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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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10
libc/sysv/consts.sh
View file

@ -225,6 +225,7 @@ syscon mmap MAP_SHARED 1 1 1 1 1 1 # forced consensus & faked nt
syscon mmap MAP_PRIVATE 2 2 2 2 2 2 # forced consensus & faked nt
syscon mmap MAP_TYPE 15 15 15 15 15 15 # mask for type of mapping
syscon mmap MAP_FIXED 0x10 0x10 0x10 0x10 0x10 0x10 # unix consensus; openbsd appears to forbid; faked nt
syscon mmap MAP_FIXED_NOREPLACE 0x8000000 0x8000000 0x8000000 0x8000000 0x8000000 0x8000000 # handled and defined by cosmo runtime; 0x100000 on linux 4.7+
syscon mmap MAP_ANONYMOUS 0x20 0x1000 0x1000 0x1000 0x1000 0x20 # bsd consensus; faked nt
syscon mmap MAP_GROWSDOWN 0x0100 0 0x0400 0x4000 0x4000 0x100000 # mandatory for OpenBSD stacks; MAP_STACK on Free/OpenBSD; MEM_TOP_DOWN on NT
syscon mmap MAP_CONCEAL 0 0 0x20000 0x8000 0x8000 0 # omit from core dumps; MAP_NOCORE on FreeBSD
@ -506,7 +507,7 @@ syscon rlimit RLIMIT_RSS 5 5 5 5 5 127 # max physical memory size
syscon rlimit RLIMIT_NPROC 6 7 7 7 7 127 # max number of processes; see fork()→EAGAIN; bsd consensus
syscon rlimit RLIMIT_NOFILE 7 8 8 8 8 127 # max number of open files; see accept()→EMFILE/ENFILE; bsd consensus
syscon rlimit RLIMIT_MEMLOCK 8 6 6 6 6 127 # max locked-in-memory address space; bsd consensus
syscon rlimit RLIMIT_AS 9 5 10 127 10 127 # max virtual memory size in bytes
syscon rlimit RLIMIT_AS 9 5 10 127 10 127 # max virtual memory size in bytes; this one actually works; we set this to RLIMIT_DATA on OpenBSD
syscon rlimit RLIMIT_LOCKS 10 127 127 127 127 127 # max flock() / fcntl() locks; bsd consensus
syscon rlimit RLIMIT_SIGPENDING 11 127 127 127 127 127 # max sigqueue() can enqueue; bsd consensus
syscon rlimit RLIMIT_MSGQUEUE 12 127 127 127 127 127 # meh posix message queues; bsd consensus
@ -592,10 +593,12 @@ syscon sicode POLL_ERR 4 4 4 4 4 4 # SIGIO; i/o error; unix conse
syscon sicode POLL_PRI 5 5 5 5 5 5 # SIGIO; high priority input available; unix consensus
syscon sicode POLL_HUP 6 6 6 6 6 6 # SIGIO; device disconnected; unix consensus
# sigalstack() values
# sigaltstack() values
#
# group name GNU/Systemd XNU's Not UNIX! FreeBSD OpenBSD NetBSD The New Technology Commentary
syscon ss SIGSTKSZ 0x2000 0x020000 0x8800 0x7000 0x7000 0x2000
syscon ss SS_ONSTACK 1 1 1 1 1 1 # unix consensus
syscon ss SS_DISABLE 2 4 4 4 4 2 # bsd consensus
# clock_{gettime,settime} timers
#
@ -1898,9 +1901,6 @@ syscon misc MT_ST_CAN_PARTITIONS 0x0400 0 0 0 0 0
syscon misc MT_ST_HPLOADER_OFFSET 0x2710 0 0 0 0 0
syscon misc MT_ST_SCSI2LOGICAL 0x0800 0 0 0 0 0
syscon misc SS_ONSTACK 1 1 1 1 1 0 # unix consensus
syscon misc SS_DISABLE 2 4 4 4 4 0 # bsd consensus
syscon misc SYNC_FILE_RANGE_WAIT_AFTER 4 0 0 0 0 0
syscon misc SYNC_FILE_RANGE_WAIT_BEFORE 1 0 0 0 0 0
syscon misc SYNC_FILE_RANGE_WRITE 2 0 0 0 0 0