From: Sergiu Moga <sergiu@unikraft.io>
Date: Fri, 7 Feb 2025 10:25:11 +0000 (+0200)
Subject: lib/ramfs: Use kernel internal `clock_gettime` variant
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=1434864988dbbea21039d2c20f3f02e28385c6b1;p=unikraft%2Funikraft.git

lib/ramfs: Use kernel internal `clock_gettime` variant

Use the kernel internal variant of `clock_gettime`,
`uk_sys_clock_gettime`.
This helps avoid unnecessary execution of the syscall wrappers'
logic of syscall shim that would have otherwise been run through
`uk_syscall_r_clock_gettime`.

Lastly, since now RAMFS uses a definition available only through
posix-time, add a dependency to it in the Config.uk. Ideally,
this should have been a depends on HAVE_TIME and an imply, but seeing
that currently this is the only library offering us time services,
do it like this for now.

Signed-off-by: Sergiu Moga <sergiu@unikraft.io>
Approved-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Andrei Tatar <andrei@unikraft.io>
GitHub-Closes: #1587
---

diff --git a/lib/ramfs/Config.uk b/lib/ramfs/Config.uk
index 52e4388c4..79926dcbe 100644
--- a/lib/ramfs/Config.uk
+++ b/lib/ramfs/Config.uk
@@ -2,3 +2,4 @@ config LIBRAMFS
 	bool "ramfs: simple RAM file system"
 	default n
 	depends on LIBVFSCORE
+	select LIBPOSIX_TIME
diff --git a/lib/ramfs/ramfs_vnops.c b/lib/ramfs/ramfs_vnops.c
index df08d159f..292a789f4 100644
--- a/lib/ramfs/ramfs_vnops.c
+++ b/lib/ramfs/ramfs_vnops.c
@@ -56,6 +56,8 @@
 #include <fcntl.h>
 #include <vfscore/fs.h>
 
+#include <uk/posix-time.h>
+
 /* 16 bits are enough for file mode as defined by POSIX, the rest we can use */
 #define RAMFS_MODEMASK 0xffff
 #define RAMFS_DELMODE 0x10000
@@ -70,8 +72,19 @@ set_times_to_now(struct timespec *time1, struct timespec *time2,
 		 struct timespec *time3)
 {
 	struct timespec now;
+	int rc;
+
+	rc = uk_sys_clock_gettime(CLOCK_REALTIME, &now);
+	if (unlikely(rc)) {
+		/*
+		 * We do not consider this a fatal error, but rather
+		 * something that might indicate a misconfigured kernel.
+		 * Just print the error and ignore.
+		 */
+		uk_pr_err("Failed to set current time for vnode: %d\n", rc);
+		UK_ASSERT(rc < 0);
+	}
 
-	clock_gettime(CLOCK_REALTIME, &now);
 	if (time1)
 		memcpy(time1, &now, sizeof(struct timespec));
 	if (time2)