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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
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94
libc/runtime/memtrack.internal.h
View file

@ -4,12 +4,14 @@
#include "libc/macros.internal.h"
#include "libc/nt/enum/version.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
#define _kAutomapStart 0x0000100080000000 /* asan can't spread its poison */
#define _kAutomapSize 0x00000fff80000000 /* beyond the above mem address */
#define _kFixedmapStart 0x0000200000000000
#define _kAutomapStart 0x0000100080000000
#define _kAutomapSize 0x00000fff80000000
#define _kFixedmapStart 0x0000300000000000
#define _kFixedmapSize 0x00000fff80000000
/*
* TODO: Why can't we allocate addresses above 4GB on Windows 7 x64?
@ -18,8 +20,9 @@ COSMOPOLITAN_C_START_
#define MEMTRACK_ADDRESS(NORMAL, WIN7) \
(!(IsWindows() && NtGetVersion() < kNtVersionWindows10) ? NORMAL : WIN7)
#define kAutomapStart MEMTRACK_ADDRESS(_kAutomapStart, 0x10000000)
#define kAutomapSize MEMTRACK_ADDRESS(_kAutomapSize, 0x40000000)
#define kFixedmapStart MEMTRACK_ADDRESS(_kFixedmapStart, 0x50000000)
#define kAutomapSize MEMTRACK_ADDRESS(_kAutomapSize, 0x30000000)
#define kFixedmapStart MEMTRACK_ADDRESS(_kFixedmapStart, 0x40000000)
#define kFixedmapSize MEMTRACK_ADDRESS(_kFixedmapSize, 0x30000000)
struct MemoryInterval {
int x;
@ -37,6 +40,9 @@ struct MemoryIntervals {
extern hidden struct MemoryIntervals _mmi;
const char *DescribeFrame(int);
void PrintSystemMappings(int) hidden;
char *DescribeMapping(int, int, char[hasatleast 8]) hidden;
bool AreMemoryIntervalsOk(const struct MemoryIntervals *) nosideeffect hidden;
void PrintMemoryIntervals(int, const struct MemoryIntervals *) hidden;
int TrackMemoryInterval(struct MemoryIntervals *, int, int, long, int,
@ -46,8 +52,70 @@ int ReleaseMemoryIntervals(struct MemoryIntervals *, int, int,
void ReleaseMemoryNt(struct MemoryIntervals *, int, int) hidden;
int UntrackMemoryIntervals(void *, size_t) hidden;
static inline noasan unsigned FindMemoryInterval(
const struct MemoryIntervals *mm, int x) {
forceinline pureconst bool IsAutoFrame(int x) {
return (kAutomapStart >> 16) <= x &&
x <= ((kAutomapStart + (kAutomapSize - 1)) >> 16);
}
forceinline pureconst bool IsArenaFrame(int x) {
return 0x5000 <= x && x < 0x7ffe;
}
forceinline pureconst bool IsShadowFrame(int x) {
return 0x7fff <= x && x < 0x10008000;
}
forceinline pureconst bool IsStackFrame(int x) {
return (GetStaticStackAddr(0) >> 16) <= x &&
x <= ((GetStaticStackAddr(0) + (GetStackSize() - FRAMESIZE)) >> 16);
}
forceinline pureconst bool IsFixedFrame(int x) {
return (kFixedmapStart >> 16) <= x &&
x <= ((kFixedmapStart + (kFixedmapSize - 1)) >> 16);
}
forceinline pureconst bool OverlapsImageSpace(const void *p, size_t n) {
const unsigned char *start, *ender;
if (n) {
start = p;
ender = start + (n - 1);
return ((_base <= start && start < _end) ||
(_base <= ender && ender < _end) ||
(start < _base && _end <= ender));
} else {
return 0;
}
}
forceinline pureconst bool OverlapsArenaSpace(const void *p, size_t n) {
intptr_t x, y;
if (n) {
x = (intptr_t)p;
y = x + (n - 1);
return ((0x50000000 <= x && x <= 0x7ffdffff) ||
(0x50000000 <= y && y <= 0x7ffdffff) ||
(x < 0x50000000 && 0x7ffdffff < y));
} else {
return 0;
}
}
forceinline pureconst bool OverlapsShadowSpace(const void *p, size_t n) {
intptr_t x, y;
if (n) {
x = (intptr_t)p;
y = x + (n - 1);
return ((0x7fff0000 <= x && x <= 0x10007fffffff) ||
(0x7fff0000 <= y && y <= 0x10007fffffff) ||
(x < 0x7fff0000 && 0x10007fffffff < y));
} else {
return 0;
}
}
forceinline unsigned FindMemoryInterval(const struct MemoryIntervals *mm,
int x) {
unsigned l, m, r;
l = 0;
r = mm->i;
@ -62,6 +130,18 @@ static inline noasan unsigned FindMemoryInterval(
return l;
}
forceinline bool IsMemtracked(int x, int y) {
unsigned i;
i = FindMemoryInterval(&_mmi, x);
if (i == _mmi.i) return false;
if (!(_mmi.p[i].x <= x && x <= _mmi.p[i].y)) return false;
for (;;) {
if (y <= _mmi.p[i].y) return true;
if (++i == _mmi.i) return false;
if (_mmi.p[i].x != _mmi.p[i - 1].y + 1) return false;
}
}
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_RUNTIME_MEMTRACK_H_ */