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Make C memory safe like Rust

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This change enables Address Sanitizer systemically w/ `make MODE=dbg`.
Our version of Rust's `unsafe` keyword is named `noasan` which is used
for two functions that do aligned memory chunking, like `strcpy.c` and
we need to fix the tiny DEFLATE code, but that's it everything else is
fabulous you can have all the fischer price security blankets you need

Best of all is we're now able to use the ASAN data in Blinkenlights to
colorize the memory dumps. See the screenshot below of a test program:

  https://justine.lol/blinkenlights/asan.png

Which is operating on float arrays stored on the stack, with red areas
indicating poisoned memory, and the green areas indicate valid memory.
This commit is contained in:
Justine Tunney 2021-02-01 03:33:13 -08:00
parent fdc3fa9148
commit 1ff9ab95ac
153 changed files with 2545 additions and 2077 deletions
Download patch file Download diff file Expand all files Collapse all files

14
libc/sysv/consts.sh
View file

@ -437,28 +437,28 @@ syscon utime UTIME_OMIT 0x3ffffffe 0x3ffffffe -2 -1 0x3ffffffe # polyf
# getauxval() keys
#
# group name GNU/Systemd XNU's Not UNIX FreeBSD OpenBSD XENIX Commentary
syscon auxv AT_EXECFD 2 0 2 0 0
syscon auxv AT_PHDR 3 0 3 0 0
syscon auxv AT_EXECFD 2 0 2 0 0 # file descriptor of program
syscon auxv AT_PHDR 3 0 3 0 0 # address of program headers of executable
syscon auxv AT_PHENT 4 0 4 0 0
syscon auxv AT_PHNUM 5 0 5 0 0
syscon auxv AT_PAGESZ 6 0 6 0 0
syscon auxv AT_BASE 7 0 7 0 0
syscon auxv AT_ENTRY 9 0 9 0 0
syscon auxv AT_BASE 7 0 7 0 0 # address of program interpreter
syscon auxv AT_ENTRY 9 0 9 0 0 # entry address of executable
syscon auxv AT_NOTELF 10 0 10 0 0
syscon auxv AT_OSRELDATE 0 0 18 0 0
syscon auxv AT_UID 11 0 0 0 0
syscon auxv AT_EUID 12 0 0 0 0
syscon auxv AT_GID 13 0 0 0 0
syscon auxv AT_EGID 14 0 0 0 0
syscon auxv AT_PLATFORM 15 0 0 0 0 # RHEL5.0 limit
syscon auxv AT_PLATFORM 15 0 0 0 0 # address of string with hardware platform for rpath interpretation [RHEL5.0 LIMIT]
syscon auxv AT_CLKTCK 17 0 0 0 0
syscon auxv AT_DCACHEBSIZE 19 0 0 0 0
syscon auxv AT_ICACHEBSIZE 20 0 0 0 0
syscon auxv AT_UCACHEBSIZE 21 0 0 0 0
syscon auxv AT_SECURE 23 0 0 0 0
syscon auxv AT_BASE_PLATFORM 24 0 0 0 0
syscon auxv AT_RANDOM 25 0 0 0 0
syscon auxv AT_EXECFN 31 999 999 999 999 # faked on non-linux
syscon auxv AT_RANDOM 25 0 0 0 0 # address of sixteen bytes of random data
syscon auxv AT_EXECFN 31 999 999 999 999 # address of string containing first argument passed to execve() used when running program [faked on non-linux]
syscon auxv AT_SYSINFO_EHDR 33 0 0 0 0
syscon auxv AT_NO_AUTOMOUNT 0x0800 0 0 0 0

87
libc/sysv/systemfive.S
View file

@ -17,6 +17,9 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/dce.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/nr.h"
#include "libc/sysv/consts/map.h"
#include "libc/macros.h"
.source __FILE__
@ -161,9 +164,10 @@ systemfive.xnu:
/ Initializes System Five system call support.
/
/ (1) Extracts parameters passed by kernel,
/ (2) Detects O/S without issuing system calls,
/ (3) Unpacks numbers.
/ (1) Extracts parameters passed by kernel
/ (2) Detects OS without issuing system calls
/ (3) Unpacks magnums from libc/sysv/consts.sh
/ (4) Replaces stack with one we control
/
/ @param %r15 is auxv
/ @note OpenBSD devs: let us know if you start using auxv
@ -219,26 +223,17 @@ systemfive.init.os:
pop %rax
add %rcx,%rax
stosq #→ __systemfive
/ 𝑠𝑙𝑖𝑑𝑒
systemfive.init.magnums:
push %rdi
ezlea syscon.start,di
ezlea syscon.end,bx
call systemfive.sleb128unpacker
pop %rdi
/ 𝑠𝑙𝑖𝑑𝑒
systemfive.init.done:
pop %rsi
pop %rbx
.init.end 300,_init_systemfive,globl,hidden
.text.startup
systemfive.sleb128unpacker:
.leafprologue
or $-1,%r9
2: cmp %rbx,%rdi
jnb 5f
xor %ecx,%ecx
xor %edx,%edx
3: lodsb
3: lodsb # decodes sleb128
mov %rax,%r8
and $127,%r8d
sal %cl,%r8
@ -252,14 +247,66 @@ systemfive.sleb128unpacker:
sal %cl,%rax
or %rax,%rdx
4: mov %rdx,%rax
cmpq $0,(%rdi) # don't change consts already set
cmovne (%rdi),%rax # @see WinMain() for example
cmpq $0,(%rdi) # dont change if set
cmovne (%rdi),%rax # @see WinMain()
stosq
jmp 2b
5: .leafepilogue
.previous
5: pop %rdi
pop %rsi
pop %rbx
/ 𝑠𝑙𝑖𝑑𝑒
#ifndef TINY
systemfive.init.stack:
testb IsWindows() # already did this
jnz systemfive.init.done
testb IsOpenbsd() # todo fix openbsd
jnz systemfive.init.done
push %rdi
push %rsi
mov __NR_mmap,%eax
mov $0x700000000000-STACKSIZE,%rdi
mov $STACKSIZE,%esi
mov $PROT_READ|PROT_WRITE,%edx
mov $MAP_PRIVATE|MAP_FIXED,%r10d
or MAP_ANONYMOUS,%r10d
or MAP_GROWSDOWN,%r10d
or $-1,%r8
xor %r9d,%r9d
push %r9 # openbsd:pad
/ clc
syscall
pop %r9
jnc 2f
1: mov %eax,%edi
mov __NR_exit_group,%eax
syscall
2: test %rax,%rax
js 1b
.weak _mmi
ezlea _mmi,cx
test %rcx,%rcx
jz 3f
movb $1,(%rcx) # _mmi.i
movl $(0x700000000000-STACKSIZE)>>16,8(%rcx) # _mmi.p[0].x
movl $(0x700000000000-1)>>16,12(%rcx) # _mmi.p[0].y
mov %edx,20(%rcx) # _mmi.p[0].prot
mov %r10d,24(%rcx) # _mmi.p[0].flags
3: pop %rsi
pop %rdi
leave
pop %rcx
lea STACKSIZE(%rax),%rsp
push %rcx
xor %ebp,%ebp
push %rbp
mov %rsp,%rbp
/ 𝑠𝑙𝑖𝑑𝑒
#endif /* TINY */
systemfive.init.done:
nop
.init.end 300,_init_systemfive,globl,hidden
/ Sections for varint encoded numbers.
/ Sections for varint encoded magic numbers.
/
/ These sections are all ordered by (group_name, constant_name).
/ They're populated by modules simply referencing the symbols.