// SPDX-License-Identifier: GPL-2.0
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#include <errno.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <inttypes.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/param.h>
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#include "parse-events.h"
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#include "evlist.h"
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#include "evsel.h"
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#include "thread_map.h"
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#include "cpumap.h"
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#include "machine.h"
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#include "event.h"
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#include "thread.h"
|
|
#include "tests.h"
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#include "sane_ctype.h"
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#define BUFSZ 1024
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#define READLEN 128
|
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struct state {
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u64 done[1024];
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size_t done_cnt;
|
};
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static unsigned int hex(char c)
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{
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if (c >= '0' && c <= '9')
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return c - '0';
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if (c >= 'a' && c <= 'f')
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return c - 'a' + 10;
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return c - 'A' + 10;
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}
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static size_t read_objdump_chunk(const char **line, unsigned char **buf,
|
size_t *buf_len)
|
{
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size_t bytes_read = 0;
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unsigned char *chunk_start = *buf;
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|
/* Read bytes */
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while (*buf_len > 0) {
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char c1, c2;
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/* Get 2 hex digits */
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c1 = *(*line)++;
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if (!isxdigit(c1))
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break;
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c2 = *(*line)++;
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if (!isxdigit(c2))
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break;
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/* Store byte and advance buf */
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**buf = (hex(c1) << 4) | hex(c2);
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(*buf)++;
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(*buf_len)--;
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bytes_read++;
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/* End of chunk? */
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if (isspace(**line))
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break;
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}
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/*
|
* objdump will display raw insn as LE if code endian
|
* is LE and bytes_per_chunk > 1. In that case reverse
|
* the chunk we just read.
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*
|
* see disassemble_bytes() at binutils/objdump.c for details
|
* how objdump chooses display endian)
|
*/
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if (bytes_read > 1 && !bigendian()) {
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unsigned char *chunk_end = chunk_start + bytes_read - 1;
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unsigned char tmp;
|
|
while (chunk_start < chunk_end) {
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tmp = *chunk_start;
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*chunk_start = *chunk_end;
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*chunk_end = tmp;
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chunk_start++;
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chunk_end--;
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}
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}
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return bytes_read;
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}
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static size_t read_objdump_line(const char *line, unsigned char *buf,
|
size_t buf_len)
|
{
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const char *p;
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size_t ret, bytes_read = 0;
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/* Skip to a colon */
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p = strchr(line, ':');
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if (!p)
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return 0;
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p++;
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/* Skip initial spaces */
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while (*p) {
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if (!isspace(*p))
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break;
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p++;
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}
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do {
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ret = read_objdump_chunk(&p, &buf, &buf_len);
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bytes_read += ret;
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p++;
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} while (ret > 0);
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/* return number of successfully read bytes */
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return bytes_read;
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}
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static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr)
|
{
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char *line = NULL;
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size_t line_len, off_last = 0;
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ssize_t ret;
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int err = 0;
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u64 addr, last_addr = start_addr;
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while (off_last < *len) {
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size_t off, read_bytes, written_bytes;
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unsigned char tmp[BUFSZ];
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ret = getline(&line, &line_len, f);
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if (feof(f))
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break;
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if (ret < 0) {
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pr_debug("getline failed\n");
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err = -1;
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break;
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}
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/* read objdump data into temporary buffer */
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read_bytes = read_objdump_line(line, tmp, sizeof(tmp));
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if (!read_bytes)
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continue;
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if (sscanf(line, "%"PRIx64, &addr) != 1)
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continue;
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if (addr < last_addr) {
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pr_debug("addr going backwards, read beyond section?\n");
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break;
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}
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last_addr = addr;
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/* copy it from temporary buffer to 'buf' according
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* to address on current objdump line */
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off = addr - start_addr;
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if (off >= *len)
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break;
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written_bytes = MIN(read_bytes, *len - off);
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memcpy(buf + off, tmp, written_bytes);
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off_last = off + written_bytes;
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}
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/* len returns number of bytes that could not be read */
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*len -= off_last;
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free(line);
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return err;
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}
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static int read_via_objdump(const char *filename, u64 addr, void *buf,
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size_t len)
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{
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char cmd[PATH_MAX * 2];
