xref: /openbmc/linux/tools/perf/arch/s390/util/machine.c (revision 50df3be7)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <unistd.h>
3 #include <stdio.h>
4 #include <string.h>
5 #include <internal/lib.h> // page_size
6 #include "machine.h"
7 #include "api/fs/fs.h"
8 #include "debug.h"
9 #include "symbol.h"
10 
11 int arch__fix_module_text_start(u64 *start, u64 *size, const char *name)
12 {
13 	u64 m_start = *start;
14 	char path[PATH_MAX];
15 
16 	snprintf(path, PATH_MAX, "module/%.*s/sections/.text",
17 				(int)strlen(name) - 2, name + 1);
18 	if (sysfs__read_ull(path, (unsigned long long *)start) < 0) {
19 		pr_debug2("Using module %s start:%#lx\n", path, m_start);
20 		*start = m_start;
21 	} else {
22 		/* Successful read of the modules segment text start address.
23 		 * Calculate difference between module start address
24 		 * in memory and module text segment start address.
25 		 * For example module load address is 0x3ff8011b000
26 		 * (from /proc/modules) and module text segment start
27 		 * address is 0x3ff8011b870 (from file above).
28 		 *
29 		 * Adjust the module size and subtract the GOT table
30 		 * size located at the beginning of the module.
31 		 */
32 		*size -= (*start - m_start);
33 	}
34 
35 	return 0;
36 }
37 
38 /* On s390 kernel text segment start is located at very low memory addresses,
39  * for example 0x10000. Modules are located at very high memory addresses,
40  * for example 0x3ff xxxx xxxx. The gap between end of kernel text segment
41  * and beginning of first module's text segment is very big.
42  * Therefore do not fill this gap and do not assign it to the kernel dso map.
43  */
44 void arch__symbols__fixup_end(struct symbol *p, struct symbol *c)
45 {
46 	if (strchr(p->name, '[') == NULL && strchr(c->name, '['))
47 		/* Last kernel symbol mapped to end of page */
48 		p->end = roundup(p->end, page_size);
49 	else
50 		p->end = c->start;
51 	pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end);
52 }
53