// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2019 ARM Limited */
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <sys/auxv.h>
#include <linux/auxvec.h>
#include <ucontext.h>
#include <asm/unistd.h>
#include <kselftest.h>
#include "test_signals.h"
#include "test_signals_utils.h"
#include "testcases/testcases.h"
extern struct tdescr *current;
static int sig_copyctx = SIGTRAP;
static char const *const feats_names[FMAX_END] = {
" SSBS ",
" SVE ",
" SME ",
" FA64 ",
" SME2 ",
};
#define MAX_FEATS_SZ 128
static char feats_string[MAX_FEATS_SZ];
static inline char *feats_to_string(unsigned long feats)
{
size_t flen = MAX_FEATS_SZ - 1;
feats_string[0] = '\0';
for (int i = 0; i < FMAX_END; i++) {
if (feats & (1UL << i)) {
size_t tlen = strlen(feats_names[i]);
assert(flen > tlen);
flen -= tlen;
strncat(feats_string, feats_names[i], flen);
}
}
return feats_string;
}
static void unblock_signal(int signum)
{
sigset_t sset;
sigemptyset(&sset);
sigaddset(&sset, signum);
sigprocmask(SIG_UNBLOCK, &sset, NULL);
}
static void default_result(struct tdescr *td, bool force_exit)
{
if (td->result == KSFT_SKIP) {
fprintf(stderr, "==>> completed. SKIP.\n");
} else if (td->pass) {
fprintf(stderr, "==>> completed. PASS(1)\n");
td->result = KSFT_PASS;
} else {
fprintf(stdout, "==>> completed. FAIL(0)\n");
td->result = KSFT_FAIL;
}
if (force_exit)
exit(td->result);
}
/*
* The following handle_signal_* helpers are used by main default_handler
* and are meant to return true when signal is handled successfully:
* when false is returned instead, it means that the signal was somehow
* unexpected in that context and it was NOT handled; default_handler will
* take care of such unexpected situations.
*/
static bool handle_signal_unsupported(struct tdescr *td,
siginfo_t *si, void *uc)
{
if (feats_ok(td))
return false;
/* Mangling PC to avoid loops on original SIGILL */
((ucontext_t *)uc)->uc_mcontext.pc += 4;
if (!td->initialized) {
fprintf(stderr,
"Got SIG_UNSUPP @test_init. Ignore.\n");
} else {
fprintf(stderr,
"-- RX SIG_UNSUPP on unsupported feat...OK\n");
td->pass = 1;
default_result(current, 1);
}
return true;
}
static bool handle_signal_trigger(struct tdescr *td,
siginfo_t *si, void *uc)
{
td->triggered = 1;
/* ->run was asserted NON-NULL in test_setup() already */
td->run(td, si, uc);
return true;
}
static bool handle_signal_ok(struct tdescr *td,
siginfo_t *si, void *uc)
{
/*
* it's a bug in the test code when this assert fail:
* if sig_trig was defined, it must have been used before getting here.
*/
assert(!td->sig_trig || td->triggered);
fprintf(stderr,
"SIG_OK -- SP:0x%llX si_addr@:%p si_code:%d token@:%p offset:%ld\n",
((ucontext_t *)uc)->uc_mcontext.sp,
si->si_addr, si->si_code, td->token, td->token - si->si_addr);
/*
* fake_sigreturn tests, which have sanity_enabled=1, set, at the very
* last time, the token field to the SP address used to place the fake
* sigframe: so token==0 means we never made it to the end,
* segfaulting well-before, and the test is possibly broken.
*/
if (!td->sanity_disabled && !td->token) {
fprintf(stdout,
"current->token ZEROED...test is probably broken!\n");
abort();
}
/*
* Trying to narrow down the SEGV to the ones generated by Kernel itself
* via arm64_notify_segfault(). This is a best-effort check anyway, and
* the si_code check may need to change if this aspect of the kernel
* ABI changes.
