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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

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.