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const char *fmt;
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FILE *f;
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int ret;
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fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s";
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ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len,
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filename);
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if (ret <= 0 || (size_t)ret >= sizeof(cmd))
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return -1;
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pr_debug("Objdump command is: %s\n", cmd);
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/* Ignore objdump errors */
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strcat(cmd, " 2>/dev/null");
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f = popen(cmd, "r");
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if (!f) {
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pr_debug("popen failed\n");
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return -1;
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}
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ret = read_objdump_output(f, buf, &len, addr);
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if (len) {
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pr_debug("objdump read too few bytes: %zd\n", len);
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if (!ret)
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ret = len;
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}
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pclose(f);
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return ret;
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}
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static void dump_buf(unsigned char *buf, size_t len)
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{
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size_t i;
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for (i = 0; i < len; i++) {
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pr_debug("0x%02x ", buf[i]);
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if (i % 16 == 15)
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pr_debug("\n");
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}
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pr_debug("\n");
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}
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static int read_object_code(u64 addr, size_t len, u8 cpumode,
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struct thread *thread, struct state *state)
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{
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struct addr_location al;
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unsigned char buf1[BUFSZ];
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unsigned char buf2[BUFSZ];
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size_t ret_len;
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u64 objdump_addr;
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const char *objdump_name;
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char decomp_name[KMOD_DECOMP_LEN];
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bool decomp = false;
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int ret;
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pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
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if (!thread__find_map(thread, cpumode, addr, &al) || !al.map->dso) {
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if (cpumode == PERF_RECORD_MISC_HYPERVISOR) {
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pr_debug("Hypervisor address can not be resolved - skipping\n");
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return 0;
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}
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pr_debug("thread__find_map failed\n");
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return -1;
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}
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pr_debug("File is: %s\n", al.map->dso->long_name);
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if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
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!dso__is_kcore(al.map->dso)) {
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pr_debug("Unexpected kernel address - skipping\n");
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return 0;
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}
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pr_debug("On file address is: %#"PRIx64"\n", al.addr);
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if (len > BUFSZ)
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len = BUFSZ;
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/* Do not go off the map */
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if (addr + len > al.map->end)
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len = al.map->end - addr;
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/* Read the object code using perf */
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ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine,
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al.addr, buf1, len);
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if (ret_len != len) {
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pr_debug("dso__data_read_offset failed\n");
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return -1;
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}
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/*
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* Converting addresses for use by objdump requires more information.
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* map__load() does that. See map__rip_2objdump() for details.
|
*/
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if (map__load(al.map))
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return -1;
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/* objdump struggles with kcore - try each map only once */
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if (dso__is_kcore(al.map->dso)) {
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size_t d;
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for (d = 0; d < state->done_cnt; d++) {
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if (state->done[d] == al.map->start) {
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pr_debug("kcore map tested already");
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pr_debug(" - skipping\n");
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return 0;
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}
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}
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if (state->done_cnt >= ARRAY_SIZE(state->done)) {
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pr_debug("Too many kcore maps - skipping\n");
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return 0;
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}
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state->done[state->done_cnt++] = al.map->start;
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}
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objdump_name = al.map->dso->long_name;
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if (dso__needs_decompress(al.map->dso)) {
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if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
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decomp_name,
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sizeof(decomp_name)) < 0) {
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pr_debug("decompression failed\n");
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return -1;
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}
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decomp = true;
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objdump_name = decomp_name;
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}
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/* Read the object code using objdump */
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objdump_addr = map__rip_2objdump(al.map, al.addr);
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ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
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if (decomp)
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unlink(objdump_name);
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if (ret > 0) {
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/*
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* The kernel maps are inaccurate - assume objdump is right in
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* that case.
|
*/
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if (cpumode == PERF_RECORD_MISC_KERNEL ||
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cpumode == PERF_RECORD_MISC_GUEST_KERNEL) {
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len -= ret;
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if (len) {
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pr_debug("Reducing len to %zu\n", len);
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} else if (dso__is_kcore(al.map->dso)) {
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/*
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* objdump cannot handle very large segments
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* that may be found in kcore.
