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Improve memory safety

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This commit makes numerous refinements to cosmopolitan memory handling.

The default stack size has been reduced from 2mb to 128kb. A new macro
is now provided so you can easily reconfigure the stack size to be any
value you want. Work around the breaking change by adding to your main:

    STATIC_STACK_SIZE(0x00200000);  // 2mb stack

If you're not sure how much stack you need, then you can use:

    STATIC_YOINK("stack_usage_logging");

After which you can `sort -nr o/$MODE/stack.log`. Based on the unit test
suite, nothing in the Cosmopolitan repository (except for Python) needs
a stack size greater than 30kb. There are also new macros for detecting
the size and address of the stack at runtime, e.g. GetStackAddr(). We
also now support sigaltstack() so if you want to see nice looking crash
reports whenever a stack overflow happens, you can put this in main():

    ShowCrashReports();

Under `make MODE=dbg` and `make MODE=asan` the unit testing framework
will now automatically print backtraces of memory allocations when
things like memory leaks happen. Bugs are now fixed in ASAN global
variable overrun detection. The memtrack and asan runtimes also handle
edge cases now. The new tools helped to identify a few memory leaks,
which are fixed by this change.

This change should fix an issue reported in #288 with ARG_MAX limits.
Fixing this doubled the performance of MKDEPS.COM and AR.COM yet again.
This commit is contained in:
Justine Tunney 2021-10-13 17:27:13 -07:00
parent a0b39f886c
commit 226aaf3547
317 changed files with 6474 additions and 3993 deletions
Download patch file Download diff file Expand all files Collapse all files

