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Fix issue with stack creation on OpenBSD

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This commit is contained in:
Justine Tunney 2022-08-14 01:19:58 -07:00
parent 2e54c8f9fc
commit e1699c5b68
1 changed files with 18 additions and 2 deletions
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20
libc/runtime/cosmo.S
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@ -38,10 +38,12 @@ cosmo: push %rbp
mov %rsi,%r13 mov %rsi,%r13
mov %rdx,%r14 mov %rdx,%r14
mov %rcx,%r15 mov %rcx,%r15
#ifdef SYSDEBUG #ifdef SYSDEBUG
call __strace_init call __strace_init
mov %eax,%r12d mov %eax,%r12d
#endif /* SYSDEBUG */ #endif /* SYSDEBUG */
#ifdef __FAST_MATH__ #ifdef __FAST_MATH__
push %rax push %rax
stmxcsr (%rsp) stmxcsr (%rsp)
@ -49,7 +51,11 @@ cosmo: push %rbp
ldmxcsr (%rsp) ldmxcsr (%rsp)
pop %rax pop %rax
#endif #endif
// run assembly init
call _init call _init
// call constructors
ezlea __init_array_start,ax # static ctors in forward order ezlea __init_array_start,ax # static ctors in forward order
.weak __init_array_start # could be called multiple times .weak __init_array_start # could be called multiple times
ezlea __init_array_end,cx # idempotency recommended ezlea __init_array_end,cx # idempotency recommended
@ -64,11 +70,14 @@ cosmo: push %rbp
pop %rax pop %rax
add $8,%rax add $8,%rax
jmp 1b jmp 1b
// call main()
2: call .Largs 2: call .Largs
.weak main .weak main
call main call main
xchg %eax,%edi xchg %eax,%edi
call exit call exit
.Largs: mov %r12d,%edi .Largs: mov %r12d,%edi
mov %r13,%rsi mov %r13,%rsi
mov %r14,%rdx mov %r14,%rdx
@ -103,6 +112,7 @@ cosmo: push %rbp
jnz 9f jnz 9f
push %rdi push %rdi
push %rsi push %rsi
// allocate stack // allocate stack
movabs $ape_stack_vaddr,%rdi movabs $ape_stack_vaddr,%rdi
mov $ape_stack_memsz,%esi mov $ape_stack_memsz,%esi
@ -118,16 +128,22 @@ cosmo: push %rbp
pop %rdi pop %rdi
cmp $-1,%rax cmp $-1,%rax
je 9f je 9f
// switch stacks // switch stacks
//
// we subtract 8 because the openbsd kernel always checks rsp
// is on a MAP_STACK interval non-inclusively of stack + size
leave leave
pop %rcx pop %rcx # return address
sub $8,%r8d # openbsd:stackbound
lea (%rax,%r8),%rsp lea (%rax,%r8),%rsp
mov $ape_stack_align,%eax # openbsd:stackbound mov $ape_stack_align,%eax
neg %rax neg %rax
and %rax,%rsp and %rax,%rsp
push %rcx push %rcx
push %rbp push %rbp
mov %rsp,%rbp mov %rsp,%rbp
9: nop 9: nop
.init.end 304,_init_stack .init.end 304,_init_stack
.weak ape_stack_prot .weak ape_stack_prot