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*/
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pr_debug("objdump failed for kcore");
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pr_debug(" - skipping\n");
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return 0;
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} else {
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return -1;
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}
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}
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}
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if (ret < 0) {
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pr_debug("read_via_objdump failed\n");
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return -1;
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}
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/* The results should be identical */
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if (memcmp(buf1, buf2, len)) {
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pr_debug("Bytes read differ from those read by objdump\n");
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pr_debug("buf1 (dso):\n");
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dump_buf(buf1, len);
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pr_debug("buf2 (objdump):\n");
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dump_buf(buf2, len);
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return -1;
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}
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pr_debug("Bytes read match those read by objdump\n");
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return 0;
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}
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static int process_sample_event(struct machine *machine,
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struct perf_evlist *evlist,
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union perf_event *event, struct state *state)
|
{
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struct perf_sample sample;
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struct thread *thread;
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int ret;
|
|
if (perf_evlist__parse_sample(evlist, event, &sample)) {
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pr_debug("perf_evlist__parse_sample failed\n");
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return -1;
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}
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thread = machine__findnew_thread(machine, sample.pid, sample.tid);
|
if (!thread) {
|
pr_debug("machine__findnew_thread failed\n");
|
return -1;
|
}
|
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ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state);
|
thread__put(thread);
|
return ret;
|
}
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static int process_event(struct machine *machine, struct perf_evlist *evlist,
|
union perf_event *event, struct state *state)
|
{
|
if (event->header.type == PERF_RECORD_SAMPLE)
|
return process_sample_event(machine, evlist, event, state);
|
|
if (event->header.type == PERF_RECORD_THROTTLE ||
|
event->header.type == PERF_RECORD_UNTHROTTLE)
|
return 0;
|
|
if (event->header.type < PERF_RECORD_MAX) {
|
int ret;
|
|
ret = machine__process_event(machine, event, NULL);
|
if (ret < 0)
|
pr_debug("machine__process_event failed, event type %u\n",
|
event->header.type);
|
return ret;
