Using util_path_sysfs always leaves 5 bytes of memory unfreed as the
value for the sysfs mount point is stored in a static variable to avoid
multiple queries of /proc/mount.
$ valgrind ./util_path_example sysfs
==3629315== Memcheck, a memory error detector
==3629315== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==3629315== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==3629315== Command: ./util_path_example sysfs
==3629315==
Path for cpu: "/sys/devices/system/cpu"
Path for memory: "/sys/devices/system/memory"
==3629315==
==3629315== HEAP SUMMARY:
==3629315== in use at exit: 5 bytes in 1 blocks
==3629315== total heap usage: 22 allocs, 21 frees, 18,435 bytes allocated
==3629315==
==3629315== LEAK SUMMARY:
==3629315== definitely lost: 0 bytes in 0 blocks
==3629315== indirectly lost: 0 bytes in 0 blocks
==3629315== possibly lost: 0 bytes in 0 blocks
==3629315== still reachable: 5 bytes in 1 blocks
==3629315== suppressed: 0 bytes in 0 blocks
==3629315== Rerun with --leak-check=full to see details of leaked memory
==3629315==
==3629315== For lists of detected and suppressed errors, rerun with: -s
==3629315== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
As per the Kernel rules for accessing sysfs information [1], searching
for the sysfs mount point is a waste of time and systems that don't have
sysfs mounted at /sys are considered broken.
With those things in mind, util_path_sysfs() and especially
sys_mount_point() can be simplified. sys_mount_point() will always
return '/sys' unless the environment variable SYSFS_ROOT is set.
With SYSFS_ROOT still being present, special container setups or test
case scenarios are still possible but might need to be modified if they
previously relied on util_path_sysfs() automatically finding the correct
sysfs mount point.
To make things more secure against malicious strings in SYSFS_ROOT,
secure_getenv() is being used and the ordering of creating the formatted
path string in util_path_sysfs() is changed slightly.
Furthermore, the static variable is removed as no complicated query of
the /proc fs is required anymore. Memory for the sysfs mount point value
is properly freed now at the end of util_path_sysfs().
[1] https://www.kernel.org/doc/html/latest/admin-guide/sysfs-rules.html
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The functions use the C99 _Bool type in form of the alias bool from
stdbool.h as return type. Scalars are implicitly converted to _Bool.
Values equal to zero to 0 (false). Nonzero values to 1 (true).
Therefore the explicit conversion using the ternary operator ?: with
true and false is not required.
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Testing whether a file is a directory or a regular file by masking the
struct stat field st_mode with S_IFDIR or S_IFREG is wrong. Depending
on the values of the macros S_IF* sockets and symbolic links might
erroneously be considered as regular files and block special files as
directories.
The file type encoded in the struct stat field st_mode is actually an
enumeration. To test whether a file is a directory or a regular file
either extract the file type from st_mode using the mask S_IFMT and
compare it against S_IFDIR or S_IFREG or simply use the macros S_ISDIR()
and S_ISREG().
Fixes: b627b8d8e1 ("Initial s390-tools-2.0.0 import")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
For root the functions util_path_is_readable() and util_path_is_writable()
do not take the path's permissions into account. The function access()
succeeds as root is allowed to read/write any file regardless of its
permissions.
Introduce the functions util_path_is_readonly_file() and
util_path_is_writeonly_file() to test whether a path is a regular file and
is either read-only (neither user, group, nor other have write permission,
but one or more of user, group, and other have read permission) or
write-only (neither user, group, nor other have read permission, but one
or more of user, group, and other have write permission).
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is based on the s390-tools-1.39.0 version.
Changes on top of s390-tools-1.39.0:
- Add MIT license to all source files
- Add LICENSE file
- Transform REAMDE to README.md (markdown)
- Add AUTHORS.md file
- Add CONTRIBUTING.md file
- Move changelog from README to CHANGELOG.md file
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
