tools/perf/arch/s390/util/machine.c

   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 }