|
}
|
|
return 0;
|
}
|
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static int process_events(struct machine *machine, struct perf_evlist *evlist,
|
struct state *state)
|
{
|
union perf_event *event;
|
struct perf_mmap *md;
|
int i, ret;
|
|
for (i = 0; i < evlist->nr_mmaps; i++) {
|
md = &evlist->mmap[i];
|
if (perf_mmap__read_init(md) < 0)
|
continue;
|
|
while ((event = perf_mmap__read_event(md)) != NULL) {
|
ret = process_event(machine, evlist, event, state);
|
perf_mmap__consume(md);
|
if (ret < 0)
|
return ret;
|
}
|
perf_mmap__read_done(md);
|
}
|
return 0;
|
}
|
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static int comp(const void *a, const void *b)
|
{
|
return *(int *)a - *(int *)b;
|
}
|
|
static void do_sort_something(void)
|
{
|
int buf[40960], i;
|
|
for (i = 0; i < (int)ARRAY_SIZE(buf); i++)
|
buf[i] = ARRAY_SIZE(buf) - i - 1;
|
|
qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp);
|
|
for (i = 0; i < (int)ARRAY_SIZE(buf); i++) {
|
if (buf[i] != i) {
|
pr_debug("qsort failed\n");
|
break;
|
}
|
}
|
}
|
|
static void sort_something(void)
|
{
|
int i;
|
|
for (i = 0; i < 10; i++)
|
do_sort_something();
|
}
|
|
static void syscall_something(void)
|
{
|
int pipefd[2];
|
int i;
|
|
for (i = 0; i < 1000; i++) {
|
if (pipe(pipefd) < 0) {
|
pr_debug("pipe failed\n");
|
break;
|
}
|
close(pipefd[1]);
|
close(pipefd[0]);
|
}
|
}
|
|
static void fs_something(void)
|
{
|
const char *test_file_name = "temp-perf-code-reading-test-file--";
|
FILE *f;
|
int i;
|
|
for (i = 0; i < 1000; i++) {
|
f = fopen(test_file_name, "w+");
|
if (f) {
|
fclose(f);
|
unlink(test_file_name);
|
}
|
}
|
}
|
|
static const char *do_determine_event(bool excl_kernel)
|
{
|
const char *event = excl_kernel ? "cycles:u" : "cycles";
|
|
#ifdef __s390x__
|
char cpuid[128], model[16], model_c[16], cpum_cf_v[16];
|
unsigned int family;
|
int ret, cpum_cf_a;
|
|
if (get_cpuid(cpuid, sizeof(cpuid)))
|
goto out_clocks;
|
ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c,
|
model, cpum_cf_v, &cpum_cf_a);
|
if (ret != 5) /* Not available */
|
goto out_clocks;
|
if (excl_kernel && (cpum_cf_a & 4))
|
return event;
|
if (!excl_kernel && (cpum_cf_a & 2))
|
return event;
|
|
/* Fall through: missing authorization */
|
out_clocks:
|
event = excl_kernel ? "cpu-clock:u" : "cpu-clock";
|
|
#endif
|
return event;
|
}
|
|
static void do_something(void)
|
{
|
fs_something();
|
|
sort_something();
|
|
syscall_something();
|
}
|
|
enum {
|
TEST_CODE_READING_OK,
|
TEST_CODE_READING_NO_VMLINUX,
|
TEST_CODE_READING_NO_KCORE,
|
TEST_CODE_READING_NO_ACCESS,
|
TEST_CODE_READING_NO_KERNEL_OBJ,
|
};
|
|
static int do_test_code_reading(bool try_kcore)
|
{
|
struct machine *machine;
|
struct thread *thread;
|
struct record_opts opts = {
|
.mmap_pages = UINT_MAX,
|
.user_freq = UINT_MAX,
|
.user_interval = ULLONG_MAX,
|
.freq = 500,
|
.target = {
|
.uses_mmap = true,
|
},
|
};
|
struct state state = {
|
.done_cnt = 0,
|
};
|
struct thread_map *threads = NULL;
|
struct cpu_map *cpus = NULL;
|
struct perf_evlist *evlist = NULL;
|
struct perf_evsel *evsel = NULL;
|
int err = -1, ret;
|
pid_t pid;
|
struct map *map;
|
bool have_vmlinux, have_kcore, excl_kernel = false;
|
|
pid = getpid();
|
|
machine = machine__new_host();
|
machine->env = &perf_env;
|
|
ret = machine__create_kernel_maps(machine);
|
if (ret < 0) {
|
pr_debug("machine__create_kernel_maps failed\n");
|
goto out_err;
|
}
|
|
/* Force the use of kallsyms instead of vmlinux to try kcore */
|
if (try_kcore)
|
symbol_conf.kallsyms_name = "/proc/kallsyms";
|
|
/* Load kernel map */
|
