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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

2
libc/sysv/calls/__sys_munmap.s Normal file
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@ -0,0 +1,2 @@
.include "o/libc/sysv/macros.internal.inc"
.scall __sys_munmap,0x049049049204900b,globl,hidden

2
libc/sysv/calls/sigaltstack.s
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@ -1,2 +0,0 @@
.include "o/libc/sysv/macros.internal.inc"
.scall sigaltstack,0x1191200352035083,globl

2
libc/sysv/calls/sys_munmap.s
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@ -1,2 +0,0 @@
.include "o/libc/sysv/macros.internal.inc"
.scall sys_munmap,0x049049049204900b,globl,hidden

2
libc/sysv/calls/sys_sigaltstack.s Normal file
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@ -0,0 +1,2 @@
.include "o/libc/sysv/macros.internal.inc"
.scall sys_sigaltstack,0x1191200352035083,globl,hidden

10
libc/sysv/consts.sh
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@ -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

2
libc/sysv/consts/SS_DISABLE.S
View file

@ -1,2 +1,2 @@
#include "libc/sysv/consts/syscon.internal.h"
.syscon misc,SS_DISABLE,2,4,4,4,4,0
.syscon ss,SS_DISABLE,2,4,4,4,4,2

2
libc/sysv/consts/SS_ONSTACK.S
View file

@ -1,2 +1,2 @@
#include "libc/sysv/consts/syscon.internal.h"
.syscon misc,SS_ONSTACK,1,1,1,1,1,0
.syscon ss,SS_ONSTACK,1,1,1,1,1,1

11
libc/sysv/consts/map.h
View file

@ -26,11 +26,12 @@ extern const long MAP_CONCEAL;
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#define MAP_FILE 0
#define MAP_SHARED 1
#define MAP_PRIVATE 2
#define MAP_TYPE 15
#define MAP_FIXED 16
#define MAP_FILE 0
#define MAP_SHARED 1
#define MAP_PRIVATE 2
#define MAP_TYPE 15
#define MAP_FIXED 16
#define MAP_FIXED_NOREPLACE 0x8000000
#define MAP_32BIT SYMBOLIC(MAP_32BIT)
#define MAP_ANONYMOUS SYMBOLIC(MAP_ANONYMOUS)

13
libc/sysv/consts/mremap.h
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@ -1,16 +1,7 @@
#ifndef COSMOPOLITAN_LIBC_SYSV_CONSTS_MREMAP_H_
#define COSMOPOLITAN_LIBC_SYSV_CONSTS_MREMAP_H_
#include "libc/runtime/symbolic.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
extern const long MREMAP_FIXED;
extern const long MREMAP_MAYMOVE;
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#define MREMAP_MAYMOVE LITERALLY(1)
#define MREMAP_FIXED LITERALLY(2)
#define MREMAP_MAYMOVE 1
#define MREMAP_FIXED 2
#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_MREMAP_H_ */

2
libc/sysv/consts/sig.h
View file

@ -27,7 +27,6 @@ extern const long SIGRTMAX;
extern const long SIGRTMIN;
extern const long SIGSEGV;
extern const long SIGSTKFLT;
extern const long SIGSTKSZ;
extern const long SIGSTOP;
extern const long SIGSYS;
extern const long SIGTERM;
@ -75,7 +74,6 @@ COSMOPOLITAN_C_END_
#define SIGRTMIN SYMBOLIC(SIGRTMIN)
#define SIGSEGV LITERALLY(11)
#define SIGSTKFLT SYMBOLIC(SIGSTKFLT)
#define SIGSTKSZ SYMBOLIC(SIGSTKSZ)
#define SIGSTOP SYMBOLIC(SIGSTOP)
#define SIGSYS SYMBOLIC(SIGSYS)
#define SIGTERM LITERALLY(15)

15
libc/sysv/consts/ss.h Normal file
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@ -0,0 +1,15 @@
#ifndef COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_
#define COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
extern const long SS_DISABLE;
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#define SIGSTKSZ STACKSIZE
#define SS_ONSTACK 1
#define SS_DISABLE SS_DISABLE
#endif /* COSMOPOLITAN_LIBC_SYSV_CONSTS_SS_H_ */