*/
if (td->sig_ok == SIGSEGV && si->si_code != SEGV_ACCERR) {
fprintf(stdout,
"si_code != SEGV_ACCERR...test is probably broken!\n");
abort();
}
td->pass = 1;
/*
* Some tests can lead to SEGV loops: in such a case we want to
* terminate immediately exiting straight away; some others are not
* supposed to outlive the signal handler code, due to the content of
* the fake sigframe which caused the signal itself.
*/
default_result(current, 1);
return true;
}
static bool handle_signal_copyctx(struct tdescr *td,
siginfo_t *si, void *uc_in)
{
ucontext_t *uc = uc_in;
struct _aarch64_ctx *head;
struct extra_context *extra, *copied_extra;
size_t offset = 0;
size_t to_copy;
ASSERT_GOOD_CONTEXT(uc);
/* Mangling PC to avoid loops on original BRK instr */
uc->uc_mcontext.pc += 4;
/*
* Check for an preserve any extra data too with fixups.
*/
head = (struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
head = get_header(head, EXTRA_MAGIC, td->live_sz, &offset);
if (head) {
extra = (struct extra_context *)head;
/*
* The extra buffer must be immediately after the
* extra_context and a 16 byte terminator. Include it
* in the copy, this was previously validated in
* ASSERT_GOOD_CONTEXT().
*/
to_copy = __builtin_offsetof(ucontext_t,
uc_mcontext.__reserved);
to_copy += offset + sizeof(struct extra_context) + 16;
to_copy += extra->size;
copied_extra = (struct extra_context *)&(td->live_uc->uc_mcontext.__reserved[offset]);
} else {
copied_extra = NULL;
to_copy = sizeof(ucontext_t);
}
if (to_copy > td->live_sz) {
fprintf(stderr,
"Not enough space to grab context, %lu/%lu bytes\n",
td->live_sz, to_copy);
return false;
}
memcpy(td->live_uc, uc, to_copy);
/*
* If there was any EXTRA_CONTEXT fix up the size to be the
* struct extra_context and the following terminator record,
* this means that the rest of the code does not need to have
* special handling for the record and we don't need to fix up
* datap for the new location.
*/
if (copied_extra)
copied_extra->head.size = sizeof(*copied_extra) + 16;
td->live_uc_valid = 1;
fprintf(stderr,
"%lu byte GOOD CONTEXT grabbed from sig_copyctx handler\n",
to_copy);
return true;
}
static void default_handler(int signum, siginfo_t *si, void *uc)
{
if (current->sig_unsupp && signum == current->sig_unsupp &&
handle_signal_unsupported(current, si, uc)) {
fprintf(stderr, "Handled SIG_UNSUPP\n");
} else if (current->sig_trig && signum == current->sig_trig &&
handle_signal_trigger(current, si, uc)) {
fprintf(stderr, "Handled SIG_TRIG\n");
} else if (current->sig_ok && signum == current->sig_ok &&
handle_signal_ok(current, si, uc)) {
fprintf(stderr, "Handled SIG_OK\n");
} else if (signum == sig_copyctx && current->live_uc &&
handle_signal_copyctx(current, si, uc)) {
fprintf(stderr, "Handled SIG_COPYCTX\n");
} else {
if (signum == SIGALRM && current->timeout) {
fprintf(stderr, "-- Timeout !\n");
} else {
fprintf(stderr,
"-- RX UNEXPECTED SIGNAL: %d code %d address %p\n",
signum, si->si_code, si->si_addr);
}
default_result(current, 1);
}
}
static int default_setup(struct tdescr *td)
{
struct sigaction sa;
sa.sa_sigaction = default_handler;
sa.sa_flags = SA_SIGINFO | SA_RESTART;
sa.sa_flags |= td->sa_flags;
sigemptyset(&sa.sa_mask);
/* uncatchable signals naturally skipped ... */
for (int sig = 1; sig < 32; sig++)
sigaction(sig, &sa, NULL);
/*
* RT Signals default disposition is Term but they cannot be
* generated by the Kernel in response to our tests; so just catch
* them all and report them as UNEXPECTED signals.
