A user reports that ndctl fails to compile on MUSL systems:
daxctl/device.c: In function 'parse_device_options':
daxctl/device.c:377:26: error: implicit declaration of function 'basename'
[-Wimplicit-function-declaration]
377 | device = basename(argv[0]);
| ^~~~~~~~
There are two versions of basename() with different behaviors:
GNU basename() from <string.h>: doesn't modify its argument
POSIX basename() from <libgen.h>: may modify its argument
glibc provides both versions, while MUSL libc only provides the POSIX
version. Previous code relied on the GNU extension without a header
or used the POSIX version inconsistently.
Introduce a new helper path_basename() that returns the portion of a
path after the last '/', the full string if no '/' is present, and a
trailing '/' returns an empty string. This avoids libc-specific
basename() behavior and is safe for argv style and arbitrary paths.
Closes: https://github.com/pmem/ndctl/issues/283
Signed-off-by: Alison Schofield <[email protected]>
---
Changes in v2:
- Replace open coded strrchr() logic with new helper (Marc, Dan)
- Comment that new helper (Marc)
- Update commit msg
daxctl/device.c | 4 ++--
daxctl/lib/libdaxctl.c | 7 ++++---
util/util.h | 15 +++++++++++++++
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/daxctl/device.c b/daxctl/device.c
index e3993b17c260..a4e36b130a09 100644
--- a/daxctl/device.c
+++ b/daxctl/device.c
@@ -362,11 +362,11 @@ static const char *parse_device_options(int argc, const
char **argv,
};
unsigned long long units = 1;
int i, rc = 0;
- char *device = NULL;
+ const char *device = NULL;
argc = parse_options(argc, argv, options, u, 0);
if (argc > 0)
- device = basename(argv[0]);
+ device = path_basename(argv[0]);
/* Handle action-agnostic non-option arguments */
if (argc == 0 &&
diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c
index b7fa0de0b73d..02ae7e50b123 100644
--- a/daxctl/lib/libdaxctl.c
+++ b/daxctl/lib/libdaxctl.c
@@ -3,7 +3,6 @@
#include <stdio.h>
#include <errno.h>
#include <limits.h>
-#include <libgen.h>
#include <stdlib.h>
#include <dirent.h>
#include <unistd.h>
@@ -15,6 +14,7 @@
#include <ccan/array_size/array_size.h>
#include <util/log.h>
+#include <util/util.h>
#include <util/sysfs.h>
#include <util/iomem.h>
#include <daxctl/libdaxctl.h>
@@ -389,7 +389,8 @@ DAXCTL_EXPORT int daxctl_dev_is_system_ram_capable(struct
daxctl_dev *dev)
{
const char *devname = daxctl_dev_get_devname(dev);
struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
- char *mod_path, *mod_base;
+ const char *mod_base;
+ char *mod_path;
char path[200];
const int len = sizeof(path);
@@ -408,7 +409,7 @@ DAXCTL_EXPORT int daxctl_dev_is_system_ram_capable(struct
daxctl_dev *dev)
if (!mod_path)
return false;
- mod_base = basename(mod_path);
+ mod_base = path_basename(mod_path);
if (strcmp(mod_base, dax_modules[DAXCTL_DEV_MODE_RAM]) == 0) {
free(mod_path);
return true;
diff --git a/util/util.h b/util/util.h
index 58db06530c37..b7913b499d82 100644
--- a/util/util.h
+++ b/util/util.h
@@ -93,6 +93,21 @@ static inline int is_absolute_path(const char *path)
return path[0] == '/';
}
+/*
+ * path_basename() is a basename() style helper for paths that may not
+ * contain a '/'. Unlike devpath_to_devname() in util/sysfs.h, which
+ * assumes a valid sysfs-style path and requires at least one '/', this
+ * helper can return the full string when no path separator is present.
+ * It avoids libc-specific basename() behavior and is safe for argv style
+ * inputs.
+ */
+static inline const char *path_basename(const char *path)
+{
+ const char *p = strrchr(path, '/');
+
+ return p ? p + 1 : path;
+}
+
void usage(const char *err) NORETURN;
void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
--
2.37.3
