/*
* 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) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Linux for s390 port by D.J. Barrow
* <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#ifndef NSIG
# warning NSIG is not defined, using 32
# define NSIG 32
#elif NSIG < 32
# error NSIG < 32
#endif
/* The libc headers do not define this constant since it should only be
used by the implementation. So we define it here. */
#ifndef SA_RESTORER
# ifdef ASM_SA_RESTORER
# define SA_RESTORER ASM_SA_RESTORER
# endif
#endif
/*
* Some architectures define SA_RESTORER in their headers,
* but do not actually have sa_restorer.
*
* Some architectures, otherwise, do not define SA_RESTORER in their headers,
* but actually have sa_restorer.
*/
#ifdef SA_RESTORER
# if defined HPPA || defined IA64
# define HAVE_SA_RESTORER 0
# else
# define HAVE_SA_RESTORER 1
# endif
#else /* !SA_RESTORER */
# if defined SPARC || defined SPARC64 || defined M68K
# define HAVE_SA_RESTORER 1
# else
# define HAVE_SA_RESTORER 0
# endif
#endif
#include "xlat/sigact_flags.h"
#include "xlat/sigprocmaskcmds.h"
/* Anonymous realtime signals. */
#ifndef ASM_SIGRTMIN
/* Linux kernel >= 3.18 defines SIGRTMIN to 32 on all architectures. */
# define ASM_SIGRTMIN 32
#endif
#ifndef ASM_SIGRTMAX
/* Under glibc 2.1, SIGRTMAX et al are functions, but __SIGRTMAX is a
constant. This is what we want. Otherwise, just use SIGRTMAX. */
# ifdef SIGRTMAX
# ifndef __SIGRTMAX
# define __SIGRTMAX SIGRTMAX
# endif
# endif
# ifdef __SIGRTMAX
# define ASM_SIGRTMAX __SIGRTMAX
# endif
#endif
/* Note on the size of sigset_t:
*
* In glibc, sigset_t is an array with space for 1024 bits (!),
* even though all arches supported by Linux have only 64 signals
* except MIPS, which has 128. IOW, it is 128 bytes long.
*
* In-kernel sigset_t is sized correctly (it is either 64 or 128 bit long).
* However, some old syscall return only 32 lower bits (one word).
* Example: sys_sigpending vs sys_rt_sigpending.
*
* Be aware of this fact when you try to
* memcpy(&tcp->u_arg[1], &something, sizeof(sigset_t))
* - sizeof(sigset_t) is much bigger than you think,
* it may overflow tcp->u_arg[] array, and it may try to copy more data
* than is really available in <something>.
* Similarly,
* umoven(tcp, addr, sizeof(sigset_t), &sigset)
* may be a bad idea: it'll try to read much more data than needed
* to fetch a sigset_t.
* Use (NSIG / 8) as a size instead.
*/
const char *
signame(const int sig)
{
static char buf[sizeof("SIGRT_%u") + sizeof(int)*3];
if (sig >= 0) {
const unsigned int s = sig;
if (s < nsignals)
return signalent[s];
#ifdef ASM_SIGRTMAX
if (s >= ASM_SIGRTMIN && s <= ASM_SIGRTMAX) {
sprintf(buf, "SIGRT_%u", s - ASM_SIGRTMIN);
return buf;
}
#endif
}
sprintf(buf, "%d", sig);
return buf;
}
static unsigned int
popcount32(const uint32_t *a, unsigned int size)
{
unsigned int count = 0;
for (; size; ++a, --size) {
uint32_t x = *a;
#ifdef HAVE___BUILTIN_POPCOUNT
count += __builtin_popcount(x);
#else
for (; x; ++count)
x &= x - 1;
#endif
}
return count;
}
const char *
sprintsigmask_n(const char *prefix, const void *sig_mask, unsigned int bytes)
{
/*
* The maximum number of signal names to be printed is NSIG * 2 / 3.
* Most of signal names have length 7,
* average length of signal names is less than 7.
* The length of prefix string does not exceed 16.
