106 lines
4.4 KiB
C
106 lines
4.4 KiB
C
|
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
||
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
||
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
||
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
||
|
|
│ │
|
||
|
|
│ This program is free software; you can redistribute it and/or modify │
|
||
|
|
│ it under the terms of the GNU General Public License as published by │
|
||
|
|
│ the Free Software Foundation; version 2 of the License. │
|
||
|
|
│ │
|
||
|
|
│ This program is distributed in the hope that it will be useful, but │
|
||
|
|
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
|
||
|
|
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
|
||
|
|
│ General Public License for more details. │
|
||
|
|
│ │
|
||
|
|
│ You should have received a copy of the GNU General Public License │
|
||
|
|
│ along with this program; if not, write to the Free Software │
|
||
|
|
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
|
||
|
|
│ 02110-1301 USA │
|
||
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
||
|
|
#include "libc/bits/safemacros.h"
|
||
|
|
#include "libc/calls/calls.h"
|
||
|
|
#include "libc/calls/struct/sigaction.h"
|
||
|
|
#include "libc/calls/ucontext.h"
|
||
|
|
#include "libc/runtime/buffer.h"
|
||
|
|
#include "libc/runtime/runtime.h"
|
||
|
|
#include "libc/stdio/stdio.h"
|
||
|
|
#include "libc/str/str.h"
|
||
|
|
#include "libc/sysv/consts/fileno.h"
|
||
|
|
#include "libc/sysv/consts/prot.h"
|
||
|
|
#include "libc/sysv/consts/sa.h"
|
||
|
|
#include "libc/sysv/consts/sig.h"
|
||
|
|
#include "libc/testlib/testlib.h"
|
||
|
|
#include "libc/x/x.h"
|
||
|
|
#include "third_party/xed/x86.h"
|
||
|
|
|
||
|
|
char *p;
|
||
|
|
bool segfaulted_;
|
||
|
|
struct GuardedBuffer b_;
|
||
|
|
struct sigaction oldsegv_;
|
||
|
|
struct XedDecodedInst xedd_;
|
||
|
|
|
||
|
|
void RestrictPage(void *addr, unsigned flags) {
|
||
|
|
addr = (void *)rounddown((intptr_t)addr, PAGESIZE);
|
||
|
|
EXPECT_NE(-1, mprotect(addr, PAGESIZE, flags));
|
||
|
|
}
|
||
|
|
|
||
|
|
void OnSegLol(int sig, struct siginfo *si, struct ucontext *uc) {
|
||
|
|
size_t i;
|
||
|
|
uint8_t *rip;
|
||
|
|
segfaulted_ = true;
|
||
|
|
rip = (uint8_t *)uc->uc_mcontext.rip;
|
||
|
|
RestrictPage(rip, PROT_READ | PROT_WRITE | PROT_EXEC);
|
||
|
|
ASSERT_EQ(XED_ERROR_NONE,
|
||
|
|
xed_instruction_length_decode(xed_decoded_inst_zero_set_mode(
|
||
|
|
&xedd_, XED_MACHINE_MODE_LONG_64),
|
||
|
|
rip, XED_MAX_INSTRUCTION_BYTES));
|
||
|
|
for (i = 0; i < xedd_.decoded_length; ++i) rip[i] = 0x90; /* NOP */
|
||
|
|
RestrictPage(rip, PROT_READ | PROT_EXEC);
|
||
|
|
}
|
||
|
|
|
||
|
|
void SetUp(void) {
|
||
|
|
segfaulted_ = false;
|
||
|
|
memset(&b_, 0, sizeof(b_));
|
||
|
|
ASSERT_NE(-1, xsigaction(SIGSEGV, OnSegLol, SA_RESETHAND | SA_RESTART, 0,
|
||
|
|
&oldsegv_));
|
||
|
|
}
|
||
|
|
|
||
|
|
void TearDown(void) {
|
||
|
|
EXPECT_NE(-1, sigaction(SIGSEGV, &oldsegv_, NULL));
|
||
|
|
bfree(&b_);
|
||
|
|
EXPECT_EQ(NULL, b_.p);
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(balloc, createsGuardPage) {
|
||
|
|
ASSERT_NE(NULL, (p = balloc(&b_, 1, 1)));
|
||
|
|
EXPECT_EQ(p, b_.p);
|
||
|
|
p[0] = '.';
|
||
|
|
ASSERT_FALSE(segfaulted_);
|
||
|
|
/* TODO(jart): fix me!!! */
|
||
|
|
/* p[1 + __BIGGEST_ALIGNMENT__] = '!'; */
|
||
|
|
/* EXPECT_TRUE(segfaulted_); */
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(balloc, aligned_roundsUp) {
|
||
|
|
ASSERT_NE(NULL, (p = balloc(&b_, 128, 1)));
|
||
|
|
EXPECT_EQ(0, (intptr_t)b_.p & 127);
|
||
|
|
p[127] = '.';
|
||
|
|
ASSERT_FALSE(segfaulted_);
|
||
|
|
/* TODO(jart): fix me!!! */
|
||
|
|
/* p[128 + __BIGGEST_ALIGNMENT__] = '!'; */
|
||
|
|
/* EXPECT_TRUE(segfaulted_); */
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(balloc, multipleCalls_avoidsNeedlessSyscalls) {
|
||
|
|
size_t c;
|
||
|
|
c = g_syscount;
|
||
|
|
ASSERT_NE(NULL, (p = balloc(&b_, 1, 31337)));
|
||
|
|
EXPECT_GT(g_syscount, c);
|
||
|
|
c = g_syscount;
|
||
|
|
ASSERT_NE(NULL, (p = balloc(&b_, 1, 31337 / 2)));
|
||
|
|
EXPECT_EQ(g_syscount, c);
|
||
|
|
c = g_syscount;
|
||
|
|
ASSERT_NE(NULL, (p = balloc(&b_, 1, 31337 * 2)));
|
||
|
|
EXPECT_GT(g_syscount, c);
|
||
|
|
}
|