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[ld.so] Call all image global ctors, not just libc

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With the move to dynamic executables, crt0's _start was only ever
calling libc's __init_libc, which only ran libc's init_array list. Now
make crt0 itself (which is statically linked into every executable) call
it's own init_array list and have ld.so call every other image's ctor
lists.
This commit is contained in:
Justin C. Miller
2024-04-29 01:07:18 -07:00
parent 70af5a31cd
commit 7322df98f5
4 changed files with 71 additions and 34 deletions
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48
src/libraries/libc/arch/amd64/crt/crt0.s
View File

@@ -5,6 +5,52 @@ extern exit
extern __init_libj6
extern __init_libc
extern __preinit_array_start
extern __preinit_array_end
extern __init_array_start
extern __init_array_end
global __run_ctor_list:function hidden (__run_ctor_list.end - __run_ctor_list)
__run_ctor_list:
push rbp
mov rbp, rsp
push rbx
push r12
mov rbx, rdi
mov r12, rsi
.start:
cmp rbx, r12
je .fin
mov rax, [rbx]
call rax
add rbx, 8
jmp .start
.fin:
pop r12
pop rbx
pop rbp
ret
.end:
global __run_global_ctors:function hidden (__run_global_ctors.end - __run_global_ctors)
__run_global_ctors:
push rbp
mov rbp, rsp
lea rdi, [rel __preinit_array_start]
lea rsi, [rel __preinit_array_end]
call __run_ctor_list
lea rdi, [rel __init_array_start]
lea rsi, [rel __init_array_end]
call __run_ctor_list
pop rbp
ret
.end:
; Put the address of the given symbol in rax
; This macro is the same as in util/got.inc,
; but crt0 can't have a dep on libutil
@@ -31,6 +77,8 @@ _libc_crt0_start:
lookup_GOT __init_libc
call rax
call __run_global_ctors
mov rdi, 0
mov rsi, rsp
mov rdx, 0 ; TODO: actually parse stack for argc, argv, envp

27
src/libraries/libc/arch/amd64/init.cpp
View File

@@ -1,33 +1,6 @@
#include <stddef.h>
using cb = void (*)(void);
extern cb __preinit_array_start;
extern cb __preinit_array_end;
extern cb __init_array_start;
extern cb __init_array_end;
namespace {
void
run_ctor_list(cb *p, cb *end)
{
while (p && end && p < end) {
if (p) (*p)();
++p;
}
}
void
run_global_ctors()
{
run_ctor_list(&__preinit_array_start, &__preinit_array_end);
run_ctor_list(&__init_array_start, &__init_array_end);
}
} // namespace
extern "C" void
__init_libc()
{
run_global_ctors();
}