*/
static char outstr[128 + 8 * (NSIG * 2 / 3)];
char *s;
const uint32_t *mask;
uint32_t inverted_mask[NSIG / 32];
unsigned int size;
int i;
char sep;
s = stpcpy(outstr, prefix);
mask = sig_mask;
/* length of signal mask in 4-byte words */
size = (bytes >= NSIG / 8) ? NSIG / 32 : (bytes + 3) / 4;
/* check whether 2/3 or more bits are set */
if (popcount32(mask, size) >= size * 32 * 2 / 3) {
/* show those signals that are NOT in the mask */
unsigned int j;
for (j = 0; j < size; ++j)
inverted_mask[j] = ~mask[j];
mask = inverted_mask;
*s++ = '~';
}
sep = '[';
for (i = 0; (i = next_set_bit(mask, i, size * 32)) >= 0; ) {
++i;
*s++ = sep;
if ((unsigned) i < nsignals) {
s = stpcpy(s, signalent[i] + 3);
}
#ifdef ASM_SIGRTMAX
else if (i >= ASM_SIGRTMIN && i <= ASM_SIGRTMAX) {
s += sprintf(s, "RT_%u", i - ASM_SIGRTMIN);
}
#endif
else {
s += sprintf(s, "%u", i);
}
sep = ' ';
}
if (sep == '[')
*s++ = sep;
*s++ = ']';
*s = '\0';
return outstr;
}
#define sprintsigmask_val(prefix, mask) \
sprintsigmask_n((prefix), &(mask), sizeof(mask))
#define tprintsigmask_val(prefix, mask) \
tprints(sprintsigmask_n((prefix), &(mask), sizeof(mask)))
void
printsignal(int nr)
{
tprints(signame(nr));
}
void
print_sigset_addr_len(struct tcb *tcp, long addr, long len)
{
char mask[NSIG / 8];
if (!addr) {
tprints("NULL");
return;
}
/* Here len is usually equals NSIG / 8 or current_wordsize.
* But we code this defensively:
*/
if (len < 0) {
bad:
tprintf("%#lx", addr);
return;
}
if (len >= NSIG / 8)
len = NSIG / 8;
else
len = (len + 3) & ~3;
if (umoven(tcp, addr, len, mask) < 0)
goto bad;
tprints(sprintsigmask_n("", mask, len));
}
SYS_FUNC(sigsetmask)
{
if (entering(tcp)) {
tprintsigmask_val("", tcp->u_arg[0]);
}
else if (!syserror(tcp)) {
tcp->auxstr = sprintsigmask_val("old mask ", tcp->u_rval);
return RVAL_HEX | RVAL_STR;
}
return 0;
}
#ifdef HAVE_SIGACTION
struct old_sigaction {
/* sa_handler may be a libc #define, need to use other name: */
#ifdef MIPS
unsigned int sa_flags;
void (*__sa_handler)(int);
/* Kernel treats sa_mask as an array of longs. */
unsigned long sa_mask[NSIG / sizeof(long) ? NSIG / sizeof(long) : 1];
#else
void (*__sa_handler)(int);
unsigned long sa_mask;
unsigned long sa_flags;
#endif /* !MIPS */
#if HAVE_SA_RESTORER
void (*sa_restorer)(void);
#endif
};
struct old_sigaction32 {
/* sa_handler may be a libc #define, need to use other name: */
uint32_t __sa_handler;
uint32_t sa_mask;
uint32_t sa_flags;
#if HAVE_SA_RESTORER
uint32_t sa_restorer;
#endif
};
static void
decode_old_sigaction(struct tcb *tcp, long addr)
{
struct old_sigaction sa;
int r;
if (!addr) {
tprints("NULL");
return;
}
if (!verbose(tcp) || (exiting(tcp) && syserror(tcp))) {
tprintf("%#lx", addr);
return;
}
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
if (current_wordsize != sizeof(sa.__sa_handler) && current_wordsize == 4) {