127
libc/intrin/ubsan.c
View file

@ -22,6 +22,7 @@
#include "libc/calls/calls.h"
#include "libc/fmt/fmt.h"
#include "libc/log/internal.h"
#include "libc/log/libfatal.internal.h"
#include "libc/log/log.h"
#include "libc/nt/runtime.h"
#include "libc/runtime/internal.h"
@ -151,55 +152,19 @@ static bool __ubsan_negative(struct UbsanTypeDescriptor *t, uintptr_t x) {
return __ubsan_signed(t) && (intptr_t)x < 0;
}
static size_t __ubsan_strlen(const char *s) {
size_t n = 0;
while (*s++) ++n;
return n;
}
static char *__ubsan_stpcpy(char *d, const char *s) {
size_t i;
for (i = 0;; ++i) {
if (!(d[i] = s[i])) {
return d + i;
}
}
}
static char *__ubsan_poscpy(char *p, uintptr_t i) {
int j = 0;
do {
p[j++] = i % 10 + '0';
i /= 10;
} while (i > 0);
reverse(p, j);
return p + j;
}
static char *__ubsan_intcpy(char *p, intptr_t i) {
if (i >= 0) return __ubsan_poscpy(p, i);
*p++ = '-';
return __ubsan_poscpy(p, -i);
}
static char *__ubsan_hexcpy(char *p, uintptr_t x, int k) {
while (k) *p++ = "0123456789abcdef"[(x >> (k -= 4)) & 15];
return p;
}
static char *__ubsan_itpcpy(char *p, struct UbsanTypeDescriptor *t,
uintptr_t x) {
if (__ubsan_signed(t)) {
return __ubsan_intcpy(p, x);
return __intcpy(p, x);
} else {
return __ubsan_poscpy(p, x);
return __uintcpy(p, x);
}
}
static const char *__ubsan_dubnul(const char *s, unsigned i) {
size_t n;
while (i--) {
if ((n = __ubsan_strlen(s))) {
if ((n = __strlen(s))) {
s += n + 1;
} else {
return NULL;
@ -222,53 +187,11 @@ static uintptr_t __ubsan_extend(struct UbsanTypeDescriptor *t, uintptr_t x) {
return x;
}
static privileged noinline wontreturn void __ubsan_exit(int rc) {
if (!IsWindows()) {
asm volatile("syscall"
: /* no outputs */
: "a"(__NR_exit_group), "D"(rc)
: "memory");
unreachable;
} else {
ExitProcess(rc);
}
}
static privileged noinline ssize_t __ubsan_write(const void *data,
size_t size) {
ssize_t rc;
uint32_t wrote;
if (!IsWindows()) {
asm volatile("syscall"
: "=a"(rc)
: "0"(__NR_write), "D"(2), "S"(data), "d"(size)
: "rcx", "r11", "memory");
return rc;
} else {
if (WriteFile(GetStdHandle(kNtStdErrorHandle), data, size, &wrote, 0)) {
return wrote;
} else {
return -1;
}
}
}
static ssize_t __ubsan_write_string(const char *s) {
return __ubsan_write(s, __ubsan_strlen(s));
}
void __ubsan_abort(const struct UbsanSourceLocation *loc,
const char *description) {
char buf[1024], *p = buf;
p = __ubsan_stpcpy(p, "error: ");
p = __ubsan_stpcpy(p, loc->file), *p++ = ':';
p = __ubsan_intcpy(p, loc->line);
p = __ubsan_stpcpy(p, ": ");
p = __ubsan_stpcpy(p, description);
p = __ubsan_stpcpy(p, "\r\n");
__ubsan_write_string(buf);
__printf("\r\n%s:%d: ubsan error: %s\r\n", loc->file, loc->line, description);
if (weaken(__die)) weaken(__die)();
__ubsan_exit(134);
_Exit(134);
}
static const char *__ubsan_describe_shift(
@ -291,11 +214,11 @@ void __ubsan_handle_shift_out_of_bounds(struct UbsanShiftOutOfBoundsInfo *info,
char buf[512], *p = buf;
lhs = __ubsan_extend(info->lhs_type, lhs);
rhs = __ubsan_extend(info->rhs_type, rhs);
p = __ubsan_stpcpy(p, __ubsan_describe_shift(info, lhs, rhs)), *p++ = ' ';
p = __stpcpy(p, __ubsan_describe_shift(info, lhs, rhs)), *p++ = ' ';
p = __ubsan_itpcpy(p, info->lhs_type, lhs), *p++ = ' ';
p = __ubsan_stpcpy(p, info->lhs_type->name), *p++ = ' ';
p = __stpcpy(p, info->lhs_type->name), *p++ = ' ';
p = __ubsan_itpcpy(p, info->rhs_type, rhs), *p++ = ' ';
p = __ubsan_stpcpy(p, info->rhs_type->name);
p = __stpcpy(p, info->rhs_type->name);
__ubsan_abort(&info->location, buf);
}
@ -307,12 +230,12 @@ void __ubsan_handle_shift_out_of_bounds_abort(
void __ubsan_handle_out_of_bounds(struct UbsanOutOfBoundsInfo *info,
uintptr_t index) {
char buf[512], *p = buf;
p = __ubsan_stpcpy(p, info->index_type->name);
p = __ubsan_stpcpy(p, " index ");
p = __stpcpy(p, info->index_type->name);
p = __stpcpy(p, " index ");
p = __ubsan_itpcpy(p, info->index_type, index);
p = __ubsan_stpcpy(p, " into ");
p = __ubsan_stpcpy(p, info->array_type->name);
p = __ubsan_stpcpy(p, " out of bounds");
p = __stpcpy(p, " into ");
p = __stpcpy(p, info->array_type->name);
p = __stpcpy(p, " out of bounds");
__ubsan_abort(&info->location, buf);
}
@ -328,19 +251,19 @@ void __ubsan_handle_type_mismatch(struct UbsanTypeMismatchInfo *info,
if (!pointer) __ubsan_abort(&info->location, "null pointer access");
kind = __ubsan_dubnul(kUbsanTypeCheckKinds, info->type_check_kind);
if (info->alignment && (pointer & (info->alignment - 1))) {
p = __ubsan_stpcpy(p, "unaligned ");
p = __ubsan_stpcpy(p, kind), *p++ = ' ';
p = __ubsan_stpcpy(p, info->type->name), *p++ = ' ', *p++ = '@';
p = __stpcpy(p, "unaligned ");
p = __stpcpy(p, kind), *p++ = ' ';
p = __stpcpy(p, info->type->name), *p++ = ' ', *p++ = '@';
p = __ubsan_itpcpy(p, info->type, pointer);
p = __ubsan_stpcpy(p, " align ");
p = __ubsan_intcpy(p, info->alignment);
p = __stpcpy(p, " align ");
p = __intcpy(p, info->alignment);
} else {
p = __ubsan_stpcpy(p, "insufficient size\r\n\t");
p = __ubsan_stpcpy(p, kind);
p = __ubsan_stpcpy(p, " address 0x");
p = __ubsan_hexcpy(p, pointer, sizeof(pointer) * CHAR_BIT);
p = __ubsan_stpcpy(p, " with insufficient space for object of type ");
p = __ubsan_stpcpy(p, info->type->name);
p = __stpcpy(p, "insufficient size\r\n\t");
p = __stpcpy(p, kind);
p = __stpcpy(p, " address 0x");
p = __fixcpy(p, pointer, sizeof(pointer) * CHAR_BIT);
p = __stpcpy(p, " with insufficient space for object of type ");
p = __stpcpy(p, info->type->name);
}
__ubsan_abort(&info->location, buf);
}