map = machine__kernel_map(machine);
|
ret = map__load(map);
|
if (ret < 0) {
|
pr_debug("map__load failed\n");
|
goto out_err;
|
}
|
have_vmlinux = dso__is_vmlinux(map->dso);
|
have_kcore = dso__is_kcore(map->dso);
|
|
/* 2nd time through we just try kcore */
|
if (try_kcore && !have_kcore)
|
return TEST_CODE_READING_NO_KCORE;
|
|
/* No point getting kernel events if there is no kernel object */
|
if (!have_vmlinux && !have_kcore)
|
excl_kernel = true;
|
|
threads = thread_map__new_by_tid(pid);
|
if (!threads) {
|
pr_debug("thread_map__new_by_tid failed\n");
|
goto out_err;
|
}
|
|
ret = perf_event__synthesize_thread_map(NULL, threads,
|
perf_event__process, machine, false, 500);
|
if (ret < 0) {
|
pr_debug("perf_event__synthesize_thread_map failed\n");
|
goto out_err;
|
}
|
|
thread = machine__findnew_thread(machine, pid, pid);
|
if (!thread) {
|
pr_debug("machine__findnew_thread failed\n");
|
goto out_put;
|
}
|
|
cpus = cpu_map__new(NULL);
|
if (!cpus) {
|
pr_debug("cpu_map__new failed\n");
|
goto out_put;
|
}
|
|
while (1) {
|
const char *str;
|
|
evlist = perf_evlist__new();
|
if (!evlist) {
|
pr_debug("perf_evlist__new failed\n");
|
goto out_put;
|
}
|
|
perf_evlist__set_maps(evlist, cpus, threads);
|
|
str = do_determine_event(excl_kernel);
|
pr_debug("Parsing event '%s'\n", str);
|
ret = parse_events(evlist, str, NULL);
|
if (ret < 0) {
|
pr_debug("parse_events failed\n");
|
goto out_put;
|
}
|
|
perf_evlist__config(evlist, &opts, NULL);
|
|
evsel = perf_evlist__first(evlist);
|
|
evsel->attr.comm = 1;
|
evsel->attr.disabled = 1;
|
evsel->attr.enable_on_exec = 0;
|
|
ret = perf_evlist__open(evlist);
|
if (ret < 0) {
|
if (!excl_kernel) {
|
excl_kernel = true;
|
/*
|
* Both cpus and threads are now owned by evlist
|
* and will be freed by following perf_evlist__set_maps
|
* call. Getting refference to keep them alive.
|
*/
|
cpu_map__get(cpus);
|
thread_map__get(threads);
|
perf_evlist__set_maps(evlist, NULL, NULL);
|
perf_evlist__delete(evlist);
|
evlist = NULL;
|
continue;
|
}
|
|
if (verbose > 0) {
|
char errbuf[512];
|
perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
|
pr_debug("perf_evlist__open() failed!\n%s\n", errbuf);
|
}
|
|
goto out_put;
|
}
|
break;
|
}
|
|
ret = perf_evlist__mmap(evlist, UINT_MAX);
|
if (ret < 0) {
|
pr_debug("perf_evlist__mmap failed\n");
|
goto out_put;
|
}
|
|
perf_evlist__enable(evlist);
|
|
do_something();
|
|
perf_evlist__disable(evlist);
|
|
ret = process_events(machine, evlist, &state);
|
if (ret < 0)
|
goto out_put;
|
|
if (!have_vmlinux && !have_kcore && !try_kcore)
|
err = TEST_CODE_READING_NO_KERNEL_OBJ;
|
else if (!have_vmlinux && !try_kcore)
|
err = TEST_CODE_READING_NO_VMLINUX;
|
else if (excl_kernel)
|
err = TEST_CODE_READING_NO_ACCESS;
|
else
|
err = TEST_CODE_READING_OK;
|
out_put:
|
thread__put(thread);
|
out_err:
|
|
if (evlist) {
|
perf_evlist__delete(evlist);
|
} else {
|
cpu_map__put(cpus);
|
thread_map__put(threads);
|
}
|
machine__delete_threads(machine);
|
machine__delete(machine);
|
|
return err;
|
}
|
|
int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused)
|
{
|
int ret;
|
|
ret = do_test_code_reading(false);
|
if (!ret)
|
ret = do_test_code_reading(true);
|
|
switch (ret) {
|
case TEST_CODE_READING_OK:
|
return 0;
|
case TEST_CODE_READING_NO_VMLINUX:
|
pr_debug("no vmlinux\n");
|
return 0;
|
case TEST_CODE_READING_NO_KCORE:
|
pr_debug("no kcore\n");
|
return 0;
|
case TEST_CODE_READING_NO_ACCESS:
|
pr_debug("no access\n");
|
return 0;
|
case TEST_CODE_READING_NO_KERNEL_OBJ:
|
pr_debug("no kernel obj\n");
|
return 0;
|
default:
|
return -1;
|
};
|
}
|