struct old_sigaction32 sa32;
r = umove(tcp, addr, &sa32);
if (r >= 0) {
memset(&sa, 0, sizeof(sa));
sa.__sa_handler = (void*)(uintptr_t)sa32.__sa_handler;
sa.sa_flags = sa32.sa_flags;
#if HAVE_SA_RESTORER && defined SA_RESTORER
sa.sa_restorer = (void*)(uintptr_t)sa32.sa_restorer;
#endif
sa.sa_mask = sa32.sa_mask;
}
} else
#endif
{
r = umove(tcp, addr, &sa);
}
if (r < 0) {
tprints("{...}");
return;
}
/* Architectures using function pointers, like
* hppa, may need to manipulate the function pointer
* to compute the result of a comparison. However,
* the __sa_handler function pointer exists only in
* the address space of the traced process, and can't
* be manipulated by strace. In order to prevent the
* compiler from generating code to manipulate
* __sa_handler we cast the function pointers to long. */
if ((long)sa.__sa_handler == (long)SIG_ERR)
tprints("{SIG_ERR, ");
else if ((long)sa.__sa_handler == (long)SIG_DFL)
tprints("{SIG_DFL, ");
else if ((long)sa.__sa_handler == (long)SIG_IGN)
tprints("{SIG_IGN, ");
else
tprintf("{%#lx, ", (long) sa.__sa_handler);
#ifdef MIPS
tprintsigmask_addr("", sa.sa_mask);
#else
tprintsigmask_val("", sa.sa_mask);
#endif
tprints(", ");
printflags(sigact_flags, sa.sa_flags, "SA_???");
#if HAVE_SA_RESTORER && defined SA_RESTORER
if (sa.sa_flags & SA_RESTORER)
tprintf(", %p", sa.sa_restorer);
#endif
tprints("}");
}
SYS_FUNC(sigaction)
{
if (entering(tcp)) {
printsignal(tcp->u_arg[0]);
tprints(", ");
decode_old_sigaction(tcp, tcp->u_arg[1]);
tprints(", ");
} else
decode_old_sigaction(tcp, tcp->u_arg[2]);
return 0;
}
SYS_FUNC(signal)
{
if (entering(tcp)) {
printsignal(tcp->u_arg[0]);
tprints(", ");
switch (tcp->u_arg[1]) {
case (long) SIG_ERR:
tprints("SIG_ERR");
break;
case (long) SIG_DFL:
tprints("SIG_DFL");
break;
case (long) SIG_IGN:
tprints("SIG_IGN");
break;
default:
tprintf("%#lx", tcp->u_arg[1]);
}
return 0;
}
else if (!syserror(tcp)) {
switch (tcp->u_rval) {
case (long) SIG_ERR:
tcp->auxstr = "SIG_ERR"; break;
case (long) SIG_DFL:
tcp->auxstr = "SIG_DFL"; break;
case (long) SIG_IGN:
tcp->auxstr = "SIG_IGN"; break;
default:
tcp->auxstr = NULL;
}
return RVAL_HEX | RVAL_STR;
}
return 0;
}
#endif /* HAVE_SIGACTION */
SYS_FUNC(siggetmask)
{
if (exiting(tcp)) {
tcp->auxstr = sprintsigmask_val("mask ", tcp->u_rval);
}
return RVAL_HEX | RVAL_STR;
}
SYS_FUNC(sigsuspend)
{
if (entering(tcp)) {
tprintsigmask_val("", tcp->u_arg[2]);
}
return 0;
}
#ifdef HAVE_SIGACTION
/* "Old" sigprocmask, which operates with word-sized signal masks */
SYS_FUNC(sigprocmask)
{
# ifdef ALPHA
if (entering(tcp)) {
/*
* Alpha/OSF is different: it doesn't pass in two pointers,
* but rather passes in the new bitmask as an argument and
* then returns the old bitmask. This "works" because we
* only have 64 signals to worry about. If you want more,
* use of the rt_sigprocmask syscall is required.
