Commit a0bb5f88 authored by Thomas Weißschuh's avatar Thomas Weißschuh
Browse files

tools/nolibc: add support for getrlimit/setrlimit 



The implementation uses the prlimit64 systemcall as that is available on
all architectures.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/20231123-nolibc-rlimit-v1-2-a428b131de2a@weissschuh.net/


Acked-by: default avatarWilly Tarreau <w@1wt.eu>
parent 7b20478b

tools/include/nolibc/sys.h

+38 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/fcntl.h> /* for O_* and AT_* */

#include <linux/stat.h>  /* for statx() */

#include <linux/prctl.h>

#include <linux/resource.h>



#include "arch.h"

#include "errno.h"
@@ -898,6 +899,43 @@ int reboot(int cmd) 
}





/*

 * int getrlimit(int resource, struct rlimit *rlim);

 * int setrlimit(int resource, const struct rlimit *rlim);

 */



static __attribute__((unused))

int sys_prlimit64(pid_t pid, int resource,

		  const struct rlimit64 *new_limit, struct rlimit64 *old_limit)

{

	return my_syscall4(__NR_prlimit64, pid, resource, new_limit, old_limit);

}



static __attribute__((unused))

int getrlimit(int resource, struct rlimit *rlim)

{

	struct rlimit64 rlim64;

	int ret;



	ret = __sysret(sys_prlimit64(0, resource, NULL, &rlim64));

	rlim->rlim_cur = rlim64.rlim_cur;

	rlim->rlim_max = rlim64.rlim_max;



	return ret;

}



static __attribute__((unused))

int setrlimit(int resource, const struct rlimit *rlim)

{

	struct rlimit64 rlim64 = {

		.rlim_cur = rlim->rlim_cur,

		.rlim_max = rlim->rlim_max,

	};



	return __sysret(sys_prlimit64(0, resource, &rlim64, NULL));

}





/*

 * int sched_yield(void);

 */

tools/testing/selftests/nolibc/nolibc-test.c

+29 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <sys/mount.h>

#include <sys/prctl.h>

#include <sys/reboot.h>

#include <sys/resource.h>

#include <sys/stat.h>

#include <sys/syscall.h>

#include <sys/sysmacros.h>
@@ -839,6 +840,33 @@ int test_pipe(void) 
	return !!memcmp(buf, msg, len);

}



int test_rlimit(void)

{

	struct rlimit rlim = {

		.rlim_cur = 1 << 20,

		.rlim_max = 1 << 21,

	};

	int ret;



	ret = setrlimit(RLIMIT_CORE, &rlim);

	if (ret)

		return -1;



	rlim.rlim_cur = 0;

	rlim.rlim_max = 0;



	ret = getrlimit(RLIMIT_CORE, &rlim);

	if (ret)

		return -1;



	if (rlim.rlim_cur != 1 << 20)

		return -1;

	if (rlim.rlim_max != 1 << 21)

		return -1;



	return 0;

}





/* Run syscall tests between IDs <min> and <max>.

 * Return 0 on success, non-zero on failure.
@@ -928,6 +956,7 @@ int run_syscall(int min, int max) 
		CASE_TEST(poll_fault);        EXPECT_SYSER(1, poll(NULL, 1, 0), -1, EFAULT); break;

		CASE_TEST(prctl);             EXPECT_SYSER(1, prctl(PR_SET_NAME, (unsigned long)NULL, 0, 0, 0), -1, EFAULT); break;

		CASE_TEST(read_badf);         EXPECT_SYSER(1, read(-1, &tmp, 1), -1, EBADF); break;

		CASE_TEST(rlimit);            EXPECT_SYSZR(1, test_rlimit()); break;

		CASE_TEST(rmdir_blah);        EXPECT_SYSER(1, rmdir("/blah"), -1, ENOENT); break;

		CASE_TEST(sched_yield);       EXPECT_SYSZR(1, sched_yield()); break;

		CASE_TEST(select_null);       EXPECT_SYSZR(1, ({ struct timeval tv = { 0 }; select(0, NULL, NULL, NULL, &tv); })); break;