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thunks: bind more state to handle
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This allows to exit comcom64 in different win31 DOS prompts in
any order.
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@stsp
stsp committed Aug 9, 2024
1 parent f2076b2 commit d4cc47e
Showing 1 changed file with 62 additions and 44 deletions.
106 changes: 62 additions & 44 deletions src/libc/dj64/thunks.c
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Original file line number Diff line number Diff line change
Expand Up @@ -51,11 +51,6 @@

int __crt0_startup_flags;

static dpmi_regs s_regs;
static int recur_cnt;
static int objcnt;
static jmp_buf *noret_jmp;

struct udisp {
dj64dispatch_t *disp;
const struct elf_ops *eops;
Expand All @@ -66,13 +61,17 @@ struct udisp {
unsigned cs;
main_t *main;
int full_init;
dpmi_regs s_regs;
int recur_cnt;
int objcnt;
jmp_buf *noret_jmp;
#define MAX_OBJS 50
#define MAX_RECUR 10
uint32_t objs[MAX_RECUR][MAX_OBJS];
};
#define MAX_HANDLES 10
static struct udisp udisps[MAX_HANDLES];
static const struct dj64_api *dj64api;
#define MAX_OBJS 50
#define MAX_RECUR 10
static uint32_t objs[MAX_RECUR][MAX_OBJS];
static dj64dispatch_t *disp_fn;
static struct athunks *u_athunks;
static struct athunks *u_pthunks;
Expand All @@ -89,7 +88,7 @@ struct ctx_hooks {
static struct ctx_hooks chooks[MAX_CTX_HOOKS];
static int num_chooks;

static void do_rm_dosobj(uint32_t fa);
static void do_rm_dosobj(struct udisp *u, uint32_t fa);

void djloudvprintf(const char *format, va_list vl)
{
Expand Down Expand Up @@ -134,27 +133,27 @@ uint32_t djptr2addr(const uint8_t *ptr)
return dj64api->ptr2addr(ptr);
}

static int _dj64_call(int libid, int fn, dpmi_regs *regs, uint8_t *sp,
unsigned esi, dj64dispatch_t *disp)
static int _dj64_call(struct udisp *u, int libid, int fn, dpmi_regs *regs,
uint8_t *sp, unsigned esi, dj64dispatch_t *disp)
{
int len;
UDWORD res;
int rc;
jmp_buf noret;

s_regs = *regs;
u->s_regs = *regs;
if ((rc = setjmp(noret))) {
int i;
/* gc lost objects, esp in ABORT case */
for (i = 0; i < MAX_OBJS; i++) {
if (objs[recur_cnt - 1][i])
do_rm_dosobj(objs[recur_cnt - 1][i]);
if (u->objs[u->recur_cnt - 1][i])
do_rm_dosobj(u, u->objs[u->recur_cnt - 1][i]);
}
return (rc == ASM_NORET ? DJ64_RET_NORET : DJ64_RET_ABORT);
}
noret_jmp = &noret;
u->noret_jmp = &noret;
res = (libid ? disp : dj64_thunk_call)(fn, sp, &len);
*regs = s_regs;
*regs = u->s_regs;
switch (len) {
case 0:
break;
Expand Down Expand Up @@ -182,20 +181,20 @@ static int dj64_call(int handle, int libid, int fn, unsigned esi, uint8_t *sp)
sp += sizeof(*regs) + 8; // skip regs, ebp, eip to get stack args
assert(handle < MAX_HANDLES);
u = &udisps[handle];
assert(recur_cnt < MAX_RECUR);
recur_cnt++;
assert(u->recur_cnt < MAX_RECUR);
u->recur_cnt++;
for (i = 0; i < num_chooks; i++)
chooks[i].restore(handle);
saved_noret = noret_jmp;
last_objcnt = objcnt;
ret = _dj64_call(libid, fn, regs, sp, esi, u->disp);
assert(objcnt == last_objcnt); // make sure no leaks, esp on NORETURN
noret_jmp = saved_noret;
saved_noret = u->noret_jmp;
last_objcnt = u->objcnt;
ret = _dj64_call(u, libid, fn, regs, sp, esi, u->disp);
assert(u->objcnt == last_objcnt); // make sure no leaks, esp on NORETURN
u->noret_jmp = saved_noret;
if (ret == DJ64_RET_OK) {
for (i = 0; i < num_chooks; i++)
chooks[i].save();
}
recur_cnt--;
u->recur_cnt--;
return ret;
}