2
libc/sysv/restorert.S
View file

@ -24,7 +24,7 @@
__restore_bt:
nop
.endfn __restore_bt,globl,hidden
nop # gap so that GetSymbol(st, addr - 1) fails
nop # gap so that __get_symbol(st, addr - 1) fails
.align 16
__restore_rt: # @see gdb/amd64-linux-tdep.c
mov $0x000f,%rax # [sic]

4
libc/sysv/syscalls.sh
View file

@ -47,7 +47,7 @@ scall sys_lseek 0x0c70c71de20c7008 globl hidden # netbsd+openbsd:evilpad
scall __sys_mmap 0x0c50c51dd20c5009 globl hidden # netbsd+openbsd:pad
scall sys_msync 0x115100041204101a globl hidden
scall sys_mprotect 0x04a04a04a204a00a globl hidden
scall sys_munmap 0x049049049204900b globl hidden
scall __sys_munmap 0x049049049204900b globl hidden
scall sys_sigaction 0x15402e1a0202e00d globl hidden # rt_sigaction on Lunix; it's complicated on NetBSD
scall sys_sigprocmask 0x125030154203000e globl hidden # a.k.a. rt_sigprocmask, openbsd:byvalue
scall sys_ioctl 0x0360360362036010 globl hidden
@ -164,7 +164,7 @@ scall getresuid 0xfff119168ffff076 globl # semantics aren't well-defined
scall getresgid 0xfff11b169ffff078 globl # semantics aren't well-defined
scall sigpending 0x124034034203407f globl # rt_sigpending on linux
scall sys_sigsuspend 0x12606f155206f082 globl hidden # openbsd:byvalue
scall sigaltstack 0x1191200352035083 globl
scall sys_sigaltstack 0x1191200352035083 globl hidden
scall sys_mknod 0x1c200e00e200e085 globl hidden
scall mknodat 0x1cc14022fffff103 globl # FreeBSD 12+
scall sys_mkfifo 0x0840840842084fff globl hidden

35
libc/sysv/systemfive.S
View file

@ -21,6 +21,7 @@
#include "libc/sysv/consts/nr.h"
#include "libc/sysv/consts/map.h"
#include "libc/macros.internal.h"
#include "libc/sysv/consts/prot.h"
#include "libc/nexgen32e/macros.h"
/* ▄▄▄
@ -349,6 +350,34 @@ _init_systemfive_stack: # determinism ftw!
syscall
2: test %rax,%rax
js 1b
// prevent operating system from auto-mapping stack
// we guarantee stack overflows are always detected
// so long as you never use -DSTACK_FRAME_UNLIMITED
// TODO: Why does this fail sometimes with FreeBSD?
testb IsFreebsd()
jnz 9f
push %rax
push %rdx
push %r11
mov __NR_mprotect,%eax
mov $PAGESIZE,%esi
xor %edx,%edx # PROT_NONE
syscall
pop %r11
pop %rdx
pop %rax
9:
// update the memory intervals
// m.i 0 4
// m.n 8 4
// m.p 16 8
// m.p[0].x 24 4
// m.p[0].y 28 4
// m.p[0].h 32 8
// m.p[0].prot 40 4
// m.p[0].flags 44 4
.weak _mmi
ezlea _mmi,cx
test %rcx,%rcx
@ -360,12 +389,14 @@ _init_systemfive_stack: # determinism ftw!
movb $1,(%rcx) # _mmi.i
mov %r11d,24(%rcx) # _mmi.s[0].x
mov %r9d,28(%rcx) # _mmi.s[0].y
mov %edx,36(%rcx) # _mmi.s[0].prot
mov %r10d,40(%rcx) # _mmi.s[0].flags
orq $-1,32(%rcx) # _mmi.s[0].h
mov %edx,40(%rcx) # _mmi.s[0].prot
mov %r10d,44(%rcx) # _mmi.s[0].flags
3: pop %r9 # restore stack size
pop %rsi
pop %rdi
leave
// switch stacks
pop %rcx
lea (%rax,%r9),%rsp
sub $ape_stack_align,%rsp # openbsd:stackbound