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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

19
libc/calls/sigenter-xnu.c
View file

@ -18,10 +18,13 @@
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/metasigaltstack.h"
#include "libc/calls/struct/siginfo.h"
#include "libc/calls/typedef/sigaction_f.h"
#include "libc/calls/ucontext.h"
#include "libc/intrin/repstosb.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/sa.h"
/**
* @fileoverview XNU kernel callback normalization.
@ -45,12 +48,6 @@ struct __darwin_siginfo {
uint64_t __pad[7];
};
struct __darwin_sigaltstack {
void *ss_sp;
uint64_t ss_size;
int32_t ss_flags;
};
struct __darwin_mmst_reg {
char __mmst_reg[10];
char __mmst_rsrv[6];
@ -368,7 +365,7 @@ struct __darwin_mcontext64 {
struct __darwin_ucontext {
int32_t uc_onstack;
uint32_t uc_sigmask;
struct __darwin_sigaltstack uc_stack;
struct sigaltstack_bsd uc_stack;
struct __darwin_ucontext *uc_link;
uint64_t uc_mcsize;
struct __darwin_mcontext64 *uc_mcontext;
@ -387,7 +384,7 @@ noasan static void linuxexceptionstate2xnu(
}
noasan static void xnuthreadstate2linux(
ucontext_t *uc, mcontext_t *mc, struct __darwin_x86_thread_state64 *xnuss) {
mcontext_t *mc, struct __darwin_x86_thread_state64 *xnuss) {
mc->rdi = xnuss->__rdi;
mc->rsi = xnuss->__rsi;
mc->rbp = xnuss->__rbp;
@ -401,7 +398,6 @@ noasan static void xnuthreadstate2linux(
mc->gs = xnuss->__gs;
mc->fs = xnuss->__fs;
mc->eflags = xnuss->__rflags;
uc->uc_flags = xnuss->__rflags;
mc->r8 = xnuss->__r8;
mc->r9 = xnuss->__r9;
mc->r10 = xnuss->__r10;
@ -427,7 +423,6 @@ noasan static void linuxthreadstate2xnu(
xnuss->__gs = mc->gs;
xnuss->__fs = mc->fs;
xnuss->__rflags = mc->eflags;
xnuss->__rflags = uc->uc_flags;
xnuss->__r8 = mc->r8;
xnuss->__r9 = mc->r9;
xnuss->__r10 = mc->r10;
@ -484,6 +479,7 @@ noasan void __sigenter_xnu(void *fn, int infostyle, int sig,
if (rva >= kSigactionMinRva) {
repstosb(&g, 0, sizeof(g));
if (xnuctx) {
g.uc.uc_flags = xnuctx->uc_onstack ? SA_ONSTACK : 0;
g.uc.uc_sigmask.__bits[0] = xnuctx->uc_sigmask;
g.uc.uc_stack.ss_sp = xnuctx->uc_stack.ss_sp;
g.uc.uc_stack.ss_flags = xnuctx->uc_stack.ss_flags;
@ -498,8 +494,7 @@ noasan void __sigenter_xnu(void *fn, int infostyle, int sig,
if (xnuctx->uc_mcsize >=
(sizeof(struct __darwin_x86_exception_state64) +
sizeof(struct __darwin_x86_thread_state64))) {
xnuthreadstate2linux(&g.uc, &g.uc.uc_mcontext,
&xnuctx->uc_mcontext->__ss);
xnuthreadstate2linux(&g.uc.uc_mcontext, &xnuctx->uc_mcontext->__ss);
}
if (xnuctx->uc_mcsize >= sizeof(struct __darwin_mcontext64)) {
xnussefpustate2linux(&g.uc.__fpustate, &xnuctx->uc_mcontext->__fs);