Check on-disk structure sizes against known values.
Use this to catch inadvertent changes in structure size due to padding
and alignment issues, etc.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
db/Makefile | 2 -
db/init.c | 3 +
db/ondisk.c | 63 +++++++++++++++++++++++
db/ondisk.h | 139 +++++++++++++++++++++++++++++++++++++++++++++++++++
libxfs/xfs_format.h | 4 +
5 files changed, 210 insertions(+), 1 deletion(-)
create mode 100644 db/ondisk.c
create mode 100644 db/ondisk.h
diff --git a/db/Makefile b/db/Makefile
index 8260da3..ba3e942 100644
--- a/db/Makefile
+++ b/db/Makefile
@@ -12,7 +12,7 @@ HFILES = addr.h agf.h agfl.h agi.h attr.h attrshort.h bit.h block.h bmap.h \
dir2.h dir2sf.h dquot.h echo.h faddr.h field.h \
flist.h fprint.h frag.h freesp.h hash.h help.h init.h inode.h input.h \
io.h logformat.h malloc.h metadump.h output.h print.h quit.h sb.h \
- sig.h strvec.h text.h type.h write.h attrset.h symlink.h
+ sig.h strvec.h text.h type.h write.h attrset.h symlink.h ondisk.h
CFILES = $(HFILES:.h=.c)
LSRCFILES = xfs_admin.sh xfs_ncheck.sh xfs_metadump.sh
diff --git a/db/init.c b/db/init.c
index c0472c8..d6df093 100644
--- a/db/init.c
+++ b/db/init.c
@@ -28,6 +28,7 @@
#include "output.h"
#include "malloc.h"
#include "type.h"
+#include "ondisk.h"
static char **cmdline;
static int ncmdline;
@@ -60,6 +61,8 @@ init(
struct xfs_buf *bp;
int c;
+ xfs_check_ondisk_structs();
+
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
diff --git a/db/ondisk.c b/db/ondisk.c
new file mode 100644
index 0000000..532333d
--- /dev/null
+++ b/db/ondisk.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2016 Oracle.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libxfs.h"
+#include "ondisk.h"
+
+void
+xfs_check_ondisk_structs(void)
+{
+ /* on-disk structures */
+ XFS_CHECK_STRUCT_SIZE(struct xfs_dsb, 264);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_agf, 224);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_agi, 336);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_agfl, 36);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_timestamp, 8);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_dinode, 176);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_disk_dquot, 104);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_dqblk, 136);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_dsymlink_hdr, 56);
+ XFS_CHECK_STRUCT_SIZE(xfs_alloc_rec_t, 8);
+ XFS_CHECK_STRUCT_SIZE(xfs_alloc_key_t, 8);
+ XFS_CHECK_STRUCT_SIZE(xfs_alloc_ptr_t, 4);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_rec, 16);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_key, 4);
+ XFS_CHECK_STRUCT_SIZE(xfs_inobt_ptr_t, 4);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_bmdr_block, 4);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_rec, 16);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_key, 8);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_btree_block, 72);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_acl_entry, 12);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_acl, 4);
+
+ /* log structures */
+ XFS_CHECK_STRUCT_SIZE(struct xfs_trans_header, 16);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_32, 52);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_64, 56);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_ictimestamp, 8);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_icdinode, 176);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_extent_32, 12);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_extent_64, 16);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 28);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_64, 32);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_32, 28);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_64, 32);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_dq_logformat, 24);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_qoff_logformat, 20);
+ XFS_CHECK_STRUCT_SIZE(struct xfs_icreate_log, 28);
+}
diff --git a/db/ondisk.h b/db/ondisk.h
new file mode 100644
index 0000000..b5784d1
--- /dev/null
+++ b/db/ondisk.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2016 Oracle.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __XFS_DB_ONDISK_H
+#define __XFS_DB_ONDISK_H
+
+/* Compile time object size, -1 for unknown */
+#ifndef __compiletime_error
+# define __compiletime_error(message)
+/*
+ * Sparse complains of variable sized arrays due to the temporary variable in
+ * __compiletime_assert. Unfortunately we can't just expand it out to make
+ * sparse see a constant array size without breaking compiletime_assert on old
+ * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
+ */
+# ifndef __CHECKER__
+# define __compiletime_error_fallback(condition) \
+ do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
+# endif
+#endif
+#ifndef __compiletime_error_fallback
+# define __compiletime_error_fallback(condition) do { } while (0)
+#endif
+
+#define __compiletime_assert(condition, msg, prefix, suffix) \
+ do { \
+ bool __cond = !(condition); \
+ extern void prefix ## suffix(void) __compiletime_error(msg); \
+ if (__cond) \
+ prefix ## suffix(); \
+ __compiletime_error_fallback(__cond); \
+ } while (0)
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+ __compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg: a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+ _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
+#ifdef __CHECKER__
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
+#define BUILD_BUG_ON_ZERO(e) (0)
+#define BUILD_BUG_ON_NULL(e) ((void*)0)
+#define BUILD_BUG_ON_INVALID(e) (0)
+#define BUILD_BUG_ON_MSG(cond, msg) (0)
+#define BUILD_BUG_ON(condition) (0)
+#define BUILD_BUG() (0)
+#else /* __CHECKER__ */
+
+/* Force a compilation error if a constant expression is not a power of 2 */
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
+ BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
+
+/* Force a compilation error if condition is true, but also produce a
+ result (of value 0 and type size_t), so the expression can be used
+ e.g. in a structure initializer (or where-ever else comma expressions
+ aren't permitted). */
+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
+
+/*
+ * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
+ * expression but avoids the generation of any code, even if that expression
+ * has side-effects.
+ */
+#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
+
+/**
+ * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
+ * error message.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * See BUILD_BUG_ON for description.
+ */
+#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
+
+/**
+ * BUILD_BUG_ON - break compile if a condition is true.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * If you have some code which relies on certain constants being equal, or
+ * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
+ * detect if someone changes it.
+ *
+ * The implementation uses gcc's reluctance to create a negative array, but gcc
+ * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
+ * inline functions). Luckily, in 4.3 they added the "error" function
+ * attribute just for this type of case. Thus, we use a negative sized array
+ * (should always create an error on gcc versions older than 4.4) and then call
+ * an undefined function with the error attribute (should always create an
+ * error on gcc 4.3 and later). If for some reason, neither creates a
+ * compile-time error, we'll still have a link-time error, which is harder to
+ * track down.
+ */
+#ifndef __OPTIMIZE__
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+#else
+#define BUILD_BUG_ON(condition) \
+ BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
+#endif
+
+/**
+ * BUILD_BUG - break compile if used.
+ *
+ * If you have some code that you expect the compiler to eliminate at
+ * build time, you should use BUILD_BUG to detect if it is
+ * unexpectedly used.
+ */
+#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
+
+#endif /* __CHECKER__ */
+
+void xfs_check_ondisk_structs(void);
+
+#endif /* __XFS_DB_ONDISK_H */
diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index a35009a..c4c0c1c 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -1505,4 +1505,8 @@ struct xfs_acl {
#define SGI_ACL_FILE_SIZE (sizeof(SGI_ACL_FILE)-1)
#define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1)
+#define XFS_CHECK_STRUCT_SIZE(structname, size) \
+ BUILD_BUG_ON_MSG(sizeof(structname) != (size), "XFS: sizeof(struct " \
+ #structname ") is wrong, expected " #size)
+
#endif /* __XFS_FORMAT_H__ */
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