*/
for (int sig = SIGRTMIN; sig <= SIGRTMAX; sig++)
sigaction(sig, &sa, NULL);
/* just in case...unblock explicitly all we need */
if (td->sig_trig)
unblock_signal(td->sig_trig);
if (td->sig_ok)
unblock_signal(td->sig_ok);
if (td->sig_unsupp)
unblock_signal(td->sig_unsupp);
if (td->timeout) {
unblock_signal(SIGALRM);
alarm(td->timeout);
}
fprintf(stderr, "Registered handlers for all signals.\n");
return 1;
}
static inline int default_trigger(struct tdescr *td)
{
return !raise(td->sig_trig);
}
int test_init(struct tdescr *td)
{
if (td->sig_trig == sig_copyctx) {
fprintf(stdout,
"Signal %d is RESERVED, cannot be used as a trigger. Aborting\n",
sig_copyctx);
return 0;
}
/* just in case */
unblock_signal(sig_copyctx);
td->minsigstksz = getauxval(AT_MINSIGSTKSZ);
if (!td->minsigstksz)
td->minsigstksz = MINSIGSTKSZ;
fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz);
if (td->feats_required || td->feats_incompatible) {
td->feats_supported = 0;
/*
* Checking for CPU required features using both the
* auxval and the arm64 MRS Emulation to read sysregs.
*/
if (getauxval(AT_HWCAP) & HWCAP_SSBS)
td->feats_supported |= FEAT_SSBS;
if (getauxval(AT_HWCAP) & HWCAP_SVE)
td->feats_supported |= FEAT_SVE;
if (getauxval(AT_HWCAP2) & HWCAP2_SME)
td->feats_supported |= FEAT_SME;
if (getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)
td->feats_supported |= FEAT_SME_FA64;
if (getauxval(AT_HWCAP2) & HWCAP2_SME2)
td->feats_supported |= FEAT_SME2;
if (feats_ok(td)) {
if (td->feats_required & td->feats_supported)
fprintf(stderr,
"Required Features: [%s] supported\n",
feats_to_string(td->feats_required &
td->feats_supported));
if (!(td->feats_incompatible & td->feats_supported))
fprintf(stderr,
"Incompatible Features: [%s] absent\n",
feats_to_string(td->feats_incompatible));
} else {
if ((td->feats_required & td->feats_supported) !=
td->feats_supported)
fprintf(stderr,
"Required Features: [%s] NOT supported\n",
feats_to_string(td->feats_required &
~td->feats_supported));
if (td->feats_incompatible & td->feats_supported)
fprintf(stderr,
"Incompatible Features: [%s] supported\n",
feats_to_string(td->feats_incompatible &
~td->feats_supported));
td->result = KSFT_SKIP;
return 0;
}
}
/* Perform test specific additional initialization */
if (td->init && !td->init(td)) {
fprintf(stderr, "FAILED Testcase initialization.\n");
return 0;
}
td->initialized = 1;
fprintf(stderr, "Testcase initialized.\n");
return 1;
}
int test_setup(struct tdescr *td)
{
/* assert core invariants symptom of a rotten testcase */
assert(current);
assert(td);
assert(td->name);
assert(td->run);
/* Default result is FAIL if test setup fails */
td->result = KSFT_FAIL;
if (td->setup)
return td->setup(td);
else
return default_setup(td);
}
int test_run(struct tdescr *td)
{
if (td->trigger)
return td->trigger(td);
else if (td->sig_trig)
return default_trigger(td);
else
return td->run(td, NULL, NULL);
}
void test_result(struct tdescr *td)
{
if (td->initialized && td->result != KSFT_SKIP && td->check_result)
td->check_result(td);
default_result(td, 0);
}
void test_cleanup(struct tdescr *td)
{
if (td->cleanup)
td->cleanup(td);
}
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