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/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 2005-2007 Roland McGrath <roland@redhat.com>
* Copyright (c) 2006-2007 Ulrich Drepper <drepper@redhat.com>
* Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
* Copyright (c) 2005-2015 Dmitry V. Levin <ldv@strace.io>
* Copyright (c) 2014-2022 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
#include "xstring.h"
#include "kernel_fcntl.h"
#include "number_set.h"
#include <linux/openat2.h>
#include <linux/fcntl.h>
#include "xlat/open_access_modes.h"
#include "xlat/open_mode_flags.h"
#include "xlat/open_resolve_flags.h"
/* The fd is an "int", so when decoding x86 on x86_64, we need to force sign
* extension to get the right value. We do this by declaring fd as int here.
*/
void
print_dirfd(struct tcb *tcp, int fd)
{
if (fd == AT_FDCWD) {
print_xlat_d(AT_FDCWD);
if (!is_number_in_set(DECODE_FD_PATH, decode_fd_set))
goto done;
int proc_pid = get_proc_pid(tcp->pid);
if (!proc_pid)
goto done;
static const char cwd_path[] = "/proc/%u/cwd";
char linkpath[sizeof(cwd_path) + sizeof(int) * 3];
xsprintf(linkpath, cwd_path, proc_pid);
char buf[PATH_MAX];
ssize_t n = readlink(linkpath, buf, sizeof(buf));
if ((size_t) n >= sizeof(buf))
goto done;
tprint_associated_info_begin();
print_quoted_string_ex(buf, n,
QUOTE_OMIT_LEADING_TRAILING_QUOTES,
"<>");
tprint_associated_info_end();
done: ;
} else {
printfd(tcp, fd);
}
#ifdef ENABLE_SECONTEXT
tcp->last_dirfd = fd;
#endif
}
/*
* low bits of the open(2) flags define access mode,
* other bits are real flags.
*/
static const char *
sprint_open_modes64(uint64_t flags)
{
static char outstr[sizeof("flags O_ACCMODE")];
char *p;
char sep;
const char *str;
sep = ' ';
p = stpcpy(outstr, "flags");
str = xlookup(open_access_modes, flags & 3);
if (str) {
*p++ = sep;
p = stpcpy(p, str);
flags &= ~3;
if (!flags)
return outstr;
sep = '|';
}
*p = '\0';
return sprintflags_ex(outstr, open_mode_flags, flags, sep,
XLAT_STYLE_ABBREV) ?: outstr;
}
const char *
sprint_open_modes(unsigned int flags)
{
return sprint_open_modes64(flags);
}
static void
tprint_open_modes64(uint64_t flags)
{
print_xlat_ex(flags, sprint_open_modes64(flags) + sizeof("flags"),
XLAT_STYLE_DEFAULT);
}
void
tprint_open_modes(unsigned int flags)
{
tprint_open_modes64(flags);
}
static int
decode_open(struct tcb *tcp, int offset)
{
/* pathname */
printpath(tcp, tcp->u_arg[offset]);
tprint_arg_next();
/* flags */
tprint_open_modes(tcp->u_arg[offset + 1]);
if (tcp->u_arg[offset + 1] & (O_CREAT | __O_TMPFILE)) {
tprint_arg_next();
/* mode */
print_numeric_umode_t(tcp->u_arg[offset + 2]);
}
return RVAL_DECODED | RVAL_FD;
}
SYS_FUNC(open)
{
return decode_open(tcp, 0);
}
static void
print_open_how(struct tcb *tcp, kernel_ulong_t addr, kernel_ulong_t size)
{
enum { OPEN_HOW_MIN_SIZE = 24 };
struct open_how how;
if (size < OPEN_HOW_MIN_SIZE) {
printaddr(addr);
return;
}
if (umoven_or_printaddr(tcp, addr, MIN(size, sizeof(how)), &how))
return;
tprint_struct_begin();
PRINT_FIELD_OBJ_VAL(how, flags, tprint_open_modes64);
if ((how.flags & (O_CREAT | __O_TMPFILE)) || how.mode) {
tprint_struct_next();
PRINT_FIELD_OBJ_U(how, mode, print_numeric_ll_umode_t);
}
tprint_struct_next();
PRINT_FIELD_FLAGS(how, resolve, open_resolve_flags, "RESOLVE_???");
if (size > sizeof(how)) {
print_nonzero_bytes(tcp, tprint_struct_next, addr, sizeof(how),
MIN(size, get_pagesize()), QUOTE_FORCE_HEX);
}
tprint_struct_end();
}
SYS_FUNC(openat)
{
/* dirfd */
print_dirfd(tcp, tcp->u_arg[0]);
tprint_arg_next();
return decode_open(tcp, 1);
}
SYS_FUNC(openat2)
{
/* dirfd */
print_dirfd(tcp, tcp->u_arg[0]);
tprint_arg_next();
/* pathname */
printpath(tcp, tcp->u_arg[1]);
tprint_arg_next();
/* how */
print_open_how(tcp, tcp->u_arg[2], tcp->u_arg[3]);
tprint_arg_next();
/* size */
PRINT_VAL_U(tcp->u_arg[3]);
return RVAL_DECODED | RVAL_FD;
}
SYS_FUNC(creat)
{
/* pathname */
printpath(tcp, tcp->u_arg[0]);
tprint_arg_next();
/* mode */
print_numeric_umode_t(tcp->u_arg[1]);
return RVAL_DECODED | RVAL_FD;
}
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