xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/clock_gettime/clock_gettime03.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2020 Cyril Hrubis <[email protected]>
4  */
5 
6 /*
7  * [Description]
8  *
9  * After a call to unshare(CLONE_NEWTIME) a new timer namespace is created, the
10  * process that has called the unshare() can adjust offsets for CLOCK_MONOTONIC
11  * and CLOCK_BOOTTIME for its children by writing to the '/proc/self/timens_offsets'.
12  *
13  * The child processes also switch to the initial parent namespace and checks
14  * that the offset is set to 0.
15  */
16 
17 #define _GNU_SOURCE
18 #include "time64_variants.h"
19 #include "tst_safe_clocks.h"
20 #include "tst_timer.h"
21 #include "lapi/sched.h"
22 
23 static struct tcase {
24 	int clk_id;
25 	int clk_off;
26 	int off;
27 } tcases[] = {
28 	{CLOCK_MONOTONIC, CLOCK_MONOTONIC, 10},
29 	{CLOCK_BOOTTIME, CLOCK_BOOTTIME, 10},
30 
31 	{CLOCK_MONOTONIC, CLOCK_MONOTONIC, -10},
32 	{CLOCK_BOOTTIME, CLOCK_BOOTTIME, -10},
33 
34 	{CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC, 100},
35 	{CLOCK_MONOTONIC_COARSE, CLOCK_MONOTONIC, 100},
36 };
37 
38 static struct tst_ts now, then, parent_then;
39 static int parent_ns;
40 static long long delta = 10;
41 
42 static struct time64_variants variants[] = {
43 	{ .clock_gettime = libc_clock_gettime, .ts_type = TST_LIBC_TIMESPEC, .desc = "vDSO or syscall with libc spec"},
44 
45 #if (__NR_clock_gettime != __LTP__NR_INVALID_SYSCALL)
46 	{ .clock_gettime = sys_clock_gettime, .ts_type = TST_KERN_OLD_TIMESPEC, .desc = "syscall with old kernel spec"},
47 #endif
48 
49 #if (__NR_clock_gettime64 != __LTP__NR_INVALID_SYSCALL)
50 	{ .clock_gettime = sys_clock_gettime64, .ts_type = TST_KERN_TIMESPEC, .desc = "syscall time64 with kernel spec"},
51 #endif
52 };
53 
child(struct time64_variants * tv,struct tcase * tc)54 static void child(struct time64_variants *tv, struct tcase *tc)
55 {
56 	long long diff;
57 
58 	if (tv->clock_gettime(tc->clk_id, tst_ts_get(&then))) {
59 		tst_res(TFAIL | TERRNO, "clock_gettime(%s) failed",
60 			tst_clock_name(tc->clk_id));
61 		return;
62 	}
63 
64 	SAFE_SETNS(parent_ns, CLONE_NEWTIME);
65 
66 	if (tv->clock_gettime(tc->clk_id, tst_ts_get(&parent_then))) {
67 		tst_res(TFAIL | TERRNO, "clock_gettime(%s) failed",
68 			tst_clock_name(tc->clk_id));
69 		return;
70 	}
71 
72 	diff = tst_ts_diff_ms(then, now);
73 
74 	if (diff - tc->off * 1000 > delta) {
75 		tst_res(TFAIL, "Wrong offset (%s) read %llims",
76 		        tst_clock_name(tc->clk_id), diff);
77 	} else {
78 		tst_res(TPASS, "Offset (%s) is correct %llims",
79 		        tst_clock_name(tc->clk_id), diff);
80 	}
81 
82 	diff = tst_ts_diff_ms(parent_then, now);
83 
84 	if (diff > delta) {
85 		tst_res(TFAIL, "Wrong offset (%s) read %llims",
86 		        tst_clock_name(tc->clk_id), diff);
87 	} else {
88 		tst_res(TPASS, "Offset (%s) is correct %llims",
89 		        tst_clock_name(tc->clk_id), diff);
90 	}
91 }
92 
verify_ns_clock(unsigned int n)93 static void verify_ns_clock(unsigned int n)
94 {
95 	struct time64_variants *tv = &variants[tst_variant];
96 	struct tcase *tc = &tcases[n];
97 
98 	SAFE_UNSHARE(CLONE_NEWTIME);
99 
100 	SAFE_FILE_PRINTF("/proc/self/timens_offsets", "%d %d 0",
101 	                 tc->clk_off, tc->off);
102 
103 	if (tv->clock_gettime(tc->clk_id, tst_ts_get(&now))) {
104 		tst_res(TFAIL | TERRNO, "%d clock_gettime(%s) failed",
105 			__LINE__, tst_clock_name(tc->clk_id));
106 		return;
107 	}
108 
109 	if (!SAFE_FORK())
110 		child(tv, tc);
111 }
112 
setup(void)113 static void setup(void)
114 {
115 	struct time64_variants *tv = &variants[tst_variant];
116 
117 	if (tst_is_virt(VIRT_ANY)) {
118 		tst_res(TINFO, "Running in a VM, multiply the delta by 10.");
119 		delta *= 10;
120 	}
121 
122 	now.type = then.type = parent_then.type = tv->ts_type;
123 	tst_res(TINFO, "Testing variant: %s", variants[tst_variant].desc);
124 	parent_ns = SAFE_OPEN("/proc/self/ns/time_for_children", O_RDONLY);
125 }
126 
cleanup(void)127 static void cleanup(void)
128 {
129 	SAFE_CLOSE(parent_ns);
130 }
131 
132 static struct tst_test test = {
133 	.setup = setup,
134 	.cleanup = cleanup,
135 	.tcnt = ARRAY_SIZE(tcases),
136 	.test = verify_ns_clock,
137 	.test_variants = ARRAY_SIZE(variants),
138 	.needs_root = 1,
139 	.forks_child = 1,
140 	.needs_kconfigs = (const char *[]) {
141 		"CONFIG_TIME_NS=y",
142 		NULL
143 	}
144 };
145