openafs/acinclude.m4

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dnl This file contains the common configuration code which would
dnl otherwise be duplicated between configure and configure-libafs.
dnl
dnl NB: Because this code is a macro, references to positional shell
dnl parameters must be done like $[]1 instead of $1
AC_DEFUN([OPENAFS_CONFIGURE_COMMON],[
cf: Set CC before calling AC_PROG_CC On some platforms (HPUX, SOLARIS, AIX), we forcibly set CC or set a default CC, because we must use a specific compiler to build kernel modules, and we specify certain compiler-specific flags. But we do this after AC_PROG_CC has run, which also searches for a compiler to use, and runs a few tests against it. AC_PROG_CC often chooses a different compiler (it prefers gcc if it's available). As a result, some compiler-derived info may be wrong, which can yield confusing results, even breaking the build depending on what the user's PATH is, or what compilers are installed on the system. We can avoid all of this if we move our CC-setting logic to before AC_PROG_CC is called. This is a little tricky, because our logic to set AFS_SYSNAME requires the C compiler, so we must do this before OPENAFS_SYSNAME, and also before AC_USE_SYSTEM_EXTENSIONS, or any other autoconf macro that uses the C compiler. Move our CC-setting logic into a new macro, OPENAFS_PATH_CC, which is separate from OPENAFS_CONFIGURE_COMMON and must be called before OPENAFS_CONFIGURE_COMMON. Add some safeguards to try to detect if AC_PROG_CC is already called to try to prevent future changes from breaking this; this isn't perfect, but it's better than nothing. Change-Id: I7c327df5acc5d1ff701b70825eecaaaab4aa44a8 Reviewed-on: https://gerrit.openafs.org/15456 Reviewed-by: Cheyenne Wills <cwills@sinenomine.net> Reviewed-by: Ben Huntsman <ben@huntsmans.net> Tested-by: BuildBot <buildbot@rampaginggeek.com> Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
2023-05-19 22:53:55 +01:00
AC_USE_SYSTEM_EXTENSIONS
AC_PROG_CC
OPENAFS_AUTOHEADER_TOP
OPENAFS_AUTOHEADER_BOTTOM
OPENAFS_TOPDIRS
#BOZO_SAVE_CORES pam
OPENAFS_OPTIONS
OPENAFS_DOC
dnl Checks for UNIX variants.
AC_SEARCH_LIBS([strerror],[cposix])
dnl Various compiler setup.
AC_TYPE_PID_T
AC_TYPE_SIZE_T
dnl Checks for programs.
AC_PROG_INSTALL
AC_PROG_LN_S
AC_PROG_RANLIB
AC_PROG_YACC
OPENAFS_LEX
dnl Checks
OPENAFS_FORCE_ABS_INSTALL
OPENAFS_CHECK_BIGENDIAN
OPENAFS_PRINTF_TAKES_Z_LEN
OPENAFS_OSTYPE
OPENAFS_SYSNAME
OPENAFS_OSCONF
OPENAFS_LINUX_CHECKS
OPENAFS_C_ATOMIC_CHECKS
OPENAFS_SOCKET_CHECKS
OPENAFS_LIBRARY_CHECKS
AC_CHECK_RESOLV_RETRANS
OPENAFS_SOCKOPT_CHECK
OPENAFS_PTHREAD_CHECKS
HOST_CPU="$host_cpu"
OPENAFS_BSD_CHECKS
OPENAFS_OPTION_TESTS
OPENAFS_TIVOLI_TESTS
OPENAFS_HEADER_CHECKS
OPENAFS_MEMBER_CHECKS
OPENAFS_LIBINTL_CHECKS
OPENAFS_MORE_OPTION_TESTS
OPENAFS_FUNCTION_CHECKS
OPENAFS_ROKEN
OPENAFS_HCRYPTO
OPENAFS_CURSES
OPENAFS_C_ATTRIBUTE
OPENAFS_C_PRAGMA
