/*
 * Minimal BPF JIT image disassembler
 *
 * Disassembles BPF JIT compiler emitted opcodes back to asm insn's for
 * debugging or verification purposes.
 *
 * There is no Makefile. Compile with
 *
 *   `gcc -Wall -O2 bpf_jit_disasm.c -o bpf_jit_disasm -lopcodes -lbfd -ldl`
 *
 * or similar.
 *
 * To get the disassembly of the JIT code, do the following:
 *
 *  1) `echo 2 > /proc/sys/net/core/bpf_jit_enable`
 *  2) Load a BPF filter (e.g. `tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24`)
 *  3) Run e.g. `bpf_jit_disasm -o` to read out the last JIT code
 *
 * Copyright 2013 Daniel Borkmann <borkmann@redhat.com>
 * Licensed under the GNU General Public License, version 2.0 (GPLv2)
 *
 * Note: this is part of the Linux kernel and can be found under tools/net/.
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <bfd.h>
#include <dis-asm.h>
#include <sys/klog.h>
#include <sys/types.h>
#include <regex.h>

static void get_exec_path(char *tpath, size_t size)
{
	char *path;
	ssize_t len;

	snprintf(tpath, size, "/proc/%d/exe", (int) getpid());
	tpath[size - 1] = 0;

	path = strdup(tpath);
	assert(path);

	len = readlink(path, tpath, size);
	tpath[len] = 0;

	free(path);
}

static void get_asm_insns(uint8_t *image, size_t len, unsigned long base,
			  int opcodes)
{
	int count, i, pc = 0;
	char tpath[256];
	struct disassemble_info info;
	disassembler_ftype disassemble;
	bfd *bfdf;

	memset(tpath, 0, sizeof(tpath));
	get_exec_path(tpath, sizeof(tpath));

	bfdf = bfd_openr(tpath, NULL);
	assert(bfdf);
	assert(bfd_check_format(bfdf, bfd_object));

	init_disassemble_info(&info, stdout, (fprintf_ftype) fprintf);
	info.arch = bfd_get_arch(bfdf);
	info.mach = bfd_get_mach(bfdf);
	info.buffer = image;
	info.buffer_length = len;

	disassemble_init_for_target(&info);

	disassemble = disassembler(bfdf);
	assert(disassemble);

	do {
		printf("%4x:\t", pc);

		count = disassemble(pc, &info);

		if (opcodes) {
			printf("\n\t");
			for (i = 0; i < count; ++i)
				printf("%02x ", (uint8_t) image[pc + i]);
		}
		printf("\n");

		pc += count;
	} while(count > 0 && pc < len);

	bfd_close(bfdf);
}

static char *get_klog_buff(int *klen)
{
	int ret, len = klogctl(10, NULL, 0);
	char *buff = malloc(len);

	assert(buff && klen);
	ret = klogctl(3, buff, len);
	assert(ret >= 0);
	*klen = ret;

	return buff;
}

static void put_klog_buff(char *buff)
{
	free(buff);
}

static int get_last_jit_image(char *haystack, size_t hlen,
			      uint8_t *image, size_t ilen,
			      unsigned long *base)
{
	char *ptr, *pptr, *tmp;
	off_t off = 0;
	int ret, flen, proglen, pass, ulen = 0;
	regmatch_t pmatch[1];
	regex_t regex;

	if (hlen == 0)
		return 0;

	ret = regcomp(&regex, "flen=[[:alnum:]]+ proglen=[[:digit:]]+ "
		      "pass=[[:digit:]]+ image=[[:xdigit:]]+", REG_EXTENDED);
	assert(ret == 0);

	ptr = haystack;
	while (1) {
		ret = regexec(&regex, ptr, 1, pmatch, 0);
		if (ret == 0) {
			ptr += pmatch[0].rm_eo;
			off += pmatch[0].rm_eo;
			assert(off < hlen);
		} else
			break;
	}

	ptr = haystack + off - (pmatch[0].rm_eo - pmatch[0].rm_so);
	ret = sscanf(ptr, "flen=%d proglen=%d pass=%d image=%lx",
		     &flen, &proglen, &pass, base);
	if (ret != 4)
		return 0;

	tmp = ptr = haystack + off;
	while ((ptr = strtok(tmp, "\n")) != NULL && ulen < ilen) {
		tmp = NULL;
		if (!strstr(ptr, "JIT code"))
			continue;
		pptr = ptr;
		while ((ptr = strstr(pptr, ":")))
			pptr = ptr + 1;
		ptr = pptr;
		do {
			image[ulen++] = (uint8_t) strtoul(pptr, &pptr, 16);
			if (ptr == pptr || ulen >= ilen) {
				ulen--;
				break;
			}
			ptr = pptr;
		} while (1);
	}

	assert(ulen == proglen);
	printf("%d bytes emitted from JIT compiler (pass:%d, flen:%d)\n",
	       proglen, pass, flen);
	printf("%lx + <x>:\n", *base);

	regfree(&regex);
	return ulen;
}

int main(int argc, char **argv)
{
	int len, klen, opcodes = 0;
	char *kbuff;
	unsigned long base;
	uint8_t image[4096];

	if (argc > 1) {
		if (!strncmp("-o", argv[argc - 1], 2)) {
			opcodes = 1;
		} else {
			printf("usage: bpf_jit_disasm [-o: show opcodes]\n");
			exit(0);
		}
	}

	bfd_init();
	memset(image, 0, sizeof(image));

	kbuff = get_klog_buff(&klen);

	len = get_last_jit_image(kbuff, klen, image, sizeof(image), &base);
	if (len > 0 && base > 0)
		get_asm_insns(image, len, base, opcodes);

	put_klog_buff(kbuff);

	return 0;
}
n></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-25 14:30:04 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-25 14:30:04 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/sound/hda_register.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>3ddc76dfc786cc6f87852693227fb0b1f124f807</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/sound/hda_register.h?id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>8192b4721e05cf6823087f9696db8c0c8f144b02</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/sound/hda_register.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>include/sound/hda_register.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/sound/hda_register.h?h=nds-private-remove&amp;id=b272f732f888d4cf43c943a40c9aaa836f9b7431'>b272f732f888d4cf43c943a40c9aaa836f9b7431</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/sound/hda_register.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807&amp;id2=b272f732f888d4cf43c943a40c9aaa836f9b7431'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/sound/hda_register.h?h=nds-private-remove&amp;id=1f3a8e49d8f28f498b8694464623ac20aebfe62a'>1f3a8e49d8f28f498b8694464623ac20aebfe62a</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/sound/hda_register.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807&amp;id2=1f3a8e49d8f28f498b8694464623ac20aebfe62a'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</div><div class='commit-msg'>Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>Diffstat</a> (limited to 'include/sound/hda_register.h')</div><table summary='diffstat' class='diffstat'>