* Alpha:
* old = osf_sigprocmask(how, new);
* Everyone else:
* ret = sigprocmask(how, &new, &old, ...);
*/
printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
tprintsigmask_val(", ", tcp->u_arg[1]);
}
else if (!syserror(tcp)) {
tcp->auxstr = sprintsigmask_val("old mask ", tcp->u_rval);
return RVAL_HEX | RVAL_STR;
}
# else /* !ALPHA */
if (entering(tcp)) {
printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
tprints(", ");
print_sigset_addr_len(tcp, tcp->u_arg[1], current_wordsize);
tprints(", ");
}
else {
if (syserror(tcp))
tprintf("%#lx", tcp->u_arg[2]);
else
print_sigset_addr_len(tcp, tcp->u_arg[2], current_wordsize);
}
# endif /* !ALPHA */
return 0;
}
#endif /* HAVE_SIGACTION */
SYS_FUNC(kill)
{
if (entering(tcp)) {
tprintf("%ld, %s",
widen_to_long(tcp->u_arg[0]),
signame(tcp->u_arg[1])
);
}
return 0;
}
SYS_FUNC(tgkill)
{
if (entering(tcp)) {
tprintf("%ld, %ld, %s",
widen_to_long(tcp->u_arg[0]),
widen_to_long(tcp->u_arg[1]),
signame(tcp->u_arg[2])
);
}
return 0;
}
SYS_FUNC(sigpending)
{
if (exiting(tcp)) {
if (syserror(tcp))
tprintf("%#lx", tcp->u_arg[0]);
else
print_sigset_addr_len(tcp, tcp->u_arg[0], current_wordsize);
}
return 0;
}
SYS_FUNC(rt_sigprocmask)
{
/* Note: arg[3] is the length of the sigset. Kernel requires NSIG / 8 */
if (entering(tcp)) {
printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
tprints(", ");
print_sigset_addr_len(tcp, tcp->u_arg[1], tcp->u_arg[3]);
tprints(", ");
}
else {
if (syserror(tcp))
tprintf("%#lx", tcp->u_arg[2]);
else
print_sigset_addr_len(tcp, tcp->u_arg[2], tcp->u_arg[3]);
tprintf(", %lu", tcp->u_arg[3]);
}
return 0;
}
/* Structure describing the action to be taken when a signal arrives. */
struct new_sigaction
{
/* sa_handler may be a libc #define, need to use other name: */
#ifdef MIPS
unsigned int sa_flags;
void (*__sa_handler)(int);
#else
void (*__sa_handler)(int);
unsigned long sa_flags;
#endif /* !MIPS */
#if HAVE_SA_RESTORER
void (*sa_restorer)(void);
#endif
/* Kernel treats sa_mask as an array of longs. */
unsigned long sa_mask[NSIG / sizeof(long) ? NSIG / sizeof(long) : 1];
};
/* Same for i386-on-x86_64 and similar cases */
struct new_sigaction32
{
uint32_t __sa_handler;
uint32_t sa_flags;
#if HAVE_SA_RESTORER
uint32_t sa_restorer;
#endif
uint32_t sa_mask[2 * (NSIG / sizeof(long) ? NSIG / sizeof(long) : 1)];
};
static void
decode_new_sigaction(struct tcb *tcp, long addr)
{
struct new_sigaction sa;
int r;
if (!addr) {
tprints("NULL");
return;
}
if (!verbose(tcp) || (exiting(tcp) && syserror(tcp))) {
tprintf("%#lx", addr);
return;
}
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
if (current_wordsize != sizeof(sa.sa_flags) && current_wordsize == 4) {
struct new_sigaction32 sa32;
r = umove(tcp, addr, &sa32);
if (r >= 0) {
memset(&sa, 0, sizeof(sa));
sa.__sa_handler = (void*)(unsigned long)sa32.__sa_handler;
sa.sa_flags = sa32.sa_flags;
#if HAVE_SA_RESTORER && defined SA_RESTORER
sa.sa_restorer = (void*)(unsigned long)sa32.sa_restorer;
#endif
/* Kernel treats sa_mask as an array of longs.
* For 32-bit process, "long" is uint32_t, thus, for example,
* 32th bit in sa_mask will end up as bit 0 in sa_mask[1].
* But for (64-bit) kernel, 32th bit in sa_mask is
* 32th bit in 0th (64-bit) long!
* For little-endian, it's the same.
* For big-endian, we swap 32-bit words.
*/
sa.sa_mask[0] = sa32.sa_mask[0] + ((long)(sa32.sa_mask[1]) << 32);
}
} else
#endif
{
r = umove(tcp, addr, &sa);
}
if (r < 0) {
tprints("{...}");
return;
}
/* Architectures using function pointers, like
* hppa, may need to manipulate the function pointer
* to compute the result of a comparison. However,
* the __sa_handler function pointer exists only in
* the address space of the traced process, and can't
* be manipulated by strace. In order to prevent the
* compiler from generating code to manipulate
* __sa_handler we cast the function pointers to long. */
if ((long)sa.__sa_handler == (long)SIG_ERR)
tprints("{SIG_ERR, ");
else if ((long)sa.__sa_handler == (long)SIG_DFL)
tprints("{SIG_DFL, ");
else if ((long)sa.__sa_handler == (long)SIG_IGN)
tprints("{SIG_IGN, ");
else
tprintf("{%#lx, ", (long) sa.__sa_handler);
/*
* Sigset size is in tcp->u_arg[4] (SPARC)
* or in tcp->u_arg[3] (all other),
* but kernel won't handle sys_rt_sigaction
* with wrong sigset size (just returns EINVAL instead).
