From: Sergiu Moga <sergiu@unikraft.io>
Date: Thu, 13 Feb 2025 14:39:15 +0000 (+0200)
Subject: lib/posix-process: Define kernel internal resource limit syscalls
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=d40b2dca337acf4eee3407a7bbd8b97469cba53f;p=unikraft%2Funikraft.git

lib/posix-process: Define kernel internal resource limit syscalls

Add the kernel internal variants of `prlimit64`, `getrlimit` and
`setrlimit`: `uk_sys_prlimit64`, `uk_sys_getrlimit` and
`uk_sys_setrlimit` respectively.
This allows kernel internal code to call these system calls' logic
without having the syscall shim wrapper logic intervene.

Note how only `uk_sys_prlimit64` has been added to `exportsyms.uk`
since the others are defined as inline.

Signed-off-by: Sergiu Moga <sergiu@unikraft.io>
Approved-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Andrei Tatar <andrei@unikraft.io>
GitHub-Closes: #1584
---

diff --git a/lib/posix-process/deprecated.c b/lib/posix-process/deprecated.c
index 91ebe2244..7b4bd4825 100644
--- a/lib/posix-process/deprecated.c
+++ b/lib/posix-process/deprecated.c
@@ -37,6 +37,7 @@
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/resource.h>
+#include <uk/essentials.h>
 #include <uk/process.h>
 #include <uk/print.h>
 #include <uk/syscall.h>
@@ -302,8 +303,8 @@ UK_SYSCALL_R_DEFINE(int, prctl, int, option,
 	return 0; /* syscall has no effect */
 }
 
-UK_LLSYSCALL_R_DEFINE(int, prlimit64, int, pid, unsigned int, resource,
-		      struct rlimit *, new_limit, struct rlimit *, old_limit)
+int uk_sys_prlimit64(int pid, unsigned int resource,
+		     struct rlimit *new_limit, struct rlimit *old_limit)
 {
 	if (unlikely(pid != 0))
 		uk_pr_debug("Do not support prlimit64 on PID %u, use current process\n",
@@ -374,16 +375,20 @@ UK_LLSYSCALL_R_DEFINE(int, prlimit64, int, pid, unsigned int, resource,
 	return 0;
 }
 
+UK_LLSYSCALL_R_DEFINE(int, prlimit64, int, pid, unsigned int, resource,
+		      struct rlimit *, new_limit, struct rlimit *, old_limit)
+{
+	return uk_sys_prlimit64(pid, resource, new_limit, old_limit);
+}
+
 UK_SYSCALL_R_DEFINE(int, getrlimit, int, resource, struct rlimit *, rlim)
 {
-	return uk_syscall_r_prlimit64(0, (long) resource,
-				      (long) NULL, (long) rlim);
+	return uk_sys_getrlimit(resource, rlim);
 }
 
 UK_SYSCALL_R_DEFINE(int, setrlimit, int, resource, const struct rlimit *, rlim)
 {
-	return uk_syscall_r_prlimit64(0, (long) resource,
-				      (long) rlim, (long) NULL);
+	return uk_sys_setrlimit(resource, rlim);
 }
 
 UK_SYSCALL_R_DEFINE(int, getrusage, int, who,
diff --git a/lib/posix-process/exportsyms.uk b/lib/posix-process/exportsyms.uk
index 8b053daa3..20908789b 100644
--- a/lib/posix-process/exportsyms.uk
+++ b/lib/posix-process/exportsyms.uk
@@ -32,6 +32,7 @@ popen
 prctl
 uk_syscall_r_prctl
 uk_syscall_e_prctl
+uk_sys_prlimit64
 prlimit
 uk_syscall_r_prlimit64
 uk_syscall_e_prlimit64
diff --git a/lib/posix-process/include/uk/process.h b/lib/posix-process/include/uk/process.h
index dd2c1f93a..3171fb6f0 100644
--- a/lib/posix-process/include/uk/process.h
+++ b/lib/posix-process/include/uk/process.h
@@ -37,6 +37,7 @@
 #include <arch/clone.h>
 #include <uk/config.h>
 #include <stdbool.h>
+#include <sys/resource.h>
 #if CONFIG_LIBUKSCHED
 #include <uk/thread.h>
 #endif
@@ -131,6 +132,20 @@
 #endif
 #endif /* CONFIG_LIBPOSIX_PROCESS_CLONE */
 
+int uk_sys_prlimit64(int pid, unsigned int resource,
+		     struct rlimit *new_limit, struct rlimit *old_limit);
+
+static inline int uk_sys_getrlimit(int resource, struct rlimit *rlim)
+{
+	return uk_sys_prlimit64(0, resource, NULL, rlim);
+}
+
+static inline int uk_sys_setrlimit(int resource, const struct rlimit *rlim)
+{
+	return uk_sys_prlimit64(0, resource,
+				DECONST(struct rlimit *, rlim), NULL);
+}
+
 #if CONFIG_LIBUKSCHED
 int uk_posix_process_create(struct uk_alloc *a,
 			    struct uk_thread *thread,