dir: Introduce struct DirEntryFlex The directory package as implemented in AFS-2 allocates space for each directory entry as a DirEntry struct followed by 0-8 contiguous DirXEntry structs, as needed. This is implemented by: - afs_dir_NameBlobs calculates the number of blocks needed - FindBlobs allocates and returns index of entry - afs_dir_GetBlob returns pointer to 1st DirEntry struct After this, we populate DirEntry (and any contiguous DirXEntry blocks) with open code. Most existing code writes the entry's name via a string copy operation to DirEntry->name, which is only 16 bytes long. Therefore, for dir entry names that are 16 bytes or longer, OpenAFS routinely does string copies that look like buffer overruns. This has not previously caused problems because the OpenAFS code has arranged for a sufficiently large amount of contiguous memory to be available. However, this remains undefined behavior in the C abstract virtual machine; thus compilers are not required to produce safe operation. Recent changes in the OpenAFS build chain have made this approach no longer viable: 1) Linux 6.5 commit df8fc4e934c12b 'kbuild: Enable -fstrict-flex-arrays=3' modified the hardening of several kernel string operations when running with CONFIG_FORTIFY_SOURCE=y. 2) gcc 13 commit 79a89108dd352cd9288f5de35481b1280c7588a5 '__builtin_dynamic_object_size: Recognize builtin' provides some enhancements to _builtin_object_size. The Linux commit above will now use these when the kernel is built with gcc 13. When OpenAFS is built under Linux 6.5 or higher and gcc 13 or higher, the hardened strlcpy will BUG for directory entry names longer than 16 characters. Since there are multiple places where OpenAFS writes directory names, there are several symptoms that may manifest. However, the first one is usually a kernel BUG at cache manager initialization if running with afsd -dynroot _and_ there are any cell names 15 characters or longer in the client CellServDB. (A 15-character cellname reaches the 16 character limit when -dyrnoot adds the RW mountpoint ".<cellname>".) Address this by using flexible arrays (standardized with C99). A flexible array is a variable-length array that is declared with no size at all, e.g., name[]. Create an autoconf test to determine whether the compiler supports flexible arrays. Create a new struct DirEntryFlex. If the compiler supports flexible arrays, define name[]; otherwise retain the name[16] definition. Whenever we write a directory name, use DirEntryFlex so that any hardening will be satisfied that there is sufficient space for the name. However, the actual guarantee that this is true is still provided by the OpenAFS directory routines mentioned above - all of these remain unchanged. The DirEntry struct remains unchanged for continued use in OpenAFS, as well as for any out-of-tree users of the directory package. Change-Id: I6da5c6c295f051be90017084e5b3a3ef24d1271f Reviewed-on: https://gerrit.openafs.org/15573 Tested-by: BuildBot <buildbot@rampaginggeek.com> Reviewed-by: Cheyenne Wills <cwills@sinenomine.net> Reviewed-by: Benjamin Kaduk <kaduk@mit.edu> Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
2023-09-15 20:01:56 +01:00
OPENAFS_C_FLEXIBLE_ARRAY
OPENAFS_MORE_ROKEN_CHECKS
OPENAFS_NETDB_CHECKS
OPENAFS_ROKEN_HEADERS
OPENAFS_BSWAP_CHECKS
OPENAFS_PIO_CHECKS
OPENAFS_REGEX_CHECKS
OPENAFS_MORE_PTHREAD_CHECKS
OPENAFS_TYPE_CHECKS
RRA_HEADER_PAM_CONST
OPENAFS_DIRECTORY_PATHS
OPENAFS_YET_MORE_OPTION_TESTS
OPENAFS_OUTPUT_VARIABLES
OPENAFS_FUSE
OPENAFS_SWIG
OPENAFS_CROSSTOOLS
OPENAFS_LINT
OPENAFS_CRYPT_CHECKS
OPENAFS_C_STRUCT_LABEL_CHECK
OPENAFS_DIRENT_CHECKS
OPENAFS_SYS_RESOURCE_CHECKS
OPENAFS_UUID_CHECKS
OPENAFS_CTF_TOOLS_CHECKS
])