* We just fetch the right size, which is NSIG / 8.
*/
tprintsigmask_val("", sa.sa_mask);
tprints(", ");
printflags(sigact_flags, sa.sa_flags, "SA_???");
#if HAVE_SA_RESTORER && defined SA_RESTORER
if (sa.sa_flags & SA_RESTORER)
tprintf(", %p", sa.sa_restorer);
#endif
tprints("}");
}
SYS_FUNC(rt_sigaction)
{
if (entering(tcp)) {
printsignal(tcp->u_arg[0]);
tprints(", ");
decode_new_sigaction(tcp, tcp->u_arg[1]);
tprints(", ");
} else {
decode_new_sigaction(tcp, tcp->u_arg[2]);
#if defined(SPARC) || defined(SPARC64)
tprintf(", %#lx, %lu", tcp->u_arg[3], tcp->u_arg[4]);
#elif defined(ALPHA)
tprintf(", %lu, %#lx", tcp->u_arg[3], tcp->u_arg[4]);
#else
tprintf(", %lu", tcp->u_arg[3]);
#endif
}
return 0;
}
SYS_FUNC(rt_sigpending)
{
if (exiting(tcp)) {
/*
* One of the few syscalls where sigset size (arg[1])
* is allowed to be <= NSIG / 8, not strictly ==.
* This allows non-rt sigpending() syscall
* to reuse rt_sigpending() code in kernel.
*/
if (syserror(tcp))
tprintf("%#lx", tcp->u_arg[0]);
else
print_sigset_addr_len(tcp, tcp->u_arg[0], tcp->u_arg[1]);
tprintf(", %lu", tcp->u_arg[1]);
}
return 0;
}
SYS_FUNC(rt_sigsuspend)
{
if (entering(tcp)) {
/* NB: kernel requires arg[1] == NSIG / 8 */
print_sigset_addr_len(tcp, tcp->u_arg[0], tcp->u_arg[1]);
tprintf(", %lu", tcp->u_arg[1]);
}
return 0;
}
static void
print_sigqueueinfo(struct tcb *tcp, int sig, unsigned long uinfo)
{
printsignal(sig);
tprints(", ");
printsiginfo_at(tcp, uinfo);
}
SYS_FUNC(rt_sigqueueinfo)
{
if (entering(tcp)) {
tprintf("%lu, ", tcp->u_arg[0]);
print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
}
return 0;
}
SYS_FUNC(rt_tgsigqueueinfo)
{
if (entering(tcp)) {
tprintf("%lu, %lu, ", tcp->u_arg[0], tcp->u_arg[1]);
print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
}
return 0;
}
SYS_FUNC(rt_sigtimedwait)
{
/* NB: kernel requires arg[3] == NSIG / 8 */
if (entering(tcp)) {
print_sigset_addr_len(tcp, tcp->u_arg[0], tcp->u_arg[3]);
tprints(", ");
/* This is the only "return" parameter, */
if (tcp->u_arg[1] != 0)
return 0;
/* ... if it's NULL, can decode all on entry */
tprints("NULL, ");
}
else if (tcp->u_arg[1] != 0) {
/* syscall exit, and u_arg[1] wasn't NULL */
printsiginfo_at(tcp, tcp->u_arg[1]);
tprints(", ");
}
else {
/* syscall exit, and u_arg[1] was NULL */
return 0;
}
print_timespec(tcp, tcp->u_arg[2]);
tprintf(", %lu", tcp->u_arg[3]);
return 0;
};
SYS_FUNC(restart_syscall)
{
if (entering(tcp)) {
tprintf("<... resuming interrupted %s ...>",
tcp->s_prev_ent
? tcp->s_prev_ent->sys_name
: "system call"
);
}
return 0;
}
static int
do_signalfd(struct tcb *tcp, int flags_arg)
{
/* NB: kernel requires arg[2] == NSIG / 8 */
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
tprints(", ");
print_sigset_addr_len(tcp, tcp->u_arg[1], tcp->u_arg[2]);
tprintf(", %lu", tcp->u_arg[2]);
if (flags_arg >= 0) {
tprints(", ");
printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
}
}
return 0;
}
SYS_FUNC(signalfd)
{
return do_signalfd(tcp, -1);
}
SYS_FUNC(signalfd4)
{
return do_signalfd(tcp, 3);
}