debugfs_create_x8(const char *name, mode_t mode, struct dentry *parent, u8 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x8_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x8_wo); + return debugfs_create_file(name, mode, parent, value, &fops_x8); } EXPORT_SYMBOL_GPL(debugfs_create_x8); @@ -273,6 +322,13 @@ EXPORT_SYMBOL_GPL(debugfs_create_x8); struct dentry *debugfs_create_x16(const char *name, mode_t mode, struct dentry *parent, u16 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x16_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x16_wo); + return debugfs_create_file(name, mode, parent, value, &fops_x16); } EXPORT_SYMBOL_GPL(debugfs_create_x16); @@ -290,6 +346,13 @@ EXPORT_SYMBOL_GPL(debugfs_create_x16); struct dentry *debugfs_create_x32(const char *name, mode_t mode, struct dentry *parent, u32 *value) { + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x32_ro); + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + return debugfs_create_file(name, mode, parent, value, &fops_x32_wo); + return debugfs_create_file(name, mode, parent, value, &fops_x32); } EXPORT_SYMBOL_GPL(debugfs_create_x32); -- 1.6.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/