Expand Down Expand Up @@ -354,8 +353,8 @@ int DJ64_INIT_ONCE_FN(const struct dj64_api *api, int api_ver)
return ret;
}

static uint64_t do_asm_call(struct athunks *pt, unsigned cs, int num,
uint8_t *sp, uint8_t len, int flags)
static uint64_t do_asm_call(struct udisp *u, struct athunks *pt,
unsigned cs, int num, uint8_t *sp, uint8_t len, int flags)
{
int rc;
dpmi_paddr pma;
Expand All @@ -365,23 +364,23 @@ static uint64_t do_asm_call(struct athunks *pt, unsigned cs, int num,
if (flags & _TFLG_NORET) {
djlogprintf("NORET call %s: 0x%x:0x%x\n", pt->at[num].name,
pma.selector, pma.offset32);
dj64api->asm_noret(&s_regs, pma, sp, len);
longjmp(*noret_jmp, ASM_NORET);
dj64api->asm_noret(&u->s_regs, pma, sp, len);
longjmp(*u->noret_jmp, ASM_NORET);
}
djlogprintf("asm call %s: 0x%x:0x%x\n", pt->at[num].name,
pma.selector, pma.offset32);
rc = dj64api->asm_call(&s_regs, pma, sp, len);
rc = dj64api->asm_call(&u->s_regs, pma, sp, len);
djlogprintf("asm call %s returned %i:0x%x\n", pt->at[num].name,
rc, s_regs.eax);
rc, u->s_regs.eax);
switch (rc) {
case ASM_CALL_OK:
break;
case ASM_CALL_ABORT:
djlogprintf("reboot jump, %i\n", recur_cnt);
longjmp(*noret_jmp, ASM_ABORT);
djlogprintf("reboot jump, %i\n", u->recur_cnt);
longjmp(*u->noret_jmp, ASM_ABORT);
break;
}
return s_regs.eax | ((uint64_t)s_regs.edx << 32);
return u->s_regs.eax | ((uint64_t)u->s_regs.edx << 32);
}

uint64_t dj64_asm_call(int num, uint8_t *sp, uint8_t len, int flags)
Expand All @@ -392,7 +391,7 @@ uint64_t dj64_asm_call(int num, uint8_t *sp, uint8_t len, int flags)
int handle = dj64api->get_handle();
assert(handle < MAX_HANDLES);
u = &udisps[handle];
ret = do_asm_call(&u->core_pt, u->cs, num, sp, len, flags);
ret = do_asm_call(u, &u->core_pt, u->cs, num, sp, len, flags);
/* asm call can recursively invoke dj64, so restore context here */
for (i = 0; i < num_chooks; i++)
chooks[i].restore(handle);
Expand All @@ -408,7 +407,7 @@ uint64_t dj64_asm_call_u(int handle, int num, uint8_t *sp, uint8_t len,

assert(handle < MAX_HANDLES);
u = &udisps[handle];
ret = do_asm_call(u->pt, u->cs, num, sp, len, flags);
ret = do_asm_call(u, u->pt, u->cs, num, sp, len, flags);
/* asm call can recursively invoke dj64, so restore context here */
for (i = 0; i < num_chooks; i++)
chooks[i].restore(handle);
Expand All @@ -420,7 +419,8 @@ uint8_t *dj64_clean_stk(size_t len)
return dj64api->inc_esp(len);
}

static uint32_t *find_oh(uint32_t addr)
static uint32_t *find_oh(uint32_t addr, uint32_t objs[MAX_RECUR][MAX_OBJS],
int recur_cnt)
{
int i;

Expand All @@ -434,13 +434,19 @@ static uint32_t *find_oh(uint32_t addr)
static uint32_t do_obj_init(const void *data, uint16_t len, int is_out)
{
uint32_t ret;
int handle;
struct udisp *u;

if (dj64api->is_dos_ptr(data))
return PTR_DATA(data);
handle = dj64api->get_handle();
assert(handle < MAX_HANDLES);
u = &udisps[handle];
ret = mk_dosobj(len);
if (!is_out)
pr_dosobj(ret, data, len);
objcnt++;
*find_oh(0) = ret;
u->objcnt++;
*find_oh(0, u->objs, u->recur_cnt) = ret;
return ret;
}

Expand All @@ -456,26 +462,38 @@ uint32_t dj64_obj_oinit(const void *data, uint16_t len)

void dj64_obj_done(void *data, uint32_t fa, uint16_t len)
{
int handle;
struct udisp *u;

if (dj64api->is_dos_ptr(data))
return;
handle = dj64api->get_handle();
assert(handle < MAX_HANDLES);
u = &udisps[handle];
cp_dosobj(data, fa, len);
rm_dosobj(fa);
*find_oh(fa) = 0;
objcnt--;
*find_oh(fa, u->objs, u->recur_cnt) = 0;
u->objcnt--;
}

static void do_rm_dosobj(uint32_t fa)
static void do_rm_dosobj(struct udisp *u, uint32_t fa)
{
rm_dosobj(fa);
*find_oh(fa) = 0;
objcnt--;
*find_oh(fa, u->objs, u->recur_cnt) = 0;
u->objcnt--;
}

void dj64_rm_dosobj(const void *data, uint32_t fa)
{
int handle;
struct udisp *u;

if (dj64api->is_dos_ptr(data))
return;
do_rm_dosobj(fa);
handle = dj64api->get_handle();
assert(handle < MAX_HANDLES);
u = &udisps[handle];
do_rm_dosobj(u, fa);
}

void register_dispatch_fn(dj64dispatch_t *fn)
Expand Down

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