/**************************************************************************/

/*  mmglue: midipix architecture- and target-specific bits for musl libc  */

/*  Copyright (C) 2013--2023  SysDeer Technologies, LLC                   */

/*  Released under the Standard MIT License; see COPYING.MMGLUE.          */

/**************************************************************************/

#include <unistd.h>

#include <stdint.h>

#include <pthread.h>

#include "atomic.h"

#include "syscall.h"

#include "psxglue.h"

#include "pthread_impl.h"

volatile int __thread_list_lock;

extern const struct __ldso_vtbl * __ldso_vtbl;

extern const struct __psx_vtbl *  __psx_vtbl;

extern const struct __seh_vtbl *  __eh_vtbl;

static int __pthread_surrogate_init(struct pthread * self);

extern int __libc_start_main(

	void *	main,

	int	argc,

	char **	argv);

static void (*__global_ctors_fn)();

static void (*__global_dtors_fn)();

void _init()

{

	__global_ctors_fn();

}

void _fini()

{

	__global_dtors_fn();

}

struct __tls {

	void *		pad[16/sizeof(void *)];

	struct pthread	pt;

} __builtin_tls = {{0}};

void __init_tls (size_t * auxv)

{

	#define T __builtin_tls

	__set_thread_area(&T.pt);

	T.pt.self	= &T.pt;

	T.pt.locale	= &libc.global_locale;

	T.pt.sysinfo	= __sysinfo;

	T.pt.detach_state     = DT_JOINABLE;

	T.pt.locale           = &libc.global_locale;

	T.pt.robust_list.head = &T.pt.robust_list.head;

	libc.can_do_threads = 1;

	libc.tls_size = sizeof(struct __tls);

#if defined(__LIBC_TD_TID_ADDR_TID)

	T.pt.tid	= __syscall(SYS_set_tid_address, &T.pt.tid);

#elif defined(__LIBC_TD_TID_ADDR_JOIN_FUTEX)

	T.pt.join_futex = -1;

	T.pt.tid	= __syscall(SYS_set_tid_address, &T.pt.join_futex);

#elif defined(__LIBC_TD_TID_ADDR_DETACH_STATE)

	T.pt.tid	= __syscall(SYS_set_tid_address, &T.pt.detach_state);

#elif defined(__LIBC_TD_TID_ADDR_THREAD_LIST_LOCK)

	T.pt.tid	= __syscall(SYS_set_tid_address, &T.pt.detach_state);

	T.pt.next       = &T.pt;

	T.pt.prev       = &T.pt;

#else

	#error could not detect tid address logic.

#endif

};

void __libc_entry_routine(

	int			(*main)(),

	__psx_init_routine *	__psx_init,

	const unsigned short *	__ctty,

	int			options)

{

	int			argc;

	char **			argv;

	char **			envp;

	struct __psx_context	ctx;

	/* ctx init */

	ctx.size		= sizeof(ctx);

	ctx.options		= options;

	ctx.usrmain		= main;

	ctx.ldsoaddr		= _init;

	ctx.ctty		= __ctty;

	ctx.pthread_create_fn	= pthread_create;

	ctx.pthread_surrogate_fn= __pthread_surrogate_init;

	/* __psx_init must succeed... */

	if (__psx_init(&argc,&argv,&envp,&ctx))

		a_crash();

	/* ...and conform */

	else if (envp != argv + (argc + 1))

		a_crash();

	/* write once */

	__syscall_vtbl	= (unsigned long **)ctx.sys_vtbl;

	__ldso_vtbl	= ctx.ldso_vtbl;

	__psx_vtbl	= ctx.psx_vtbl;

	__eh_vtbl	= ctx.seh_vtbl;

	__teb_sys_idx	= ctx.teb_sys_idx;

	__teb_libc_idx	= ctx.teb_libc_idx;

	/* surrogate init/fini arrays */

	__global_ctors_fn = __psx_vtbl->do_global_ctors_fn;

	__global_dtors_fn = __psx_vtbl->do_global_dtors_fn;

	/* enter libc */

	__psx_vtbl->mm_start_main(argc,argv,__libc_start_main);

	/* guard */

	a_crash();

}

static int __pthread_surrogate_init(struct pthread * self)

{

	/**

	 * invoked by psxscl upon creation of a surrogate libc

	 * thread, which in turn may only call pthread_create();

	 *

	 * the purpose of this mecahnism is to support a scenario

	 * where a third-party library creates a non-posix thread

	 * which then calls, be it directly or via a callback

	 * function, a libc api that depends on a valid

	 * pthread_self.

	 *

	 * self: a pointer to an already zero'ed memory page

	 *

	 * struct pthread relevant members:

	 * --------------------------------

	 * cancel (already zero)

	 * canary (already zero)

	 *

	 * pthread_create() reference:

	 * 1a47ed15eebf96d0c8d5de4aea54108bc8cc3f53

	**/

	return 0;

}